[flang-commits] [clang] [flang] [llvm] [mlir] [polly] [CMake][LLVM] Add PCH infrastructure and LLVMSupport PCH (PR #176420)

[Alexis Engelke via flang-commits]

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@@ -1304,11 +1304,59 @@ if (LLVM_BUILD_INSTRUMENTED AND LLVM_BUILD_INSTRUMENTED_COVERAGE)
   message(FATAL_ERROR "LLVM_BUILD_INSTRUMENTED and LLVM_BUILD_INSTRUMENTED_COVERAGE cannot both be specified")
 endif()
 
+if(NOT DEFINED CMAKE_DISABLE_PRECOMPILE_HEADERS)
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aengelke wrote:

>  Why it's CMAKE_DISABLE_PRECOMPILE_HEADERS and not CMAKE_ENABLE_PRECOMPILE_HEADERS?

Don't ask me, that's [how CMake named the variable](https://cmake.org/cmake/help/latest/variable/CMAKE_DISABLE_PRECOMPILE_HEADERS.html#variable:CMAKE_DISABLE_PRECOMPILE_HEADERS).

#182819 should address the warnings in CMake 4.x, thanks for catching this.

https://github.com/llvm/llvm-project/pull/176420