Run rustc_codegen_gcc tests in the CI

src/bootstrap/src/core/build_steps/compile.rs

@@ -45,15 +45,42 @@ pub struct Std {
     /// When using download-rustc, we need to use a new build of `std` for running unit tests of Std itself,
     /// but we need to use the downloaded copy of std for linking to rustdoc. Allow this to be overriden by `builder.ensure` from other steps.
     force_recompile: bool,
+    extra_rust_args: &'static [&'static str],
 }
 
 impl Std {
     pub fn new(compiler: Compiler, target: TargetSelection) -> Self {
-        Self { target, compiler, crates: Default::default(), force_recompile: false }
+        Self {
+            target,
+            compiler,
+            crates: Default::default(),
+            force_recompile: false,
+            extra_rust_args: &[],
+        }
     }
 
     pub fn force_recompile(compiler: Compiler, target: TargetSelection) -> Self {
-        Self { target, compiler, crates: Default::default(), force_recompile: true }
+        Self {
+            target,
+            compiler,
+            crates: Default::default(),
+            force_recompile: true,
+            extra_rust_args: &[],
+        }
+    }
+
+    pub fn new_with_extra_rust_args(
+        compiler: Compiler,
+        target: TargetSelection,
+        extra_rust_args: &'static [&'static str],
+    ) -> Self {
+        Self {
+            target,
+            compiler,
+            crates: Default::default(),
+            force_recompile: false,
+            extra_rust_args,
+        }
     }
 }
 
@@ -81,6 +108,7 @@ impl Step for Std {
             target: run.target,
             crates,
             force_recompile: false,
+            extra_rust_args: &[],
         });
     }
 
@@ -188,6 +216,9 @@ impl Step for Std {
         if target.is_synthetic() {
             cargo.env("RUSTC_BOOTSTRAP_SYNTHETIC_TARGET", "1");
         }
+        for rustflag in self.extra_rust_args.into_iter() {
+            cargo.rustflag(rustflag);
+        }
 
         let _guard = builder.msg(
             Kind::Build,

src/bootstrap/src/core/build_steps/test.rs

@@ -3094,3 +3094,130 @@ impl Step for CodegenCranelift {
         builder.run_cmd(BootstrapCommand::from(&mut cmd).fail_fast());
     }
 }
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct CodegenGCC {
+    compiler: Compiler,
+    target: TargetSelection,
+}
+
+impl Step for CodegenGCC {
+    type Output = ();
+    const DEFAULT: bool = true;
+    const ONLY_HOSTS: bool = true;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.paths(&["compiler/rustc_codegen_gcc"])
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        let builder = run.builder;
+        let host = run.build_triple();
+        let compiler = run.builder.compiler_for(run.builder.top_stage, host, host);
+
+        if builder.doc_tests == DocTests::Only {
+            return;
+        }
+
+        let triple = run.target.triple;
+        let target_supported = if triple.contains("linux") {
+            triple.contains("x86_64")
+                || triple.contains("aarch64")
+                || triple.contains("s390x")
+                || triple.contains("riscv64gc")
+        } else if triple.contains("darwin") || triple.contains("windows") {
+            triple.contains("x86_64")
+        } else {
+            false
+        };
+        if !target_supported {
+            builder.info("target not supported by rustc_codegen_gcc. skipping");
+            return;
+        }
+
+        if builder.remote_tested(run.target) {
+            builder.info("remote testing is not supported by rustc_codegen_gcc. skipping");
+            return;
+        }
+
+        if !builder.config.rust_codegen_backends.contains(&INTERNER.intern_str("gcc")) {
+            builder.info("gcc not in rust.codegen-backends. skipping");
+            return;
+        }
+
+        builder.ensure(CodegenGCC { compiler, target: run.target });
+    }
+
+    fn run(self, builder: &Builder<'_>) {
+        let compiler = self.compiler;
+        let target = self.target;
+
+        builder.ensure(compile::Std::new_with_extra_rust_args(
+            compiler,
+            target,
+            &["-Csymbol-mangling-version=v0", "-Cpanic=abort"],
+        ));
+
+        // If we're not doing a full bootstrap but we're testing a stage2
+        // version of libstd, then what we're actually testing is the libstd
+        // produced in stage1. Reflect that here by updating the compiler that
+        // we're working with automatically.
+        let compiler = builder.compiler_for(compiler.stage, compiler.host, target);
+
+        let build_cargo = || {
+            let mut cargo = builder.cargo(
+                compiler,
+                Mode::Codegen, // Must be codegen to ensure dlopen on compiled dylibs works
+                SourceType::InTree,
+                target,
+                "run",
+            );
+            cargo.current_dir(&builder.src.join("compiler/rustc_codegen_gcc"));
+            cargo
+                .arg("--manifest-path")
+                .arg(builder.src.join("compiler/rustc_codegen_gcc/build_system/Cargo.toml"));
+            compile::rustc_cargo_env(builder, &mut cargo, target, compiler.stage);
+
+            // Avoid incremental cache issues when changing rustc
+            cargo.env("CARGO_BUILD_INCREMENTAL", "false");
+            cargo.rustflag("-Cpanic=abort");
+
+            cargo
+        };
+
+        builder.info(&format!(
+            "{} GCC stage{} ({} -> {})",
+            Kind::Test.description(),
+            compiler.stage,
+            &compiler.host,
+            target
+        ));
+        let _time = helpers::timeit(&builder);
+
+        /*
+        let mut prepare_cargo = build_cargo();
+        prepare_cargo.arg("--").arg("prepare");
+        #[allow(deprecated)]
+        builder.config.try_run(&mut prepare_cargo.into()).unwrap();
+        */
+
+        let mut cargo = build_cargo();
+
+        cargo
+            .arg("--")
+            .arg("test")
+            .arg("--use-system-gcc")
+            .arg("--use-backend")
+            .arg("gcc")
+            .arg("--out-dir")
+            .arg(builder.stage_out(compiler, Mode::ToolRustc).join("cg_gcc"))
+            .arg("--release")
+            .arg("--no-default-features")
+            .arg("--mini-tests")
+            .arg("--std-tests");
+        cargo.args(builder.config.test_args());
+
+        let mut cmd: Command = cargo.into();
+        builder.run_cmd(BootstrapCommand::from(&mut cmd).fail_fast());
+    }
+}

src/bootstrap/src/core/builder.rs

@@ -737,6 +737,7 @@ impl<'a> Builder<'a> {
                 test::Debuginfo,
                 test::UiFullDeps,
                 test::CodegenCranelift,
+                test::CodegenGCC,
                 test::Rustdoc,
                 test::RunCoverageRustdoc,
                 test::Pretty,

src/ci/run.sh

@@ -127,7 +127,7 @@ else
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.verify-llvm-ir"
 
   # Test the Cranelift backend in CI. Bootstrap knows which targets to run tests on.
-  RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.codegen-backends=llvm,cranelift"
+  RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.codegen-backends=llvm,cranelift,gcc"
 
   # We enable this for non-dist builders, since those aren't trying to produce
   # fresh binaries. We currently don't entirely support distributing a fresh