Add detection for custom Linker

docker-compose.yml

@@ -128,4 +128,11 @@ services:
     build:
       context: .
       dockerfile: ./docker/Dockerfile.arm-bare-metal
-      target: build
+      target: build
+  build-gcc-with-custom-linker:
+    build:
+      context: .
+      dockerfile: ./docker/Dockerfile
+      args:
+        compiler: gcc
+      target: build-with-custom-linker

docker/Dockerfile

@@ -16,6 +16,14 @@ RUN setup-cpp --compiler $compiler --llvm true --cmake true --doxygen true --nin
 COPY ./docker/entrypoint.sh /docker-entrypoint.sh
 ENTRYPOINT [ "/docker-entrypoint.sh" ]
 
+FROM setup AS setup-custom-linker
+
+# install linker
+RUN apt-get update && apt-get install -y \
+  binutils \
+  mold \
+  lld \
+  && rm -rf /var/lib/apt/lists/*
 
 FROM setup AS build
 COPY . /home/project_options
@@ -30,3 +38,9 @@ WORKDIR /home/project_options
 RUN git submodule update --init
 CMD ["/bin/bash", "-c", "task myproj:test"]
 
+
+FROM setup-custom-linker AS build-with-custom-linker
+COPY . /home/project_options
+WORKDIR /home/project_options
+RUN git submodule update --init
+CMD ["/bin/bash", "-c", "task myproj:build"]

docker/Taskfile.yml

@@ -6,6 +6,10 @@ tasks:
     - docker-compose up --build test-gcc
     - docker-compose down
 
+  gcc.custom-linker:
+    - docker-compose up --build build-gcc-with-custom-linker
+    - docker-compose down
+
   llvm:
     - docker-compose up --build build-llvm
     - docker-compose up --build test-llvm

src/Linker.cmake

@@ -1,5 +1,22 @@
 include_guard()
 
+# Test linker option support
+function(test_linker_option output_linker_test linker)
+  set(output_linker_test OFF PARENT_SCOPE)
+  if(NOT "${linker}" STREQUAL "")
+    include(CheckCXXCompilerFlag)
+
+    set(_linker_flag "-fuse-ld=${linker}")
+
+    check_cxx_compiler_flag(${_linker_flag} _cxx_supports_linker)
+    if("${_cxx_supports_linker}" STREQUAL "1")
+      set(${output_linker_test} ON PARENT_SCOPE)
+    else()
+      set(${output_linker_test} OFF PARENT_SCOPE)
+    endif()
+  endif()
+endfunction()
+
 # Set the linker to use for the linking phase
 macro(configure_linker _project_name _linker)
   if(NOT "${_linker}" STREQUAL "")
@@ -8,8 +25,8 @@ macro(configure_linker _project_name _linker)
 
     set(_linker_flag "-fuse-ld=${_linker}")
 
-    check_cxx_compiler_flag(${_linker_flag} _cxx_supports_linker)
-    if("${_cxx_supports_linker}" STREQUAL "1")
+    test_linker_option(_cxx_supports_linker ${_linker})
+    if(_cxx_supports_linker)
       message(TRACE "Using ${_linker} as the linker for ${_project_name}")
       target_link_options(${_project_name} INTERFACE ${_linker_flag})
     else()

src/Utilities.cmake

@@ -124,3 +124,36 @@ function(detect_architecture arch)
     set(${arch} x64 PARENT_SCOPE)
   endif()
 endfunction()
+
+# detect custom linker
+function(detect_custom_linker LINKER)
+  set(SUPPORTS_LLD OFF)
+  set(SUPPORTS_GOLD OFF)
+  set(SUPPORTS_MOLD OFF)
+  if((CMAKE_CXX_COMPILER_ID MATCHES ".*Clang.*") AND NOT WIN32)
+    find_program(PROGRAM_LLD NAMES "lld")
+    if(EXISTS ${PROGRAM_LLD})
+      test_linker_option(SUPPORTS_LLD "lld")
+    endif()
+  endif()
+  if((CMAKE_CXX_COMPILER_ID MATCHES ".*GNU.*") AND NOT WIN32)
+    find_program(PROGRAM_GOLD NAMES "gold")
+    if(EXISTS ${PROGRAM_GOLD})
+      test_linker_option(SUPPORTS_GOLD "gold")
+    endif()
+  endif()
+  if(UNIX AND NOT WIN32 AND NOT APPLE)
+    find_program(PROGRAM_MOLD NAMES "mold")
+    if(EXISTS ${PROGRAM_MOLD})
+      test_linker_option(SUPPORTS_MOLD "mold")
+    endif()
+  endif()
+
+  if(SUPPORTS_MOLD)
+    set(${LINKER} "mold" PARENT_SCOPE)
+  elseif(SUPPORTS_LLD)
+    set(${LINKER} "lld" PARENT_SCOPE)
+  elseif(SUPPORTS_GOLD)
+    set(${LINKER} "gold" PARENT_SCOPE)
+  endif()
+endfunction()

tests/myproj/CMakeLists.txt

@@ -46,6 +46,12 @@ else()
   endif()
 endif()
 
+# Detect custom linker
+if(NOT MSVC)
+  detect_custom_linker(LINKER)
+  #message(STATUS "Detect Linker: ${LINKER}")
+endif()
+
 # Initialize project_options
 # uncomment the options to enable them
 project_options(
@@ -73,6 +79,7 @@ project_options(
   # ENABLE_SANITIZER_THREAD
   # ENABLE_SANITIZER_MEMORY
   # CLANG_WARNINGS "-Weverything"
+  LINKER "${LINKER}"
 )
 # NOTE: project_options and project_warnings are defined inside project_options