Enhance pkg-config generation for interface libraries and Windows compatibility

CMake/GeneratePkgConfig.cmake

@@ -8,12 +8,13 @@ function(get_relative_link OUTPUT PATH)
   get_filename_component(NAME "${PATH}" NAME_WE)
   if (IS_ABSOLUTE ${PATH})
     get_filename_component(DIRECTORY_NAME "${PATH}" DIRECTORY)
-    if (WIN32)
-      set(${OUTPUT} "-l\"${DIRECTORY_NAME}/${NAME}\"" PARENT_SCOPE)
-    else()
-      get_filename_component(FULL_NAME "${PATH}" NAME)
-      set(${OUTPUT} "-L\"${DIRECTORY_NAME}\" -l:${FULL_NAME}" PARENT_SCOPE)
+    get_filename_component(FULL_NAME "${PATH}" NAME)
+    string(REGEX REPLACE "^lib([^.]+).*$" "\\1" LIB_NAME "${FULL_NAME}")
+    # If the regex didn't match (no lib prefix), fall back to name without extension
+    if ("${LIB_NAME}" STREQUAL "${FULL_NAME}")
+      set(LIB_NAME "${NAME}")
     endif()
+    set(${OUTPUT} "-L\"${DIRECTORY_NAME}\" -l${LIB_NAME}" PARENT_SCOPE)
     return()
   endif()
 
@@ -31,17 +32,58 @@ function(generate_pkgconfig TARGET DESCRIPTION)
   # message("Generating pkg-config for ${TARGET}")
   get_filename_component(PREFIX "${CMAKE_INSTALL_PREFIX}" REALPATH)
 
-  get_target_property(LIST "${TARGET}" LINK_LIBRARIES)
+  get_target_property(LIBRARY_TYPE "${TARGET}" TYPE)
+  if ("${LIBRARY_TYPE}" STREQUAL "INTERFACE_LIBRARY")
+    get_target_property(LIST "${TARGET}" INTERFACE_LINK_LIBRARIES)
+  else()
+    get_target_property(LIST "${TARGET}" LINK_LIBRARIES)
+  endif()
+
+  if ("${LIST}" STREQUAL "LIST-NOTFOUND")
+    set(LIST "")
+  endif()
+
+  set(INTERFACE_LIBS "")
+  if ("${LIBRARY_TYPE}" STREQUAL "INTERFACE_LIBRARY")
+    set(PROPAGATED "")
+    foreach (DEP ${LIST})
+      if (TARGET "${DEP}")
+        get_target_property(DEP_TYPE "${DEP}" TYPE)
+        if ("${DEP_TYPE}" STREQUAL "STATIC_LIBRARY" OR "${DEP_TYPE}" STREQUAL "SHARED_LIBRARY")
+          list(APPEND INTERFACE_LIBS "${DEP}")
+          get_target_property(DEP_LIBS "${DEP}" LINK_LIBRARIES)
+          if (NOT "${DEP_LIBS}" STREQUAL "DEP_LIBS-NOTFOUND")
+            list(APPEND PROPAGATED ${DEP_LIBS})
+          endif()
+        else()
+          list(APPEND PROPAGATED "${DEP}")
+        endif()
+      else()
+        list(APPEND PROPAGATED "${DEP}")
+      endif()
+    endforeach()
+    if (PROPAGATED)
+      list(REMOVE_DUPLICATES PROPAGATED)
+    endif()
+    set(LIST "${PROPAGATED}")
+  endif()
+
   set(REQS "")
   set(LIBS "")
   foreach (LIB ${LIST})
     if (TARGET "${LIB}")
+      if ("${LIBRARY_TYPE}" STREQUAL "SHARED_LIBRARY")
+        get_target_property(LIB_TYPE "${LIB}" TYPE)
+        if ("${LIB_TYPE}" STREQUAL "STATIC_LIBRARY")
+          continue()
+        endif()
+      endif()
       set(HAS_REQS 1)
       list(APPEND REQS "${LIB}")
     else()
       set(HAS_LIBS 1)
       get_relative_link(LINK "${LIB}")
-      if (NOT LINK EQUAL "")
+      if (NOT "${LINK}" STREQUAL "")
         list(APPEND LIBS "${LINK}")
       endif()
     endif()
@@ -77,22 +119,50 @@ function(generate_pkgconfig TARGET DESCRIPTION)
   endif()
 
   file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/pkgconfig")
+
+  get_target_property(TARGET_OUTPUT_NAME "${TARGET}" OUTPUT_NAME)
+  if ("${TARGET_OUTPUT_NAME}" STREQUAL "TARGET_OUTPUT_NAME-NOTFOUND")
+    set(TARGET_OUTPUT_NAME "${TARGET}")
+  endif()
+
+  if ("${LIBRARY_TYPE}" STREQUAL "INTERFACE_LIBRARY")
+    set(LIBS_LINE "")
+    foreach (ILIB ${INTERFACE_LIBS})
+      get_target_property(ILIB_OUTPUT_NAME "${ILIB}" OUTPUT_NAME)
+      if ("${ILIB_OUTPUT_NAME}" STREQUAL "ILIB_OUTPUT_NAME-NOTFOUND")
+        set(ILIB_OUTPUT_NAME "${ILIB}")
+      endif()
+      set(LIBS_LINE "${LIBS_LINE} -l${ILIB_OUTPUT_NAME}")
+    endforeach()
+    set(LIBS_LINE "Libs: -L\"${PKGCONFIG_LIBDIR}\"${LIBS_LINE}")
+  else()
+    set(LIBS_LINE "Libs: -L\"${PKGCONFIG_LIBDIR}\" -l${TARGET_OUTPUT_NAME}")
+  endif()
+
+  get_target_property(_td_iface_defs "${TARGET}" INTERFACE_COMPILE_DEFINITIONS)
+  set(CFLAGS_DEFS "")
+  if (NOT "${_td_iface_defs}" STREQUAL "_td_iface_defs-NOTFOUND")
+    foreach(_def ${_td_iface_defs})
+      string(APPEND CFLAGS_DEFS " -D${_def}")
+    endforeach()
+    unset(_def)
+  endif()
+  unset(_td_iface_defs)
+
   file(GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/pkgconfig/${TARGET}.pc" CONTENT
 "prefix=${PREFIX}
 
 Name: ${TARGET}
 Description: ${DESCRIPTION}
 Version: ${PROJECT_VERSION}
 
-CFlags: -I\"${PKGCONFIG_INCLUDEDIR}\"
-Libs: -L\"${PKGCONFIG_LIBDIR}\" -l${TARGET}
+CFlags: -I\"${PKGCONFIG_INCLUDEDIR}\"${CFLAGS_DEFS}
+${LIBS_LINE}
 ${REQUIRES}${LIBRARIES}")
 
-  get_target_property(LIBRARY_TYPE "${TARGET}" TYPE)
-  if (LIBRARY_TYPE STREQUAL "STATIC_LIBRARY" OR LIBRARY_TYPE STREQUAL "SHARED_LIBRARY")
+  if ("${LIBRARY_TYPE}" STREQUAL "STATIC_LIBRARY" OR "${LIBRARY_TYPE}" STREQUAL "SHARED_LIBRARY" OR
+      "${LIBRARY_TYPE}" STREQUAL "INTERFACE_LIBRARY")
     install(FILES "${CMAKE_CURRENT_BINARY_DIR}/pkgconfig/${TARGET}.pc" DESTINATION "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
-  elseif (LIBRARY_TYPE STREQUAL "INTERFACE_LIBRARY")
-    # TODO: support interface libraries
   else()
     message(FATAL_ERROR "Don't know how to handle ${TARGET} of type ${LIBRARY_TYPE}")
   endif()