Changed: #1111 Create a CMake macro to check if we should link to an external lib or not

code/CMakeModules/CheckDepends.cmake

@@ -1,20 +1,5 @@
 # Macros to check if a library needs to be manually linked to another one
 # because it's using a symbol from it but it's not linked to
-#
-# Syntax:
-# CHECK_DEPENDS(MYLIBRARY OTHERLIBRARY SYMBOL MUSTLINK)
-#
-# Sets the following variables:
-#   XYZ_LIBRARY_MUSTLINK
-#
-# Example:
-# Check if we need to explicitly link to libz with libpng
-# CHECK_DEPENDS(PNG_LIBRARY ZLIB_LIBRARY inflate)
-# objdump -p /usr/lib/libwwwxml.so | grep expat
-# objdump -T /usr/lib/libwwwxml.so | grep "*UND*" | grep XML_ParserCreate
-# objdump -p <lib> | grep <libray>
-# objdump -T <lib> | grep "*UND*" | grep <function>
-#
 
 # CHECK_UNDEFINED_SYMBOL
 # Macro to check if a library is calling an undefined symbol
@@ -35,15 +20,24 @@ MACRO(CHECK_UNDEFINED_SYMBOL MYLIBRARY SYMBOL SYMBOL_FOUND)
   ELSEIF(UNIX)
     IF(CMAKE_OBJDUMP)
       # Use objdump to check if a library is using an external symbol
-      EXEC_PROGRAM(${CMAKE_OBJDUMP} ARGS "-T ${MYLIBRARY} | grep ${SYMBOL}" OUTPUT_VARIABLE OBJDUMP_SYMBOL)
-      message(STATUS "OBJDUMP_SYMBOL = ${OBJDUMP_SYMBOL}")
+      EXEC_PROGRAM(${CMAKE_OBJDUMP} ARGS "-T ${${MYLIBRARY}} | grep ${SYMBOL}" OUTPUT_VARIABLE OBJDUMP_SYMBOL)
       IF(NOT OBJDUMP_SYMBOL MATCHES "UND")
         SET(${SYMBOL_FOUND} FALSE)
-      ENDIF(OBJDUMP_SYMBOL MATCHES "UND")
+      ENDIF(NOT OBJDUMP_SYMBOL MATCHES "UND")
     ENDIF(CMAKE_OBJDUMP)
   ENDIF(WIN32)
 ENDMACRO(CHECK_UNDEFINED_SYMBOL)
 
+# CHECK_LINKED_LIBRARY
+# Macro to check if a library is linked to another one
+#
+# Syntax:
+# CHECK_LINKED_LIBRARY(MYLIBRARY OTHERLIBRARY LIBRARY_FOUND)
+# LIBRARY_FOUND will be set to TRUE or FALSE
+#
+# Example:
+# CHECK_LINKED_LIBRARY(PNG_LIBRARY ZLIB_LIBRARY ZLIB_FOUND)
+#
 MACRO(CHECK_LINKED_LIBRARY MYLIBRARY OTHERLIBRARY LIBRARY_FOUND)
   SET(${LIBRARY_FOUND} FALSE)
   IF(WIN32)
@@ -52,8 +46,9 @@ MACRO(CHECK_LINKED_LIBRARY MYLIBRARY OTHERLIBRARY LIBRARY_FOUND)
     # TODO: use otool to detect if a library is using a symbol
   ELSEIF(UNIX)
     IF(CMAKE_OBJDUMP)
+      GET_FILENAME_COMPONENT(LIBNAME ${${OTHERLIBRARY}} NAME)
       # Use objdump to check if a library is linked to another library
-      EXEC_PROGRAM(${CMAKE_OBJDUMP} ARGS "-p ${MYLIBRARY} | grep ${OTHERLIBRARY}" OUTPUT_VARIABLE OBJDUMP_LIBRARY)
+      EXEC_PROGRAM(${CMAKE_OBJDUMP} ARGS "-p ${${MYLIBRARY}} | grep ${LIBNAME}" OUTPUT_VARIABLE OBJDUMP_LIBRARY)
       IF(OBJDUMP_LIBRARY MATCHES "NEEDED")
         SET(${LIBRARY_FOUND} TRUE)
       ENDIF(OBJDUMP_LIBRARY MATCHES "NEEDED")
@@ -75,6 +70,16 @@ MACRO(CHECK_DEPENDS MYLIBRARY OTHERLIBRARY SYMBOL MUSTLINK)
   ENDIF(SYMBOL_FOUND AND NOT LIBRARY_FOUND)
 ENDMACRO(CHECK_DEPENDS)
 
+# LINK_DEPENDS
+# Macro to link a library if a symbol is used but is not already linked to it
+#
+# Syntax:
+# LINK_DEPENDS(LIBRARIES MYLIBRARY OTHERLIBRARY SYMBOL)
+# OTHERLIBRARY_LINKED will be set to TRUE or FALSE
+#
+# Example:
+# LINK_DEPENDS(PNG_LIBRARIES PNG_LIBRARY ZLIB_LIBRARY inflate)
+#
 MACRO(LINK_DEPENDS LIBRARIES MYLIBRARY OTHERLIBRARY SYMBOL)
   SET(MUST_LINK FALSE)
   IF(${MYLIBRARY} AND ${OTHERLIBRARY} AND NOT ${OTHERLIBRARY}_LINKED)
@@ -88,7 +93,6 @@ MACRO(LINK_DEPENDS LIBRARIES MYLIBRARY OTHERLIBRARY SYMBOL)
         CHECK_LINKED_LIBRARY(${MYLIBRARY} ${OTHERLIBRARY} LIBRARY_FOUND)
       ENDIF(SYMBOL_FOUND)
 
-#      CHECK_DEPENDS(${MYLIBRARY} ${${OTHERLIBRARY}} ${SYMBOL} MUST_LINK)
       IF(SYMBOL_FOUND AND NOT LIBRARY_FOUND)
         MESSAGE(STATUS "Underlinking found: ${${MYLIBRARY}} needs ${${OTHERLIBRARY}} but is not linked to, manually linking...")
         SET(MUST_LINK TRUE)
@@ -97,7 +101,9 @@ MACRO(LINK_DEPENDS LIBRARIES MYLIBRARY OTHERLIBRARY SYMBOL)
   ENDIF(${MYLIBRARY} AND ${OTHERLIBRARY} AND NOT ${OTHERLIBRARY}_LINKED)
   IF(MUST_LINK)
     MESSAGE(STATUS "Linking with ${${OTHERLIBRARY}}")
-    SET(${OTHERLIBRARY}_LINKED TRUE)
     SET(${LIBRARIES} ${${LIBRARIES}} ${${OTHERLIBRARY}})
   ENDIF(MUST_LINK)
+  IF(LIBRARY_FOUND)
+    SET(${OTHERLIBRARY}_LINKED TRUE)
+  ENDIF(LIBRARY_FOUND)
 ENDMACRO(LINK_DEPENDS)