dsymutil: Re-add missing -latomic

[maflcko]

This was accidentally removed in https://reviews.llvm.org/D137799#4657404 / https://reviews.llvm.org/D137799#C3933303OL44, and downstream projects are forced to add it back. For example, https://git.savannah.gnu.org/cgit/guix.git/commit/?id=4e26331a5ee87928a16888c36d51e270f0f10f90

Fix this, by re-adding it.

[llvmbot]

@llvm/pr-subscribers-debuginfo

Author: None (maflcko)

Changes

This was accidentally removed in https://reviews.llvm.org/D137799#4657404 / https://reviews.llvm.org/D137799#C3933303OL44, and downstream projects are forced to add it back. For example, https://git.savannah.gnu.org/cgit/guix.git/commit/?id=4e26331a5ee87928a16888c36d51e270f0f10f90

Fix this, by re-adding it.

---

Full diff: https://github.com/llvm/llvm-project/pull/85380.diff

1 Files Affected:

• (modified) llvm/tools/dsymutil/CMakeLists.txt (+1-1)

diff --git a/llvm/tools/dsymutil/CMakeLists.txt b/llvm/tools/dsymutil/CMakeLists.txt
index 53f882e90b4e92..da371e6b728f77 100644
--- a/llvm/tools/dsymutil/CMakeLists.txt
+++ b/llvm/tools/dsymutil/CMakeLists.txt
@@ -45,4 +45,4 @@ if(APPLE AND NOT LLVM_TOOL_LLVM_DRIVER_BUILD)
   target_link_libraries(dsymutil PRIVATE "-framework CoreFoundation")
 endif(APPLE AND NOT LLVM_TOOL_LLVM_DRIVER_BUILD)
 
-# target_link_libraries(dsymutil PRIVATE ${LLVM_ATOMIC_LIB})
+target_link_libraries(dsymutil PRIVATE ${LLVM_ATOMIC_LIB})

[maflcko]

mbr

[petrhosek]

This change broke our builders that use LLVM toolchain and don't have a GNU toolchain installed.

I agree that the change made in https://reviews.llvm.org/D137799 shouldn't have landed without a separate review, but this change is also incorrect because the following:

llvm-project/llvm/cmake/modules/CheckAtomic.cmake

Line 92 in 4078763

set(LLVM_ATOMIC_LIB "-latomic")

unconditionally appends -latomic which is GNU specific, compiler-rt version is called -lclang_rt.atomic, and on systems that don't have a GNU toolchain but have LLVM toolchain such as ours, it's going to result in a link failure.

Since this change also landed without a review, can you please revert it and make another PR that also fixes the logic in CheckAtomic.cmake and is reviewed and approved by build system owners?

[gulfemsavrun]

I currently reverted the change. Let's have a more detailed discussion how we can implement this without breaking our builders as @petrhosek pointed above and the downstream projects that @maflcko mentioned.