Author: Nicolai Hähnle Date: 2022-10-28T15:48:20+02:00 New Revision: dce78646f07ff67f7d4887525e908dbf47d9e86b
URL: https://github.com/llvm/llvm-project/commit/dce78646f07ff67f7d4887525e908dbf47d9e86b DIFF: https://github.com/llvm/llvm-project/commit/dce78646f07ff67f7d4887525e908dbf47d9e86b.diff LOG: clang-tblgen build: avoid duplicate inclusion of libLLVMSupport TableGen executables are supposed to never be linked against libLLVM-*.so, even when LLVM_LINK_LLVM_DYLIB=ON, presumably for cross-compilation. It turns out that clang-tblgen *did* link against libLLVM-*.so, indirectly so via the clangSupport. This lead to a regression in what should have been unrelated work of cleaning up ManagedStatics in LLVMSupport. A running clang-tblgen process ended up with two copies of a cl::opt static global: - one from libLLVMSupport linked statically into clang-tblgen as a direct dependency - one from libLLVMSupport linked into libLLVM-*.so, which clang-tblgen linked against due to the clangSupport dependency For a bit more context, see the discussion at https://discourse.llvm.org/t/flang-aarch64-dylib-buildbot-need-help-understanding-a-regression-in-clang-tblgen/64871/ None of the potential solutions I could find are perfect. Presumably one possible solution would be to remove "Support" from the explicit dependencies of clang-tblgen. However, relying on the transitive inclusion via clangSupport seems risky, and in any case this wouldn't address the issue of clang-tblgen surprisingly linking against libLLVM-*.so. This change instead creates a second version of the clangSupport library that is explicitly linked statically, to be used by clang-tblgen. v2: - define an alias so that clang-tblgen can always link against "clangSupport_tablegen" - use add_llvm_library(... BUILDTREE_ONLY ...) v3: - use the object library version of clangSupport if available Differential Revision: https://reviews.llvm.org/D134637 Added: Modified: clang/lib/Support/CMakeLists.txt clang/utils/TableGen/CMakeLists.txt Removed: ################################################################################ diff --git a/clang/lib/Support/CMakeLists.txt b/clang/lib/Support/CMakeLists.txt index c24324bd7b0d3..8ea5620052ed8 100644 --- a/clang/lib/Support/CMakeLists.txt +++ b/clang/lib/Support/CMakeLists.txt @@ -9,8 +9,24 @@ set(LLVM_LINK_COMPONENTS Support ) -add_clang_library(clangSupport +set(clangSupport_sources RISCVVIntrinsicUtils.cpp ) +add_clang_library(clangSupport ${clangSupport_sources}) + +if (NOT XCODE) + add_library(clangSupport_tablegen ALIAS obj.clangSupport) +elseif (NOT LLVM_LINK_LLVM_DYLIB) + add_library(clangSupport_tablegen ALIAS clangSupport) +else() + # Build a version of the support library that does not link against + # libLLVM-*.so, to be used by clang-tblgen. This is so clang-tblgen doesn't + # link against libLLVMSupport twice (once statically and once via + # libLLVM-*.so). + add_llvm_library(clangSupport_tablegen + BUILDTREE_ONLY STATIC DISABLE_LLVM_LINK_LLVM_DYLIB + ${clangSupport_sources}) +endif() + set(LLVM_COMMON_DEPENDS ${LLVM_COMMON_DEPENDS_OLD}) diff --git a/clang/utils/TableGen/CMakeLists.txt b/clang/utils/TableGen/CMakeLists.txt index 4666d4d7aa5ce..f136cbfee5fa1 100644 --- a/clang/utils/TableGen/CMakeLists.txt +++ b/clang/utils/TableGen/CMakeLists.txt @@ -25,6 +25,6 @@ add_tablegen(clang-tblgen CLANG TableGen.cpp ) -target_link_libraries(clang-tblgen PRIVATE clangSupport) +target_link_libraries(clang-tblgen PRIVATE clangSupport_tablegen) set_target_properties(clang-tblgen PROPERTIES FOLDER "Clang tablegenning") _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
