[all-commits] [llvm/llvm-project] b36bdf: [cmake] Centralize LLVM_ENABLE_WARNINGS option

[Dave Lee via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: b36bdfe5ca0c2b863248f327b03d41516b38dc11
      https://github.com/llvm/llvm-project/commit/b36bdfe5ca0c2b863248f327b03d41516b38dc11
  Author: Dave Lee <davelee.com at gmail.com>
  Date:   2020-09-21 (Mon, 21 Sep 2020)

  Changed paths:
    M clang/CMakeLists.txt
    M flang/CMakeLists.txt
    M libunwind/CMakeLists.txt
    M llvm/CMakeLists.txt
    M llvm/cmake/modules/HandleLLVMOptions.cmake
    M llvm/cmake/modules/LLVMConfig.cmake.in
    M llvm/runtimes/CMakeLists.txt

  Log Message:
  -----------
  [cmake] Centralize LLVM_ENABLE_WARNINGS option

Configure default value of `LLVM_ENABLE_WARNINGS` in `HandleLLVMOptions.cmake`.

`LLVM_ENABLE_WARNINGS` is documented as ON by default, but `HandleLLVMOptions` assumes the default has been set somewhere else. If it has not been explicitly set, then `HandleLLVMOptions` implicitly uses OFF as a default.

This removes the various `option()` declarations in favor of a single declaration in `HandleLLVMOptions`. This will prevent the unwanted use of `-w` that is mentioned in a couple of the comments.

Reviewed By: DavidTruby, #libunwind, JDevlieghere, compnerd

Differential Revision: https://reviews.llvm.org/D87243