The source files located in src are built into a (shared) library.
Each source file located in src/bin results in one corresponding executable, which is linked against the library.
Similarly, each source file in test and benchmark results in one executable for unit testing / benchmarking.
The goal is to implement the mC compiler as (shared) library.
This implementation is then used by dedicated binaries, like mCc and mC_to_dot.
As C does not feature namespaces, the names of all symbols are prefixed with mCc_ followed by another prefix for their corresponding unit (eg ast_).
Please adhere to this convention to prevent conflicts with other software.
ClangFormat is used to format the entire code-base. A configuration is provided.
The file meson.build contains all build system settings, each source file is listed there.
It is not recommended to glob for source files.
If you really wanna glob for source files, see the related FAQ entry
Otherwise, extend the lists upon adding new source files.
The default build-type is configured to release.
Pass --buildtype=debug to meson when creating the build directory to obtain a debug build.
Meson also provides debugoptimized which is commonly used during development.
While the compiler itself is written in C, unit tests are written in C++.
Each unit should have a corresponding file in test containing the relevant unit tests.
For convenience, each unit test suit is compiled into a separate executable.
Pay attention when combining C and C++ code.
Strange errors may occur when handled incorrectly.
Consider passing additional flags (eg -Wc++-compat) to the C compiler for more warnings.
Meson provides a --wrapper flag to run tests through arbitrary programs, for instance:
$ meson test --wrapper 'valgrind --error-exitcode=1 --leak-check=full'
Full output can be obtained by also passing --verbose.
If you encounter segfaults happening at random, catch them by repeating unit tests multiple times with GDB attached:
$ meson test --repeat 1000000 --gdb
Valid example inputs are placed inside doc/examples.
They can be compiled with mCc using the provided Bash script test/integration.
flex and bison are used to generate the lexer and parser, respectively.
Their input files are scanner.l and parser.y and have their own special syntax.
The resulting files are scanner.c, scanner.h, parser.tab.c, and parser.tab.h, which are all considered implementation details.
The main interface of the parser is defined by parser.h and should be free of implementation details.
The AST is defined in ast.h.
Nodes are encoded in 2 levels, structs for node types (eg statement, expression, literal, ...) and tagged unions to distinguish their variants (eg call expression, binary operation, ...).
Furthermore, a visitor mechanism is provided in ast_visit.h.
An AST printer for the Dot Format is provided. Together with Graphviz, ASTs can be visualised.
$ cat ../doc/examples/fib.mC | ./mC_to_dot | xdot -
or
$ cat ../doc/examples/fib.mC | ./mC_to_dot | dot -Tpng > fib.mC.png
$ xdg-open fib.mC.png
Note that for this very purpose a dedicated executable mC_to_dot is created.
It is recommended to add other utility executables for debugging and scripting purposes.
Prefer this method to adding additional flags to the main compiler executable mCc.
Meson will generate a doc target, given doxygen was found on your system.
You'll need to manually invoke it (ninja doc) to generate doxygen output.
The resulting documentation will be placed inside builddir/doc.
If lcov, gcovr, and genhtml are available on your system, you can generate HTML coverage report directly via Meson.
See the respective documentation for details.
This will also generate an XML report which can be loaded in most IDEs (via a plugin).
Since this is only here to get you started, only a small portion of the grammar has been implemented.
Yet this should make it much easier to work with flex / bison than starting from scratch.
Be sure to understand the provided code before using it! Notify me if you find any mistakes which should be patched.