Rollup merge of rust-lang#48297 - glaubitz:sparc-linux, r=estebank

Add missing pieces for sparc-linux-gnu support

I noticed that while Rust has CABI support for 32-bit SPARC, there are still some pieces missing to be able to use Rust on a 32-Bit SPARC system like Gentoo which still defaults to a 32-bit port unlike Debian's sparc64 port.

This PR is an attempt to add the missing pieces. I will send the necessary changes for libc in a separate PR.

CC @jrtc27

src/bootstrap/bootstrap.py

@@ -294,7 +294,7 @@ def default_build_triple():
             raise ValueError('unknown byteorder: {}'.format(sys.byteorder))
         # only the n64 ABI is supported, indicate it
         ostype += 'abi64'
-    elif cputype == 'sparcv9' or cputype == 'sparc64':
+    elif cputype == 'sparc' or cputype == 'sparcv9' or cputype == 'sparc64':
         pass
     else:
         err = "unknown cpu type: {}".format(cputype)

src/bootstrap/native.rs

@@ -484,6 +484,7 @@ impl Step for Openssl {
             "powerpc64-unknown-linux-gnu" => "linux-ppc64",
             "powerpc64le-unknown-linux-gnu" => "linux-ppc64le",
             "s390x-unknown-linux-gnu" => "linux64-s390x",
+            "sparc-unknown-linux-gnu" => "linux-sparcv9",
             "sparc64-unknown-linux-gnu" => "linux64-sparcv9",
             "sparc64-unknown-netbsd" => "BSD-sparc64",
             "x86_64-apple-darwin" => "darwin64-x86_64-cc",

src/librustc_back/target/mod.rs

@@ -146,6 +146,7 @@ supported_targets! {
     ("powerpc64-unknown-linux-gnu", powerpc64_unknown_linux_gnu),
     ("powerpc64le-unknown-linux-gnu", powerpc64le_unknown_linux_gnu),
     ("s390x-unknown-linux-gnu", s390x_unknown_linux_gnu),
+    ("sparc-unknown-linux-gnu", sparc_unknown_linux_gnu),
     ("sparc64-unknown-linux-gnu", sparc64_unknown_linux_gnu),
     ("arm-unknown-linux-gnueabi", arm_unknown_linux_gnueabi),
     ("arm-unknown-linux-gnueabihf", arm_unknown_linux_gnueabihf),

src/librustc_back/target/sparc_unknown_linux_gnu.rs

@@ -0,0 +1,34 @@
+// Copyright 2018 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 LinkerFlavor;
+use target::{Target, TargetResult};
+
+pub fn target() -> TargetResult {
+    let mut base = super::linux_base::opts();
+    base.cpu = "v9".to_string();
+    base.max_atomic_width = Some(64);
+    base.pre_link_args.get_mut(&LinkerFlavor::Gcc).unwrap().push("-mv8plus".to_string());
+    base.exe_allocation_crate = None;
+
+    Ok(Target {
+        llvm_target: "sparc-unknown-linux-gnu".to_string(),
+        target_endian: "big".to_string(),
+        target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
+        data_layout: "E-m:e-p:32:32-i64:64-f128:64-n32-S64".to_string(),
+        arch: "sparc".to_string(),
+        target_os: "linux".to_string(),
+        target_env: "gnu".to_string(),
+        target_vendor: "unknown".to_string(),
+        linker_flavor: LinkerFlavor::Gcc,
+        options: base,
+    })
+}

src/tools/build-manifest/src/main.rs

@@ -86,6 +86,7 @@ static TARGETS: &'static [&'static str] = &[
     "powerpc64-unknown-linux-gnu",
     "powerpc64le-unknown-linux-gnu",
     "s390x-unknown-linux-gnu",
+    "sparc-unknown-linux-gnu",
     "sparc64-unknown-linux-gnu",
     "sparcv9-sun-solaris",
     "wasm32-unknown-emscripten",