CMake: Enforce CMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON with v3.27+

Author: kinke

.circleci/config.yml

@@ -79,7 +79,6 @@ commonSteps: &commonSteps
             -DCMAKE_BUILD_TYPE=Release \
             -DD_COMPILER=$PWD/../host-ldc/bin/ldmd2 \
             -DLDC_LINK_MANUALLY=OFF \
-            -DCMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON \
             $EXTRA_CMAKE_FLAGS
           ninja -j$PARALLELISM obj/ldc2.o all ldc2-unittest all-test-runners
           bin/ldc2 -version

.cirrus.yml

@@ -26,7 +26,6 @@ common_steps_template: &COMMON_STEPS_TEMPLATE
       -DCMAKE_INSTALL_PREFIX=$installDir \
       -DINCLUDE_INSTALL_DIR=$installDir/import \
       -DLDC_LINK_MANUALLY=OFF \
-      -DCMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON \
       "${extraFlags[@]}"
     ninja -j$PARALLELISM obj/ldc2.o all ldc2-unittest all-test-runners
     bin/ldc2 -version
@@ -406,8 +405,7 @@ task:
       -DLLVM_ROOT_DIR=$PWD/../llvm \
       -DD_COMPILER=$PWD/../host-ldc/bin/ldmd2 \
       -DBUILD_SHARED_LIBS=OFF \
-      -DBUILD_LTO_LIBS=ON \
-      -DCMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON
+      -DBUILD_LTO_LIBS=ON
     ninja -j$PARALLELISM obj/ldc2.o all
     bin/ldc2 -version
   << : *COMMON_STEPS_TEMPLATE

.github/actions/helper-build-ldc/action.yml

@@ -35,7 +35,6 @@ runs:
           -DLLVM_ROOT_DIR="$PWD/../${{ inputs.llvm_dir }}" \
           -DD_COMPILER='${{ inputs.host_dc }}' \
           -DLDC_LINK_MANUALLY=OFF \
-          -DCMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON \
           ${{ inputs.specify_install_dir == 'true' && '-DCMAKE_INSTALL_PREFIX="$installDir"' || '' }} \
           ${{ inputs.specify_install_dir == 'true' && '-DINCLUDE_INSTALL_DIR="$installDir/import"' || '' }} \
           ${{ inputs.cmake_flags }}
@@ -58,7 +57,6 @@ runs:
           "-DD_COMPILER=${{ inputs.host_dc }}" ^
           -DCMAKE_C_COMPILER=clang-cl ^
           -DCMAKE_CXX_COMPILER=clang-cl ^
-          -DCMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON ^
           ${{ inputs.specify_install_dir == 'true' && '"-DCMAKE_INSTALL_PREFIX=%installDir%"' || '' }} ^
           ${{ inputs.specify_install_dir == 'true' && '"-DINCLUDE_INSTALL_DIR=%installDir%\import"' || '' }} ^
           ${{ inputs.cmake_flags }}

.github/workflows/supported_llvm_versions.yml

@@ -121,7 +121,6 @@ jobs:
             -DCMAKE_BUILD_TYPE=Release \
             -DLLVM_ROOT_DIR="$PWD/llvm" \
             -DLDC_LINK_MANUALLY=OFF \
-            -DCMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY=ON \
             ${{ matrix.cmake_flags }}
           ninja obj/ldc2.o all ldc2-unittest all-test-runners
           bin/ldc2 --version

CMakeLists.txt

@@ -1,6 +1,12 @@
 cmake_minimum_required(VERSION 3.4.3)
 if(POLICY CMP0025)
-  cmake_policy(SET CMP0025 NEW)
+    cmake_policy(SET CMP0025 NEW)
+endif()
+if(${CMAKE_VERSION} VERSION_GREATER "3.26.9")
+    # Prevent implicit dependencies for custom commands, e.g.,
+    # `obj/ldc2.o` depending on `lib/libldc.a` with LDC_LINK_MANUALLY=ON.
+    # Only supported since CMake v3.27 unfortunately.
+    set(CMAKE_ADD_CUSTOM_COMMAND_DEPENDS_EXPLICIT_ONLY ON)
 endif()
 
 project(ldc)