Auto merge of #35060 - japaric:arm-musl, r=alexcrichton

Add ARM MUSL targets

Rebase of #33189.

I tested this by producing a std for `arm-unknown-linux-musleabi` then I cross compiled Hello world to said target. Checked that the produced binary was statically linked and verified that the binary worked under QEMU.

This depends on rust-lang/libc#341. I'll have to update this PR after that libc PR is merged.

I'm also working on generating ARM musl cross toolchain via crosstool-ng. Once I verified those work, I'll send a PR to rust-buildbot.

r? @alexcrichton
cc @timonvo

Author: bors

configure

@@ -1192,7 +1192,7 @@ do
             ;;
 
 
-        x86_64-*-musl)
+        x86_64-*-musl | arm-*-musleabi)
             if [ ! -f $CFG_MUSL_ROOT/lib/libc.a ]
             then
                 err "musl libc $CFG_MUSL_ROOT/lib/libc.a not found"

mk/cfg/arm-unknown-linux-musleabi.mk

@@ -0,0 +1,3 @@
+# This file is intentially left empty to indicate that, while this target is
+# supported, it's not supported using plain GNU Make builds. Use a --rustbuild
+# instead.

mk/cfg/arm-unknown-linux-musleabihf.mk

@@ -0,0 +1,3 @@
+# This file is intentially left empty to indicate that, while this target is
+# supported, it's not supported using plain GNU Make builds. Use a --rustbuild
+# instead.

mk/cfg/armv7-unknown-linux-musleabihf.mk

@@ -0,0 +1,3 @@
+# This file is intentially left empty to indicate that, while this target is
+# supported, it's not supported using plain GNU Make builds. Use a --rustbuild
+# instead.

src/bootstrap/Cargo.lock

@@ -92,8 +92,7 @@ pub fn std_link(build: &Build,
     }
     add_to_sysroot(&out_dir, &libdir);
 
-    if target.contains("musl") &&
-       (target.contains("x86_64") || target.contains("i686")) {
+    if target.contains("musl") && !target.contains("mips") {
         copy_third_party_objects(build, target, &libdir);
     }
 }

src/bootstrap/compile.rs

@@ -109,7 +109,7 @@ pub fn check(build: &mut Build) {
         }
 
         // Make sure musl-root is valid if specified
-        if target.contains("musl") && (target.contains("x86_64") || target.contains("i686")) {
+        if target.contains("musl") && !target.contains("mips") {
             match build.config.musl_root {
                 Some(ref root) => {
                     if fs::metadata(root.join("lib/libc.a")).is_err() {

src/bootstrap/sanity.rs

@@ -16,7 +16,7 @@ libc = { path = "../rustc/libc_shim" }
 
 [build-dependencies]
 build_helper = { path = "../build_helper" }
-gcc = "0.3.17"
+gcc = "0.3.27"
 
 [features]
 debug = []

src/liballoc_jemalloc/Cargo.toml

@@ -73,7 +73,16 @@ fn main() {
                    .replace("\\", "/"))
        .current_dir(&build_dir)
        .env("CC", compiler.path())
-       .env("EXTRA_CFLAGS", cflags)
+       .env("EXTRA_CFLAGS", cflags.clone())
+       // jemalloc generates Makefile deps using GCC's "-MM" flag. This means
+       // that GCC will run the preprocessor, and only the preprocessor, over
+       // jemalloc's source files. If we don't specify CPPFLAGS, then at least
+       // on ARM that step fails with a "Missing implementation for 32-bit
+       // atomic operations" error. This is because no "-march" flag will be
+       // passed to GCC, and then GCC won't define the
+       // "__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4" macro that jemalloc needs to
+       // select an atomic operation implementation.
+       .env("CPPFLAGS", cflags.clone())
        .env("AR", &ar)
        .env("RANLIB", format!("{} s", ar.display()));
 

src/liballoc_jemalloc/build.rs

@@ -11,4 +11,4 @@ crate-type = ["dylib"]
 
 [build-dependencies]
 build_helper = { path = "../build_helper" }
-gcc = "0.3"
+gcc = "0.3.27"

src/libflate/Cargo.toml

@@ -0,0 +1,34 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use target::{Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::linux_musl_base::opts();
+
+    // Most of these settings are copied from the arm_unknown_linux_gnueabi
+    // target.
+    base.features = "+v6".to_string();
+    base.max_atomic_width = 64;
+    Ok(Target {
+        // It's important we use "gnueabi" and not "musleabi" here. LLVM uses it
+        // to determine the calling convention and float ABI, and it doesn't
+        // support the "musleabi" value.
+        llvm_target: "arm-unknown-linux-gnueabi".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "32".to_string(),
+        data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
+        arch: "arm".to_string(),
+        target_os: "linux".to_string(),
+        target_env: "musl".to_string(),
+        target_vendor: "unknown".to_string(),
+        options: base,
+    })
+}

src/liblibc

@@ -0,0 +1,34 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use target::{Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::linux_musl_base::opts();
+
+    // Most of these settings are copied from the arm_unknown_linux_gnueabihf
+    // target.
+    base.features = "+v6,+vfp2".to_string();
+    base.max_atomic_width = 64;
+    Ok(Target {
+        // It's important we use "gnueabihf" and not "musleabihf" here. LLVM
+        // uses it to determine the calling convention and float ABI, and it
+        // doesn't support the "musleabihf" value.
+        llvm_target: "arm-unknown-linux-gnueabihf".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "32".to_string(),
+        data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
+        arch: "arm".to_string(),
+        target_os: "linux".to_string(),
+        target_env: "musl".to_string(),
+        target_vendor: "unknown".to_string(),
+        options: base,
+    })
+}

src/librustc_back/target/arm_unknown_linux_musleabi.rs

@@ -0,0 +1,35 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use target::{Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::linux_musl_base::opts();
+
+    // Most of these settings are copied from the armv7_unknown_linux_gnueabihf
+    // target.
+    base.features = "+v7,+vfp3,+neon".to_string();
+    base.cpu = "cortex-a8".to_string();
+    base.max_atomic_width = 64;
+    Ok(Target {
+        // It's important we use "gnueabihf" and not "musleabihf" here. LLVM
+        // uses it to determine the calling convention and float ABI, and LLVM
+        // doesn't support the "musleabihf" value.
+        llvm_target: "armv7-unknown-linux-gnueabihf".to_string(),
+        target_endian: "little".to_string(),
+        target_pointer_width: "32".to_string(),
+        data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
+        arch: "arm".to_string(),
+        target_os: "linux".to_string(),
+        target_env: "musl".to_string(),
+        target_vendor: "unknown".to_string(),
+        options: base,
+    })
+}

src/librustc_back/target/arm_unknown_linux_musleabihf.rs

@@ -134,7 +134,10 @@ supported_targets! {
     ("powerpc64le-unknown-linux-gnu", powerpc64le_unknown_linux_gnu),
     ("arm-unknown-linux-gnueabi", arm_unknown_linux_gnueabi),
     ("arm-unknown-linux-gnueabihf", arm_unknown_linux_gnueabihf),
+    ("arm-unknown-linux-musleabi", arm_unknown_linux_musleabi),
+    ("arm-unknown-linux-musleabihf", arm_unknown_linux_musleabihf),
     ("armv7-unknown-linux-gnueabihf", armv7_unknown_linux_gnueabihf),
+    ("armv7-unknown-linux-musleabihf", armv7_unknown_linux_musleabihf),
     ("aarch64-unknown-linux-gnu", aarch64_unknown_linux_gnu),
     ("x86_64-unknown-linux-musl", x86_64_unknown_linux_musl),
     ("i686-unknown-linux-musl", i686_unknown_linux_musl),

src/librustc_back/target/armv7_unknown_linux_musleabihf.rs

@@ -17,4 +17,4 @@ rustc_bitflags = { path = "../librustc_bitflags" }
 
 [build-dependencies]
 build_helper = { path = "../build_helper" }
-gcc = "0.3"
+gcc = "0.3.27"

src/librustc_back/target/mod.rs

@@ -28,4 +28,4 @@ log = { path = "../liblog" }
 
 [build-dependencies]
 build_helper = { path = "../build_helper" }
-gcc = "0.3"
+gcc = "0.3.27"

src/librustc_llvm/Cargo.toml

@@ -24,7 +24,7 @@ unwind = { path = "../libunwind" }
 
 [build-dependencies]
 build_helper = { path = "../build_helper" }
-gcc = "0.3"
+gcc = "0.3.27"
 
 [features]
 backtrace = []

src/librustdoc/Cargo.toml

@@ -16,7 +16,7 @@ fn main() {
     let target = env::var("TARGET").unwrap();
 
     if target.contains("linux") {
-        if target.contains("musl") && (target.contains("x86_64") || target.contains("i686")) {
+        if target.contains("musl") && !target.contains("mips") {
             println!("cargo:rustc-link-lib=static=unwind");
         } else if !target.contains("android") {
             println!("cargo:rustc-link-lib=gcc_s");