9d11b089ad
This patch adds a `-Z linker-flavor` flag to rustc which can be used to invoke
the linker using a different interface.
For example, by default rustc assumes that all the Linux targets will be linked
using GCC. This makes it impossible to use LLD as a linker using just `-C
linker=ld.lld` because that will invoke LLD with invalid command line
arguments. (e.g. rustc will pass -Wl,--gc-sections to LLD but LLD doesn't
understand that; --gc-sections would be the right argument)
With this patch one can pass `-Z linker-flavor=ld` to rustc to invoke the linker
using a LD-like interface. This way, `rustc -C linker=ld.lld -Z
linker-flavor=ld` will invoke LLD with the right arguments.
`-Z linker-flavor` accepts 4 different arguments: `em` (emcc), `ld`,
`gcc`, `msvc` (link.exe). `em`, `gnu` and `msvc` cover all the existing linker
interfaces. `ld` is a new flavor for interfacing GNU's ld and LLD.
This patch also changes target specifications. `linker-flavor` is now a
mandatory field that specifies the *default* linker flavor that the target will
use. This change also makes the linker interface *explicit*; before, it used to
be derived from other fields like linker-is-gnu, is-like-msvc,
is-like-emscripten, etc.
Another change to target specifications is that the fields `pre-link-args`,
`post-link-args` and `late-link-args` now expect a map from flavor to linker
arguments.
``` diff
- "pre-link-args": ["-Wl,--as-needed", "-Wl,-z,-noexecstack"],
+ "pre-link-args": {
+ "gcc": ["-Wl,--as-needed", "-Wl,-z,-noexecstack"],
+ "ld": ["--as-needed", "-z,-noexecstack"],
+ },
```
[breaking-change] for users of custom targets specifications
52 lines
2.1 KiB
Rust
52 lines
2.1 KiB
Rust
// Copyright 2014 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 std::env;
|
|
|
|
use target::{LinkArgs, TargetOptions};
|
|
|
|
pub fn opts() -> TargetOptions {
|
|
// ELF TLS is only available in macOS 10.7+. If you try to compile for 10.6
|
|
// either the linker will complain if it is used or the binary will end up
|
|
// segfaulting at runtime when run on 10.6. Rust by default supports macOS
|
|
// 10.7+, but there is a standard environment variable,
|
|
// MACOSX_DEPLOYMENT_TARGET, which is used to signal targeting older
|
|
// versions of macOS. For example compiling on 10.10 with
|
|
// MACOSX_DEPLOYMENT_TARGET set to 10.6 will cause the linker to generate
|
|
// warnings about the usage of ELF TLS.
|
|
//
|
|
// Here we detect what version is being requested, defaulting to 10.7. ELF
|
|
// TLS is flagged as enabled if it looks to be supported.
|
|
let deployment_target = env::var("MACOSX_DEPLOYMENT_TARGET").ok();
|
|
let version = deployment_target.as_ref().and_then(|s| {
|
|
let mut i = s.splitn(2, ".");
|
|
i.next().and_then(|a| i.next().map(|b| (a, b)))
|
|
}).and_then(|(a, b)| {
|
|
a.parse::<u32>().and_then(|a| b.parse::<u32>().map(|b| (a, b))).ok()
|
|
}).unwrap_or((10, 7));
|
|
|
|
TargetOptions {
|
|
// macOS has -dead_strip, which doesn't rely on function_sections
|
|
function_sections: false,
|
|
dynamic_linking: true,
|
|
executables: true,
|
|
target_family: Some("unix".to_string()),
|
|
is_like_osx: true,
|
|
has_rpath: true,
|
|
dll_prefix: "lib".to_string(),
|
|
dll_suffix: ".dylib".to_string(),
|
|
archive_format: "bsd".to_string(),
|
|
pre_link_args: LinkArgs::new(),
|
|
exe_allocation_crate: super::maybe_jemalloc(),
|
|
has_elf_tls: version >= (10, 7),
|
|
.. Default::default()
|
|
}
|
|
}
|