Auto merge of #148481 - GuillaumeGomez:subtree-update_cg_gcc_2025-11-04, r=GuillaumeGomez

Sync rustc_codegen_gcc subtree
cc `@antoyo`
r? ghost

Author: bors

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }

compiler/rustc_codegen_gcc/.github/workflows/release.yml

@@ -62,7 +62,7 @@ jobs:
  - name: Build
 run: |
  ./y.sh prepare --only-libcore
-EMBED_LTO_BITCODE=1 ./y.sh build --sysroot --release --release-sysroot
+ ./y.sh build --sysroot --release --release-sysroot
  ./y.sh test --cargo-tests
  ./y.sh clean all
 
@@ -72,26 +72,36 @@ jobs:
  git config --global user.name "User"
  ./y.sh prepare
 
- - name: Add more failing tests because of undefined symbol errors (FIXME)
-run: cat tests/failing-lto-tests.txt >> tests/failing-ui-tests.txt
-
  - name: Run tests
 run: |
  # FIXME(antoyo): we cannot enable LTO for stdarch tests currently because of some failing LTO tests using proc-macros.
- # FIXME(antoyo): this should probably not be needed since we embed the LTO bitcode.
- printf '[profile.release]\nlto = "fat"\n' >> build/build_sysroot/sysroot_src/library/Cargo.toml
- EMBED_LTO_BITCODE=1 ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
+ CG_RUSTFLAGS="-Cembed-bitcode=yes" ./y.sh test --release --clean --release-sysroot --build-sysroot --keep-lto-tests ${{ matrix.commands }}
 
- - name: Run y.sh cargo build
+ - name: LTO test
 run: |
-EMBED_LTO_BITCODE=1 CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
+ CHANNEL="release" ./y.sh cargo build --release --manifest-path tests/hello-world/Cargo.toml
  call_found=$(objdump -dj .text tests/hello-world/target/release/hello_world | grep -c "call .*mylib.*my_func" ) ||:
  if [ $call_found -gt 0 ]; then
  echo "ERROR: call my_func found in asm"
  echo "Test is done with LTO enabled, hence inlining should occur across crates"
  exit 1
  fi
 
+ - name: Cross-language LTO test
+run: |
+ pushd tests/cross_lang_lto
+ gcc -c -flto add.c -masm=intel -fPIC -O3
+ ar rcs libadd.a add.o
+ popd
+
+ CHANNEL="release" CG_RUSTFLAGS="-L native=. -Clinker-plugin-lto -Clinker=gcc" ./y.sh cargo build --release --manifest-path tests/cross_lang_lto/Cargo.toml
+ call_found=$(objdump -dj .text tests/cross_lang_lto/target/release/cross_lang_lto | grep -c "call .*my_add" ) ||:
+ if [ $call_found -gt 0 ]; then
+ echo "ERROR: call my_add found in asm"
+ echo "Test is done with cross-language LTO enabled, hence inlining should occur across object files"
+ exit 1
+ fi
+
 # Summary job for the merge queue.
 # ALL THE PREVIOUS JOBS NEED TO BE ADDED TO THE `needs` SECTION OF THIS JOB!
 success_release:

compiler/rustc_codegen_gcc/.github/workflows/stdarch.yml

@@ -41,7 +41,7 @@ jobs:
 # TODO: remove when we have binutils version 2.43 in the repo.
  - name: Install more recent binutils
 run: |
- echo "deb http://archive.ubuntu.com/ubuntu oracular main universe" | sudo tee /etc/apt/sources.list.d/oracular-copies.list
+ echo "deb http://archive.ubuntu.com/ubuntu plucky main universe" | sudo tee /etc/apt/sources.list.d/plucky-copies.list
  sudo apt-get update
  sudo apt-get install binutils
 

compiler/rustc_codegen_gcc/Cargo.lock

@@ -56,18 +56,18 @@ dependencies = [
 
 [[package]]
 name = "gccjit"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4a0e310ef75f396cd11b2443b353d55376656ca92c13cba36f92b7aff346ac1a"
+checksum = "60362e038e71e4bdc1a5b23fb45e1aba587b5947fe0db58f4871d95608f89eca"
 dependencies = [
 "gccjit_sys",
 ]
 
 [[package]]
 name = "gccjit_sys"
-version = "0.8.2"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ed7572b30cd32430294dde6fb70822d58e67c6846a548647e8739776a0125b"
+checksum = "ddd542c8414e122217551c6af6b7d33acf51a227aee85276f218c087525e01bb"
 dependencies = [
 "libc",
 ]

compiler/rustc_codegen_gcc/Cargo.toml

@@ -24,7 +24,7 @@ default = ["master"]
 [dependencies]
 object = { version = "0.37.0", default-features = false, features = ["std", "read"] }
 tempfile = "3.20"
-gccjit = "2.8"
+gccjit = "2.10"
 #gccjit = { git = "https://github.com/rust-lang/gccjit.rs" }
 
 # Local copy.

compiler/rustc_codegen_gcc/Readme.md

@@ -70,11 +70,17 @@ $ ../gcc/configure \
 $ make -j4 # You can replace `4` with another number depending on how many cores you have.
 ```
 
-If you want to run libgccjit tests, you will need to also enable the C++ language in the `configure`:
+If you want to run libgccjit tests, you will need to
+* Enable the C++ language in the `configure` step:
 
 ```bash
 --enable-languages=jit,c++
 ```
+* Install [dejagnu](https://www.gnu.org/software/dejagnu/#downloading) to run the tests:
+
+```bash
+$ sudo apt install dejagnu
+```
 
 Then to run libgccjit tests:
 
@@ -135,16 +141,6 @@ $ CHANNEL="release" $CG_GCCJIT_DIR/y.sh cargo run
 
 If you compiled cg_gccjit in debug mode (aka you didn't pass `--release` to `./y.sh test`) you should use `CHANNEL="debug"` instead or omit `CHANNEL="release"` completely.
 
-### LTO
-
-To use LTO, you need to set the variable `EMBED_LTO_BITCODE=1` in addition to setting `lto = "fat"` in the `Cargo.toml`.
-
-Failing to set `EMBED_LTO_BITCODE` will give you the following error:
-
-```
-error: failed to copy bitcode to object file: No such file or directory (os error 2)
-```
-
 ### Rustc
 
 If you want to run `rustc` directly, you can do so with:

compiler/rustc_codegen_gcc/build_system/src/build.rs

@@ -149,6 +149,9 @@ pub fn build_sysroot(env: &HashMap<String, String>, config: &ConfigInfo) -> Resu
 
 // Copy files to sysroot
 let sysroot_path = start_dir.join(format!("sysroot/lib/rustlib/{}/lib/", config.target_triple));
+// To avoid errors like "multiple candidates for `rmeta` dependency `core` found", we clean the
+// sysroot directory before copying the sysroot build artifacts.
+let _ = fs::remove_dir_all(&sysroot_path);
 create_dir(&sysroot_path)?;
 letmut copier = |dir_to_copy:&Path| {
 // FIXME: should not use shell command!

compiler/rustc_codegen_gcc/build_system/src/clean.rs

@@ -69,8 +69,13 @@ fn clean_all() -> Result<(), String> {
 }
 
 fnclean_ui_tests() -> Result<(),String>{
-let path = Path::new(crate::BUILD_DIR).join("rust/build/x86_64-unknown-linux-gnu/test/ui/");
-run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+let directories = ["run-make","run-make-cargo","ui"];
+for directory in directories {
+let path = Path::new(crate::BUILD_DIR)
+.join("rust/build/x86_64-unknown-linux-gnu/test/")
+.join(directory);
+run_command(&[&"find",&path,&"-name",&"stamp",&"-delete"],None)?;
+}
 Ok(())
 }
 

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,49 @@
+use std::ffi::OsStr;
 use std::fs;
 use std::path::{Path,PathBuf};
+use std::process::Output;
 
 usecrate::rustc_info::get_rustc_path;
 usecrate::utils::{
  cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
  run_command_with_output, walk_dir,
 };
 
+// This is needed on systems where nothing is configured.
+// git really needs something here, or it will fail.
+// Even using --author is not enough.
+constGIT_CMD:[&dynAsRef<OsStr>;9] = [
+&"git",
+&"-c",
+&"user.name=None",
+&"-c",
+&"user.email=none@example.com",
+&"-c",
+&"core.autocrlf=false",
+&"-c",
+&"commit.gpgSign=false",
+];
+
+fnrun_git_command(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<Output,String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command(git_cmd, cwd)
+}
+
+fnrun_git_command_with_output(
+command:&dynAsRef<OsStr>,
+input:&[&dynAsRef<OsStr>],
+cwd:Option<&Path>,
+) -> Result<(),String>{
+let git_cmd =
+&GIT_CMD.into_iter().chain([command]).chain(input.iter().cloned()).collect::<Vec<_>>()[..];
+run_command_with_output(git_cmd, cwd)
+}
+
 fnprepare_libcore(
 sysroot_path:&Path,
 libgccjit12_patches:bool,
@@ -55,19 +92,12 @@ fn prepare_libcore(
 run_command(&[&"cp",&"-r",&rustlib_dir.join("library"),&sysroot_dir],None)?;
 
 println!("[GIT] init (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"init"],Some(&sysroot_dir))?;
+run_git_command(&"init",&[],Some(&sysroot_dir))?;
 println!("[GIT] add (cwd): `{}`", sysroot_dir.display());
-run_command(&[&"git",&"add",&"."],Some(&sysroot_dir))?;
+run_git_command(&"add",&[&"."],Some(&sysroot_dir))?;
 println!("[GIT] commit (cwd): `{}`", sysroot_dir.display());
 
-// This is needed on systems where nothing is configured.
-// git really needs something here, or it will fail.
-// Even using --author is not enough.
-run_command(&[&"git",&"config",&"user.email",&"none@example.com"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"user.name",&"None"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"core.autocrlf",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"config",&"commit.gpgSign",&"false"],Some(&sysroot_dir))?;
-run_command(&[&"git",&"commit",&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
+run_git_command(&"commit",&[&"-m",&"Initial commit",&"-q"],Some(&sysroot_dir))?;
 
 letmut patches = Vec::new();
 walk_dir(
@@ -105,10 +135,11 @@ fn prepare_libcore(
 for file_path in patches {
 println!("[GIT] apply `{}`", file_path.display());
 let path = Path::new("../../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(&sysroot_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(&sysroot_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(&sysroot_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(&sysroot_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(&sysroot_dir),
 )?;
 }
@@ -124,10 +155,11 @@ fn prepare_rand() -> Result<(), String> {
 let rand_dir = Path::new("build/rand");
 println!("[GIT] apply `{file_path}`");
 let path = Path::new("../..").join(file_path);
-run_command_with_output(&[&"git",&"apply",&path],Some(rand_dir))?;
-run_command_with_output(&[&"git",&"add",&"-A"],Some(rand_dir))?;
-run_command_with_output(
-&[&"git",&"commit",&"--no-gpg-sign",&"-m",&format!("Patch {}", path.display())],
+run_git_command_with_output(&"apply",&[&path],Some(rand_dir))?;
+run_git_command_with_output(&"add",&[&"-A"],Some(rand_dir))?;
+run_git_command_with_output(
+&"commit",
+&[&"-m",&format!("Patch {}", path.display())],
 Some(rand_dir),
 )?;
 
@@ -154,8 +186,8 @@ where
 println!("`{}` has already been cloned", clone_result.repo_name);
 }
 let repo_path = Path::new(crate::BUILD_DIR).join(&clone_result.repo_name);
-run_command(&[&"git",&"checkout",&"--",&"."],Some(&repo_path))?;
-run_command(&[&"git",&"checkout",&checkout_commit],Some(&repo_path))?;
+run_git_command(&"checkout",&[&"--",&"."],Some(&repo_path))?;
+run_git_command(&"checkout",&[&checkout_commit],Some(&repo_path))?;
 ifletSome(extra) = extra {
 extra(&repo_path)?;
 }