https://github.com/definelicht updated https://github.com/llvm/llvm-project/pull/183541
>From 664fb4f28eb2930e8473a7096aeef21d265714c9 Mon Sep 17 00:00:00 2001 From: Johannes de Fine Licht <[email protected]> Date: Thu, 26 Feb 2026 15:36:03 +0100 Subject: [PATCH] [CMake] Propagate dependencies to OBJECT libraries in `add_llvm_library` Previously, transitively inherited calls to `target_include_directories(foo SYSTEM ...)` were being squashed into a flat list of includes, effectively stripping off `-isystem` and unintentionally forwarding warnings from such dependencies. To correctly propagate `SYSTEM` dependencies, use `target_link_libraries` to forward the parent target's link dependencies to the OBJECT library (similar to the `_static` flow below). Unlike a flat `target_include_directories`, this lets CMake resolve transitive SYSTEM include directories through the proper dependency chain. Note that `target_link_libraries` on an OBJECT library propagates all usage requirements, not just includes. This also brings in transitive `INTERFACE_COMPILE_DEFINITIONS`, `INTERFACE_COMPILE_OPTIONS`, and `INTERFACE_COMPILE_FEATURES`. This is arguably more correct, as the OBJECT library compiles the same sources and should see the same flags. The existing `target_include_directories` call is retained for include directories set directly on the target (not through link dependencies). CMake deduplicates include directories that appear through both paths. Compile definitions and options may technically appear twice (once via the OBJECT library, once via the consuming target), but duplicate `-D` and flag entries are harmless in practice. Also fix `clang_target_link_libraries` and `mlir_target_link_libraries` to forward the link type (PUBLIC/PRIVATE/INTERFACE) to `obj.*` targets. Previously the type keyword was silently dropped, resulting in plain- signature `target_link_libraries` calls. This is now required because the new keyword-signature call in `llvm_add_library` would otherwise conflict (CMake requires all calls on a target to use the same signature). --- clang/cmake/modules/AddClang.cmake | 2 +- llvm/cmake/modules/AddLLVM.cmake | 7 ++++++- mlir/cmake/modules/AddMLIR.cmake | 2 +- 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/clang/cmake/modules/AddClang.cmake b/clang/cmake/modules/AddClang.cmake index 4059fc3e986c7..61e49b55f15e4 100644 --- a/clang/cmake/modules/AddClang.cmake +++ b/clang/cmake/modules/AddClang.cmake @@ -217,7 +217,7 @@ endmacro() function(clang_target_link_libraries target type) if (TARGET obj.${target}) - target_link_libraries(obj.${target} ${ARGN}) + target_link_libraries(obj.${target} ${type} ${ARGN}) endif() get_property(LLVM_DRIVER_TOOLS GLOBAL PROPERTY LLVM_DRIVER_TOOLS) diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake index f59002bc6c837..386ffd99c570b 100644 --- a/llvm/cmake/modules/AddLLVM.cmake +++ b/llvm/cmake/modules/AddLLVM.cmake @@ -636,7 +636,12 @@ function(llvm_add_library name) # Do add_dependencies(obj) later due to CMake issue 14747. list(APPEND objlibs ${obj_name}) - # Bring in the target include directories from our original target. + # Bring in the target include directories and link info from our original + # target. target_link_libraries propagates transitive dependencies with + # proper SYSTEM include handling from IMPORTED targets. + # target_include_directories propagates include directories set directly on + # the target. + target_link_libraries(${obj_name} PRIVATE $<TARGET_PROPERTY:${name},LINK_LIBRARIES>) target_include_directories(${obj_name} PRIVATE $<TARGET_PROPERTY:${name},INCLUDE_DIRECTORIES>) set_target_properties(${obj_name} PROPERTIES FOLDER "${subproject_title}/Object Libraries") diff --git a/mlir/cmake/modules/AddMLIR.cmake b/mlir/cmake/modules/AddMLIR.cmake index b240aeba23109..60b73876d53fe 100644 --- a/mlir/cmake/modules/AddMLIR.cmake +++ b/mlir/cmake/modules/AddMLIR.cmake @@ -769,7 +769,7 @@ endfunction(mlir_check_all_link_libraries) # used. function(mlir_target_link_libraries target type) if (TARGET obj.${target}) - target_link_libraries(obj.${target} ${ARGN}) + target_link_libraries(obj.${target} ${type} ${ARGN}) endif() if (MLIR_LINK_MLIR_DYLIB) _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
