Community
-
Mailing List
+
Mailing List
General questions or comments for the Git community can be sent to the mailing list by using the email address git@vger.kernel.org.
@@ -34,7 +34,7 @@
Mailing List
If you're a downstream packager of Git, consider joining the
Git packagers mailing list for low-volume announcements from the developers, as well as other discussion related to packaging & porting Git.
-
Bug Reporting
+
Bug Reporting
Bugs in git can be reported directly to the mailing list (see above for
@@ -68,14 +68,14 @@
Bug Reporting
guide helpful for producing useful bug reports.
-
Reporting Security Issues
+
Reporting Security Issues
Issues which are security relevant should be disclosed privately to
the Git Security mailing list.
-
IRC Channel
+
IRC Channel
If the manpages and this book aren’t enough and you need in-person help, you can try the #git channel on the Libera Chat IRC server (irc.libera.chat). These channels are regularly filled with hundreds of people who are all very knowledgeable about Git and are often willing to help.
@@ -86,22 +86,22 @@
IRC Channel
If you need specific help about one of the for-profit Git hosting sites, you might try their own IRC channels (such as
#github or
#gitlab) on the same IRC server.
-
Discord Server
+
Discord Server
The Git Community Discord Server also has many knowledgeable and helpful people. Additionally, it provides a space to be able to voice chat about patches, designs, or anything else Git related.
-
Newsletter
+
Newsletter
There is a monthly community newsletter called "Git Rev News", with its archive and its latest edition. Information on how to subscribe can be found on the dedicated webpage.
-
Contributing to Git
+
Contributing to Git
- The Documentation directory in the Git source code has several files of interest to developers who are looking to help contribute. After reading the coding guidelines and code of conduct, you can learn }}">how to submit patches. If you are just starting out, you can read the }}">My First Contribution tutorial. For those looking to get more deeply involved, there is a howto for Git maintainers.
+ The Documentation directory in the Git source code has several files of interest to developers who are looking to help contribute. After reading the }}">coding guidelines and code of conduct, you can learn }}">how to submit patches. If you are just starting out, you can read the }}">My First Contribution tutorial. For those looking to get more deeply involved, there is a howto for Git maintainers.
diff --git a/data/docs_extra.yml b/data/docs_extra.yml
new file mode 100644
index 0000000000..9c80fa561d
--- /dev/null
+++ b/data/docs_extra.yml
@@ -0,0 +1,9 @@
+---
+git_project_specific:
+ - BreakingChanges
+ - CodingGuidelines
+ - MyFirstContribution
+ - MyFirstObjectWalk
+ - ReviewingGuidelines
+ - SubmittingPatches
+---
diff --git a/external/docs/asciidoc/0317be45e7d36ce28b9d4ac17272a2d4ca57d620 b/external/docs/asciidoc/0317be45e7d36ce28b9d4ac17272a2d4ca57d620
new file mode 100644
index 0000000000..003393ed16
--- /dev/null
+++ b/external/docs/asciidoc/0317be45e7d36ce28b9d4ac17272a2d4ca57d620
@@ -0,0 +1,754 @@
+Like other projects, we also have some guidelines to keep to the
+code. For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
+
+ - Log messages to explain your changes are as important as the
+ changes themselves. Clearly written code and in-code comments
+ explain how the code works and what is assumed from the surrounding
+ context. The log messages explain what the changes wanted to
+ achieve and why the changes were necessary (more on this in the
+ accompanying SubmittingPatches document).
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here are some language
+specific ones. Note that Documentation/ToolsForGit.txt document
+has a collection of tips to help you use some external tools
+to conform to these guidelines.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parsable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - If a command sequence joined with && or || or | spans multiple
+ lines, put each command on a separate line and put && and || and |
+ operators at the end of each line, rather than the start. This
+ means you don't need to use \ to join lines, since the above
+ operators imply the sequence isn't finished.
+
+ (incorrect)
+ grep blob verify_pack_result \
+ | awk -f print_1.awk \
+ | sort >actual &&
+ ...
+
+ (correct)
+ grep blob verify_pack_result |
+ awk -f print_1.awk |
+ sort >actual &&
+ ...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+ - Even though "local" is not part of POSIX, we make heavy use of it
+ in our test suite. We do not use it in scripted Porcelains, and
+ hopefully nobody starts using "local" before they are reimplemented
+ in C ;-)
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. As of Git v2.35.0 Git requires C99 (we check
+ "__STDC_VERSION__"). You should not use features from a newer C
+ standard, even if your compiler groks them.
+
+ New C99 features have been phased in gradually, if something's new
+ in C99 but not used yet don't assume that it's safe to use, some
+ compilers we target have only partial support for it. These are
+ considered safe to use:
+
+ . since around 2007 with 2b6854c863a, we have been using
+ initializer elements which are not computable at load time. E.g.:
+
+ const char *args[] = {"constant", variable, NULL};
+
+ . since early 2012 with e1327023ea, we have been using an enum
+ definition whose last element is followed by a comma. This, like
+ an array initializer that ends with a trailing comma, can be used
+ to reduce the patch noise when adding a new identifier at the end.
+
+ . since mid 2017 with cbc0f81d, we have been using designated
+ initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+ . since mid 2017 with 512f41cf, we have been using designated
+ initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+ . since early 2021 with 765dc168882, we have been using variadic
+ macros, mostly for printf-like trace and debug macros.
+
+ . since late 2021 with 44ba10d6, we have had variables declared in
+ the for loop "for (int i = 0; i < 10; i++)".
+
+ New C99 features that we cannot use yet:
+
+ . %z and %zu as a printf() argument for a size_t (the %z being for
+ the POSIX-specific ssize_t). Instead you should use
+ printf("%"PRIuMAX, (uintmax_t)v). These days the MSVC version we
+ rely on supports %z, but the C library used by MinGW does not.
+
+ . Shorthand like ".a.b = *c" in struct initializations is known to
+ trip up an older IBM XLC version, use ".a = { .b = *c }" instead.
+ See the 33665d98 (reftable: make assignments portable to AIX xlc
+ v12.01, 2022-03-28).
+
+ - Variables have to be declared at the beginning of the block, before
+ the first statement (i.e. -Wdeclaration-after-statement).
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - Do not explicitly compare an integral value with constant 0 or '\0',
+ or a pointer value with constant NULL. For instance, to validate that
+ counted array is initialized but has no elements, write:
+
+ if (!ptr || cnt)
+ BUG("empty array expected");
+
+ and not:
+
+ if (ptr == NULL || cnt != 0);
+ BUG("empty array expected");
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+ in the header file that exposes the API to its callers. Use what is
+ in "strbuf.h" as a model for the appropriate tone and level of
+ detail.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations and sha1dc/, must be either "git-compat-util.h" or
+ one of the approved headers that includes it first for you. (The
+ approved headers currently include "cache.h", "builtin.h",
+ "t/helper/test-tool.h", "xdiff/xinclude.h", or
+ "reftable/system.h"). You do not have to include more than one of
+ these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+ Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+ run `GIT_DEBUGGER=" " ./bin-wrappers/git foo` to
+ use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+ ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+
+Program Output
+
+ We make a distinction between a Git command's primary output and
+ output which is merely chatty feedback (for instance, status
+ messages, running transcript, or progress display), as well as error
+ messages. Roughly speaking, a Git command's primary output is that
+ which one might want to capture to a file or send down a pipe; its
+ chatty output should not interfere with these use-cases.
+
+ As such, primary output should be sent to the standard output stream
+ (stdout), and chatty output should be sent to the standard error
+ stream (stderr). Examples of commands which produce primary output
+ include `git log`, `git show`, and `git branch --list` which generate
+ output on the stdout stream.
+
+ Not all Git commands have primary output; this is often true of
+ commands whose main function is to perform an action. Some action
+ commands are silent, whereas others are chatty. An example of a
+ chatty action commands is `git clone` with its "Cloning into
+ ''..." and "Checking connectivity..." status messages which it
+ sends to the stderr stream.
+
+ Error messages from Git commands should always be sent to the stderr
+ stream.
+
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize the first word, only because it is the first word
+ in the message ("unable to open %s", not "Unable to open %s"). But
+ "SHA-3 not supported" is fine, because the reason the first word is
+ capitalized is not because it is at the beginning of the sentence,
+ but because the word would be spelled in capital letters even when
+ it appeared in the middle of the sentence.
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ In order to ensure the documentation is inclusive, avoid assuming
+ that an unspecified example person is male or female, and think
+ twice before using "he", "him", "she", or "her". Here are some
+ tips to avoid use of gendered pronouns:
+
+ - Prefer succinctness and matter-of-factly describing functionality
+ in the abstract. E.g.
+
+ --short:: Emit output in the short-format.
+
+ and avoid something like these overly verbose alternatives:
+
+ --short:: Use this to emit output in the short-format.
+ --short:: You can use this to get output in the short-format.
+ --short:: A user who prefers shorter output could....
+ --short:: Should a person and/or program want shorter output, he
+ she/they/it can...
+
+ This practice often eliminates the need to involve human actors in
+ your description, but it is a good practice regardless of the
+ avoidance of gendered pronouns.
+
+ - When it becomes awkward to stick to this style, prefer "you" when
+ addressing the hypothetical user, and possibly "we" when
+ discussing how the program might react to the user. E.g.
+
+ You can use this option instead of --xyz, but we might remove
+ support for it in future versions.
+
+ while keeping in mind that you can probably be less verbose, e.g.
+
+ Use this instead of --xyz. This option might be removed in future
+ versions.
+
+ - If you still need to refer to an example person that is
+ third-person singular, you may resort to "singular they" to avoid
+ "he/she/him/her", e.g.
+
+ A contributor asks their upstream to pull from them.
+
+ Note that this sounds ungrammatical and unnatural to those who
+ learned that "they" is only used for third-person plural, e.g.
+ those who learn English as a second language in some parts of the
+ world.
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ [...]
+ (Zero or more of .)
+
+ --exec-path[=]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [-q | --quiet]
+ [--utf8 | --no-utf8]
+
+ Use spacing around "|" token(s), but not immediately after opening or
+ before closing a [] or () pair:
+ Do: [-q | --quiet]
+ Don't: [-q|--quiet]
+
+ Don't use spacing around "|" tokens when they're used to seperate the
+ alternate arguments of an option:
+ Do: --track[=(direct|inherit)]
+ Don't: --track[=(direct | inherit)]
+
+ Parentheses are used for grouping:
+ [( | )...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(-p )...]
+ (Any number of option -p, each with one argument.)
+
+ git remote set-head (-a | -d | )
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, URLs, pathnames (files and directories), configuration and
+ environment variables) must be typeset in monospace (i.e. wrapped with
+ backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `http://git.example.com`
+ `.git/config`
+ `GIT_DIR`
+ `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/13e8ae1a74ea153fbfe36c0a08113b8f89595b00 b/external/docs/asciidoc/13e8ae1a74ea153fbfe36c0a08113b8f89595b00
new file mode 100644
index 0000000000..48aa4edfbd
--- /dev/null
+++ b/external/docs/asciidoc/13e8ae1a74ea153fbfe36c0a08113b8f89595b00
@@ -0,0 +1,589 @@
+Like other projects, we also have some guidelines to keep to the
+code. For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here they are.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parseable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No strlen ${#parameter}.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - Inside Arithmetic Expansion, spell shell variables with $ in front
+ of them, as some shells do not grok $((x)) while accepting $(($x))
+ just fine (e.g. dash older than 0.5.4).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use -E;
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. That means that you should not use C99
+ initializers, even if a lot of compilers grok it.
+
+ - Variables have to be declared at the beginning of the block.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document it.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations, must be either "git-compat-util.h", "cache.h" or
+ "builtin.h". You do not have to include more than one of these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+ - For Emacs, it's useful to put the following in
+ GIT_CHECKOUT/.dir-locals.el, assuming you use cperl-mode:
+
+ ;; note the first part is useful for C editing, too
+ ((nil . ((indent-tabs-mode . t)
+ (tab-width . 8)
+ (fill-column . 80)))
+ (cperl-mode . ((cperl-indent-level . 8)
+ (cperl-extra-newline-before-brace . nil)
+ (cperl-merge-trailing-else . t))))
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.6 and 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+ - When you must differentiate between Unicode literals and byte string
+ literals, it is OK to use the 'b' prefix. Even though the Python
+ documentation for version 2.6 does not mention this prefix, it has
+ been supported since version 2.6.0.
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize ("unable to open %s", not "Unable to open %s")
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ []
+ (Zero or one .)
+
+ --exec-path[=]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [-q | --quiet]
+ [--utf8 | --no-utf8]
+
+ Parentheses are used for grouping:
+ [( | )...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(-p )...]
+ (Any number of option -p, each with one argument.)
+
+ git remote set-head (-a | -d | )
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, configuration and environment variables) must be
+ typeset in monospace (i.e. wrapped with backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `GIT_DIR`
+ `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/201fe4605e6de6698b4916de3fa8b194a71c5f64 b/external/docs/asciidoc/201fe4605e6de6698b4916de3fa8b194a71c5f64
new file mode 100644
index 0000000000..8579530710
--- /dev/null
+++ b/external/docs/asciidoc/201fe4605e6de6698b4916de3fa8b194a71c5f64
@@ -0,0 +1,610 @@
+Like other projects, we also have some guidelines to keep to the
+code. For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here they are.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parseable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No strlen ${#parameter}.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - Inside Arithmetic Expansion, spell shell variables with $ in front
+ of them, as some shells do not grok $((x)) while accepting $(($x))
+ just fine (e.g. dash older than 0.5.4).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - If a command sequence joined with && or || or | spans multiple
+ lines, put each command on a separate line and put && and || and |
+ operators at the end of each line, rather than the start. This
+ means you don't need to use \ to join lines, since the above
+ operators imply the sequence isn't finished.
+
+ (incorrect)
+ grep blob verify_pack_result \
+ | awk -f print_1.awk \
+ | sort >actual &&
+ ...
+
+ (correct)
+ grep blob verify_pack_result |
+ awk -f print_1.awk |
+ sort >actual &&
+ ...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use -E;
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. That means that you should not use C99
+ initializers, even if a lot of compilers grok it.
+
+ - Variables have to be declared at the beginning of the block.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+ in the header file that exposes the API to its callers. Use what is
+ in "strbuf.h" as a model for the appropriate tone and level of
+ detail.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations, must be either "git-compat-util.h", "cache.h" or
+ "builtin.h". You do not have to include more than one of these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+ - For Emacs, it's useful to put the following in
+ GIT_CHECKOUT/.dir-locals.el, assuming you use cperl-mode:
+
+ ;; note the first part is useful for C editing, too
+ ((nil . ((indent-tabs-mode . t)
+ (tab-width . 8)
+ (fill-column . 80)))
+ (cperl-mode . ((cperl-indent-level . 8)
+ (cperl-extra-newline-before-brace . nil)
+ (cperl-merge-trailing-else . t))))
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.6 and 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+ - When you must differentiate between Unicode literals and byte string
+ literals, it is OK to use the 'b' prefix. Even though the Python
+ documentation for version 2.6 does not mention this prefix, it has
+ been supported since version 2.6.0.
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize ("unable to open %s", not "Unable to open %s")
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ []
+ (Zero or one .)
+
+ --exec-path[=]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [-q | --quiet]
+ [--utf8 | --no-utf8]
+
+ Parentheses are used for grouping:
+ [( | )...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(-p )...]
+ (Any number of option -p, each with one argument.)
+
+ git remote set-head (-a | -d | )
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, configuration and environment variables) must be
+ typeset in monospace (i.e. wrapped with backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `GIT_DIR`
+ `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/251eb6d9ec08d864904404e8cc131eca8ec72284 b/external/docs/asciidoc/251eb6d9ec08d864904404e8cc131eca8ec72284
new file mode 100644
index 0000000000..d42a418009
--- /dev/null
+++ b/external/docs/asciidoc/251eb6d9ec08d864904404e8cc131eca8ec72284
@@ -0,0 +1,179 @@
+Reviewing Patches in the Git Project
+====================================
+
+Introduction
+------------
+The Git development community is a widely distributed, diverse, ever-changing
+group of individuals. Asynchronous communication via the Git mailing list poses
+unique challenges when reviewing or discussing patches. This document contains
+some guiding principles and helpful tools you can use to make your reviews both
+more efficient for yourself and more effective for other contributors.
+
+Note that none of the recommendations here are binding or in any way a
+requirement of participation in the Git community. They are provided as a
+resource to supplement your skills as a contributor.
+
+Principles
+----------
+
+Selecting patch(es) to review
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+If you are looking for a patch series in need of review, start by checking
+the latest "What's cooking in git.git" email
+(https://lore.kernel.org/git/xmqqilm1yp3m.fsf@gitster.g/[example]). The "What's
+cooking" emails & replies can be found using the query `s:"What's cooking"` on
+the https://lore.kernel.org/git/[`lore.kernel.org` mailing list archive];
+alternatively, you can find the contents of the "What's cooking" email tracked
+in `whats-cooking.txt` on the `todo` branch of Git. Topics tagged with "Needs
+review" and those in the "[New Topics]" section are typically those that would
+benefit the most from additional review.
+
+Patches can also be searched manually in the mailing list archive using a query
+like `s:"PATCH" -s:"Re:"`. You can browse these results for topics relevant to
+your expertise or interest.
+
+If you've already contributed to Git, you may also be CC'd in another
+contributor's patch series. These are topics where the author feels that your
+attention is warranted. This may be because their patch changes something you
+wrote previously (making you a good judge of whether the new approach does or
+doesn't work), or because you have the expertise to provide an exceptionally
+helpful review. There is no requirement to review these patches but, in the
+spirit of open source collaboration, you should strongly consider doing so.
+
+Reviewing patches
+~~~~~~~~~~~~~~~~~
+While every contributor takes their own approach to reviewing patches, here are
+some general pieces of advice to make your reviews as clear and helpful as
+possible. The advice is broken into two rough categories: high-level reviewing
+guidance, and concrete tips for interacting with patches on the mailing list.
+
+==== High-level guidance
+- Remember to review the content of commit messages for correctness and clarity,
+ in addition to the code change in the patch's diff. The commit message of a
+ patch should accurately and fully explain the code change being made in the
+ diff.
+
+- Reviewing test coverage is an important - but easy to overlook - component of
+ reviews. A patch's changes may be covered by existing tests, or new tests may
+ be introduced to exercise new behavior. Checking out a patch or series locally
+ allows you to manually mutate lines of new & existing tests to verify expected
+ pass/fail behavior. You can use this information to verify proper coverage or
+ to suggest additional tests the author could add.
+
+- When providing a recommendation, be as clear as possible about whether you
+ consider it "blocking" (the code would be broken or otherwise made worse if an
+ issue isn't fixed) or "non-blocking" (the patch could be made better by taking
+ the recommendation, but acceptance of the series does not require it).
+ Non-blocking recommendations can be particularly ambiguous when they are
+ related to - but outside the scope of - a series ("nice-to-have"s), or when
+ they represent only stylistic differences between the author and reviewer.
+
+- When commenting on an issue, try to include suggestions for how the author
+ could fix it. This not only helps the author to understand and fix the issue,
+ it also deepens and improves your understanding of the topic.
+
+- Reviews do not need to exclusively point out problems. Positive
+ reviews indicate that it is not only the original author of the
+ patches who care about the issue the patches address, and are
+ highly encouraged.
+
+- Do not hesitate to give positive reviews on a series from your
+ work colleague. If your positive review is written well, it will
+ not make you look as if you two are representing corporate
+ interest on a series that is otherwise uninteresting to other
+ community members and shoving it down their throat.
+
+- Write a positive review in such a way that others can understand
+ why you support the goal, the approach, and the implementation the
+ patches took. Make sure to demonstrate that you did thoroughly read
+ the series and understood problem area well enough to be able to
+ say that the patches are written well. Feel free to "think out
+ loud" in your review: describe how you read & understood a complex section of
+ a patch, ask a question about something that confused you, point out something
+ you found exceptionally well-written, etc.
+
+- In particular, uplifting feedback goes a long way towards
+ encouraging contributors to participate more actively in the Git
+ community.
+
+==== Performing your review
+- Provide your review comments per-patch in a plaintext "Reply-All" email to the
+ relevant patch. Comments should be made inline, immediately below the relevant
+ section(s).
+
+- You may find that the limited context provided in the patch diff is sometimes
+ insufficient for a thorough review. In such cases, you can review patches in
+ your local tree by either applying patches with linkgit:git-am[1] or checking
+ out the associated branch from https://github.com/gitster/git once the series
+ is tracked there.
+
+- Large, complicated patch diffs are sometimes unavoidable, such as when they
+ refactor existing code. If you find such a patch difficult to parse, try
+ reviewing the diff produced with the `--color-moved` and/or
+ `--ignore-space-change` options.
+
+- If a patch is long, you are encouraged to delete parts of it that are
+ unrelated to your review from the email reply. Make sure to leave enough
+ context for readers to understand your comments!
+
+- If you cannot complete a full review of a series all at once, consider letting
+ the author know (on- or off-list) if/when you plan to review the rest of the
+ series.
+
+Completing a review
+~~~~~~~~~~~~~~~~~~~
+Once each patch of a series is reviewed, the author (and/or other contributors)
+may discuss the review(s). This may result in no changes being applied, or the
+author will send a new version of their patch(es).
+
+After a series is rerolled in response to your or others' review, make sure to
+re-review the updates. If you are happy with the state of the patch series,
+explicitly indicate your approval (typically with a reply to the latest
+version's cover letter). Optionally, you can let the author know that they can
+add a "Reviewed-by: " trailer if they resubmit the reviewed patch verbatim
+in a later iteration of the series.
+
+Finally, subsequent "What's cooking" emails may explicitly ask whether a
+reviewed topic is ready for merging to the `next` branch (typically phrased
+"Will merge to \'next\'?"). You can help the maintainer and author by responding
+with a short description of the state of your (and others', if applicable)
+review, including the links to the relevant thread(s).
+
+Terminology
+-----------
+nit: ::
+ Denotes a small issue that should be fixed, such as a typographical error
+ or misalignment of conditions in an `if()` statement.
+
+aside: ::
+optional: ::
+non-blocking: ::
+ Indicates to the reader that the following comment should not block the
+ acceptance of the patch or series. These are typically recommendations
+ related to code organization & style, or musings about topics related to
+ the patch in question, but beyond its scope.
+
+s///::
+ Shorthand for "you wrote , but I think you meant ," usually
+ for misspellings or other typographical errors. The syntax is a reference
+ to "substitute" command commonly found in Unix tools such as `ed`, `sed`,
+ `vim`, and `perl`.
+
+cover letter::
+ The "Patch 0" of a multi-patch series. This email describes the
+ high-level intent and structure of the patch series to readers on the
+ Git mailing list. It is also where the changelog notes and range-diff of
+ subsequent versions are provided by the author.
++
+On single-patch submissions, cover letter content is typically not sent as a
+separate email. Instead, it is inserted between the end of the patch's commit
+message (after the `---`) and the beginning of the diff.
+
+#leftoverbits::
+ Used by either an author or a reviewer to describe features or suggested
+ changes that are out-of-scope of a given patch or series, but are relevant
+ to the topic for the sake of discussion.
+
+See Also
+--------
+link:/docs/MyFirstContribution[MyFirstContribution]
diff --git a/external/docs/asciidoc/2e9671e52ffadcf2df658fe919633f6aba936a06 b/external/docs/asciidoc/2e9671e52ffadcf2df658fe919633f6aba936a06
new file mode 100644
index 0000000000..3263245b03
--- /dev/null
+++ b/external/docs/asciidoc/2e9671e52ffadcf2df658fe919633f6aba936a06
@@ -0,0 +1,917 @@
+Like other projects, we also have some guidelines for our code. For
+Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. https://lore.kernel.org/all/20100126160632.3bdbe172.akpm@linux-foundation.org/
+
+ - Log messages to explain your changes are as important as the
+ changes themselves. Clearly written code and in-code comments
+ explain how the code works and what is assumed from the surrounding
+ context. The log messages explain what the changes wanted to
+ achieve and why the changes were necessary (more on this in the
+ accompanying SubmittingPatches document).
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code are expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here are some language
+specific ones. Note that Documentation/ToolsForGit.txt document
+has a collection of tips to help you use some external tools
+to conform to these guidelines.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parsable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - If a command sequence joined with && or || or | spans multiple
+ lines, put each command on a separate line and put && and || and |
+ operators at the end of each line, rather than the start. This
+ means you don't need to use \ to join lines, since the above
+ operators imply the sequence isn't finished.
+
+ (incorrect)
+ grep blob verify_pack_result \
+ | awk -f print_1.awk \
+ | sort >actual &&
+ ...
+
+ (correct)
+ grep blob verify_pack_result |
+ awk -f print_1.awk |
+ sort >actual &&
+ ...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+ - Even though "local" is not part of POSIX, we make heavy use of it
+ in our test suite. We do not use it in scripted Porcelains, and
+ hopefully nobody starts using "local" before all shells that matter
+ support it (notably, ksh from AT&T Research does not support it yet).
+
+ - Some versions of shell do not understand "export variable=value",
+ so we write "variable=value" and then "export variable" on two
+ separate lines.
+
+ - Some versions of dash have broken variable assignment when prefixed
+ with "local", "export", and "readonly", in that the value to be
+ assigned goes through field splitting at $IFS unless quoted.
+
+ (incorrect)
+ local variable=$value
+ local variable=$(command args)
+
+ (correct)
+ local variable="$value"
+ local variable="$(command args)"
+
+ - The common construct
+
+ VAR=VAL command args
+
+ to temporarily set and export environment variable VAR only while
+ "command args" is running is handy, but this triggers an
+ unspecified behaviour according to POSIX when used for a command
+ that is not an external command (like shell functions). Indeed,
+ dash 0.5.10.2-6 on Ubuntu 20.04, /bin/sh on FreeBSD 13, and AT&T
+ ksh all make a temporary assignment without exporting the variable,
+ in such a case. As it does not work portably across shells, do not
+ use this syntax for shell functions. A common workaround is to do
+ an explicit export in a subshell, like so:
+
+ (incorrect)
+ VAR=VAL func args
+
+ (correct)
+ (
+ VAR=VAL &&
+ export VAR &&
+ func args
+ )
+
+ but be careful that the effect "func" makes to the variables in the
+ current shell will be lost across the subshell boundary.
+
+ - Use octal escape sequences (e.g. "\302\242"), not hexadecimal (e.g.
+ "\xc2\xa2") in printf format strings, since hexadecimal escape
+ sequences are not portable.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - Nested C preprocessor directives are indented after the hash by one
+ space per nesting level.
+
+ #if FOO
+ # include
+ # if BAR
+ # include
+ # endif
+ #endif
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - When using DEVELOPER=1 mode, you may see warnings from the compiler
+ like "error: unused parameter 'foo' [-Werror=unused-parameter]",
+ which indicates that a function ignores its argument. If the unused
+ parameter can't be removed (e.g., because the function is used as a
+ callback and has to match a certain interface), you can annotate
+ the individual parameters with the UNUSED (or MAYBE_UNUSED)
+ keyword, like "int foo UNUSED".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. As of Git v2.35.0 Git requires C99 (we check
+ "__STDC_VERSION__"). You should not use features from a newer C
+ standard, even if your compiler groks them.
+
+ New C99 features have been phased in gradually, if something's new
+ in C99 but not used yet don't assume that it's safe to use, some
+ compilers we target have only partial support for it. These are
+ considered safe to use:
+
+ . since around 2007 with 2b6854c863a, we have been using
+ initializer elements which are not computable at load time. E.g.:
+
+ const char *args[] = { "constant", variable, NULL };
+
+ . since early 2012 with e1327023ea, we have been using an enum
+ definition whose last element is followed by a comma. This, like
+ an array initializer that ends with a trailing comma, can be used
+ to reduce the patch noise when adding a new identifier at the end.
+
+ . since mid 2017 with cbc0f81d, we have been using designated
+ initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+ . since mid 2017 with 512f41cf, we have been using designated
+ initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+ . since early 2021 with 765dc168882, we have been using variadic
+ macros, mostly for printf-like trace and debug macros.
+
+ . since late 2021 with 44ba10d6, we have had variables declared in
+ the for loop "for (int i = 0; i < 10; i++)".
+
+ New C99 features that we cannot use yet:
+
+ . %z and %zu as a printf() argument for a size_t (the %z being for
+ the POSIX-specific ssize_t). Instead you should use
+ printf("%"PRIuMAX, (uintmax_t)v). These days the MSVC version we
+ rely on supports %z, but the C library used by MinGW does not.
+
+ . Shorthand like ".a.b = *c" in struct initializations is known to
+ trip up an older IBM XLC version, use ".a = { .b = *c }" instead.
+ See the 33665d98 (reftable: make assignments portable to AIX xlc
+ v12.01, 2022-03-28).
+
+ - Variables have to be declared at the beginning of the block, before
+ the first statement (i.e. -Wdeclaration-after-statement). It is
+ encouraged to have a blank line between the end of the declarations
+ and the first statement in the block.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - A binary operator (other than ",") and ternary conditional "?:"
+ have a space on each side of the operator to separate it from its
+ operands. E.g. "A + 1", not "A+1".
+
+ - A unary operator (other than "." and "->") have no space between it
+ and its operand. E.g. "(char *)ptr", not "(char *) ptr".
+
+ - Do not explicitly compare an integral value with constant 0 or '\0',
+ or a pointer value with constant NULL. For instance, to validate that
+ counted array is initialized but has no elements, write:
+
+ if (!ptr || cnt)
+ BUG("empty array expected");
+
+ and not:
+
+ if (ptr == NULL || cnt != 0);
+ BUG("empty array expected");
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+ in the header file that exposes the API to its callers. Use what is
+ in "strbuf.h" as a model for the appropriate tone and level of
+ detail.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations and sha1dc/, must be . This
+ header file insulates other header files and source files from
+ platform differences, like which system header files must be
+ included in what order, and what C preprocessor feature macros must
+ be defined to trigger certain features we expect out of the system.
+ A collorary to this is that C files should not directly include
+ system header files themselves.
+
+ There are some exceptions, because certain group of files that
+ implement an API all have to include the same header file that
+ defines the API and it is convenient to include
+ there. Namely:
+
+ - the implementation of the built-in commands in the "builtin/"
+ directory that include "builtin.h" for the cmd_foo() prototype
+ definition,
+
+ - the test helper programs in the "t/helper/" directory that include
+ "t/helper/test-tool.h" for the cmd__foo() prototype definition,
+
+ - the xdiff implementation in the "xdiff/" directory that includes
+ "xdiff/xinclude.h" for the xdiff machinery internals,
+
+ - the unit test programs in "t/unit-tests/" directory that include
+ "t/unit-tests/test-lib.h" that gives them the unit-tests
+ framework, and
+
+ - the source files that implement reftable in the "reftable/"
+ directory that include "reftable/system.h" for the reftable
+ internals,
+
+ are allowed to assume that they do not have to include
+ themselves, as it is included as the first
+ '#include' in these header files. These headers must be the first
+ header file to be "#include"d in them, though.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+ Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+ run `GIT_DEBUGGER=" " ./bin-wrappers/git foo` to
+ use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+ ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
+ - The primary data structure that a subsystem 'S' deals with is called
+ `struct S`. Functions that operate on `struct S` are named
+ `S_()` and should generally receive a pointer to `struct S` as
+ first parameter. E.g.
+
+ struct strbuf;
+
+ void strbuf_add(struct strbuf *buf, ...);
+
+ void strbuf_reset(struct strbuf *buf);
+
+ is preferred over:
+
+ struct strbuf;
+
+ void add_string(struct strbuf *buf, ...);
+
+ void reset_strbuf(struct strbuf *buf);
+
+ - There are several common idiomatic names for functions performing
+ specific tasks on a structure `S`:
+
+ - `S_init()` initializes a structure without allocating the
+ structure itself.
+
+ - `S_release()` releases a structure's contents without freeing the
+ structure.
+
+ - `S_clear()` is equivalent to `S_release()` followed by `S_init()`
+ such that the structure is directly usable after clearing it. When
+ `S_clear()` is provided, `S_init()` shall not allocate resources
+ that need to be released again.
+
+ - `S_free()` releases a structure's contents and frees the
+ structure.
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8.1 and later ("use Perl 5.008001").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+For Python scripts:
+
+ - We follow PEP-8 (https://peps.python.org/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+
+Program Output
+
+ We make a distinction between a Git command's primary output and
+ output which is merely chatty feedback (for instance, status
+ messages, running transcript, or progress display), as well as error
+ messages. Roughly speaking, a Git command's primary output is that
+ which one might want to capture to a file or send down a pipe; its
+ chatty output should not interfere with these use-cases.
+
+ As such, primary output should be sent to the standard output stream
+ (stdout), and chatty output should be sent to the standard error
+ stream (stderr). Examples of commands which produce primary output
+ include `git log`, `git show`, and `git branch --list` which generate
+ output on the stdout stream.
+
+ Not all Git commands have primary output; this is often true of
+ commands whose main function is to perform an action. Some action
+ commands are silent, whereas others are chatty. An example of a
+ chatty action commands is `git clone` with its "Cloning into
+ ''..." and "Checking connectivity..." status messages which it
+ sends to the stderr stream.
+
+ Error messages from Git commands should always be sent to the stderr
+ stream.
+
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize the first word, only because it is the first word
+ in the message ("unable to open %s", not "Unable to open %s"). But
+ "SHA-3 not supported" is fine, because the reason the first word is
+ capitalized is not because it is at the beginning of the sentence,
+ but because the word would be spelled in capital letters even when
+ it appeared in the middle of the sentence.
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuation marks (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ In order to ensure the documentation is inclusive, avoid assuming
+ that an unspecified example person is male or female, and think
+ twice before using "he", "him", "she", or "her". Here are some
+ tips to avoid use of gendered pronouns:
+
+ - Prefer succinctness and matter-of-factly describing functionality
+ in the abstract. E.g.
+
+ `--short`:: Emit output in the short-format.
+
+ and avoid something like these overly verbose alternatives:
+
+ `--short`:: Use this to emit output in the short-format.
+ `--short`:: You can use this to get output in the short-format.
+ `--short`:: A user who prefers shorter output could....
+ `--short`:: Should a person and/or program want shorter output, he
+ she/they/it can...
+
+ This practice often eliminates the need to involve human actors in
+ your description, but it is a good practice regardless of the
+ avoidance of gendered pronouns.
+
+ - When it becomes awkward to stick to this style, prefer "you" when
+ addressing the hypothetical user, and possibly "we" when
+ discussing how the program might react to the user. E.g.
+
+ You can use this option instead of `--xyz`, but we might remove
+ support for it in future versions.
+
+ while keeping in mind that you can probably be less verbose, e.g.
+
+ Use this instead of `--xyz`. This option might be removed in future
+ versions.
+
+ - If you still need to refer to an example person that is
+ third-person singular, you may resort to "singular they" to avoid
+ "he/she/him/her", e.g.
+
+ A contributor asks their upstream to pull from them.
+
+ Note that this sounds ungrammatical and unnatural to those who
+ learned that "they" is only used for third-person plural, e.g.
+ those who learn English as a second language in some parts of the
+ world.
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+
+Markup:
+
+ Literal parts (e.g. use of command-line options, command names,
+ branch names, URLs, pathnames (files and directories), configuration and
+ environment variables) must be typeset as verbatim (i.e. wrapped with
+ backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `http://git.example.com`
+ `.git/config`
+ `GIT_DIR`
+ `HEAD`
+ `umask`(2)
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ Placeholders are spelled in lowercase and enclosed in
+ angle brackets surrounded by underscores:
+ __
+ __
+
+ If a placeholder has multiple words, they are separated by dashes:
+ __
+ __
+
+ A placeholder is not enclosed in backticks, as it is not a literal.
+
+ When needed, use a distinctive identifier for placeholders, usually
+ made of a qualification and a type:
+ __
+ __
+
+ When literal and placeholders are mixed, each markup is applied for
+ each sub-entity. If they are stuck, a special markup, called
+ unconstrained formatting is required.
+ Unconstrained formating for placeholders is ____
+ Unconstrained formatting for literal formatting is ++like this++
+ `--jobs` __
+ ++--sort=++____
+ ____++/.git++
+ ++remote.++____++.mirror++
+
+ caveat: ++ unconstrained format is not verbatim and may expand
+ content. Use Asciidoc escapes inside them.
+
+Synopsis Syntax
+
+ Syntax grammar is formatted neither as literal nor as placeholder.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Possibility of multiple occurrences is indicated by three dots:
+ __...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ [__...]
+ (Zero or more of .)
+
+ ++--exec-path++[++=++____]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [__...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [`-q` | `--quiet`]
+ [`--utf8` | `--no-utf8`]
+
+ Use spacing around "|" token(s), but not immediately after opening or
+ before closing a [] or () pair:
+ Do: [`-q` | `--quiet`]
+ Don't: [`-q`|`--quiet`]
+
+ Don't use spacing around "|" tokens when they're used to separate the
+ alternate arguments of an option:
+ Do: ++--track++[++=++(`direct`|`inherit`)]`
+ Don't: ++--track++[++=++(`direct` | `inherit`)]
+
+ Parentheses are used for grouping:
+ [(__ | __)...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(`-p` __)...]
+ (Any number of option -p, each with one argument.)
+
+ `git remote set-head` __ (`-a` | `-d` | __)
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ `--diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]`
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/32781022f7f5c49bc62c2cc3ab09bee44cc04945 b/external/docs/asciidoc/32781022f7f5c49bc62c2cc3ab09bee44cc04945
new file mode 100644
index 0000000000..8d3a467c01
--- /dev/null
+++ b/external/docs/asciidoc/32781022f7f5c49bc62c2cc3ab09bee44cc04945
@@ -0,0 +1,758 @@
+Like other projects, we also have some guidelines for our code. For
+Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. https://lore.kernel.org/all/20100126160632.3bdbe172.akpm@linux-foundation.org/
+
+ - Log messages to explain your changes are as important as the
+ changes themselves. Clearly written code and in-code comments
+ explain how the code works and what is assumed from the surrounding
+ context. The log messages explain what the changes wanted to
+ achieve and why the changes were necessary (more on this in the
+ accompanying SubmittingPatches document).
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code are expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here are some language
+specific ones. Note that Documentation/ToolsForGit.txt document
+has a collection of tips to help you use some external tools
+to conform to these guidelines.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parsable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - If a command sequence joined with && or || or | spans multiple
+ lines, put each command on a separate line and put && and || and |
+ operators at the end of each line, rather than the start. This
+ means you don't need to use \ to join lines, since the above
+ operators imply the sequence isn't finished.
+
+ (incorrect)
+ grep blob verify_pack_result \
+ | awk -f print_1.awk \
+ | sort >actual &&
+ ...
+
+ (correct)
+ grep blob verify_pack_result |
+ awk -f print_1.awk |
+ sort >actual &&
+ ...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+ - Even though "local" is not part of POSIX, we make heavy use of it
+ in our test suite. We do not use it in scripted Porcelains, and
+ hopefully nobody starts using "local" before they are reimplemented
+ in C ;-)
+
+ - Use octal escape sequences (e.g. "\302\242"), not hexadecimal (e.g.
+ "\xc2\xa2") in printf format strings, since hexadecimal escape
+ sequences are not portable.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. As of Git v2.35.0 Git requires C99 (we check
+ "__STDC_VERSION__"). You should not use features from a newer C
+ standard, even if your compiler groks them.
+
+ New C99 features have been phased in gradually, if something's new
+ in C99 but not used yet don't assume that it's safe to use, some
+ compilers we target have only partial support for it. These are
+ considered safe to use:
+
+ . since around 2007 with 2b6854c863a, we have been using
+ initializer elements which are not computable at load time. E.g.:
+
+ const char *args[] = {"constant", variable, NULL};
+
+ . since early 2012 with e1327023ea, we have been using an enum
+ definition whose last element is followed by a comma. This, like
+ an array initializer that ends with a trailing comma, can be used
+ to reduce the patch noise when adding a new identifier at the end.
+
+ . since mid 2017 with cbc0f81d, we have been using designated
+ initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+ . since mid 2017 with 512f41cf, we have been using designated
+ initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+ . since early 2021 with 765dc168882, we have been using variadic
+ macros, mostly for printf-like trace and debug macros.
+
+ . since late 2021 with 44ba10d6, we have had variables declared in
+ the for loop "for (int i = 0; i < 10; i++)".
+
+ New C99 features that we cannot use yet:
+
+ . %z and %zu as a printf() argument for a size_t (the %z being for
+ the POSIX-specific ssize_t). Instead you should use
+ printf("%"PRIuMAX, (uintmax_t)v). These days the MSVC version we
+ rely on supports %z, but the C library used by MinGW does not.
+
+ . Shorthand like ".a.b = *c" in struct initializations is known to
+ trip up an older IBM XLC version, use ".a = { .b = *c }" instead.
+ See the 33665d98 (reftable: make assignments portable to AIX xlc
+ v12.01, 2022-03-28).
+
+ - Variables have to be declared at the beginning of the block, before
+ the first statement (i.e. -Wdeclaration-after-statement).
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - Do not explicitly compare an integral value with constant 0 or '\0',
+ or a pointer value with constant NULL. For instance, to validate that
+ counted array is initialized but has no elements, write:
+
+ if (!ptr || cnt)
+ BUG("empty array expected");
+
+ and not:
+
+ if (ptr == NULL || cnt != 0);
+ BUG("empty array expected");
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+ in the header file that exposes the API to its callers. Use what is
+ in "strbuf.h" as a model for the appropriate tone and level of
+ detail.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations and sha1dc/, must be either "git-compat-util.h" or
+ one of the approved headers that includes it first for you. (The
+ approved headers currently include "builtin.h",
+ "t/helper/test-tool.h", "xdiff/xinclude.h", or
+ "reftable/system.h"). You do not have to include more than one of
+ these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+ Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+ run `GIT_DEBUGGER=" " ./bin-wrappers/git foo` to
+ use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+ ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+
+Program Output
+
+ We make a distinction between a Git command's primary output and
+ output which is merely chatty feedback (for instance, status
+ messages, running transcript, or progress display), as well as error
+ messages. Roughly speaking, a Git command's primary output is that
+ which one might want to capture to a file or send down a pipe; its
+ chatty output should not interfere with these use-cases.
+
+ As such, primary output should be sent to the standard output stream
+ (stdout), and chatty output should be sent to the standard error
+ stream (stderr). Examples of commands which produce primary output
+ include `git log`, `git show`, and `git branch --list` which generate
+ output on the stdout stream.
+
+ Not all Git commands have primary output; this is often true of
+ commands whose main function is to perform an action. Some action
+ commands are silent, whereas others are chatty. An example of a
+ chatty action commands is `git clone` with its "Cloning into
+ ''..." and "Checking connectivity..." status messages which it
+ sends to the stderr stream.
+
+ Error messages from Git commands should always be sent to the stderr
+ stream.
+
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize the first word, only because it is the first word
+ in the message ("unable to open %s", not "Unable to open %s"). But
+ "SHA-3 not supported" is fine, because the reason the first word is
+ capitalized is not because it is at the beginning of the sentence,
+ but because the word would be spelled in capital letters even when
+ it appeared in the middle of the sentence.
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ In order to ensure the documentation is inclusive, avoid assuming
+ that an unspecified example person is male or female, and think
+ twice before using "he", "him", "she", or "her". Here are some
+ tips to avoid use of gendered pronouns:
+
+ - Prefer succinctness and matter-of-factly describing functionality
+ in the abstract. E.g.
+
+ --short:: Emit output in the short-format.
+
+ and avoid something like these overly verbose alternatives:
+
+ --short:: Use this to emit output in the short-format.
+ --short:: You can use this to get output in the short-format.
+ --short:: A user who prefers shorter output could....
+ --short:: Should a person and/or program want shorter output, he
+ she/they/it can...
+
+ This practice often eliminates the need to involve human actors in
+ your description, but it is a good practice regardless of the
+ avoidance of gendered pronouns.
+
+ - When it becomes awkward to stick to this style, prefer "you" when
+ addressing the hypothetical user, and possibly "we" when
+ discussing how the program might react to the user. E.g.
+
+ You can use this option instead of --xyz, but we might remove
+ support for it in future versions.
+
+ while keeping in mind that you can probably be less verbose, e.g.
+
+ Use this instead of --xyz. This option might be removed in future
+ versions.
+
+ - If you still need to refer to an example person that is
+ third-person singular, you may resort to "singular they" to avoid
+ "he/she/him/her", e.g.
+
+ A contributor asks their upstream to pull from them.
+
+ Note that this sounds ungrammatical and unnatural to those who
+ learned that "they" is only used for third-person plural, e.g.
+ those who learn English as a second language in some parts of the
+ world.
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ [...]
+ (Zero or more of .)
+
+ --exec-path[=]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [-q | --quiet]
+ [--utf8 | --no-utf8]
+
+ Use spacing around "|" token(s), but not immediately after opening or
+ before closing a [] or () pair:
+ Do: [-q | --quiet]
+ Don't: [-q|--quiet]
+
+ Don't use spacing around "|" tokens when they're used to separate the
+ alternate arguments of an option:
+ Do: --track[=(direct|inherit)]
+ Don't: --track[=(direct | inherit)]
+
+ Parentheses are used for grouping:
+ [( | )...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(-p )...]
+ (Any number of option -p, each with one argument.)
+
+ git remote set-head (-a | -d | )
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, URLs, pathnames (files and directories), configuration and
+ environment variables) must be typeset in monospace (i.e. wrapped with
+ backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `http://git.example.com`
+ `.git/config`
+ `GIT_DIR`
+ `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/32f7e6163d58c1215034f5d599a90e3e9fcf84b4 b/external/docs/asciidoc/32f7e6163d58c1215034f5d599a90e3e9fcf84b4
new file mode 100644
index 0000000000..b20b2f94f1
--- /dev/null
+++ b/external/docs/asciidoc/32f7e6163d58c1215034f5d599a90e3e9fcf84b4
@@ -0,0 +1,735 @@
+Like other projects, we also have some guidelines to keep to the
+code. For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
+
+ - Log messages to explain your changes are as important as the
+ changes themselves. Clearly written code and in-code comments
+ explain how the code works and what is assumed from the surrounding
+ context. The log messages explain what the changes wanted to
+ achieve and why the changes were necessary (more on this in the
+ accompanying SubmittingPatches document).
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here they are.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parsable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - If a command sequence joined with && or || or | spans multiple
+ lines, put each command on a separate line and put && and || and |
+ operators at the end of each line, rather than the start. This
+ means you don't need to use \ to join lines, since the above
+ operators imply the sequence isn't finished.
+
+ (incorrect)
+ grep blob verify_pack_result \
+ | awk -f print_1.awk \
+ | sort >actual &&
+ ...
+
+ (correct)
+ grep blob verify_pack_result |
+ awk -f print_1.awk |
+ sort >actual &&
+ ...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use -E;
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+ - Even though "local" is not part of POSIX, we make heavy use of it
+ in our test suite. We do not use it in scripted Porcelains, and
+ hopefully nobody starts using "local" before they are reimplemented
+ in C ;-)
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. You should not use features from newer C
+ standard, even if your compiler groks them.
+
+ There are a few exceptions to this guideline:
+
+ . since early 2012 with e1327023ea, we have been using an enum
+ definition whose last element is followed by a comma. This, like
+ an array initializer that ends with a trailing comma, can be used
+ to reduce the patch noise when adding a new identifier at the end.
+
+ . since mid 2017 with cbc0f81d, we have been using designated
+ initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+ . since mid 2017 with 512f41cf, we have been using designated
+ initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+ . since early 2021 with 765dc168882, we have been using variadic
+ macros, mostly for printf-like trace and debug macros.
+
+ These used to be forbidden, but we have not heard any breakage
+ report, and they are assumed to be safe.
+
+ - Variables have to be declared at the beginning of the block, before
+ the first statement (i.e. -Wdeclaration-after-statement).
+
+ - Declaring a variable in the for loop "for (int i = 0; i < 10; i++)"
+ is still not allowed in this codebase. We are in the process of
+ allowing it by waiting to see that 44ba10d6 (revision: use C99
+ declaration of variable in for() loop, 2021-11-14) does not get
+ complaints. Let's revisit this around November 2022.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - Do not explicitly compare an integral value with constant 0 or '\0',
+ or a pointer value with constant NULL. For instance, to validate that
+ counted array is initialized but has no elements, write:
+
+ if (!ptr || cnt)
+ BUG("empty array expected");
+
+ and not:
+
+ if (ptr == NULL || cnt != 0);
+ BUG("empty array expected");
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+ in the header file that exposes the API to its callers. Use what is
+ in "strbuf.h" as a model for the appropriate tone and level of
+ detail.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations, must be either "git-compat-util.h", "cache.h" or
+ "builtin.h". You do not have to include more than one of these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+ Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+ run `GIT_DEBUGGER=" " ./bin-wrappers/git foo` to
+ use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+ ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+ - For Emacs, it's useful to put the following in
+ GIT_CHECKOUT/.dir-locals.el, assuming you use cperl-mode:
+
+ ;; note the first part is useful for C editing, too
+ ((nil . ((indent-tabs-mode . t)
+ (tab-width . 8)
+ (fill-column . 80)))
+ (cperl-mode . ((cperl-indent-level . 8)
+ (cperl-extra-newline-before-brace . nil)
+ (cperl-merge-trailing-else . t))))
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+
+Program Output
+
+ We make a distinction between a Git command's primary output and
+ output which is merely chatty feedback (for instance, status
+ messages, running transcript, or progress display), as well as error
+ messages. Roughly speaking, a Git command's primary output is that
+ which one might want to capture to a file or send down a pipe; its
+ chatty output should not interfere with these use-cases.
+
+ As such, primary output should be sent to the standard output stream
+ (stdout), and chatty output should be sent to the standard error
+ stream (stderr). Examples of commands which produce primary output
+ include `git log`, `git show`, and `git branch --list` which generate
+ output on the stdout stream.
+
+ Not all Git commands have primary output; this is often true of
+ commands whose main function is to perform an action. Some action
+ commands are silent, whereas others are chatty. An example of a
+ chatty action commands is `git clone` with its "Cloning into
+ ''..." and "Checking connectivity..." status messages which it
+ sends to the stderr stream.
+
+ Error messages from Git commands should always be sent to the stderr
+ stream.
+
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize the first word, only because it is the first word
+ in the message ("unable to open %s", not "Unable to open %s"). But
+ "SHA-3 not supported" is fine, because the reason the first word is
+ capitalized is not because it is at the beginning of the sentence,
+ but because the word would be spelled in capital letters even when
+ it appeared in the middle of the sentence.
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ In order to ensure the documentation is inclusive, avoid assuming
+ that an unspecified example person is male or female, and think
+ twice before using "he", "him", "she", or "her". Here are some
+ tips to avoid use of gendered pronouns:
+
+ - Prefer succinctness and matter-of-factly describing functionality
+ in the abstract. E.g.
+
+ --short:: Emit output in the short-format.
+
+ and avoid something like these overly verbose alternatives:
+
+ --short:: Use this to emit output in the short-format.
+ --short:: You can use this to get output in the short-format.
+ --short:: A user who prefers shorter output could....
+ --short:: Should a person and/or program want shorter output, he
+ she/they/it can...
+
+ This practice often eliminates the need to involve human actors in
+ your description, but it is a good practice regardless of the
+ avoidance of gendered pronouns.
+
+ - When it becomes awkward to stick to this style, prefer "you" when
+ addressing the the hypothetical user, and possibly "we" when
+ discussing how the program might react to the user. E.g.
+
+ You can use this option instead of --xyz, but we might remove
+ support for it in future versions.
+
+ while keeping in mind that you can probably be less verbose, e.g.
+
+ Use this instead of --xyz. This option might be removed in future
+ versions.
+
+ - If you still need to refer to an example person that is
+ third-person singular, you may resort to "singular they" to avoid
+ "he/she/him/her", e.g.
+
+ A contributor asks their upstream to pull from them.
+
+ Note that this sounds ungrammatical and unnatural to those who
+ learned that "they" is only used for third-person plural, e.g.
+ those who learn English as a second language in some parts of the
+ world.
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ []
+ (Zero or one .)
+
+ --exec-path[=]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [-q | --quiet]
+ [--utf8 | --no-utf8]
+
+ Parentheses are used for grouping:
+ [( | )...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(-p )...]
+ (Any number of option -p, each with one argument.)
+
+ git remote set-head (-a | -d | )
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, URLs, pathnames (files and directories), configuration and
+ environment variables) must be typeset in monospace (i.e. wrapped with
+ backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `http://git.example.com`
+ `.git/config`
+ `GIT_DIR`
+ `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/384992bd708c35d0869455bfb756632a1ced33f2 b/external/docs/asciidoc/384992bd708c35d0869455bfb756632a1ced33f2
new file mode 100644
index 0000000000..227f46ae40
--- /dev/null
+++ b/external/docs/asciidoc/384992bd708c35d0869455bfb756632a1ced33f2
@@ -0,0 +1,645 @@
+Like other projects, we also have some guidelines to keep to the
+code. For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here they are.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parsable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - If a command sequence joined with && or || or | spans multiple
+ lines, put each command on a separate line and put && and || and |
+ operators at the end of each line, rather than the start. This
+ means you don't need to use \ to join lines, since the above
+ operators imply the sequence isn't finished.
+
+ (incorrect)
+ grep blob verify_pack_result \
+ | awk -f print_1.awk \
+ | sort >actual &&
+ ...
+
+ (correct)
+ grep blob verify_pack_result |
+ awk -f print_1.awk |
+ sort >actual &&
+ ...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use -E;
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. You should not use features from newer C
+ standard, even if your compiler groks them.
+
+ There are a few exceptions to this guideline:
+
+ . since early 2012 with e1327023ea, we have been using an enum
+ definition whose last element is followed by a comma. This, like
+ an array initializer that ends with a trailing comma, can be used
+ to reduce the patch noise when adding a new identifier at the end.
+
+ . since mid 2017 with cbc0f81d, we have been using designated
+ initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+ . since mid 2017 with 512f41cf, we have been using designated
+ initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+ These used to be forbidden, but we have not heard any breakage
+ report, and they are assumed to be safe.
+
+ - Variables have to be declared at the beginning of the block, before
+ the first statement (i.e. -Wdeclaration-after-statement).
+
+ - Declaring a variable in the for loop "for (int i = 0; i < 10; i++)"
+ is still not allowed in this codebase.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - Do not explicitly compare an integral value with constant 0 or '\0',
+ or a pointer value with constant NULL. For instance, to validate that
+ counted array is initialized but has no elements, write:
+
+ if (!ptr || cnt)
+ BUG("empty array expected");
+
+ and not:
+
+ if (ptr == NULL || cnt != 0);
+ BUG("empty array expected");
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: ", e.g.
+
+ /*
+ * TRANSLATORS: here is a comment that explains the string to
+ * be translated, that follows immediately after it.
+ */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+ in the header file that exposes the API to its callers. Use what is
+ in "strbuf.h" as a model for the appropriate tone and level of
+ detail.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations, must be either "git-compat-util.h", "cache.h" or
+ "builtin.h". You do not have to include more than one of these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+ with "static". Variables that are visible to other source files
+ must be declared with "extern" in header files. However, function
+ declarations should not use "extern", as that is already the default.
+
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+ Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+ run `GIT_DEBUGGER=" " ./bin-wrappers/git foo` to
+ use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+ ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+ - For Emacs, it's useful to put the following in
+ GIT_CHECKOUT/.dir-locals.el, assuming you use cperl-mode:
+
+ ;; note the first part is useful for C editing, too
+ ((nil . ((indent-tabs-mode . t)
+ (tab-width . 8)
+ (fill-column . 80)))
+ (cperl-mode . ((cperl-indent-level . 8)
+ (cperl-extra-newline-before-brace . nil)
+ (cperl-merge-trailing-else . t))))
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.6 and 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+ - When you must differentiate between Unicode literals and byte string
+ literals, it is OK to use the 'b' prefix. Even though the Python
+ documentation for version 2.6 does not mention this prefix, it has
+ been supported since version 2.6.0.
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize ("unable to open %s", not "Unable to open %s")
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ []
+ (Zero or one .)
+
+ --exec-path[=]
+ (Option with an optional argument. Note that the "=" is inside the
+ brackets.)
+
+ [...]
+ (Zero or more of . Note that the dots are inside, not
+ outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+ [-q | --quiet]
+ [--utf8 | --no-utf8]
+
+ Parentheses are used for grouping:
+ [( | )...]
+ (Any number of either or . Parens are needed to make
+ it clear that "..." pertains to both and .)
+
+ [(-p )...]
+ (Any number of option -p, each with one argument.)
+
+ git remote set-head (-a | -d | )
+ (One and only one of "-a", "-d" or "" _must_ (no square
+ brackets) be provided.)
+
+ And a somewhat more contrived example:
+ --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+ Here "=" is outside the brackets, because "--diff-filter=" is a
+ valid usage. "*" has its own pair of brackets, because it can
+ (optionally) be specified only when one or more of the letters is
+ also provided.
+
+ A note on notation:
+ Use 'git' (all lowercase) when talking about commands i.e. something
+ the user would type into a shell and use 'Git' (uppercase first letter)
+ when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, URLs, pathnames (files and directories), configuration and
+ environment variables) must be typeset in monospace (i.e. wrapped with
+ backticks):
+ `--pretty=oneline`
+ `git rev-list`
+ `remote.pushDefault`
+ `http://git.example.com`
+ `.git/config`
+ `GIT_DIR`
+ `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+ `GIT_DIR` is specified
+ `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+ Correct:
+ `--pretty=oneline`
+ Incorrect:
+ `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/external/docs/asciidoc/384de0c2eb9bf8e5b95cd22ef5740abd694022d6 b/external/docs/asciidoc/384de0c2eb9bf8e5b95cd22ef5740abd694022d6
new file mode 100644
index 0000000000..fd27dcc85e
--- /dev/null
+++ b/external/docs/asciidoc/384de0c2eb9bf8e5b95cd22ef5740abd694022d6
@@ -0,0 +1,162 @@
+Reviewing Patches in the Git Project
+====================================
+
+Introduction
+------------
+The Git development community is a widely distributed, diverse, ever-changing
+group of individuals. Asynchronous communication via the Git mailing list poses
+unique challenges when reviewing or discussing patches. This document contains
+some guiding principles and helpful tools you can use to make your reviews both
+more efficient for yourself and more effective for other contributors.
+
+Note that none of the recommendations here are binding or in any way a
+requirement of participation in the Git community. They are provided as a
+resource to supplement your skills as a contributor.
+
+Principles
+----------
+
+Selecting patch(es) to review
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+If you are looking for a patch series in need of review, start by checking
+the latest "What's cooking in git.git" email
+(https://lore.kernel.org/git/xmqqilm1yp3m.fsf@gitster.g/[example]). The "What's
+cooking" emails & replies can be found using the query `s:"What's cooking"` on
+the https://lore.kernel.org/git/[`lore.kernel.org` mailing list archive];
+alternatively, you can find the contents of the "What's cooking" email tracked
+in `whats-cooking.txt` on the `todo` branch of Git. Topics tagged with "Needs
+review" and those in the "[New Topics]" section are typically those that would
+benefit the most from additional review.
+
+Patches can also be searched manually in the mailing list archive using a query
+like `s:"PATCH" -s:"Re:"`. You can browse these results for topics relevant to
+your expertise or interest.
+
+If you've already contributed to Git, you may also be CC'd in another
+contributor's patch series. These are topics where the author feels that your
+attention is warranted. This may be because their patch changes something you
+wrote previously (making you a good judge of whether the new approach does or
+doesn't work), or because you have the expertise to provide an exceptionally
+helpful review. There is no requirement to review these patches but, in the
+spirit of open source collaboration, you should strongly consider doing so.
+
+Reviewing patches
+~~~~~~~~~~~~~~~~~
+While every contributor takes their own approach to reviewing patches, here are
+some general pieces of advice to make your reviews as clear and helpful as
+possible. The advice is broken into two rough categories: high-level reviewing
+guidance, and concrete tips for interacting with patches on the mailing list.
+
+==== High-level guidance
+- Remember to review the content of commit messages for correctness and clarity,
+ in addition to the code change in the patch's diff. The commit message of a
+ patch should accurately and fully explain the code change being made in the
+ diff.
+
+- Reviewing test coverage is an important - but easy to overlook - component of
+ reviews. A patch's changes may be covered by existing tests, or new tests may
+ be introduced to exercise new behavior. Checking out a patch or series locally
+ allows you to manually mutate lines of new & existing tests to verify expected
+ pass/fail behavior. You can use this information to verify proper coverage or
+ to suggest additional tests the author could add.
+
+- When providing a recommendation, be as clear as possible about whether you
+ consider it "blocking" (the code would be broken or otherwise made worse if an
+ issue isn't fixed) or "non-blocking" (the patch could be made better by taking
+ the recommendation, but acceptance of the series does not require it).
+ Non-blocking recommendations can be particularly ambiguous when they are
+ related to - but outside the scope of - a series ("nice-to-have"s), or when
+ they represent only stylistic differences between the author and reviewer.
+
+- When commenting on an issue, try to include suggestions for how the author
+ could fix it. This not only helps the author to understand and fix the issue,
+ it also deepens and improves your understanding of the topic.
+
+- Reviews do not need to exclusively point out problems. Feel free to "think out
+ loud" in your review: describe how you read & understood a complex section of
+ a patch, ask a question about something that confused you, point out something
+ you found exceptionally well-written, etc. In particular, uplifting feedback
+ goes a long way towards encouraging contributors to participate more actively
+ in the Git community.
+
+==== Performing your review
+- Provide your review comments per-patch in a plaintext "Reply-All" email to the
+ relevant patch. Comments should be made inline, immediately below the relevant
+ section(s).
+
+- You may find that the limited context provided in the patch diff is sometimes
+ insufficient for a thorough review. In such cases, you can review patches in
+ your local tree by either applying patches with linkgit:git-am[1] or checking
+ out the associated branch from https://github.com/gitster/git once the series
+ is tracked there.
+
+- Large, complicated patch diffs are sometimes unavoidable, such as when they
+ refactor existing code. If you find such a patch difficult to parse, try
+ reviewing the diff produced with the `--color-moved` and/or
+ `--ignore-space-change` options.
+
+- If a patch is long, you are encouraged to delete parts of it that are
+ unrelated to your review from the email reply. Make sure to leave enough
+ context for readers to understand your comments!
+
+- If you cannot complete a full review of a series all at once, consider letting
+ the author know (on- or off-list) if/when you plan to review the rest of the
+ series.
+
+Completing a review
+~~~~~~~~~~~~~~~~~~~
+Once each patch of a series is reviewed, the author (and/or other contributors)
+may discuss the review(s). This may result in no changes being applied, or the
+author will send a new version of their patch(es).
+
+After a series is rerolled in response to your or others' review, make sure to
+re-review the updates. If you are happy with the state of the patch series,
+explicitly indicate your approval (typically with a reply to the latest
+version's cover letter). Optionally, you can let the author know that they can
+add a "Reviewed-by: " trailer if they resubmit the reviewed patch verbatim
+in a later iteration of the series.
+
+Finally, subsequent "What's cooking" emails may explicitly ask whether a
+reviewed topic is ready for merging to the `next` branch (typically phrased
+"Will merge to \'next\'?"). You can help the maintainer and author by responding
+with a short description of the state of your (and others', if applicable)
+review, including the links to the relevant thread(s).
+
+Terminology
+-----------
+nit: ::
+ Denotes a small issue that should be fixed, such as a typographical error
+ or misalignment of conditions in an `if()` statement.
+
+aside: ::
+optional: ::
+non-blocking: ::
+ Indicates to the reader that the following comment should not block the
+ acceptance of the patch or series. These are typically recommendations
+ related to code organization & style, or musings about topics related to
+ the patch in question, but beyond its scope.
+
+s///::
+ Shorthand for "you wrote , but I think you meant ," usually
+ for misspellings or other typographical errors. The syntax is a reference
+ to "substitute" command commonly found in Unix tools such as `ed`, `sed`,
+ `vim`, and `perl`.
+
+cover letter::
+ The "Patch 0" of a multi-patch series. This email describes the
+ high-level intent and structure of the patch series to readers on the
+ Git mailing list. It is also where the changelog notes and range-diff of
+ subsequent versions are provided by the author.
++
+On single-patch submissions, cover letter content is typically not sent as a
+separate email. Instead, it is inserted between the end of the patch's commit
+message (after the `---`) and the beginning of the diff.
+
+#leftoverbits::
+ Used by either an author or a reviewer to describe features or suggested
+ changes that are out-of-scope of a given patch or series, but are relevant
+ to the topic for the sake of discussion.
+
+See Also
+--------
+link:/docs/MyFirstContribution[MyFirstContribution]
diff --git a/external/docs/asciidoc/39bbf29f884e401a43d2af98c30539f335176513 b/external/docs/asciidoc/39bbf29f884e401a43d2af98c30539f335176513
new file mode 100644
index 0000000000..a4191aa388
--- /dev/null
+++ b/external/docs/asciidoc/39bbf29f884e401a43d2af98c30539f335176513
@@ -0,0 +1,584 @@
+Like other projects, we also have some guidelines to keep to the
+code. For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+ ignore your needs should your system not conform to it."
+ We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+ it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+ this is not in POSIX, it (is so convenient | makes the code
+ much more readable | has other good characteristics) and
+ practically all the platforms we care about support it, so
+ let's use it".
+
+ Again, we live in the real world, and it is sometimes a
+ judgement call, the decision based more on real world
+ constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+ preparatory clean-up step is good, but otherwise avoid useless code
+ churn for the sake of conforming to the style.
+
+ "Once it _is_ in the tree, it's not really worth the patch noise to
+ go and fix it up."
+ Cf. http://article.gmane.org/gmane.linux.kernel/943020
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here they are.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+ like this:
+
+ case "$variable" in
+ pattern1)
+ do this
+ ;;
+ pattern2)
+ do that
+ ;;
+ esac
+
+ - Redirection operators should be written with space before, but no
+ space after them. In other words, write 'echo test >"$file"'
+ instead of 'echo test> $file' or 'echo test > $file'. Note that
+ even though it is not required by POSIX to double-quote the
+ redirection target in a variable (as shown above), our code does so
+ because some versions of bash issue a warning without the quotes.
+
+ (incorrect)
+ cat hello > world < universe
+ echo hello >$world
+
+ (correct)
+ cat hello >world "$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+ properly nests. It should have been the way Bourne spelled
+ it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+ $PATH, you should use 'type ', instead of 'which '.
+ The output of 'which' is not machine parseable and its exit code
+ is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+ namely:
+
+ - We use ${parameter-word} and its [-=?+] siblings, and their
+ colon'ed "unset or null" form.
+
+ - We use ${parameter#word} and its [#%] siblings, and their
+ doubled "longest matching" form.
+
+ - No "Substring Expansion" ${parameter:offset:length}.
+
+ - No shell arrays.
+
+ - No strlen ${#parameter}.
+
+ - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - Inside Arithmetic Expansion, spell shell variables with $ in front
+ of them, as some shells do not grok $((x)) while accepting $(($x))
+ just fine (e.g. dash older than 0.5.4).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+ "then" should be on the next line for if statements, and "do"
+ should be on the next line for "while" and "for".
+
+ (incorrect)
+ if test -f hello; then
+ do this
+ fi
+
+ (correct)
+ if test -f hello
+ then
+ do this
+ fi
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+ functions.
+
+ - We prefer a space between the function name and the parentheses,
+ and no space inside the parentheses. The opening "{" should also
+ be on the same line.
+
+ (incorrect)
+ my_function(){
+ ...
+
+ (correct)
+ my_function () {
+ ...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+ [::], [==], or [..]) for portability.
+
+ - We do not use \{m,n\};
+
+ - We do not use -E;
+
+ - We do not use ? or + (which are \{0,1\} and \{1,\}
+ respectively in BRE) but that goes without saying as these
+ are ERE elements not BRE (note that \? and \+ are not even part
+ of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+ interface translatable. See "Marking strings for translation" in
+ po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+ or "||" to concatenate multiple "test" commands instead, because
+ the use of "-a/-o" is often error-prone. E.g.
+
+ test -n "$x" -a "$a" = "$b"
+
+ is buggy and breaks when $x is "=", but
+
+ test -n "$x" && test "$a" = "$b"
+
+ does not have such a problem.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+ 8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+ and we recommend you to enable the DEVELOPER makefile knob to
+ ensure your patch is clear of all compiler warnings we care about,
+ by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+ including old ones. That means that you should not use C99
+ initializers, even if a lot of compilers grok it.
+
+ - Variables have to be declared at the beginning of the block.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+ name, i.e. "char *string", not "char* string" or
+ "char * string". This makes it easier to understand code
+ like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+ parentheses and not around functions. So:
+
+ while (condition)
+ func(bar + 1);
+
+ and not:
+
+ while( condition )
+ func (bar+1);
+
+ - We avoid using braces unnecessarily. I.e.
+
+ if (bla) {
+ x = 1;
+ }
+
+ is frowned upon. But there are a few exceptions:
+
+ - When the statement extends over a few lines (e.g., a while loop
+ with an embedded conditional, or a comment). E.g.:
+
+ while (foo) {
+ if (x)
+ one();
+ else
+ two();
+ }
+
+ if (foo) {
+ /*
+ * This one requires some explanation,
+ * so we're better off with braces to make
+ * it obvious that the indentation is correct.
+ */
+ doit();
+ }
+
+ - When there are multiple arms to a conditional and some of them
+ require braces, enclose even a single line block in braces for
+ consistency. E.g.:
+
+ if (foo) {
+ doit();
+ } else {
+ one();
+ two();
+ three();
+ }
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable. You may put comments
+ in, but comments invariably tend to stale out when the code
+ they were describing changes. Often splitting a function
+ into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+ the text. E.g.
+
+ /*
+ * A very long
+ * multi-line comment.
+ */
+
+ Note however that a comment that explains a translatable string to
+ translators uses a convention of starting with a magic token
+ "TRANSLATORS: " immediately after the opening delimiter, even when
+ it spans multiple lines. We do not add an asterisk at the beginning
+ of each line, either. E.g.
+
+ /* TRANSLATORS: here is a comment that explains the string
+ to be translated, that follows immediately after it */
+ _("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+ at all.
+
+ - There are two schools of thought when it comes to comparison,
+ especially inside a loop. Some people prefer to have the less stable
+ value on the left hand side and the more stable value on the right hand
+ side, e.g. if you have a loop that counts variable i down to the
+ lower bound,
+
+ while (i > lower_bound) {
+ do something;
+ i--;
+ }
+
+ Other people prefer to have the textual order of values match the
+ actual order of values in their comparison, so that they can
+ mentally draw a number line from left to right and place these
+ values in order, i.e.
+
+ while (lower_bound < i) {
+ do something;
+ i--;
+ }
+
+ Both are valid, and we use both. However, the more "stable" the
+ stable side becomes, the more we tend to prefer the former
+ (comparison with a constant, "i > 0", is an extreme example).
+ Just do not mix styles in the same part of the code and mimic
+ existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+ logical line into multiple lines. Some people push the second and
+ subsequent lines far enough to the right with tabs and align them:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ while other people prefer to align the second and the subsequent
+ lines with the column immediately inside the opening parenthesis,
+ with tabs and spaces, following our "tabstop is always a multiple
+ of 8" convention:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of ||
+ the_source_text) {
+ ...
+
+ Both are valid, and we use both. Again, just do not mix styles in
+ the same part of the code and mimic existing styles in the
+ neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+ a binary operator, so that the result looks like a parse tree when
+ you turn your head 90-degrees counterclockwise:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to
+ || span_more_than_a_single_line_of_the_source_text) {
+
+ while other people prefer to leave the operator at the end of the
+ line:
+
+ if (the_beginning_of_a_very_long_expression_that_has_to ||
+ span_more_than_a_single_line_of_the_source_text) {
+
+ Both are valid, but we tend to use the latter more, unless the
+ expression gets fairly complex, in which case the former tends to
+ be easier to read. Again, just do not mix styles in the same part
+ of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+ equal, it is preferable to split after the operator at higher
+ level in the parse tree. That is, this is more preferable:
+
+ if (a_very_long_variable * that_is_used_in +
+ a_very_long_expression) {
+ ...
+
+ than
+
+ if (a_very_long_variable *
+ that_is_used_in + a_very_long_expression) {
+ ...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+ constructs, can be extremely confusing to others. Avoid them,
+ unless there is a compelling reason to use them.
+
+ - Use the API. No, really. We have a strbuf (variable length
+ string), several arrays with the ALLOC_GROW() macro, a
+ string_list for sorted string lists, a hash map (mapping struct
+ objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document it.
+
+ - The first #include in C files, except in platform specific compat/
+ implementations, must be either "git-compat-util.h", "cache.h" or
+ "builtin.h". You do not have to include more than one of these.
+
+ - A C file must directly include the header files that declare the
+ functions and the types it uses, except for the functions and types
+ that are made available to it by including one of the header files
+ it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+ or perl first, so that changes in semantics can be easily
+ changed and discussed. Many Git commands started out like
+ that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+ usually should stay away from scripting languages not already
+ used in the Git core command set (unless your command is clearly
+ separate from it, such as an importer to convert random-scm-X
+ repositories to Git).
+
+ - When we pass pair to functions, we should try to
+ pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+ translatable. See "Marking strings for translation" in po/README.
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+ result easier to follow.
+
+ ... do something ...
+ do_this() unless (condition);
+ ... do something else ...
+
+ is more readable than:
+
+ ... do something ...
+ unless (condition) {
+ do_this();
+ }
+ ... do something else ...
+
+ *only* when the condition is so rare that do_this() will be almost
+ always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+ - For Emacs, it's useful to put the following in
+ GIT_CHECKOUT/.dir-locals.el, assuming you use cperl-mode:
+
+ ;; note the first part is useful for C editing, too
+ ((nil . ((indent-tabs-mode . t)
+ (tab-width . 8)
+ (fill-column . 80)))
+ (cperl-mode . ((cperl-indent-level . 8)
+ (cperl-extra-newline-before-brace . nil)
+ (cperl-merge-trailing-else . t))))
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.6 and 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+ also be compatible with Python 3.1 and later.
+
+ - When you must differentiate between Unicode literals and byte string
+ literals, it is OK to use the 'b' prefix. Even though the Python
+ documentation for version 2.6 does not mention this prefix, it has
+ been supported since version 2.6.0.
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize ("unable to open %s", not "Unable to open %s")
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+ . The section name indicates the affected subsystem.
+
+ . The subsection name, if any, indicates which of an unbounded set
+ of things to set the value for.
+
+ . The variable name describes the effect of tweaking this knob.
+
+ The section and variable names that consist of multiple words are
+ formed by concatenating the words without punctuations (e.g. `-`),
+ and are broken using bumpyCaps in documentation as a hint to the
+ reader.
+
+ When choosing the variable namespace, do not use variable name for
+ specifying possibly unbounded set of things, most notably anything
+ an end user can freely come up with (e.g. branch names). Instead,
+ use subsection names or variable values, like the existing variable
+ branch..description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+
+ --sort=
+ --abbrev[=]
+
+ If a placeholder has multiple words, they are separated by dashes:
+
+ --template=
+
+ Possibility of multiple occurrences is indicated by three dots:
+ ...
+ (One or more of .)
+
+ Optional parts are enclosed in square brackets:
+ []
+ (Zero or one .)
+
+ --exec-path[=