Shorten linker output even more when `--verbose` is not present

- Don't show environment variables. Seeing PATH is almost never useful, and it can be extremely long.
- For .rlibs in the sysroot, replace crate hashes with a `"-*"` string. This will expand to the full crate name when pasted into the shell.
- Move `.rlib` to outside the glob.
- Abbreviate the sysroot path to `<sysroot>` wherever it appears in the arguments.

This also adds an example of the linker output as a run-make test. Currently it only runs on x86_64-unknown-linux-gnu, because each platform has its own linker arguments. So that it's stable across machines, pass BUILD_ROOT as an argument through compiletest through to run-make tests.

- Only use linker-flavor=gnu-cc if we're actually going to compare the output. It doesn't exist on MacOS.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/tools/compiletest/src/runtest/run_make.rs b/src/tools/compiletest/src/runtest/run_make.rs
index 8a49d630535..7ef16e4a966 100644
--- a/src/tools/compiletest/src/runtest/run_make.rs
+++ b/src/tools/compiletest/src/runtest/run_make.rs
@@ -414,6 +414,8 @@ impl TestCx<'_> {
             // Provide path to checkout root. This is the top-level directory containing
             // rust-lang/rust checkout.
             .env("SOURCE_ROOT", &source_root)
+            // Path to the build directory. This is usually the same as `source_root.join("build").join("host")`.
+            .env("BUILD_ROOT", &build_root)
             // Provide path to stage-corresponding rustc.
             .env("RUSTC", &self.config.rustc_path)
             // Provide the directory to libraries that are needed to run the *compiler*. This is not