Auto merge of rust-lang#85395 - 12101111:build-crt, r=petrochenkov

Build crtbegin.o/crtend.o from source code

Build crtbengin.o/crtend.o from source code instead of copying from gcc.

The crtbegin and crtend implementation from llvm don't need `crtbeginS.o` for PIC. `crtbegin{,S,T}.o` is unified into one generic `crtbegin.o`. See the comments in https://reviews.llvm.org/D28791#1419436 and https://reviews.llvm.org/D28791#1420914

fix: rust-lang#85310 , fix: rust-lang#47551 , fix: rust-lang#84033

Author: bors

src/bootstrap/builder.rs

@@ -369,7 +369,8 @@ impl<'a> Builder<'a> {
                 tool::Rustfmt,
                 tool::Miri,
                 tool::CargoMiri,
-                native::Lld
+                native::Lld,
+                native::CrtBeginEnd
             ),
             Kind::Check | Kind::Clippy { .. } | Kind::Fix | Kind::Format => describe!(
                 check::Std,

src/bootstrap/compile.rs

@@ -199,8 +199,9 @@ fn copy_self_contained_objects(
                 DependencyType::TargetSelfContained,
             );
         }
+        let crt_path = builder.ensure(native::CrtBeginEnd { target });
         for &obj in &["crtbegin.o", "crtbeginS.o", "crtend.o", "crtendS.o"] {
-            let src = compiler_file(builder, builder.cc(target), target, obj);
+            let src = crt_path.join(obj);
             let target = libdir_self_contained.join(obj);
             builder.copy(&src, &target);
             target_deps.push((target, DependencyType::TargetSelfContained));

src/bootstrap/native.rs

@@ -858,3 +858,69 @@ impl HashStamp {
         fs::write(&self.path, self.hash.as_deref().unwrap_or(b""))
     }
 }
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub struct CrtBeginEnd {
+    pub target: TargetSelection,
+}
+
+impl Step for CrtBeginEnd {
+    type Output = PathBuf;
+
+    fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
+        run.path("src/llvm-project/compiler-rt/lib/crt")
+    }
+
+    fn make_run(run: RunConfig<'_>) {
+        run.builder.ensure(CrtBeginEnd { target: run.target });
+    }
+
+    /// Build crtbegin.o/crtend.o for musl target.
+    fn run(self, builder: &Builder<'_>) -> Self::Output {
+        let out_dir = builder.native_dir(self.target).join("crt");
+
+        if builder.config.dry_run {
+            return out_dir;
+        }
+
+        let crtbegin_src = builder.src.join("src/llvm-project/compiler-rt/lib/crt/crtbegin.c");
+        let crtend_src = builder.src.join("src/llvm-project/compiler-rt/lib/crt/crtend.c");
+        if up_to_date(&crtbegin_src, &out_dir.join("crtbegin.o"))
+            && up_to_date(&crtend_src, &out_dir.join("crtendS.o"))
+        {
+            return out_dir;
+        }
+
+        builder.info("Building crtbegin.o and crtend.o");
+        t!(fs::create_dir_all(&out_dir));
+
+        let mut cfg = cc::Build::new();
+
+        if let Some(ar) = builder.ar(self.target) {
+            cfg.archiver(ar);
+        }
+        cfg.compiler(builder.cc(self.target));
+        cfg.cargo_metadata(false)
+            .out_dir(&out_dir)
+            .target(&self.target.triple)
+            .host(&builder.config.build.triple)
+            .warnings(false)
+            .debug(false)
+            .opt_level(3)
+            .file(crtbegin_src)
+            .file(crtend_src);
+
+        // Those flags are defined in src/llvm-project/compiler-rt/lib/crt/CMakeLists.txt
+        // Currently only consumer of those objects is musl, which use .init_array/.fini_array
+        // instead of .ctors/.dtors
+        cfg.flag("-std=c11")
+            .define("CRT_HAS_INITFINI_ARRAY", None)
+            .define("EH_USE_FRAME_REGISTRY", None);
+
+        cfg.compile("crt");
+
+        t!(fs::copy(out_dir.join("crtbegin.o"), out_dir.join("crtbeginS.o")));
+        t!(fs::copy(out_dir.join("crtend.o"), out_dir.join("crtendS.o")));
+        out_dir
+    }
+}

src/ci/docker/host-x86_64/dist-various-1/Dockerfile

@@ -144,7 +144,11 @@ ENV TARGETS=$TARGETS,armv7a-none-eabi
 # riscv targets currently do not need a C compiler, as compiler_builtins
 # doesn't currently have it enabled, and the riscv gcc compiler is not
 # installed.
-ENV CC_mipsel_unknown_linux_musl=mipsel-openwrt-linux-gcc \
+ENV CFLAGS_armv5te_unknown_linux_musleabi="-march=armv5te -marm -mfloat-abi=soft" \
+    CFLAGS_arm_unknown_linux_musleabi="-march=armv6 -marm" \
+    CFLAGS_arm_unknown_linux_musleabihf="-march=armv6 -marm -mfpu=vfp" \
+    CFLAGS_armv7_unknown_linux_musleabihf="-march=armv7-a" \
+    CC_mipsel_unknown_linux_musl=mipsel-openwrt-linux-gcc \
     CC_mips_unknown_linux_musl=mips-openwrt-linux-gcc \
     CC_mips64el_unknown_linux_muslabi64=mips64el-linux-gnuabi64-gcc \
     CC_mips64_unknown_linux_muslabi64=mips64-linux-gnuabi64-gcc \

src/test/run-make-fulldeps/issue-47551/Makefile

@@ -0,0 +1,9 @@
+# only-linux
+# ignore-32bit
+
+-include ../tools.mk
+
+all:
+	$(RUSTC) eh_frame-terminator.rs
+	$(call RUN,eh_frame-terminator) | $(CGREP) '1122334455667788'
+	objdump --dwarf=frames $(TMPDIR)/eh_frame-terminator | $(CGREP) 'ZERO terminator'

src/test/run-make-fulldeps/issue-47551/eh_frame-terminator.rs

@@ -0,0 +1,23 @@
+// run-pass
+
+#![feature(backtrace)]
+#[derive(Clone, Copy)]
+struct Foo {
+    array: [u64; 10240],
+}
+
+impl Foo {
+    const fn new() -> Self {
+        Self {
+            array: [0x1122_3344_5566_7788; 10240]
+        }
+    }
+}
+
+static BAR: [Foo; 10240] = [Foo::new(); 10240];
+
+fn main() {
+    let bt = std::backtrace::Backtrace::force_capture();
+    println!("Hello, world! {:?}", bt);
+    println!("{:x}", BAR[0].array[0]);
+}