[flang-commits] [clang] [flang] [llvm] [CMake][Release] Statically link clang with stage1 runtimes (PR #127268)

[Tom Stellard via flang-commits]

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@@ -90,9 +88,17 @@ else()
   set(CLANG_BOOTSTRAP_TARGETS ${LLVM_RELEASE_FINAL_STAGE_TARGETS} CACHE STRING "")
 endif()
 
+if (LLVM_RELEASE_ENABLE_LTO)
+  # Enable LTO for the runtimes.  We need to configure stage1 clang to default
+  # to using lld as the linker because the stage1 toolchain will be used to
+  # build and link the runtimes.
+  set(RUNTIMES_CMAKE_ARGS "-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON -DLLVM_ENABLE_LLD=ON" CACHE STRING "")
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tstellar wrote:

`LLVM_ENABLE_LTO=Thin` causes some of the CMake checks for the runtime build to fail which fails the whole build.  `-DCMAKE_INTERPROCEDURAL_OPTIMIZATION=ON` does enable ThinLTO,  so it's effectively the same.

https://github.com/llvm/llvm-project/pull/127268