Auto merge of #54168 - kennytm:rollup, r=kennytm

Rollup of 11 pull requests

Successful merges:

 - #53371 (Do not emit E0277 on incorrect tuple destructured binding)
 - #53829 (Add rustc SHA to released DWARF debuginfo)
 - #53950 (Allow for opting out of ThinLTO and clean up LTO related cli flag handling.)
 - #53976 (Replace unwrap calls in example by expect)
 - #54070 (Add Error::description soft-deprecation to RELEASES)
 - #54076 (miri loop detector hashing)
 - #54119 (Add some unit tests for find_best_match_for_name)
 - #54147 (Add a test that tries to modify static memory at compile-time)
 - #54150 (Updated 1.29 release notes with --document-private-items flag)
 - #54163 (Update stage 0 to latest beta)
 - #54170 (COMPILER_TESTS.md has been moved)

CONTRIBUTING.md

@@ -368,8 +368,7 @@ will run all the tests on every platform we support. If it all works out,
 [merge-queue]: https://buildbot2.rust-lang.org/homu/queue/rust
 
 Speaking of tests, Rust has a comprehensive test suite. More information about
-it can be found
-[here](https://github.com/rust-lang/rust/blob/master/src/test/COMPILER_TESTS.md).
+it can be found [here][rctd].
 
 ### External Dependencies
 [external-dependencies]: #external-dependencies
@@ -654,5 +653,5 @@ are:
 [rustforge]: https://forge.rust-lang.org/
 [tlgba]: http://tomlee.co/2014/04/a-more-detailed-tour-of-the-rust-compiler/
 [ro]: http://www.rustaceans.org/
-[rctd]: ./src/test/COMPILER_TESTS.md
+[rctd]: https://rust-lang-nursery.github.io/rustc-guide/tests/intro.html
 [cheatsheet]: https://buildbot2.rust-lang.org/homu/

RELEASES.md

@@ -31,6 +31,8 @@ Cargo
   using `--target`][cargo/5614]
 - [Added the `cargo-fix` subcommand to automatically move project code from
   2015 edition to 2018.][cargo/5723]
+- [`cargo doc` can now optionally document private types using the
+  `--document-private-items` flag.][cargo/5543]
 
 Misc
 ----
@@ -68,6 +70,7 @@ Compatibility Notes
 [51178]: https://github.com/rust-lang/rust/pull/51178/
 [51122]: https://github.com/rust-lang/rust/pull/51122
 [50494]: https://github.com/rust-lang/rust/pull/50494/
+[cargo/5543]: https://github.com/rust-lang/cargo/pull/5543
 [cargo/5614]: https://github.com/rust-lang/cargo/pull/5614/
 [cargo/5723]: https://github.com/rust-lang/cargo/pull/5723/
 [cargo/5831]: https://github.com/rust-lang/cargo/pull/5831/
@@ -370,6 +373,8 @@ Compatibility Notes
 - [The maximum number for `repr(align(N))` is now 2²⁹.][50378] Previously you
   could enter higher numbers but they were not supported by LLVM. Up to 512MB
   alignment should cover all use cases.
+- The `.description()` method on the `std::error::Error` trait
+  [has been soft-deprecated][50163]. It is no longer required to implement it.
 
 [48553]: https://github.com/rust-lang/rust/pull/48553/
 [48851]: https://github.com/rust-lang/rust/pull/48851/
@@ -383,6 +388,7 @@ Compatibility Notes
 [49719]: https://github.com/rust-lang/rust/pull/49719/
 [49896]: https://github.com/rust-lang/rust/pull/49896/
 [49968]: https://github.com/rust-lang/rust/pull/49968/
+[50163]: https://github.com/rust-lang/rust/pull/50163
 [50177]: https://github.com/rust-lang/rust/pull/50177/
 [50378]: https://github.com/rust-lang/rust/pull/50378/
 [50398]: https://github.com/rust-lang/rust/pull/50398/

config.toml.example

@@ -377,6 +377,10 @@
 # Whether to verify generated LLVM IR
 #verify-llvm-ir = false
 
+# Map all debuginfo paths for libstd and crates to `/rust/$sha/$crate/...`,
+# generally only set for releases
+#remap-debuginfo = false
+
 # =============================================================================
 # Options for specific targets
 #

src/bootstrap/bin/rustc.rs

@@ -263,6 +263,10 @@ fn main() {
         if env::var_os("RUSTC_FORCE_UNSTABLE").is_some() {
             cmd.arg("-Z").arg("force-unstable-if-unmarked");
         }
+
+        if let Ok(map) = env::var("RUSTC_DEBUGINFO_MAP") {
+            cmd.arg("--remap-path-prefix").arg(&map);
+        }
     } else {
         // Override linker if necessary.
         if let Ok(host_linker) = env::var("RUSTC_HOST_LINKER") {

src/bootstrap/builder.rs

@@ -32,7 +32,7 @@ use native;
 use test;
 use tool;
 use util::{add_lib_path, exe, libdir};
-use {Build, DocTests, Mode};
+use {Build, DocTests, Mode, GitRepo};
 
 pub use Compiler;
 
@@ -876,6 +876,10 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTC_HOST_CRT_STATIC", x.to_string());
         }
 
+        if let Some(map) = self.build.debuginfo_map(GitRepo::Rustc) {
+            cargo.env("RUSTC_DEBUGINFO_MAP", map);
+        }
+
         // Enable usage of unstable features
         cargo.env("RUSTC_BOOTSTRAP", "1");
         self.add_rust_test_threads(&mut cargo);
@@ -964,7 +968,7 @@ impl<'a> Builder<'a> {
             let cc = ccacheify(&self.cc(target));
             cargo.env(format!("CC_{}", target), &cc).env("CC", &cc);
 
-            let cflags = self.cflags(target).join(" ");
+            let cflags = self.cflags(target, GitRepo::Rustc).join(" ");
             cargo
                 .env(format!("CFLAGS_{}", target), cflags.clone())
                 .env("CFLAGS", cflags.clone());

src/bootstrap/cc_detect.rs

@@ -39,7 +39,7 @@ use std::process::Command;
 use build_helper::output;
 use cc;
 
-use Build;
+use {Build, GitRepo};
 use config::Target;
 use cache::Interned;
 
@@ -107,7 +107,7 @@ pub fn find(build: &mut Build) {
 
         build.cc.insert(target, compiler);
         build.verbose(&format!("CC_{} = {:?}", &target, build.cc(target)));
-        build.verbose(&format!("CFLAGS_{} = {:?}", &target, build.cflags(target)));
+        build.verbose(&format!("CFLAGS_{} = {:?}", &target, build.cflags(target, GitRepo::Rustc)));
         if let Some(ar) = ar {
             build.verbose(&format!("AR_{} = {:?}", &target, ar));
             build.ar.insert(target, ar);

src/bootstrap/compile.rs

@@ -30,7 +30,7 @@ use filetime::FileTime;
 use serde_json;
 
 use util::{exe, libdir, is_dylib, CiEnv};
-use {Compiler, Mode};
+use {Compiler, Mode, GitRepo};
 use native;
 use tool;
 
@@ -895,7 +895,7 @@ pub fn compiler_file(builder: &Builder,
                  target: Interned<String>,
                  file: &str) -> PathBuf {
     let mut cmd = Command::new(compiler);
-    cmd.args(builder.cflags(target));
+    cmd.args(builder.cflags(target, GitRepo::Rustc));
     cmd.arg(format!("-print-file-name={}", file));
     let out = output(&mut cmd);
     PathBuf::from(out.trim())

src/bootstrap/config.rs

@@ -109,6 +109,7 @@ pub struct Config {
     pub rust_codegen_backends: Vec<Interned<String>>,
     pub rust_codegen_backends_dir: String,
     pub rust_verify_llvm_ir: bool,
+    pub rust_remap_debuginfo: bool,
 
     pub build: Interned<String>,
     pub hosts: Vec<Interned<String>>,
@@ -321,6 +322,7 @@ struct Rust {
     deny_warnings: Option<bool>,
     backtrace_on_ice: Option<bool>,
     verify_llvm_ir: Option<bool>,
+    remap_debuginfo: Option<bool>,
 }
 
 /// TOML representation of how each build target is configured.
@@ -557,6 +559,7 @@ impl Config {
             set(&mut config.deny_warnings, rust.deny_warnings.or(flags.warnings));
             set(&mut config.backtrace_on_ice, rust.backtrace_on_ice);
             set(&mut config.rust_verify_llvm_ir, rust.verify_llvm_ir);
+            set(&mut config.rust_remap_debuginfo, rust.remap_debuginfo);
 
             if let Some(ref backends) = rust.codegen_backends {
                 config.rust_codegen_backends = backends.iter()

src/bootstrap/lib.rs

@@ -237,6 +237,11 @@ pub enum DocTests {
     Only,
 }
 
+pub enum GitRepo {
+    Rustc,
+    Llvm,
+}
+
 /// Global configuration for the build system.
 ///
 /// This structure transitively contains all configuration for the build system.
@@ -738,14 +743,29 @@ impl Build {
         self.config.jobs.unwrap_or_else(|| num_cpus::get() as u32)
     }
 
+    fn debuginfo_map(&self, which: GitRepo) -> Option<String> {
+        if !self.config.rust_remap_debuginfo {
+            return None
+        }
+
+        let path = match which {
+            GitRepo::Rustc => {
+                let sha = self.rust_info.sha().expect("failed to find sha");
+                format!("/rustc/{}", sha)
+            }
+            GitRepo::Llvm => format!("/rustc/llvm"),
+        };
+        Some(format!("{}={}", self.src.display(), path))
+    }
+
     /// Returns the path to the C compiler for the target specified.
     fn cc(&self, target: Interned<String>) -> &Path {
         self.cc[&target].path()
     }
 
     /// Returns a list of flags to pass to the C compiler for the target
     /// specified.
-    fn cflags(&self, target: Interned<String>) -> Vec<String> {
+    fn cflags(&self, target: Interned<String>, which: GitRepo) -> Vec<String> {
         // Filter out -O and /O (the optimization flags) that we picked up from
         // cc-rs because the build scripts will determine that for themselves.
         let mut base = self.cc[&target].args().iter()
@@ -767,6 +787,16 @@ impl Build {
         if &*target == "i686-pc-windows-gnu" {
             base.push("-fno-omit-frame-pointer".into());
         }
+
+        if let Some(map) = self.debuginfo_map(which) {
+        let cc = self.cc(target);
+            if cc.ends_with("clang") || cc.ends_with("gcc") {
+                base.push(format!("-fdebug-prefix-map={}", map).into());
+            } else if cc.ends_with("clang-cl.exe") {
+                base.push("-Xclang".into());
+                base.push(format!("-fdebug-prefix-map={}", map).into());
+            }
+        }
         base
     }
 

src/bootstrap/native.rs

@@ -33,6 +33,7 @@ use util::{self, exe};
 use build_helper::up_to_date;
 use builder::{Builder, RunConfig, ShouldRun, Step};
 use cache::Interned;
+use GitRepo;
 
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct Llvm {
@@ -373,8 +374,8 @@ fn configure_cmake(builder: &Builder,
     }
 
     cfg.build_arg("-j").build_arg(builder.jobs().to_string());
-    cfg.define("CMAKE_C_FLAGS", builder.cflags(target).join(" "));
-    let mut cxxflags = builder.cflags(target).join(" ");
+    cfg.define("CMAKE_C_FLAGS", builder.cflags(target, GitRepo::Llvm).join(" "));
+    let mut cxxflags = builder.cflags(target, GitRepo::Llvm).join(" ");
     if building_dist_binaries {
         if builder.config.llvm_static_stdcpp && !target.contains("windows") {
             cxxflags.push_str(" -static-libstdc++");
@@ -680,7 +681,7 @@ impl Step for Openssl {
         };
         configure.arg(os);
         configure.env("CC", builder.cc(target));
-        for flag in builder.cflags(target) {
+        for flag in builder.cflags(target, GitRepo::Rustc) {
             configure.arg(flag);
         }
         // There is no specific os target for android aarch64 or x86_64,

src/bootstrap/test.rs

@@ -34,7 +34,7 @@ use tool::{self, Tool, SourceType};
 use toolstate::ToolState;
 use util::{self, dylib_path, dylib_path_var};
 use Crate as CargoCrate;
-use {DocTests, Mode};
+use {DocTests, Mode, GitRepo};
 
 const ADB_TEST_DIR: &str = "/data/tmp/work";
 
@@ -1142,7 +1142,7 @@ impl Step for Compiletest {
                     .arg("--cxx")
                     .arg(builder.cxx(target).unwrap())
                     .arg("--cflags")
-                    .arg(builder.cflags(target).join(" "))
+                    .arg(builder.cflags(target, GitRepo::Rustc).join(" "))
                     .arg("--llvm-components")
                     .arg(llvm_components.trim())
                     .arg("--llvm-cxxflags")

src/ci/run.sh

@@ -55,6 +55,7 @@ export RUST_RELEASE_CHANNEL=nightly
 if [ "$DEPLOY$DEPLOY_ALT" != "" ]; then
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --release-channel=$RUST_RELEASE_CHANNEL"
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --enable-llvm-static-stdcpp"
+  RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.remap-debuginfo"
 
   if [ "$NO_LLVM_ASSERTIONS" = "1" ]; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-llvm-assertions"