This schema is helpful for people writing custom target spec JSON. It
can provide autocomplete in the editor, and also serves as documentation
when there are documentation comments on the structs, as `schemars` will
put them in the schema.
On Unix the limits can be gargantuan anyway so we're pretty
unlikely to hit them, but might still exceed it.
We consult ARG_MAX here to get an estimate.
- 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.
- The logic is now unified for all targets (wasm targets should also be supported now)
- Additional "symlink" files like `ld64` are eliminated
- lld-wrapper is used for propagating the correct lld flavor
- Cleanup "unwrap or exit" logic in lld-wrapper