are_images_equal and many tests are linked with both libavif and libavif_internal

[wantehchang]

I found that are_images_equal and many tests are linked with both libavif and libavif_internal. This is more noticeable when BUILD_SHARED_LIBS is ON (the default), because when BUILD_SHARED_LIBS is OFF, libavif_internal is an alias of libavif.

if(BUILD_SHARED_LIBS)
    add_library(avif_internal STATIC ${AVIF_SRCS})
    ...
else()
    add_library(avif_internal ALIAS avif)
    ...
endif()

Steps to reproduce:

$ cmake -G Ninja .. -DAVIF_CODEC_AOM=SYSTEM -DAVIF_BUILD_EXAMPLES=ON -DAVIF_BUILD_APPS=ON -DAVIF_BUILD_TESTS=ON -DAVIF_LOCAL_GTEST=ON
$ ninja -v

Here are two representative linker command lines on Linux:

/usr/bin/c++ tests/CMakeFiles/aviftest_helpers.dir/gtest/aviftest_helpers.cc.o tests/CMakeFiles/are_images_equal.dir/gtest/are_images_equal.cc.o -o tests/are_images_equal -Wl,-rpath,/home/wtc/libavif.1/libavif/build libavif_apps.a libavif.so.16.0.2 /usr/lib/x86_64-linux-gnu/libpng.so /usr/lib/x86_64-linux-gnu/libz.so /usr/lib/x86_64-linux-gnu/libjpeg.so libavif_internal.a /usr/lib/x86_64-linux-gnu/libaom.so -lm

/usr/bin/c++ tests/CMakeFiles/aviftest_helpers.dir/gtest/aviftest_helpers.cc.o tests/CMakeFiles/aviftilingtest.dir/gtest/aviftilingtest.cc.o -o tests/aviftilingtest -Wl,-rpath,/home/wtc/libavif.1/libavif/build /home/wtc/libavif.1/libavif/ext/googletest/build/lib/libgtest.a /home/wtc/libavif.1/libavif/ext/googletest/build/lib/libgtest_main.a libavif_apps.a libavif.so.16.0.2 /usr/lib/x86_64-linux-gnu/libpng.so /usr/lib/x86_64-linux-gnu/libz.so /usr/lib/x86_64-linux-gnu/libjpeg.so libavif_internal.a /usr/lib/x86_64-linux-gnu/libaom.so -lm

Note that we link the executable programs with both libavif.so.16.0.2 and libavif_internal.a.

I saw the same problem when I built libavif on Windows and forgot to set BUILD_SHARED_LIBS to OFF.

[wantehchang]

@vrabaud @y-guyon

The following patch seems to fix the problem. I don't think it is the right fix. The patch is intended to pinpoint the sources of the problem (avif_apps and the avifincrtest_helpers, which depend on avif, are used with aviftest_helpers, which depends on avif_internal).

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 18629ae..40123f1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -777,7 +777,7 @@ if(AVIF_BUILD_APPS OR (AVIF_BUILD_TESTS AND (AVIF_ENABLE_FUZZTEST OR AVIF_ENABLE
         avif_apps STATIC apps/shared/avifexif.c apps/shared/avifjpeg.c apps/shared/avifpng.c apps/shared/avifutil.c
                          apps/shared/iccmaker.c apps/shared/y4m.c third_party/iccjpeg/iccjpeg.c
     )
-    target_link_libraries(avif_apps avif ${AVIF_PLATFORM_LIBRARIES} ${PNG_LIBRARY} ${ZLIB_LIBRARY} ${JPEG_LIBRARY})
+    target_link_libraries(avif_apps ${AVIF_PLATFORM_LIBRARIES} ${PNG_LIBRARY} ${ZLIB_LIBRARY} ${JPEG_LIBRARY})
     # In GitHub CI's macos-latest os image, /usr/local/include has not only the headers of libpng
     # and libjpeg but also the headers of an older version of libavif. Put the avif include
     # directory before ${PNG_PNG_INCLUDE_DIR} ${JPEG_INCLUDE_DIR} to prevent picking up old libavif
@@ -803,12 +803,12 @@ if(AVIF_BUILD_APPS)
     if(AVIF_USE_CXX)
         set_target_properties(avifenc PROPERTIES LINKER_LANGUAGE "CXX")
     endif()
-    target_link_libraries(avifenc avif_apps)
+    target_link_libraries(avifenc avif_apps avif)
     add_executable(avifdec apps/avifdec.c)
     if(AVIF_USE_CXX)
         set_target_properties(avifdec PROPERTIES LINKER_LANGUAGE "CXX")
     endif()
-    target_link_libraries(avifdec avif_apps)
+    target_link_libraries(avifdec avif_apps avif)
 
     if(NOT SKIP_INSTALL_APPS AND NOT SKIP_INSTALL_ALL)
         install(
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d174e05..8268b3d 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -97,7 +97,8 @@ if(AVIF_ENABLE_GTEST OR AVIF_ENABLE_FUZZTEST)
     endif()
 
     add_library(avifincrtest_helpers OBJECT gtest/avifincrtest_helpers.cc)
-    target_link_libraries(avifincrtest_helpers avif ${AVIF_PLATFORM_LIBRARIES} ${GTEST_LIBRARIES})
+    target_link_libraries(avifincrtest_helpers ${AVIF_PLATFORM_LIBRARIES} ${GTEST_LIBRARIES})
+    target_include_directories(avifincrtest_helpers PRIVATE $<TARGET_PROPERTY:avif,INTERFACE_INCLUDE_DIRECTORIES>)
     target_include_directories(avifincrtest_helpers PUBLIC ${GTEST_INCLUDE_DIRS})
 endif()
 

[wantehchang]

Please see the patch.txt file in patch.zip. I removed the dependency of aviftest_helpers.cc on avif_internal. This allows the tests that only call the public functions to be linked with avif rather than avif_internal.

This patch is unlikely to be the right fix. It is intended to show which tests can be linked with avif and which tests must be linked with avif_internal.