Gate PUBLIC compiler-specific flags by consumer compiler ID

.github/workflows/build_cpp.yml

@@ -221,6 +221,26 @@ jobs:
       run: build/Release/dtest.exe --runall -q
     - name: Build ancillary tools
       run: cmake --build build --config Release --target imglab htmlify dtoc --parallel 4
+    - name: Install an AVX-enabled MSVC package
+      working-directory: ${{ github.workspace }}
+      run: |
+        cmake . -B "${{ runner.temp }}/dlib-package-build" -DCMAKE_INSTALL_PREFIX="${{ runner.temp }}/dlib-package-install" -DDLIB_NO_GUI_SUPPORT=ON -DDLIB_USE_BLAS=OFF -DDLIB_USE_LAPACK=OFF -DDLIB_USE_CUDA=OFF -DUSE_AVX_INSTRUCTIONS=ON
+        cmake --build "${{ runner.temp }}/dlib-package-build" --config Release --target install --parallel 4
+    - name: Test installed package with MSVC
+      working-directory: ${{ github.workspace }}
+      run: |
+        cmake dlib/cmake_utils/test_for_dlib_config -B "${{ runner.temp }}/dlib-package-consumer-msvc" -Ddlib_DIR="${{ runner.temp }}/dlib-package-install/lib/cmake/dlib" -DDLIB_CONFIG_TEST_EXPECT_AVX=ON
+        cmake --build "${{ runner.temp }}/dlib-package-consumer-msvc" --config Release --parallel 4
+    - name: Test installed MSVC package with clang++
+      working-directory: ${{ github.workspace }}
+      run: |
+        cmake dlib/cmake_utils/test_for_dlib_config -B "${{ runner.temp }}/dlib-package-consumer-clang" -G Ninja -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=Release -Ddlib_DIR="${{ runner.temp }}/dlib-package-install/lib/cmake/dlib" -DDLIB_CONFIG_TEST_EXPECT_AVX=ON
+        cmake --build "${{ runner.temp }}/dlib-package-consumer-clang" --parallel 4
+    - name: Test installed MSVC package with clang-cl
+      working-directory: ${{ github.workspace }}
+      run: |
+        cmake dlib/cmake_utils/test_for_dlib_config -B "${{ runner.temp }}/dlib-package-consumer-clang-cl" -T ClangCL -Ddlib_DIR="${{ runner.temp }}/dlib-package-install/lib/cmake/dlib" -DDLIB_CONFIG_TEST_EXPECT_AVX=ON
+        cmake --build "${{ runner.temp }}/dlib-package-consumer-clang-cl" --config Release --parallel 4
 
   # Disable this because macos targets aren't working on github actions right now.
   #macos-latest:

dlib/CMakeLists.txt

@@ -806,13 +806,12 @@ if (NOT TARGET dlib)
    endif()
 
    target_compile_features(dlib PUBLIC cxx_std_14)
-   if((MSVC AND CMAKE_VERSION VERSION_LESS 3.11))
-      target_compile_options(dlib PUBLIC ${active_compile_opts})
-      target_compile_options(dlib PRIVATE ${active_compile_opts_private})
-   else()
-      target_compile_options(dlib PUBLIC $<$<COMPILE_LANGUAGE:CXX>:${active_compile_opts}>)
-      target_compile_options(dlib PRIVATE $<$<COMPILE_LANGUAGE:CXX>:${active_compile_opts_private}>)
-   endif()
+   # Build-tree clients share dlib's compiler, so forward the options detected
+   # above to them. Do not put those options in the installed target, where
+   # dlibConfig.cmake recreates them for the consuming compiler's frontend.
+   target_compile_options(dlib INTERFACE "$<BUILD_INTERFACE:$<$<COMPILE_LANGUAGE:CXX>:${active_compile_opts}>>")
+   target_compile_options(dlib PRIVATE $<$<COMPILE_LANGUAGE:CXX>:${active_compile_opts}>)
+   target_compile_options(dlib PRIVATE $<$<COMPILE_LANGUAGE:CXX>:${active_compile_opts_private}>)
 
    # Install the library
    if (NOT DLIB_IN_PROJECT_BUILD)

dlib/cmake_utils/dlibConfig.cmake.in

@@ -15,7 +15,7 @@
 
 
 # Our library dependencies (contains definitions for IMPORTED targets)
-if(NOT TARGET dlib-shared AND NOT dlib_BINARY_DIR)
+if(NOT TARGET dlib::dlib AND NOT TARGET dlib-shared AND NOT dlib_BINARY_DIR)
    # Compute paths
    get_filename_component(dlib_CMAKE_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
    include("${dlib_CMAKE_DIR}/dlib.cmake")
@@ -29,6 +29,73 @@ if(NOT TARGET dlib-shared AND NOT dlib_BINARY_DIR)
    endif()
    unset(dlib_deps_threads_idx)
    unset(dlib_deps_threads_check)
+
+   # Compiler options on an imported target are evaluated in the consuming
+   # project, not in the project that built dlib.  Select them here so an
+   # installed package never passes (for example) cl-style options to the
+   # clang++ driver.  MSVC is intentionally used instead of the compiler ID:
+   # CMake also sets it for compilers such as clang-cl that accept cl syntax.
+   set(_dlib_compile_options)
+   set(_dlib_compile_definitions)
+   set(_dlib_simd_level "@DLIB_SIMD_LEVEL@")
+
+   if(MSVC)
+      list(APPEND _dlib_compile_options /bigobj)
+
+      if(_dlib_simd_level STREQUAL "AVX")
+         list(APPEND _dlib_compile_options /arch:AVX)
+      elseif(_dlib_simd_level STREQUAL "SSE4")
+         if(CMAKE_SIZEOF_VOID_P EQUAL 4)
+            list(APPEND _dlib_compile_options /arch:SSE2)
+         endif()
+         list(APPEND _dlib_compile_definitions DLIB_HAVE_SSE2 DLIB_HAVE_SSE3 DLIB_HAVE_SSE41)
+      elseif(_dlib_simd_level STREQUAL "SSE2")
+         if(CMAKE_SIZEOF_VOID_P EQUAL 4)
+            list(APPEND _dlib_compile_options /arch:SSE2)
+         endif()
+         list(APPEND _dlib_compile_definitions DLIB_HAVE_SSE2)
+      endif()
+
+      if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+         if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 3.3)
+            list(APPEND _dlib_compile_options -Xclang -fcxx-exceptions)
+         endif()
+         if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
+            list(APPEND _dlib_compile_options -ftemplate-depth=500)
+         endif()
+      endif()
+   elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR
+          CMAKE_CXX_COMPILER_ID STREQUAL "Clang" OR
+          CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" OR
+          CMAKE_CXX_COMPILER_ID STREQUAL "Intel" OR
+          CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM")
+      if(_dlib_simd_level STREQUAL "AVX")
+         list(APPEND _dlib_compile_options -mavx)
+      elseif(_dlib_simd_level STREQUAL "SSE4")
+         list(APPEND _dlib_compile_options -msse4)
+      elseif(_dlib_simd_level STREQUAL "SSE2")
+         list(APPEND _dlib_compile_options -msse2)
+      elseif(_dlib_simd_level STREQUAL "NEON")
+         list(APPEND _dlib_compile_options -mfpu=neon)
+      endif()
+
+      if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+         list(APPEND _dlib_compile_options -Wreturn-type)
+      elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0.0)
+         list(APPEND _dlib_compile_options -ftemplate-depth=500)
+      endif()
+   endif()
+
+   if(_dlib_compile_options)
+      target_compile_options(dlib::dlib INTERFACE "$<$<COMPILE_LANGUAGE:CXX>:${_dlib_compile_options}>")
+   endif()
+   if(_dlib_compile_definitions)
+      target_compile_definitions(dlib::dlib INTERFACE "$<$<COMPILE_LANGUAGE:CXX>:${_dlib_compile_definitions}>")
+   endif()
+
+   unset(_dlib_compile_definitions)
+   unset(_dlib_compile_options)
+   unset(_dlib_simd_level)
 endif()
 
 set(dlib_LIBRARIES dlib::dlib)
@@ -52,6 +119,3 @@ endfunction()
 variable_watch(dlib_LIBRARIES __deprecated_var)
 variable_watch(dlib_LIBS __deprecated_var)
 variable_watch(dlib_INCLUDE_DIRS __deprecated_var)
-
-
-

dlib/cmake_utils/set_compiler_specific_options.cmake

@@ -24,25 +24,29 @@ endif()
 
 set(gcc_like_compilers GNU Clang  Intel)
 set(intel_archs x86_64 i386 i686 AMD64 amd64 x86)
+set(DLIB_SIMD_LEVEL NONE)
 
 
-# Setup some options to allow a user to enable SSE and AVX instruction use.  
+# Setup some options to allow a user to enable SSE and AVX instruction use.
 if ((";${gcc_like_compilers};" MATCHES ";${CMAKE_CXX_COMPILER_ID};")  AND
    (";${intel_archs};"        MATCHES ";${CMAKE_SYSTEM_PROCESSOR};") AND NOT USE_AUTO_VECTOR)
    option(USE_SSE2_INSTRUCTIONS "Compile your program with SSE2 instructions" OFF)
    option(USE_SSE4_INSTRUCTIONS "Compile your program with SSE4 instructions" OFF)
    option(USE_AVX_INSTRUCTIONS  "Compile your program with AVX instructions"  OFF)
    if(USE_AVX_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL AVX)
       list(APPEND active_compile_opts -mavx)
       message(STATUS "Enabling AVX instructions")
    elseif (USE_SSE4_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL SSE4)
       list(APPEND active_compile_opts -msse4)
       message(STATUS "Enabling SSE4 instructions")
    elseif(USE_SSE2_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL SSE2)
       list(APPEND active_compile_opts -msse2)
       message(STATUS "Enabling SSE2 instructions")
    endif()
-elseif (MSVC OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC") # else if using Visual Studio 
+elseif (MSVC OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC") # else if using Visual Studio
    # Use SSE2 by default when using Visual Studio.
    option(USE_SSE2_INSTRUCTIONS "Compile your program with SSE2 instructions" ON)
    option(USE_SSE4_INSTRUCTIONS "Compile your program with SSE4 instructions" OFF)
@@ -51,9 +55,11 @@ elseif (MSVC OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC") # else if using Visu
    include(CheckTypeSize)
    check_type_size( "void*" SIZE_OF_VOID_PTR)
    if(USE_AVX_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL AVX)
       list(APPEND active_compile_opts /arch:AVX)
       message(STATUS "Enabling AVX instructions")
    elseif (USE_SSE4_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL SSE4)
       # Visual studio doesn't have an /arch:SSE2 flag when building in 64 bit modes.
       # So only give it when we are doing a 32 bit build.
       if (SIZE_OF_VOID_PTR EQUAL 4)
@@ -64,6 +70,7 @@ elseif (MSVC OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC") # else if using Visu
       list(APPEND active_preprocessor_switches "-DDLIB_HAVE_SSE3")
       list(APPEND active_preprocessor_switches "-DDLIB_HAVE_SSE41")
    elseif(USE_SSE2_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL SSE2)
       # Visual studio doesn't have an /arch:SSE2 flag when building in 64 bit modes.
       # So only give it when we are doing a 32 bit build.
       if (SIZE_OF_VOID_PTR EQUAL 4)
@@ -77,6 +84,7 @@ elseif((";${gcc_like_compilers};" MATCHES ";${CMAKE_CXX_COMPILER_ID};")  AND
         ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "^arm"))
    option(USE_NEON_INSTRUCTIONS "Compile your program with ARM-NEON instructions" OFF)
    if(USE_NEON_INSTRUCTIONS)
+      set(DLIB_SIMD_LEVEL NEON)
       list(APPEND active_compile_opts -mfpu=neon)
       message(STATUS "Enabling ARM-NEON instructions")
    endif()
@@ -110,11 +118,10 @@ if (MSVC)
    # RAM.
    list(APPEND active_compile_opts_private "/MP")
 
-   if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 3.3) 
+   if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 3.3)
       # Clang can compile all Dlib's code at Windows platform. Tested with Clang 5
       list(APPEND active_compile_opts -Xclang)
       list(APPEND active_compile_opts -fcxx-exceptions)
    endif()
 endif()
 
-

dlib/cmake_utils/test_for_dlib_config/CMakeLists.txt

@@ -0,0 +1,37 @@
+cmake_minimum_required(VERSION 3.17.0)
+
+project(dlib_config_test LANGUAGES CXX)
+
+find_package(dlib CONFIG REQUIRED)
+
+get_target_property(dlib_config_test_options dlib::dlib INTERFACE_COMPILE_OPTIONS)
+find_package(dlib CONFIG REQUIRED)
+get_target_property(dlib_config_test_options_after_second_find dlib::dlib INTERFACE_COMPILE_OPTIONS)
+if(NOT "${dlib_config_test_options}" STREQUAL "${dlib_config_test_options_after_second_find}")
+   message(FATAL_ERROR "Finding the dlib package twice duplicated its compiler options")
+endif()
+
+if(MSVC)
+   if(NOT ";${dlib_config_test_options};" MATCHES "/bigobj")
+      message(FATAL_ERROR "dlib::dlib did not provide /bigobj to an MSVC-style compiler frontend")
+   endif()
+elseif(";${dlib_config_test_options};" MATCHES "/bigobj")
+   message(FATAL_ERROR "dlib::dlib provided /bigobj to a non-MSVC compiler frontend")
+endif()
+
+if(DLIB_CONFIG_TEST_EXPECT_AVX)
+   if(MSVC)
+      if(NOT ";${dlib_config_test_options};" MATCHES "/arch:AVX")
+         message(FATAL_ERROR "dlib::dlib did not translate its AVX requirement to /arch:AVX")
+      endif()
+   elseif(NOT ";${dlib_config_test_options};" MATCHES "-mavx")
+      message(FATAL_ERROR "dlib::dlib did not translate its AVX requirement to -mavx")
+   endif()
+endif()
+
+add_executable(dlib_config_test dlib_config_test.cpp)
+target_link_libraries(dlib_config_test PRIVATE dlib::dlib)
+
+if(DLIB_CONFIG_TEST_EXPECT_AVX)
+   target_compile_definitions(dlib_config_test PRIVATE DLIB_CONFIG_TEST_EXPECT_AVX)
+endif()

dlib/cmake_utils/test_for_dlib_config/dlib_config_test.cpp

@@ -0,0 +1,10 @@
+#include <dlib/simd/simd_check.h>
+
+#if defined(DLIB_CONFIG_TEST_EXPECT_AVX) && !defined(DLIB_HAVE_AVX)
+#error "The installed dlib package did not enable AVX for its consumer"
+#endif
+
+int main()
+{
+    return 0;
+}