Configure ldc2.conf compiler-specific settings in root CMakeLists.txt

the-horo · the-horo · commit 3d82ec7e71c3 · 2025-06-18T16:55:07.000+03:00
Some settings like the default wasm switches or the compiler-rt
lib-dir don't have anything to do with the runtime and, on top of
that, some are conditioned by build settings that only affect the
compiler.

Moving them out of the runtime directory improves the support for
cross-compiling because, in the scenario, some variables may be
unset in the runtime directory as there is no longer a higher-level
project to set them.

Signed-off-by: Andrei Horodniceanu &lt;a.horodniceanu@proton.me&gt;
diff --git a/.github/actions/3-build-cross/action.yml b/.github/actions/3-build-cross/action.yml
@@ -142,9 +142,9 @@ runs:
           --dFlags="${DFLAGS// /;}" \
           --ldcSrcDir="$PWD/ldc" \
           --installWithSuffix "" \
+          --confPreferDir \
           CMAKE_INSTALL_PREFIX="$PWD/install" \
           INCLUDE_INSTALL_DIR="$PWD/install/import" \
-          CONF_INST_DIR="$PWD/install/etc" \
           "${flags[@]}"
 
     - name: Cross-compile LDC executables
@@ -156,6 +156,7 @@ runs:
         specify_install_dir: true
         cmake_flags: >-
           -DCMAKE_CROSSCOMPILING=True
+          -DCONF_PREFER_DIR=ON
           ${{ inputs.os == 'osx' && '-DALTERNATIVE_MALLOC_O="$PWD/../build-mimalloc/CMakeFiles/mimalloc-obj.dir/src/static.c.o"' || '' }}
           ${{ inputs.cmake_flags }}
           ${{ inputs.with_pgo == 'true' && '-DDFLAGS_LDC=-fprofile-use=../pgo-ldc/merged.profdata' || '' }}
diff --git a/.github/actions/5-install/action.yml b/.github/actions/5-install/action.yml
@@ -20,7 +20,7 @@ runs:
         else
           # the cross-compiled runtime libs have already been installed:
           # * lib/: runtime library artifacts
-          # * etc/ldc2.conf
+          # * etc/ldc2.conf/30-ldc-runtime-lib.conf
 
           # now extend by installing the cross-compiled compiler:
           # * bin/: executables
@@ -50,8 +50,14 @@ runs:
           # /d/a/1/install => D:/a/1/install
           absInstallDir=$(cygpath --mixed "$absInstallDir")
         fi
-        perl -pi -e "s|$absInstallDir/|%%ldcbinarypath%%/../|g" install/etc/ldc2.conf
-        cat install/etc/ldc2.conf
+        # ldc2.conf is either a regular file (native builds) or a directory (cross builds)
+        if [[ -f install/etc/ldc2.conf ]]; then
+            confs=( install/etc/ldc2.conf )
+        else
+            confs=( install/etc/ldc2.conf/* )
+        fi
+        perl -pi -e "s|$absInstallDir/|%%ldcbinarypath%%/../|g" "${confs[@]}"
+        cat "${confs[@]}"
 
     - name: Rename the installation dir to test portability
       shell: bash
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -903,10 +903,6 @@ if(NOT DEFINED COMPILER_RT_LIBDIR_CONFIG)
         set(COMPILER_RT_LIBDIR_CONFIG "${COMPILER_RT_LIBDIR}")
     endif()
 endif()
-if(DEFINED COMPILER_RT_LIBDIR_CONFIG)
-    message(STATUS "Adding ${COMPILER_RT_LIBDIR_CONFIG} to lib-dirs in configuration file")
-    makeConfSection(NAME "35-ldc-compiler-rt" SECTION "default" LIB_DIRS "${COMPILER_RT_LIBDIR}")
-endif()
 
 #
 # Auxiliary build and test utils.
@@ -954,6 +950,59 @@ endif()
 #
 add_subdirectory(tools)
 
+#
+# Compiler ldc2.conf configuration
+#
+
+set(switches)
+
+# LLVM 16: Disable function specializations by default.
+# They cause miscompiles of e.g. the frontend for some targets (macOS x86_64 and Windows x64).
+if(LDC_LLVM_VER GREATER 1599 AND LDC_LLVM_VER LESS 1700)
+    list(APPEND switches "-func-specialization-size-threshold=1000000000")
+endif()
+
+if(DEFINED COMPILER_RT_LIBDIR_CONFIG)
+    message(STATUS "Adding ${COMPILER_RT_LIBDIR_CONFIG} to lib-dirs in configuration file")
+endif()
+
+list(APPEND switches "-defaultlib=phobos2-ldc,druntime-ldc")
+
+makeConfSection(NAME "35-ldc-compiler" SECTION "default"
+    BUILD
+    SWITCHES ${switches}
+    # -defaultlib is configure in runtime/CMakeLists.txt
+    POST_SWITCHES
+	"-I${PROJECT_SOURCE_DIR}/runtime/druntime/src"
+	"-I${PROJECT_BINARY_DIR}/import"
+	"-I${PROJECT_SOURCE_DIR}/runtime/phobos"
+	"-I${PROJECT_SOURCE_DIR}/runtime/jit-rt/d"
+    LIB_DIRS ${COMPILER_RT_LIBDIR_CONFIG}
+
+    INSTALL
+    SWITCHES ${switches}
+    POST_SWITCHES "-I${INCLUDE_INSTALL_DIR}"
+    LIB_DIRS ${COMPILER_RT_LIBDIR_CONFIG}
+)
+
+set(wasm_switches)
+list(APPEND wasm_switches -defaultlib=)
+# Default wasm stack is only 64kb, this is rather small, let's bump it to 1mb
+list(APPEND wasm_switches -L-z -Lstack-size=1048576)
+# Protect from stack overflow overwriting global memory
+list(APPEND wasm_switches -L--stack-first)
+if(LDC_WITH_LLD)
+    list(APPEND wasm_switches -link-internally)
+endif()
+# LLD 8+ requires (new) `--export-dynamic` for WebAssembly (https://github.com/ldc-developers/ldc/issues/3023).
+list(APPEND wasm_switches -L--export-dynamic)
+
+makeConfSection(NAME "40-ldc-wasm"
+    SECTION "^wasm(32|64)-"
+    SWITCHES ${wasm_switches}
+    LIB_DIRS OVERRIDE
+)
+
 #
 # Test and runtime targets. Note that enable_testing() is order-sensitive!
 #
diff --git a/runtime/CMakeLists.txt b/runtime/CMakeLists.txt
@@ -17,9 +17,6 @@ if(NOT LDC_EXE)
     if(NOT DEFINED DMDFE_MINOR_VERSION OR NOT DEFINED DMDFE_PATCH_VERSION)
         message(FATAL_ERROR "Please define the CMake variables DMDFE_MINOR_VERSION and DMDFE_PATCH_VERSION.")
     endif()
-    if(NOT DEFINED LDC_WITH_LLD)
-        message(FATAL_ERROR "Please define the CMake variable LDC_WITH_LLD.")
-    endif()
 endif()
 
 #
@@ -274,26 +271,6 @@ elseif(${BUILD_SHARED_LIBS} STREQUAL "OFF")
     set(switches "-link-defaultlib-shared=false")
 endif()
 
-# LLVM 16: Disable function specializations by default.
-# They cause miscompiles of e.g. the frontend for some targets (macOS x86_64 and Windows x64).
-if(LDC_LLVM_VER GREATER 1599 AND LDC_LLVM_VER LESS 1700)
-    list(APPEND switches "-func-specialization-size-threshold=1000000000")
-endif()
-
-list(APPEND switches "-defaultlib=phobos2-ldc,druntime-ldc")
-
-# Directory filled with auto-generated import files
-set(LDC_GCCBUILTINS_IMPORT_DIR "${CMAKE_BINARY_DIR}/import")
-set(build_post_switches
-    "-I${RUNTIME_DIR}/src"
-    "-I${LDC_GCCBUILTINS_IMPORT_DIR}"
-    "-I${JITRT_DIR}/d"
-)
-if(PHOBOS2_DIR)
-    list(APPEND build_post_switches "-I${PHOBOS2_DIR}")
-endif()
-set(install_post_switches "-I${INCLUDE_INSTALL_DIR}")
-
 set(build_libdir "${CMAKE_BINARY_DIR}/lib${LIB_SUFFIX}")
 set(install_libdir "${CMAKE_INSTALL_LIBDIR}")
 
@@ -308,34 +285,15 @@ makeConfSection(NAME "30-ldc-runtime-lib${LIB_SUFFIX}"
 
     BUILD
     SWITCHES ${switches}
-    POST_SWITCHES OVERRIDE ${build_post_switches}
     LIB_DIRS OVERRIDE ${build_libdir}
     RPATH ${build_rpath}
 
     INSTALL
     SWITCHES ${switches}
-    POST_SWITCHES OVERRIDE ${install_post_switches}
     LIB_DIRS OVERRIDE ${install_libdir}
     RPATH ${install_rpath}
 )
 
-set(wasm_switches -defaultlib=)
-# Default wasm stack is only 64kb, this is rather small, let's bump it to 1mb
-list(APPEND wasm_switches -L-z -Lstack-size=1048576)
-# Protect from stack overflow overwriting global memory
-list(APPEND wasm_switches -L--stack-first)
-if(LDC_WITH_LLD)
-    list(APPEND wasm_switches -link-internally)
-endif()
-# LLD 8+ requires (new) `--export-dynamic` for WebAssembly (https://github.com/ldc-developers/ldc/issues/3023).
-list(APPEND wasm_switches -L--export-dynamic)
-
-makeConfSection(NAME "40-ldc-wasm"
-    SECTION "^wasm(32|64)-"
-    SWITCHES ${wasm_switches}
-    LIB_DIRS OVERRIDE
-)
-
 # macOS has fat libraries; otherwise, append a separate config file section for the
 # multilib target and override the lib directory.
 if(MULTILIB AND NOT "${TARGET_SYSTEM}" MATCHES "APPLE")
diff --git a/runtime/ldc-build-runtime.d.in b/runtime/ldc-build-runtime.d.in
@@ -163,7 +163,6 @@ void runCMake() {
         "-DLDMD_EXE_FULL=" ~ ldmdExecutable,
         "-DDMDFE_MINOR_VERSION=@DMDFE_MINOR_VERSION@",
         "-DDMDFE_PATCH_VERSION=@DMDFE_PATCH_VERSION@",
-        "-DLDC_WITH_LLD=@LDC_WITH_LLD@",
         "-DINCLUDE_INSTALL_DIR=@INCLUDE_INSTALL_DIR@",
     ];
 
