[libc] fix unit tests in fullbuild

[SchrodingerZhu]

fixes #78743

[llvmbot]

@llvm/pr-subscribers-libc

Author: Schrodinger ZHU Yifan (SchrodingerZhu)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/78864.diff

1 Files Affected:

• (modified) libc/cmake/modules/LLVMLibCTestRules.cmake (+1-1)

diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
index 24f543f6e4c132b..9b7e9180275414a 100644
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -187,7 +187,7 @@ function(create_libc_unittest fq_target_name)
   if(LLVM_LIBC_FULL_BUILD)
     target_compile_options(
       ${fq_build_target_name}
-      PRIVATE -ffreestanding
+      PRIVATE -ffreestanding -fno-exceptions -fno-rtti -fno-unwind-tables -fno-asynchronous-unwind-tables
     )
   endif()
   if(LIBC_UNITTEST_COMPILE_OPTIONS)

[jhuber6]

I thought unit tests were supposed to be hosted even in full build mode. Though I'm unsure why we pass -ffreestanding in the first place. I forget what we do for the hermetic tests, maybe -nostdlib?

[SchrodingerZhu]

I thought unit tests were supposed to be hosted even in full build mode. Though I'm unsure why we pass -ffreestanding in the first place. I forget what we do for the hermetic tests, maybe -nostdlib?

Not sure. I do see freestanding flying around fullbuild targets everywhere.