[compiler-rt] [llvm] [LLVM][compiler-rt] Fix build with LLVM_USE_SANITIZER=Undefined (PR #120006)

[Vitaly Buka via llvm-commits]

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@@ -1066,11 +1066,12 @@ if(LLVM_USE_SANITIZER)
   endif()
   if (LLVM_USE_SANITIZER MATCHES ".*Undefined.*")
     set(IGNORELIST_FILE "${PROJECT_SOURCE_DIR}/utils/sanitizers/ubsan_ignorelist.txt")
-    if (EXISTS "${IGNORELIST_FILE}")
+    check_c_compiler_flag(-fsanitize-blacklist=${IGNORELIST_FILE} C_SUPPORTS_FSANITIZE_BLACKLIST_FLAG)
+    check_cxx_compiler_flag(-fsanitize-blacklist=${IGNORELIST_FILE} CXX_SUPPORTS_FSANITIZE_BLACKLIST_FLAG)
+    if (EXISTS "${IGNORELIST_FILE}" AND C_SUPPORTS_FSANITIZE_BLACKLIST_FLAG AND CXX_SUPPORTS_FSANITIZE_BLACKLIST_FLAG)
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vitalybuka wrote:

Ok, it was here already. 

https://github.com/llvm/llvm-project/pull/120006