Fix build error under clang on Mac

- Remove APPLE_CLANG_WARNINGS option
- Add warnings via flags instead of definitions

CMakeLists.txt

@@ -117,10 +117,6 @@ ENDIF (WITH_GLOBE)
 # Compile flag. Make it possible to turn it off.
 SET (PEDANTIC TRUE CACHE BOOL "Determines if we should compile in pedantic mode.")
 
-# whether the compiler front-end is clang on Apple (Mac OS X 10.7+)
-SET (APPLE_CLANG (APPLE AND "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang"))
-SET (APPLE_CLANG_WARNINGS TRUE CACHE BOOL "Whether to show extra compiler warnings on Mac from clang front-end not shown in gcc front-end builds")
-
 # whether unit tests should be build
 SET (ENABLE_TESTS TRUE CACHE BOOL "Build unit tests?")
 
@@ -308,13 +304,24 @@ IF (PEDANTIC)
     ADD_DEFINITIONS( /wd4610 )  # user defined constructor required (sqlite3_index_info)
     ADD_DEFINITIONS( /wd4706 )  # assignment within conditional expression (pal)
   ELSE (MSVC)
-    ADD_DEFINITIONS( -Wall -Wextra -Wno-long-long -Wformat-security -Wno-strict-aliasing )
+    IF (APPLE)
+      # add warnings via flags instead of definitions on Mac (otherwise -Wall can not be overridden per language)
+      SET(_warnings "-Wall -Wextra -Wno-long-long -Wformat-security -Wno-strict-aliasing")
+      SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_warnings}")
+      SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_warnings}")
+    ELSE (APPLE)
+      ADD_DEFINITIONS( -Wall -Wextra -Wno-long-long -Wformat-security -Wno-strict-aliasing )
+    ENDIF (APPLE)
     # Qt produces lots of warnings with strict aliasing (as of Qt 4.4.0 & GCC 4.3)
     # There are redundant declarations in Qt and GDAL
     # ADD_DEFINITIONS( -fstrict-aliasing -Wstrict-aliasing=1 -Wredundant-decls )
 
     IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-      ADD_DEFINITIONS(-Wno-return-type-c-linkage) # used in plugins and providers
+      IF (APPLE)
+        SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-return-type-c-linkage")
+      ELSE (APPLE)
+        ADD_DEFINITIONS(-Wno-return-type-c-linkage) # used in plugins and providers
+      ENDIF (APPLE)
     ENDIF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
   ENDIF (MSVC)
 

src/plugins/grass/CMakeLists.txt

@@ -11,10 +11,6 @@ ELSE (WIN32)
   ADD_DEFINITIONS(-DHAVE_POSIX_OPENPT)
 ENDIF (WIN32)
 
-IF (APPLE_CLANG AND NOT APPLE_CLANG_WARNINGS)
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-mismatched-tags ")
-ENDIF (APPLE_CLANG AND NOT APPLE_CLANG_WARNINGS)
-
 ########################################################
 # Files