strip `-Wlinker-messages` wrappers from `rust-lld` rmake test
The `tests/run-make/rust-lld` rmake test is failing locally on my M1, due to linker messages being in a different shape than the test expects: it asserts that the LLD version is the first linker message, which is seemingly not always the case on osx I guess.
```console
thread 'main' panicked at /Users/lqd/rust/lqd-rust/tests/run-make/rust-lld/rmake.rs:24:5:
the LLD version string should be present in the output logs:
warning: linker stderr: rust-lld: directory not found for option -L/usr/local/lib
LLD 20.1.0 (https://github.com/rust-lang/llvm-project.git 1c3bb96fdb6db7b8e8f24edb016099c223fdd27e)
Library search paths:
/Users/lqd/rust/lqd-rust/build/aarch64-apple-darwin/test/run-make/rust-lld/rmake_out
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/lib
Framework search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks
```
This PR normalizes away the `-Wlinker-messages` wrappers around the linker output, to remove the requirement that the linker version is the first linker message / is prefixed with the warning wrapper in the regex.
(also another strange thing to explain the pre-existing regex: it seems the LLD version is sometimes output on stderr sometimes on stdout cool stuff)
We could do this for the other lld rmake tests, but they're only enabled on x64 linux so less likely to have random linker messages appearing without anyone noticing.
The run-make test suite
The run-make test suite contains tests which are the most flexible out of all the rust-lang/rust test suites. run-make tests can basically contain arbitrary code, and are supported by the run_make_support library.
Infrastructure
A run-make test is a test recipe source file rmake.rs accompanied by its parent directory (e.g. tests/run-make/foo/rmake.rs is the foo run-make test).
The implementation for collecting and building the rmake.rs recipes are in src/tools/compiletest/src/runtest.rs, in run_rmake_test.
The setup for the rmake.rs can be summarized as a 3-stage process:
-
First, we build the
run_make_supportlibrary in bootstrap as a tool lib. -
Then, we compile the
rmake.rs"recipe" linking the support library and its dependencies in, and provide a bunch of env vars. We setup a directory structure withinbuild/<target>/test/run-make/<test-name>/ rmake.exe # recipe binary rmake_out/ # sources from test sources copied overand copy non-
rmake.rsinput support files over tormake_out/. The support library is made available as an extern prelude. -
Finally, we run the recipe binary and set
rmake_out/as the working directory.