On 5/12/22 15:44, Maarten Hoes wrote:
What I *think* I see happening, is that the '-fprofile-arcs -ftest-coverage -lgcov' flags are correctly being set on the commandlines, up until were the error occurs, which is where (i think) linking against libpng is attempted (see error below). I tried setting *FLAGS in 'external/libpng/StaticLibrary_libpng.mk', but that did not change things. Am I misunderstanding what is happening here, or perhaps modifying the wrong Makefile ? I cannot really tell what is going on here, or what to try next.
I guess it just doesn't work well to link an archive like workdir/LinkTarget/StaticLibrary/liblibpng.a built with GCC and -fprofile-arcs into a library like Library_skia built with Clang and -fprofile-arcs: GCC -fprofile-arcs embeds calls to __gcov_init etc. into the code (satisfied at link time from GCC's libgcov.a) while Clang -fprofile-arcs embeds calls to llvm_gcov_init etc. into the code (satisfied at link time from Clang's libclang_rt.profile-*.a). The way that normally works is that when you use g++ -fprofile-arcs for linking, it sneaks in a -lgcov towards the end of the command line that it passes to the linker, and when you use clang++ -fprofile-arcs for linking, it sneaks in a /path-to/libclang_rt.profile-*.a towards the end of the command line that it passes to the linker. You have (multiple, even) explicit -lgocv on your clang++ -fprofile-arcs command line for linking Library_skia, but that comes too early before the -Wl,--start-group ... $W/LinkTarget/StaticLibrary/liblibpng.a ... -Wl,--end-group, so can't be used to satisfy that archive's dependency on __gcov_init etc. (And the later, sneaked in, /path-to/libclang_rt.profile-*.a doesn't satisfy those dependencies either, as it rather supplies llvm_gcov_init etc.)
Maybe it would be best if the decision to force using Clang for building Library_skia would be explicitly opt-in or opt-out.
