57bb38b836
Implement `//@ needs-target-std` compiletest directive Closes rust-lang/rust#141863. Needed to unblock rust-lang/rust#139244 and rust-lang/rust#141856. ### Summary This PR implements a `//@ needs-target-std` compiletest directive that gates test execution based on whether the target supports std or not. For some cases, this should be preferred over e.g. some combination of `//@ ignore-none`, `//@ ignore-nvptx` and more[^none-limit]. ### Implementation limitation Unfortunately, since there is currently [no reliable way to determine from metadata whether a given target supports std or not](https://github.com/rust-lang/rust/issues/142296), we have to resort to a hack. Bootstrap currently determines whether or not a target supports std by a naive target tuple substring comparison: a target supports std if its target tuple does *not* contain one of `["-none", "nvptx", "switch"]` substrings. This PR simply pulls that hack out into `build_helpers` to avoid reimplementing the same hack in compiletest, and uses that logic to inform `//@ needs-target-std`. ### Auxiliary changes This PR additionally changes a few run-make tests to use `//@ needs-target-std` over an inconsistent combination of target-based `ignore`s. This should help with rust-lang/rust#139244. --- r? bootstrap [^none-limit]: Notably, `target_os = "none"` is **not** a sufficient condition for "target does not support std"
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.