[Driver][test] Test intended target only

[jsji]

Summary

6fe7de90b9e4e466a5c2baadafd5f72d3203651d changed GNU toolchain,
and added new RUN line to test expected behavior.

The change is for GNU toolchain only, so this will fail other toolchain,
eg: AIX.

Update the test with -target to test GNU tool chain only.

[MaskRay]

clang/test/Driver/nostdincxx.cpp

4

error: unknown target triple 'unknown-unknown-hurd-gnu', please use -triple or -arch

Perhaps this should UNSUPPORTED aix if aix does not support -nostdinc++.

[jsji]

Use -arch instead

clang/test/Driver/nostdincxx.cpp

4

No, AIX does support -nostdinc++, we don't want to unsupport this whole test

[jsji]

Remove typo.

[ted]

Why would we not want to support this on other targets, like Arm? Fixes for AIX shouldn't impact other things.

[jsji]

In D99901#2787034, @ted wrote:

Why would we not want to support this on other targets, like Arm? Fixes for AIX shouldn't impact other things.

Feel free to update the triple to include arm , as long as the tests focus on gnu tool chain only.

[hubert.reinterpretcast]

clang/test/Driver/nostdincxx.cpp

4

I believe the original fix was meant to be generally applicable but unintentionally applied in only a limited fashion. Ideally, the test would have been left as-is and the various toolchains changed similarly.

That is:

$ clang -nostdinc -nostdinc++ -xc++ /dev/null -fsyntax-only
clang-13: warning: argument unused during compilation: '-nostdinc++' [-Wunused-command-line-argument]

should not happen. I guess a way forward is to first make the change for AIX (and update the test to check on AIX) and then to commit a separate NFCI commit to apply the test broadly to see if anyone finds the test to be failing.

[thakis]

clang/test/Driver/nostdincxx.cpp

4

FYI: %clangxx is a driver invocation, not a cc1 invocation. The driver flag is --target=, not -triple.

This test, when run manually, produces:

bin/clang  -triple x86_64-unknown-unknown-gnu -fsyntax-only -nostdinc -nostdinc++ /Users/thakis/src/llvm-project/clang/test/Driver/nostdincxx.cpp
clang: error: unknown argument: '-triple'
clang: error: no such file or directory: 'x86_64-unknown-unknown-gnu'

That passes, but probably not for the reasons you want :) I fixed this in 23f256f2b198.