[libc++] Run `substitutes-in-compile-flags.sh.cpp` test on Windows.

[vvereschaka]

Summary

Fix for substitutes-in-compile-flags.sh.cpp to run it properly on Windows platform.

[vvereschaka]

Hi @ldionne,

these changes should work on Windows, Linux and Darwin platforms, but I'm not sure about the others. In case of any problems we can disable this test for Windows with https://reviews.llvm.org/D102045.

Currently this test still gets failed on the windows to linux cross builders, as example: https://lab.llvm.org/buildbot/#/builders/119/builds/3724

[curdeius]

libcxx/test/libcxx/selftest/additional_compile_flags/substitutes-in-compile-flags.sh.cpp

9–11

This comment needs to be adapted/removed.

[ldionne]

Generally LGTM with a few comments. Ship it once reviewer feedback has been applied.

libcxx/test/libcxx/selftest/additional_compile_flags/substitutes-in-compile-flags.sh.cpp

17–18

Can you name the file something like %t.escaped.grep instead? It makes it more obvious that the only purpose is to escape paths.

19

This isn't needed. We generally don't clean up the temporary files in the tests.

[vvereschaka]

@ldionne, @curdeius thank you for review.
Updated diff accordingly

• reworded comment
• %t.grep => %t.escaped.grep
• do not remove temporary file in the test.

libcxx/test/libcxx/selftest/additional_compile_flags/substitutes-in-compile-flags.sh.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // This test greps for %t, which is expanded to a path with backslashes. When
-// that is passed to grep, those backslashes would have to be escaped, which we
-// don't do right now.
-// UNSUPPORTED: windows
+// that is passed to grep, those backslashes must be escaped. We escape those
+// within the pattern into a file and use this file with 'grep'.
 
 // Make sure that substitutions are performed inside additional compiler flags.
 
 // ADDITIONAL_COMPILE_FLAGS: -I %t.1
 // ADDITIONAL_COMPILE_FLAGS: -isystem %t.2 , -isysroot %t.3
-// RUN: echo "%{compile_flags}" | grep -e '-I %t.1 -isystem %t.2 -isysroot %t.3'
+// RUN: echo "-I %t.1 -isystem %t.2 -isysroot %t.3" | sed "s/\\\/\\\\\\\/g" > %t.escaped.grep
+// RUN: echo "%{compile_flags}" | grep -e -f %t.escaped.grep