[llvm] 61fb3fb - [cmake] Disable the -Wmisleading-indentation warning with GCC

[Martin Storsjö via llvm-commits]

Author: Martin Storsjö
Date: 2022-08-31T22:26:09+03:00
New Revision: 61fb3fb458830c12b7a38273e5c149b9190ee003

URL: https://github.com/llvm/llvm-project/commit/61fb3fb458830c12b7a38273e5c149b9190ee003
DIFF: https://github.com/llvm/llvm-project/commit/61fb3fb458830c12b7a38273e5c149b9190ee003.diff

LOG: [cmake] Disable the -Wmisleading-indentation warning with GCC

We do keep using the flag with Clang, which should keep catching
such issues in buildbots.

With GCC, the warning can cause lots of loud notes about the
warning logic getting disabled in large source files.

Differential Revision: https://reviews.llvm.org/D132914

Added: 
    

Modified: 
    llvm/cmake/modules/HandleLLVMOptions.cmake

Removed: 
    


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diff  --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 37a260797a445..617c9fb1ec29e 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -792,8 +792,16 @@ if (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
   # Enable -Wstring-conversion to catch misuse of string literals.
   add_flag_if_supported("-Wstring-conversion" STRING_CONVERSION_FLAG)
 
-  # Prevent bugs that can happen with llvm's brace style.
-  add_flag_if_supported("-Wmisleading-indentation" MISLEADING_INDENTATION_FLAG)
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    # Disable the misleading indentation warning with GCC; GCC can
+    # produce noisy notes about this getting disabled in large files.
+    # See e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89549
+    check_cxx_compiler_flag("-Wmisleading-indentation" CXX_SUPPORTS_MISLEADING_INDENTATION_FLAG)
+    append_if(CXX_SUPPORTS_MISLEADING_INDENTATION_FLAG "-Wno-misleading-indentation" CMAKE_CXX_FLAGS)
+  else()
+    # Prevent bugs that can happen with llvm's brace style.
+    add_flag_if_supported("-Wmisleading-indentation" MISLEADING_INDENTATION_FLAG)
+  endif()
 
   # Enable -Wctad-maybe-unsupported to catch unintended use of CTAD.
   add_flag_if_supported("-Wctad-maybe-unsupported" CTAD_MAYBE_UNSPPORTED_FLAG)