Auto merge of #54319 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 9 pull requests

Successful merges:

 - #53522 (Add doc for impl From for Addr)
 - #54097 (rustdoc: Remove namespace for keywords)
 - #54205 (Add treat-err-as-bug flag in rustdoc)
 - #54225 (Regression test for #53675.)
 - #54232 (add `-Z dont-buffer-diagnostics`)
 - #54273 (Suggest to change numeric literal instead of casting)
 - #54299 (Issue 54246)
 - #54311 (Remove README with now-out-of-date docs about docs.)
 - #54313 (OsStr: Document that it's not NUL terminated)

Failed merges:

r? @ghost

Author: bors

src/doc/README.md

@@ -1331,6 +1331,8 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "disable user provided type assertion in NLL"),
     nll_dont_emit_read_for_match: bool = (false, parse_bool, [UNTRACKED],
         "in match codegen, do not include ReadForMatch statements (used by mir-borrowck)"),
+    dont_buffer_diagnostics: bool = (false, parse_bool, [UNTRACKED],
+        "emit diagnostics rather than buffering (breaks NLL error downgrading, sorting)."),
     polonius: bool = (false, parse_bool, [UNTRACKED],
         "enable polonius-based borrow-checker"),
     codegen_time_graph: bool = (false, parse_bool, [UNTRACKED],

src/librustc/session/config.rs

@@ -1012,6 +1012,7 @@ pub fn build_session_with_source_map(
     let can_emit_warnings = !(warnings_allow || cap_lints_allow);
 
     let treat_err_as_bug = sopts.debugging_opts.treat_err_as_bug;
+    let dont_buffer_diagnostics = sopts.debugging_opts.dont_buffer_diagnostics;
     let report_delayed_bugs = sopts.debugging_opts.report_delayed_bugs;
 
     let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
@@ -1059,6 +1060,7 @@ pub fn build_session_with_source_map(
             can_emit_warnings,
             treat_err_as_bug,
             report_delayed_bugs,
+            dont_buffer_diagnostics,
             external_macro_backtrace,
             ..Default::default()
         },

src/librustc/session/mod.rs

@@ -21,6 +21,10 @@ use std::thread::panicking;
 use syntax_pos::{MultiSpan, Span};
 
 /// Used for emitting structured error messages and other diagnostic information.
+///
+/// If there is some state in a downstream crate you would like to
+/// access in the methods of `DiagnosticBuilder` here, consider
+/// extending `HandlerFlags`, accessed via `self.handler.flags`.
 #[must_use]
 #[derive(Clone)]
 pub struct DiagnosticBuilder<'a> {
@@ -89,8 +93,14 @@ impl<'a> DiagnosticBuilder<'a> {
         self.cancel();
     }
 
-    /// Buffers the diagnostic for later emission.
-    pub fn buffer(self, buffered_diagnostics: &mut Vec<Diagnostic>) {
+    /// Buffers the diagnostic for later emission, unless handler
+    /// has disabled such buffering.
+    pub fn buffer(mut self, buffered_diagnostics: &mut Vec<Diagnostic>) {
+        if self.handler.flags.dont_buffer_diagnostics || self.handler.flags.treat_err_as_bug {
+            self.emit();
+            return;
+        }
+
         // We need to use `ptr::read` because `DiagnosticBuilder`
         // implements `Drop`.
         let diagnostic;

src/librustc_errors/diagnostic_builder.rs

@@ -303,9 +303,20 @@ thread_local!(pub static TRACK_DIAGNOSTICS: Cell<fn(&Diagnostic)> =
 
 #[derive(Default)]
 pub struct HandlerFlags {
+    /// If false, warning-level lints are suppressed.
+    /// (rustc: see `--allow warnings` and `--cap-lints`)
     pub can_emit_warnings: bool,
+    /// If true, error-level diagnostics are upgraded to bug-level.
+    /// (rustc: see `-Z treat-err-as-bug`)
     pub treat_err_as_bug: bool,
+    /// If true, immediately emit diagnostics that would otherwise be buffered.
+    /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
+    pub dont_buffer_diagnostics: bool,
+    /// If true, immediately print bugs registered with `delay_span_bug`.
+    /// (rustc: see `-Z report-delayed-bugs`)
     pub report_delayed_bugs: bool,
+    /// show macro backtraces even for non-local macros.
+    /// (rustc: see `-Z external-macro-backtrace`)
     pub external_macro_backtrace: bool,
 }
 

src/librustc_errors/lib.rs

@@ -783,7 +783,7 @@ impl EarlyLintPass for DeprecatedAttr {
     fn check_attribute(&mut self, cx: &EarlyContext, attr: &ast::Attribute) {
         for &&(n, _, ref g) in &self.depr_attrs {
             if attr.name() == n {
-                if let &AttributeGate::Gated(Stability::Deprecated(link),
+                if let &AttributeGate::Gated(Stability::Deprecated(link, suggestion),
                                              ref name,
                                              ref reason,
                                              _) = g {
@@ -792,7 +792,7 @@ impl EarlyLintPass for DeprecatedAttr {
                     let mut err = cx.struct_span_lint(DEPRECATED, attr.span, &msg);
                     err.span_suggestion_short_with_applicability(
                         attr.span,
-                        "remove this attribute",
+                        suggestion.unwrap_or("remove this attribute"),
                         String::new(),
                         Applicability::MachineApplicable
                     );

src/librustc_lint/builtin.rs

@@ -415,10 +415,55 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                                           src,
                                           if needs_paren { ")" } else { "" },
                                           expected_ty);
-            let into_suggestion = format!("{}{}{}.into()",
-                                          if needs_paren { "(" } else { "" },
-                                          src,
-                                          if needs_paren { ")" } else { "" });
+            let into_suggestion = format!(
+                "{}{}{}.into()",
+                if needs_paren { "(" } else { "" },
+                src,
+                if needs_paren { ")" } else { "" },
+            );
+            let literal_is_ty_suffixed = |expr: &hir::Expr| {
+                if let hir::ExprKind::Lit(lit) = &expr.node {
+                    lit.node.is_suffixed()
+                } else {
+                    false
+                }
+            };
+
+            let into_sugg = into_suggestion.clone();
+            let suggest_to_change_suffix_or_into = |err: &mut DiagnosticBuilder,
+                                                    note: Option<&str>| {
+                let suggest_msg = if literal_is_ty_suffixed(expr) {
+                    format!(
+                        "change the type of the numeric literal from `{}` to `{}`",
+                        checked_ty,
+                        expected_ty,
+                    )
+                } else {
+                    match note {
+                        Some(note) => format!("{}, which {}", msg, note),
+                        _ => format!("{} in a lossless way", msg),
+                    }
+                };
+
+                let suffix_suggestion = format!(
+                    "{}{}{}{}",
+                    if needs_paren { "(" } else { "" },
+                    src.trim_right_matches(&checked_ty.to_string()),
+                    expected_ty,
+                    if needs_paren { ")" } else { "" },
+                );
+
+                err.span_suggestion_with_applicability(
+                    expr.span,
+                    &suggest_msg,
+                    if literal_is_ty_suffixed(expr) {
+                        suffix_suggestion
+                    } else {
+                        into_sugg
+                    },
+                    Applicability::MachineApplicable,
+                );
+            };
 
             match (&expected_ty.sty, &checked_ty.sty) {
                 (&ty::Int(ref exp), &ty::Int(ref found)) => {
@@ -444,11 +489,9 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                             }
                         }
                         _ => {
-                            err.span_suggestion_with_applicability(
-                                expr.span,
-                                &format!("{}, which {}", msg, will_sign_extend),
-                                into_suggestion,
-                                Applicability::MachineApplicable
+                            suggest_to_change_suffix_or_into(
+                                err,
+                                Some(will_sign_extend),
                             );
                         }
                     }
@@ -477,12 +520,10 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                             }
                         }
                         _ => {
-                            err.span_suggestion_with_applicability(
-                                expr.span,
-                                &format!("{}, which {}", msg, will_zero_extend),
-                                into_suggestion,
-                                Applicability::MachineApplicable
-                            );
+                           suggest_to_change_suffix_or_into(
+                               err,
+                               Some(will_zero_extend),
+                           );
                         }
                     }
                     true
@@ -583,12 +624,10 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                 }
                 (&ty::Float(ref exp), &ty::Float(ref found)) => {
                     if found.bit_width() < exp.bit_width() {
-                        err.span_suggestion_with_applicability(
-                            expr.span,
-                            &format!("{} in a lossless way", msg),
-                            into_suggestion,
-                            Applicability::MachineApplicable
-                        );
+                       suggest_to_change_suffix_or_into(
+                           err,
+                           None,
+                       );
                     } else if can_cast {
                         err.span_suggestion_with_applicability(
                             expr.span,

src/librustc_typeck/check/demand.rs

@@ -260,9 +260,10 @@ impl DocAccessLevels for AccessLevels<DefId> {
 ///
 /// If the given `error_format` is `ErrorOutputType::Json` and no `SourceMap` is given, a new one
 /// will be created for the handler.
-pub fn new_handler(error_format: ErrorOutputType, source_map: Option<Lrc<source_map::SourceMap>>)
-    -> errors::Handler
-{
+pub fn new_handler(error_format: ErrorOutputType,
+                   source_map: Option<Lrc<source_map::SourceMap>>,
+                   treat_err_as_bug: bool,
+) -> errors::Handler {
     // rustdoc doesn't override (or allow to override) anything from this that is relevant here, so
     // stick to the defaults
     let sessopts = Options::default();
@@ -299,7 +300,7 @@ pub fn new_handler(error_format: ErrorOutputType, source_map: Option<Lrc<source_
         emitter,
         errors::HandlerFlags {
             can_emit_warnings: true,
-            treat_err_as_bug: false,
+            treat_err_as_bug,
             report_delayed_bugs: false,
             external_macro_backtrace: false,
             ..Default::default()
@@ -323,9 +324,9 @@ pub fn run_core(search_paths: SearchPaths,
                 lint_cap: Option<lint::Level>,
                 describe_lints: bool,
                 mut manual_passes: Vec<String>,
-                mut default_passes: passes::DefaultPassOption)
-    -> (clean::Crate, RenderInfo, Vec<String>)
-{
+                mut default_passes: passes::DefaultPassOption,
+                treat_err_as_bug: bool,
+) -> (clean::Crate, RenderInfo, Vec<String>) {
     // Parse, resolve, and typecheck the given crate.
 
     let cpath = match input {
@@ -388,7 +389,9 @@ pub fn run_core(search_paths: SearchPaths,
     };
     driver::spawn_thread_pool(sessopts, move |sessopts| {
         let source_map = Lrc::new(source_map::SourceMap::new(sessopts.file_path_mapping()));
-        let diagnostic_handler = new_handler(error_format, Some(source_map.clone()));
+        let diagnostic_handler = new_handler(error_format,
+                                             Some(source_map.clone()),
+                                             treat_err_as_bug);
 
         let mut sess = session::build_session_(
             sessopts, cpath, diagnostic_handler, source_map,

src/librustdoc/core.rs

@@ -1830,8 +1830,8 @@ impl Context {
             *slot.borrow_mut() = self.current.clone();
         });
 
-        let mut title = if it.is_primitive() {
-            // No need to include the namespace for primitive types
+        let mut title = if it.is_primitive() || it.is_keyword() {
+            // No need to include the namespace for primitive types and keywords
             String::new()
         } else {
             self.current.join("::")

src/librustdoc/html/render.rs

@@ -404,8 +404,11 @@ fn main_args(args: &[String]) -> isize {
                                   `short` (instead was `{}`)", arg));
         }
     };
+    let treat_err_as_bug = matches.opt_strs("Z").iter().any(|x| {
+        *x == "treat-err-as-bug"
+    });
 
-    let diag = core::new_handler(error_format, None);
+    let diag = core::new_handler(error_format, None, treat_err_as_bug);
 
     // check for deprecated options
     check_deprecated_options(&matches, &diag);
@@ -560,7 +563,7 @@ fn main_args(args: &[String]) -> isize {
     let res = acquire_input(PathBuf::from(input), externs, edition, cg, &matches, error_format,
                             move |out| {
         let Output { krate, passes, renderinfo } = out;
-        let diag = core::new_handler(error_format, None);
+        let diag = core::new_handler(error_format, None, treat_err_as_bug);
         info!("going to format");
         match output_format.as_ref().map(|s| &**s) {
             Some("html") | None => {
@@ -694,6 +697,9 @@ where R: 'static + Send,
     let force_unstable_if_unmarked = matches.opt_strs("Z").iter().any(|x| {
         *x == "force-unstable-if-unmarked"
     });
+    let treat_err_as_bug = matches.opt_strs("Z").iter().any(|x| {
+        *x == "treat-err-as-bug"
+    });
 
     let (lint_opts, describe_lints, lint_cap) = get_cmd_lint_options(matches, error_format);
 
@@ -706,7 +712,8 @@ where R: 'static + Send,
             core::run_core(paths, cfgs, externs, Input::File(cratefile), triple, maybe_sysroot,
                            display_warnings, crate_name.clone(),
                            force_unstable_if_unmarked, edition, cg, error_format,
-                           lint_opts, lint_cap, describe_lints, manual_passes, default_passes);
+                           lint_opts, lint_cap, describe_lints, manual_passes, default_passes,
+                           treat_err_as_bug);
 
         info!("finished with rustc");
 

src/librustdoc/lib.rs

@@ -34,7 +34,9 @@ use sys_common::{AsInner, IntoInner, FromInner};
 ///
 /// `OsString` and [`OsStr`] bridge this gap by simultaneously representing Rust
 /// and platform-native string values, and in particular allowing a Rust string
-/// to be converted into an "OS" string with no cost if possible.
+/// to be converted into an "OS" string with no cost if possible.  A consequence
+/// of this is that `OsString` instances are *not* `NUL` terminated; in order
+/// to pass to e.g. Unix system call, you should create a [`CStr`].
 ///
 /// `OsString` is to [`&OsStr`] as [`String`] is to [`&str`]: the former
 /// in each pair are owned strings; the latter are borrowed
@@ -65,6 +67,7 @@ use sys_common::{AsInner, IntoInner, FromInner};
 ///
 /// [`OsStr`]: struct.OsStr.html
 /// [`&OsStr`]: struct.OsStr.html
+/// [`CStr`]: struct.CStr.html
 /// [`From`]: ../convert/trait.From.html
 /// [`String`]: ../string/struct.String.html
 /// [`&str`]: ../primitive.str.html

src/libstd/ffi/os_str.rs

@@ -554,20 +554,28 @@ impl FromInner<c::sockaddr_in6> for SocketAddrV6 {
 
 #[stable(feature = "ip_from_ip", since = "1.16.0")]
 impl From<SocketAddrV4> for SocketAddr {
+    /// Converts a [`SocketAddrV4`] into a [`SocketAddr::V4`].
     fn from(sock4: SocketAddrV4) -> SocketAddr {
         SocketAddr::V4(sock4)
     }
 }
 
 #[stable(feature = "ip_from_ip", since = "1.16.0")]
 impl From<SocketAddrV6> for SocketAddr {
+    /// Converts a [`SocketAddrV6`] into a [`SocketAddr::V6`].
     fn from(sock6: SocketAddrV6) -> SocketAddr {
         SocketAddr::V6(sock6)
     }
 }
 
 #[stable(feature = "addr_from_into_ip", since = "1.17.0")]
 impl<I: Into<IpAddr>> From<(I, u16)> for SocketAddr {
+    /// Converts a tuple struct (Into<[`IpAddr`]>, `u16`) into a [`SocketAddr`].
+    ///
+    /// This conversion creates a [`SocketAddr::V4`] for a [`IpAddr::V4`]
+    /// and creates a [`SocketAddr::V6`] for a [`IpAddr::V6`].
+    ///
+    /// `u16` is treated as port of the newly created [`SocketAddr`].
     fn from(pieces: (I, u16)) -> SocketAddr {
         SocketAddr::new(pieces.0.into(), pieces.1)
     }