Fix delay-load propagation from ImageCodec

ImageCodec now publishes the MSVC delay-load requirements for the DLL-backed codecs it enables, so final consumers inherit the correct link behavior while codec implementation libraries stay private. The codec-local delay-load blocks were removed, and zlib delay loading is applied to png_shared where zlib is actually imported.

Author: Lior Lahav

Codecs/CodecJPG/CMakeLists.txt

@@ -149,7 +149,3 @@ set(TargetName CodecJPG)
 add_library (${TargetName} ${sourceFiles} )
 
 target_link_libraries(${TargetName} PRIVATE libjpeg-turbo::libjpeg-turbo)  # adjust to match built target name
-
-if (${CMAKE_SYSTEM_NAME} MATCHES "Windows" AND (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC") AND NOT MINGW)
-    target_link_options(${TargetName} PUBLIC "/DELAYLOAD:turbojpeg.dll")
-endif()

Codecs/CodecPNG/CMakeLists.txt

@@ -61,8 +61,3 @@ target_include_directories(${TargetName} PRIVATE ${LibPNGFolder})
 target_include_directories(${TargetName} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/external/libpng)
 target_link_libraries(${TargetName} png_shared )
 target_include_directories(png_shared PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/external/zlib)
-
-if (${CMAKE_SYSTEM_NAME} MATCHES "Windows" AND (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC"))
-  target_link_options(${TargetName} PUBLIC "/DELAYLOAD:$<TARGET_FILE_BASE_NAME:png_shared>.dll")
-  target_link_options(${TargetName} PUBLIC "/DELAYLOAD:$<TARGET_FILE_BASE_NAME:zlib>.dll")
-endif()

Codecs/CodecTiff/CMakeLists.txt

@@ -83,6 +83,3 @@ target_include_directories(${TargetName} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/ext
 
 
 target_link_libraries(${TargetName} tiff)
-if (${CMAKE_SYSTEM_NAME} MATCHES "Windows" AND (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC") AND NOT MINGW)
-   target_link_options(${TargetName} PUBLIC "/DELAYLOAD:$<TARGET_FILE_BASE_NAME:tiff>.dll")
-endif()

ImageCodec/CMakeLists.txt

@@ -51,4 +51,15 @@ if (${CMAKE_SYSTEM_NAME} MATCHES "Windows" AND
     (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC") AND
     NOT MINGW)
     target_link_libraries(${TargetName} PUBLIC delayimp)
+    if ( ${IMCODEC_BUILD_CODEC_JPG})
+        target_link_options(${TargetName} PUBLIC "/DELAYLOAD:turbojpeg.dll")
+    endif()
+    if ( ${IMCODEC_BUILD_CODEC_PNG})
+        target_link_options(${TargetName} PUBLIC "/DELAYLOAD:$<TARGET_FILE_BASE_NAME:png_shared>.dll")
+        set_property(TARGET png_shared APPEND PROPERTY LINK_LIBRARIES delayimp)
+        set_property(TARGET png_shared APPEND PROPERTY LINK_OPTIONS "/DELAYLOAD:$<TARGET_FILE_BASE_NAME:zlib>.dll")
+    endif()
+    if ( ${IMCODEC_BUILD_CODEC_TIFF})
+        target_link_options(${TargetName} PUBLIC "/DELAYLOAD:$<TARGET_FILE_BASE_NAME:tiff>.dll")
+    endif()
 endif()