From 4a0e5463281748ea23e5895e364be1f8559abe55 Mon Sep 17 00:00:00 2001 From: kervala Date: Sat, 2 Oct 2010 14:21:45 +0200 Subject: [PATCH] Changed: #1111 Create a CMake macro to check if we should link to an external lib or not --- code/CMakeModules/CheckDepends.cmake | 103 +++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 code/CMakeModules/CheckDepends.cmake diff --git a/code/CMakeModules/CheckDepends.cmake b/code/CMakeModules/CheckDepends.cmake new file mode 100644 index 000000000..be90e271e --- /dev/null +++ b/code/CMakeModules/CheckDepends.cmake @@ -0,0 +1,103 @@ +# 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 | grep +# objdump -T | grep "*UND*" | grep +# + +# CHECK_UNDEFINED_SYMBOL +# Macro to check if a library is calling an undefined symbol +# +# Syntax: +# CHECK_UNDEFINED_SYMBOL(MYLIBRARY SYMBOL SYMBOL_FOUND) +# SYMBOL_FOUND will be set to TRUE or FALSE +# +# Example: +# CHECK_UNDEFINED_SYMBOL(PNG_LIBRARY inflate INFLATE_FOUND) +# +MACRO(CHECK_UNDEFINED_SYMBOL MYLIBRARY SYMBOL SYMBOL_FOUND) + SET(${SYMBOL_FOUND} TRUE) + IF(WIN32) + # Always TRUE under Windows because we are using static libraries + ELSEIF(APPLE) + # TODO: use otool to detect if a library is using a symbol + ELSEIF(UNIX) + IF(CMAKE_OBJDUMP) + # Use objdump to check if a library is using an external symbol + EXEC_PROGRAM(${CMAKE_OBJDUMP} ARGS "-T ${MYLIBRARY} | grep ${SYMBOL}" OUTPUT_VARIABLE OBJDUMP_SYMBOL) + message(STATUS "OBJDUMP_SYMBOL = ${OBJDUMP_SYMBOL}") + IF(NOT OBJDUMP_SYMBOL MATCHES "UND") + SET(${SYMBOL_FOUND} FALSE) + ENDIF(OBJDUMP_SYMBOL MATCHES "UND") + ENDIF(CMAKE_OBJDUMP) + ENDIF(WIN32) +ENDMACRO(CHECK_UNDEFINED_SYMBOL) + +MACRO(CHECK_LINKED_LIBRARY MYLIBRARY OTHERLIBRARY LIBRARY_FOUND) + SET(${LIBRARY_FOUND} FALSE) + IF(WIN32) + # Always FALSE under Windows because we are using static libraries + ELSEIF(APPLE) + # TODO: use otool to detect if a library is using a symbol + ELSEIF(UNIX) + IF(CMAKE_OBJDUMP) + # Use objdump to check if a library is linked to another library + EXEC_PROGRAM(${CMAKE_OBJDUMP} ARGS "-p ${MYLIBRARY} | grep ${OTHERLIBRARY}" OUTPUT_VARIABLE OBJDUMP_LIBRARY) + IF(OBJDUMP_LIBRARY MATCHES "NEEDED") + SET(${LIBRARY_FOUND} TRUE) + ENDIF(OBJDUMP_LIBRARY MATCHES "NEEDED") + ENDIF(CMAKE_OBJDUMP) + ENDIF(WIN32) +ENDMACRO(CHECK_LINKED_LIBRARY) + +MACRO(CHECK_DEPENDS MYLIBRARY OTHERLIBRARY SYMBOL MUSTLINK) + CHECK_UNDEFINED_SYMBOL(MYLIBRARY SYMBOL SYMBOL_FOUND) + + IF(SYMBOL_FOUND) + CHECK_LINKED_LIBRARY(MYLIBRARY OTHERLIBRARY LIBRARY_FOUND) + ENDIF(SYMBOL_FOUND) + + IF(SYMBOL_FOUND AND NOT LIBRARY_FOUND) + SET(${MUSTLINK} YES) + ELSE(SYMBOL_FOUND AND NOT LIBRARY_FOUND) + SET(${MUSTLINK} NO) + ENDIF(SYMBOL_FOUND AND NOT LIBRARY_FOUND) +ENDMACRO(CHECK_DEPENDS) + +MACRO(LINK_DEPENDS LIBRARIES MYLIBRARY OTHERLIBRARY SYMBOL) + SET(MUST_LINK FALSE) + IF(${MYLIBRARY} AND ${OTHERLIBRARY} AND NOT ${OTHERLIBRARY}_LINKED) + IF(WIN32 OR WITH_STATIC) + # In static, we link all libraries because it will keep only used symbols + SET(MUST_LINK TRUE) + ELSE(WIN32 OR WITH_STATIC) + CHECK_UNDEFINED_SYMBOL(${MYLIBRARY} ${SYMBOL} SYMBOL_FOUND) + + IF(SYMBOL_FOUND) + CHECK_LINKED_LIBRARY(${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) + ENDIF(SYMBOL_FOUND AND NOT LIBRARY_FOUND) + ENDIF(WIN32 OR WITH_STATIC) + 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) +ENDMACRO(LINK_DEPENDS)