[compiler-rt][profile] Use flock shim on Windows even if detection fails

[kateinoigakukun]

This is a follow-up fix for d4efc3e, which introduced CMake-time feature test for flock. The feature test always fails on Windows, but we still need to use the flock shim provided by WindowsMMap.h regardless of the feature test result.

[kateinoigakukun]

@glandium Would you mind testing this patch with your PGO setup again? 🙏

[mstorsjo]

I think this change looks reasonable - the referenced commit d4efc3e is so large that it's hard to pick out all the various details that happen in there though. But it looks correct to me.

[aeubanks]

can we land this to unbreak coverage builds?

[glandium]

@glandium Would you mind testing this patch with your PGO setup again? 🙏

I can confirm it works.

[llvmbot]

@llvm/pr-subscribers-pgo

Author: Yuta Saito (kateinoigakukun)

Changes

This is a follow-up fix for d4efc3e, which introduced CMake-time feature test for flock. The feature test always fails on Windows, but we still need to use the flock shim provided by WindowsMMap.h regardless of the feature test result.

---

Full diff: https://github.com/llvm/llvm-project/pull/112695.diff

1 Files Affected:

• (modified) compiler-rt/lib/profile/InstrProfilingUtil.c (+4-2)

diff --git a/compiler-rt/lib/profile/InstrProfilingUtil.c b/compiler-rt/lib/profile/InstrProfilingUtil.c
index 95ec4080ba2504..c637b9d0b893cd 100644
--- a/compiler-rt/lib/profile/InstrProfilingUtil.c
+++ b/compiler-rt/lib/profile/InstrProfilingUtil.c
@@ -152,7 +152,8 @@ COMPILER_RT_VISIBILITY int lprofLockFd(int fd) {
     }
   }
   return 0;
-#elif defined(COMPILER_RT_HAS_FLOCK)
+#elif defined(COMPILER_RT_HAS_FLOCK) || defined(_WIN32)
+  // Windows doesn't have flock but WindowsMMap.h provides a shim
   flock(fd, LOCK_EX);
   return 0;
 #else
@@ -179,7 +180,8 @@ COMPILER_RT_VISIBILITY int lprofUnlockFd(int fd) {
     }
   }
   return 0;
-#elif defined(COMPILER_RT_HAS_FLOCK)
+#elif defined(COMPILER_RT_HAS_FLOCK) || defined(_WIN32)
+  // Windows doesn't have flock but WindowsMMap.h provides a shim
   flock(fd, LOCK_UN);
   return 0;
 #else

[kateinoigakukun]

@glandium Thank you for checking 🙏