Find libraries with pkgconfig

This is necessary for Flatpak, because Yocto messes with the
/usr/bin/*-config files, and really wants everyone to use pkgconfig.

A fallback is kept to build on platforms which don't have pkgconfig for
those libraries.

1 files changed, 101 insertions, 0 deletions

diff --git a/cmake/PkgConfigWithFallbackOnConfigScript.cmake b/cmake/PkgConfigWithFallbackOnConfigScript.cmake
new file mode 100644
index 00000000..563e4ab3
--- /dev/null
+++ b/cmake/PkgConfigWithFallbackOnConfigScript.cmake
@@ -0,0 +1,101 @@
+include(CMakeParseArguments)
+
+function(find_pkg_config_with_fallback_on_config_script name)
+    cmake_parse_arguments(ARGS "" "PKG_CONFIG_NAME" "CONFIG_SCRIPT_NAME" ${ARGN})
+    set(${name}_PKG_CONFIG_NAME ${ARGS_PKG_CONFIG_NAME} PARENT_SCOPE)
+    find_package(PkgConfig)
+
+    if(PKG_CONFIG_FOUND)
+        pkg_search_module(${name}_PKG_CONFIG QUIET ${ARGS_PKG_CONFIG_NAME})
+    endif(PKG_CONFIG_FOUND)
+
+    if (${name}_PKG_CONFIG_FOUND)
+        # Found via pkg-config, using it's result values
+        set(${name}_FOUND ${${name}_PKG_CONFIG_FOUND})
+
+        # Try to find real file name of libraries
+        foreach(lib ${${name}_PKG_CONFIG_LIBRARIES})
+            find_library(${name}_${lib}_LIBRARY ${lib} HINTS ${${name}_PKG_CONFIG_LIBRARY_DIRS})
+            mark_as_advanced(${name}_${lib}_LIBRARY)
+            if(NOT ${name}_${lib}_LIBRARY)
+                unset(${name}_FOUND)
+            endif(NOT ${name}_${lib}_LIBRARY)
+        endforeach(lib)
+        if(${name}_FOUND)
+            set(${name}_LIBRARIES "")
+            foreach(lib ${${name}_PKG_CONFIG_LIBRARIES})
+                list(APPEND ${name}_LIBRARIES ${${name}_${lib}_LIBRARY})
+            endforeach(lib)
+            list(REMOVE_DUPLICATES ${name}_LIBRARIES)
+            set(${name}_LIBRARIES ${${name}_LIBRARIES} PARENT_SCOPE)
+            list(GET ${name}_LIBRARIES "0" ${name}_LIBRARY)
+
+            set(${name}_FOUND ${${name}_FOUND} PARENT_SCOPE)
+            set(${name}_INCLUDE_DIRS ${${name}_PKG_CONFIG_INCLUDE_DIRS} PARENT_SCOPE)
+            set(${name}_LIBRARIES ${${name}_PKG_CONFIG_LIBRARIES} PARENT_SCOPE)
+            set(${name}_LIBRARY ${${name}_LIBRARY} PARENT_SCOPE)
+            set(${name}_VERSION ${${name}_PKG_CONFIG_VERSION} PARENT_SCOPE)
+
+            if(NOT TARGET ${ARGS_PKG_CONFIG_NAME})
+                add_library(${ARGS_PKG_CONFIG_NAME} INTERFACE IMPORTED)
+                set_property(TARGET ${ARGS_PKG_CONFIG_NAME} PROPERTY INTERFACE_COMPILE_OPTIONS "${${name}_PKG_CONFIG_CFLAGS_OTHER}")
+                set_property(TARGET ${ARGS_PKG_CONFIG_NAME} PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${${name}_PKG_CONFIG_INCLUDE_DIRS}")
+                set_property(TARGET ${ARGS_PKG_CONFIG_NAME} PROPERTY INTERFACE_LINK_LIBRARIES "${${name}_LIBRARIES}")
+            endif(NOT TARGET ${ARGS_PKG_CONFIG_NAME})
+        endif(${name}_FOUND)
+    else(${name}_PKG_CONFIG_FOUND)
+        # No success with pkg-config, try via custom a *-config script
+        find_program(${name}_CONFIG_EXECUTABLE NAMES ${ARGS_CONFIG_SCRIPT_NAME}-config)
+        mark_as_advanced(${name}_CONFIG_EXECUTABLE)
+        find_program(${name}_SH_EXECUTABLE NAMES sh)
+        mark_as_advanced(${name}_SH_EXECUTABLE)
+
+        if(${name}_CONFIG_EXECUTABLE)
+            macro(config_script_fail errcode)
+                if(${errcode})
+                    message(FATAL_ERROR "Error invoking ${ARGS_CONFIG_SCRIPT_NAME}-config: ${errcode}")
+                endif(${errcode})
+            endmacro(config_script_fail)
+            file(TO_NATIVE_PATH "${${name}_CONFIG_EXECUTABLE}" ${name}_CONFIG_EXECUTABLE)
+            file(TO_NATIVE_PATH "${${name}_SH_EXECUTABLE}" ${name}_SH_EXECUTABLE)
+
+            execute_process(COMMAND "${${name}_SH_EXECUTABLE}" "${${name}_CONFIG_EXECUTABLE}" --version
+                            OUTPUT_VARIABLE ${name}_VERSION
+                            RESULT_VARIABLE ERRCODE
+                            OUTPUT_STRIP_TRAILING_WHITESPACE)
+            config_script_fail(${ERRCODE})
+
+            execute_process(COMMAND "${${name}_SH_EXECUTABLE}" "${${name}_CONFIG_EXECUTABLE}" --api-version
+                            OUTPUT_VARIABLE ${name}_API_VERSION
+                            RESULT_VARIABLE ERRCODE
+                            OUTPUT_STRIP_TRAILING_WHITESPACE)
+            config_script_fail(${ERRCODE})
+
+            execute_process(COMMAND "${${name}_SH_EXECUTABLE}" "${${name}_CONFIG_EXECUTABLE}" --cflags
+                            OUTPUT_VARIABLE ${name}_CFLAGS
+                            RESULT_VARIABLE ERRCODE
+                            OUTPUT_STRIP_TRAILING_WHITESPACE)
+            config_script_fail(${ERRCODE})
+
+            execute_process(COMMAND "${${name}_SH_EXECUTABLE}" "${${name}_CONFIG_EXECUTABLE}" --libs
+                            OUTPUT_VARIABLE ${name}_LDFLAGS
+                            RESULT_VARIABLE ERRCODE
+                            OUTPUT_STRIP_TRAILING_WHITESPACE)
+            config_script_fail(${ERRCODE})
+
+            string(TOLOWER ${name} "${name}_LOWER")
+            string(REGEX REPLACE "^(.* |)-l([^ ]*${${name}_LOWER}[^ ]*)( .*|)$" "\\2" ${name}_LIBRARY_NAME "${${name}_LDFLAGS}")
+            string(REGEX REPLACE "^(.* |)-L([^ ]*)( .*|)$" "\\2" ${name}_LIBRARY_DIRS "${${name}_LDFLAGS}")
+            find_library(${name}_LIBRARY ${${name}_LIBRARY_NAME} HINTS ${${name}_LIBRARY_DIRS})
+            mark_as_advanced(${name}_LIBRARY)
+            unset(${name}_LIBRARY_NAME)
+            unset(${name}_LIBRARY_DIRS)
+
+            if(NOT TARGET ${name}_LOWER)
+                add_library(${name}_LOWER INTERFACE IMPORTED)
+                set_property(TARGET ${name}_LOWER PROPERTY INTERFACE_LINK_LIBRARIES "${${name}_LDFLAGS}")
+                set_property(TARGET ${name}_LOWER PROPERTY INTERFACE_COMPILE_OPTIONS "${${name}_CFLAGS}")
+            endif(NOT TARGET ${name}_LOWER)
+        endif(${name}_CONFIG_EXECUTABLE)
+    endif(${name}_PKG_CONFIG_FOUND)
+endfunction()