rust/tests/codegen/x86_64-no-macosx-deployment-target.rs

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//
// Checks that we leave the target alone when MACOSX_DEPLOYMENT_TARGET is unset.
// See issue #60235.
// compile-flags: -O --target=x86_64-apple-darwin --crate-type=rlib
// needs-llvm-components: x86
// unset-rustc-env:MACOSX_DEPLOYMENT_TARGET
#![feature(no_core, lang_items)]
#![no_core]
#[lang="sized"]
trait Sized { }
#[lang="freeze"]
trait Freeze { }
#[lang="copy"]
trait Copy { }
#[repr(C)]
pub struct Bool {
b: bool,
}
default to $ARCH-apple-macosx10.7.0 LLVM triple for darwin targets Over in #60378, we made `rustc` switch LLVM target triples dynamically based on the `MACOSX_DEPLOYMENT_TARGET` environment variable. This change was made to align with `clang`'s behavior, and therefore make cross-language LTO feasible on OS X. Otherwise, `rustc` would produce LLVM bitcode files with a target triple of `x86_64-apple-darwin`, `clang` would produce LLVM bitcode files with a target triple of `x86_64-apple-macosx$VERSION`, and the linker would complain. This change worked fine, except for one corner case: if you didn't have `MACOSX_DEPLOYMENT_TARGET` set, and you wanted to do LTO on just Rust code, you'd get warning messages similar to: ``` warning: Linking two modules of different target triples: ' is 'x86_64-apple-macosx10.7.0' whereas 'main.7rcbfp3g-cgu.4' is 'x86_64-apple-darwin' ``` This message occurs because libstd is compiled with `MACOSX_DEPLOYMENT_TARGET` set to 10.7. The LLVM bitcode distributed in libstd's rlibs, then, is tagged with the target triple of `x86_64-apple-macosx10.7.0`, while the bitcode `rustc` produces for "user" code is tagged with the target triple of `x86_64-apple-darwin`. It's not good to have LTO on just Rust code (probably much more common than cross-language LTO) warn by default. These warnings also break Cargo's testsuite. This change defaults to acting as though `MACOSX_DEPLOYMENT_TARGET` was set to 10.7. "user" code will then be given a target triple that is equivalent to the target triple libstd bitcode is already using. The above warning will therefore go away. `rustc` already assumes that compiling without `MACOSX_DEPLOYMENT_TARGET` means that we're compiling for a target compatible with OS X 10.7 (e.g. that things like TLS work properly). So this change is really just making things conform more closely to the status quo. (It's also worth noting that before and after this patch, compiling with `MACOSX_DEPLOYMENT_TARGET` set to, say, 10.9, works just fine: target triples with an "apple" version ignore OS versions when checking compatibility, so bitcode with a `x86_64-apple-macosx10.7.0` triple works just fine with bitcode with a `x86_64-apple-macosx10.9.0` triple.)
2019-05-13 15:03:48 +00:00
// CHECK: target triple = "x86_64-apple-macosx10.7.0"
#[no_mangle]
pub extern "C" fn structbool() -> Bool {
Bool { b: true }
}