Enable LTO on MSVC

Author: Anilm3

.github/workflows/build.yml

@@ -42,7 +42,7 @@ jobs:
       - name: Create Directories
         run: cmake -E make_directory ${{ github.workspace }}/build ${{ github.workspace }}/packages
       - name: Generating Build Scripts
-        run: cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLIBDDWAF_PACKAGE_PROCESSOR=${{ matrix.arch }} -DCMAKE_INSTALL_PREFIX=${{ github.workspace }} -DCPACK_PACKAGE_DIRECTORY=${{ github.workspace }}/packages ${{ github.workspace }} -A ${{ matrix.arch }}
+        run: cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLIBDDWAF_PACKAGE_PROCESSOR=${{ matrix.arch }} -DLIBDDWAF_ENABLE_LTO=ON -DCMAKE_INSTALL_PREFIX=${{ github.workspace }} -DCPACK_PACKAGE_DIRECTORY=${{ github.workspace }}/packages ${{ github.workspace }} -A ${{ matrix.arch }}
         working-directory: ${{ github.workspace }}/build
       - name: Build
         run: cmake --build . --target package --config RelWithDebInfo --verbose --target libddwaf_shared --target libddwaf_static --target tests/waf_test -j

CMakeLists.txt

@@ -108,7 +108,12 @@ if(NOT MSVC AND LIBDDWAF_TESTING AND LIBDDWAF_TEST_COVERAGE)
 endif()
 
 if (LIBDDWAF_ENABLE_LTO)
-    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -flto")
+    if (NOT MSVC)
+        set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -flto")
+    else()
+        set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /GL")
+    endif()
+
 endif()
 
 include(cmake/objects.cmake)

cmake/objects.cmake

@@ -164,7 +164,12 @@ gen_objects(libddwaf_objects)
 add_library(libddwaf_shared_objects ALIAS libddwaf_objects)
 
 if (LIBDDWAF_ENABLE_LTO)
-    target_compile_options(libddwaf_objects PRIVATE -flto)
+    if (NOT MSVC)
+        target_compile_options(libddwaf_objects PRIVATE -flto)
+    else()
+        target_compile_options(libddwaf_objects PRIVATE /GL)
+    endif()
+
 
     # If LTO is enabled, we can't use objects with -flto to generate a static
     # library, as the contents of the object is an intermediate representation.

cmake/shared.cmake

@@ -39,7 +39,10 @@ if(LINUX)
             RENAME ${BUILD_ID_SUFFIX}.debug)
     endif()
 elseif (APPLE)
-    target_link_libraries(libddwaf_shared PRIVATE -Wl,-undefined,error libddwaf_shared_objects)
+    target_link_libraries(libddwaf_shared PRIVATE
+        $<$<BOOL:${LIBDDWAF_ENABLE_LTO}>:-flto>
+        -Wl,-undefined,error
+        libddwaf_shared_objects)
 
     if(NOT (CMAKE_BUILD_TYPE MATCHES Debug))
         # Ensure that dsymutil and strip is present
@@ -66,18 +69,10 @@ elseif (APPLE)
     endif()
 elseif (MSVC)
     target_link_libraries(libddwaf_shared
-        PRIVATE ${LIBDDWAF_PRIVATE_LIBRARIES}
+        PRIVATE
+        $<$<BOOL:${LIBDDWAF_ENABLE_LTO}>:/GL>
+        ${LIBDDWAF_PRIVATE_LIBRARIES}
         PUBLIC ${LIBDDWAF_INTERFACE_LIBRARIES})
 
     install(FILES $<TARGET_PDB_FILE:libddwaf_shared> DESTINATION lib OPTIONAL)
-elseif (MINGW)
-    target_link_libraries(libddwaf_shared PUBLIC ${LIBDDWAF_INTERFACE_LIBRARIES})
-    target_link_libraries(libddwaf_shared PRIVATE
-        $<$<BOOL:${LIBDDWAF_ENABLE_LTO}>:-flto>
-        -Wl,--no-undefined
-        -Wl,-version-script=${libddwaf_SOURCE_DIR}/libddwaf.version
-        -Wl,--build-id=0x${BUILD_ID}
-        ${LIBDDWAF_PRIVATE_LIBRARIES}
-        -static-libstdc++
-        glibc_compat_time64 glibc_compat_math)
 endif()