[lld][test] Fix use of escape character in an lld test on Windows

[rupprecht]

Summary

Glob support was improved to accept \ as an escape character in r375051, but reverted as r375052 due to a failure in this test on Windows.

The reason this failure seems Windows specific is because the path separator \ is currently being relied on to be interpreted literally instead of as an escape character. Per documentation on linker input section wildcard patterns, this seems to be a bug in lld accepting \ as a literal instead of an escape character.

For example:

SECTIONS{ .foo :{ /path/to/foo.o(.foo) }} # OK: standard UNIX path
SECTIONS{ .foo :{ C:/path/to/foo.o(.foo) }} # OK: windows accepts slashes in either direction
SECTIONS{ .foo :{ C:\\path\\to\\foo.o(.foo) }} # OK: escape character used to match a literal \
SECTIONS{ .foo :{ C:\path\to\foo.o(.foo) }} # BAD: this actually matches the path C:pathtofoo.o(.foo)

This avoids the problem in the test by using %/T in place of %T to normalize the path separator to /, which windows should also accept.

This patch just fixes the test, and glob support will be be relanded separately.

For a sample buildbot error, see: http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/11578/steps/stage%201%20check/logs/stdio

[ruiu]

LGTM

[thakis]

This breaks the test on Windows: http://45.33.8.238/win/709/step_9.txt

[thakis]

Now also failing on a more reputable bot: http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/28842/steps/test-check-all/logs/stdio

[rupprecht]

In D69074#1713028, @thakis wrote:

Now also failing on a more reputable bot: http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/28842/steps/test-check-all/logs/stdio

I don't fully understand the failure, but I've committed r375131. If it doesn't work, I'll revert both.

I have a suspicion that there's a bug in the filename matching (e.g. "foo/bar.txt" and "foo\bar.txt" should be equivalent in all places on windows), but I'm not enough of a linkerscript expert to do much about it. r375131 just tries to make it consistently "foo/bar.txt".

[rupprecht]

In D69074#1713026, @thakis wrote:

This breaks the test on Windows: http://45.33.8.238/win/709/step_9.txt

Latest run: http://45.33.8.238/win/711/step_9.txt

:D

[jhenderson]

Drive-by comment, mostly as an FYI: I'm pretty sure %T has been deprecated because it can cause race conditions (multiple tests can have the same %T) and users should change to create a directory using %t and work inside there.

[MaskRay]

In D69074#1724858, @jhenderson wrote:

Drive-by comment, mostly as an FYI: I'm pretty sure %T has been deprecated because it can cause race conditions (multiple tests can have the same %T) and users should change to create a directory using %t and work inside there.

Thanks for pointing this out! %T is used a lot in lld tests. I just created a patch D69572 to fix lld/test/ELF tests.

lld/test/ELF/linkerscript/filename-spec.s

 # RUN: echo "SECTIONS{.foo :{ *y.o(.foo) *x.o(.foo) }}" > %t4.script
 # RUN: ld.lld -o %t4 --script %t4.script %tx.o %ty.o
 # RUN: llvm-objdump -s %t4 | FileCheck --check-prefix=SECONDFIRST %s
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %T/filename-spec1.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux \
 # RUN:   %p/Inputs/filename-spec.s -o %T/filename-spec2.o
 
-# RUN: echo "SECTIONS{.foo :{ %T/filename-spec2.o(.foo) %T/filename-spec1.o(.foo) }}" > %t5.script
+# RUN: echo "SECTIONS{.foo :{ %/T/filename-spec2.o(.foo) %/T/filename-spec1.o(.foo) }}" > %t5.script
 # RUN: ld.lld -o %t5 --script %t5.script \
 # RUN:   %T/filename-spec1.o %T/filename-spec2.o
 # RUN: llvm-objdump -s %t5 | FileCheck --check-prefix=SECONDFIRST %s
 
-# RUN: echo "SECTIONS{.foo :{ %T/filename-spec1.o(.foo) %T/filename-spec2.o(.foo) }}" > %t6.script
+# RUN: echo "SECTIONS{.foo :{ %/T/filename-spec1.o(.foo) %/T/filename-spec2.o(.foo) }}" > %t6.script
 # RUN: ld.lld -o %t6 --script %t6.script \
 # RUN:   %T/filename-spec1.o %T/filename-spec2.o
 # RUN: llvm-objdump -s %t6 | FileCheck --check-prefix=FIRSTY %s
 
 # RUN: mkdir -p %t.testdir1 %t.testdir2
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.testdir1/filename-spec1.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux \
 # RUN:   %p/Inputs/filename-spec.s -o %t.testdir2/filename-spec2.o