[Mlir-commits] [mlir] 1e679c0 - [CMake] Move -Wno-unused-but-set-parameter from MLIR up to LLVM (#221824)

[llvmlistbot at llvm.org]

Author: Martin Storsjö
Date: 2026-09-08T09:34:53+03:00
New Revision: 1e679c028b30b6542c8712ef2023911673e55c7c

URL: https://github.com/llvm/llvm-project/commit/1e679c028b30b6542c8712ef2023911673e55c7c
DIFF: https://github.com/llvm/llvm-project/commit/1e679c028b30b6542c8712ef2023911673e55c7c.diff

LOG: [CMake] Move -Wno-unused-but-set-parameter from MLIR up to LLVM (#221824)

This warning is known to have false positives with GCC versions before
14.

Since 3aec6a40bb4e49f9ea181ac5c949b6c7c20a5465, this warning appears
when building LLVMSupport as well - thus move the disabling of the
warning up from MLIR to all of LLVM.

In HandleLLVMOptions, the common procedure is to not check for whether
the options are supported or not, but to just hardcode the version
ranges where the options are supported, per compiler.

This option (and -Wunused-but-set-parameter) is available in GCC since
long before our minimum required version.

Added: 
    

Modified: 
    llvm/cmake/modules/HandleLLVMOptions.cmake
    mlir/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 52c6f8b92176e..45c2c55571f54 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -920,6 +920,13 @@ if (LLVM_ENABLE_WARNINGS AND (LLVM_COMPILER_IS_GCC_COMPATIBLE OR CLANG_CL))
     if (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 12.1)
       append("-Wno-dangling-pointer" CMAKE_CXX_FLAGS)
     endif()
+
+    # Silence a false positive GCC -Wunused-but-set-parameter warning in
+    # constexpr cases. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85827
+    # for details
+    if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "14.0")
+      append("-Wno-unused-but-set-parameter" CMAKE_CXX_FLAGS)
+    endif()
   endif()
 
   # The LLVM libraries have no stable C++ API, so -Wnoexcept-type is not useful.

diff  --git a/mlir/CMakeLists.txt b/mlir/CMakeLists.txt
index ec4b8f7293490..7bedfe09e798a 100644
--- a/mlir/CMakeLists.txt
+++ b/mlir/CMakeLists.txt
@@ -103,13 +103,6 @@ append_if(C_SUPPORTS_WERROR_MISMATCHED_TAGS "-Werror=mismatched-tags" CMAKE_C_FL
 append_if(C_SUPPORTS_WERROR_MISMATCHED_TAGS "-Werror=mismatched-tags" CMAKE_CXX_FLAGS)
 
 if(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
-  # Silence a false positive GCC -Wunused-but-set-parameter warning in
-  # constexpr cases. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85827
-  # for details
-  if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "14.0")
-    check_cxx_compiler_flag("-Wno-unused-but-set-parameter" CXX_SUPPORTS_WNO_UNUSED_BUT_SET_PARAMETER)
-    append_if(CXX_SUPPORTS_WNO_UNUSED_BUT_SET_PARAMETER "-Wno-unused-but-set-parameter" CMAKE_CXX_FLAGS)
-  endif()
   # Silence a false positive GCC -Wdeprecated-copy warning in cases where
   # a copy operator is defined through "using" a base class copy operator.
   if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "12.0")