Use pkg-config to support finding libraries

Using pkg-config helps to find libraries on systems where these libraries
are installed in non-standard locations.

cmake/FindAvahi.cmake

@@ -5,17 +5,44 @@
 #  AVAHI_INCLUDE_DIRS   - the avahi include directories
 #  AVAHI_LIBRARIES      - The libraries needed to use avahi
 
+# use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+find_package(PkgConfig)
 
-find_library(AVAHI_COMMON_LIB avahi-common PATHS ${COMMON_LIB_DIR})
-find_library(AVAHI_CLIENT_LIB avahi-client PATHS ${CLIENT_LIB_DIR})
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(_AVAHI avahi-client)
+endif(PKG_CONFIG_FOUND)
+
+find_library(AVAHI_COMMON_LIB NAMES avahi-common
+    PATHS
+    ${_AVAHI_LIBRARY_DIRS}
+    ${COMMON_LIB_DIR}
+)
+
+find_library(AVAHI_CLIENT_LIB NAMES avahi-client
+    PATHS
+    ${_AVAHI_LIBRARY_DIRS}
+    ${CLIENT_LIB_DIR}
+)
 
 if(AVAHI_COMMON_LIB AND AVAHI_CLIENT_LIB)
     set(AVAHI_LIBRARIES ${AVAHI_COMMON_LIB} ${AVAHI_CLIENT_LIB})
     message(STATUS "Avahi-Libs found: ${AVAHI_LIBRARIES}")
 endif()
 
-find_path(COMMON_INCLUDE_DIR watch.h  PATH_SUFFIXES avahi-common HINTS ${COMMON_INCLUDE_DIR})
-find_path(CLIENT_INCLUDE_DIR client.h PATH_SUFFIXES avahi-client HINTS ${CLIENT_INCLUDE_DIR})
+find_path(COMMON_INCLUDE_DIR watch.h
+    PATH_SUFFIXES avahi-common
+    PATHS
+    ${_AVAHI_INCLUDE_DIRS}
+    ${COMMON_INCLUDE_DIR}
+)
+
+find_path(CLIENT_INCLUDE_DIR client.h
+    PATH_SUFFIXES avahi-client
+    PATHS
+    ${_AVAHI_INCLUDE_DIRS}
+    ${CLIENT_INCLUDE_DIR}
+)
 
 if(COMMON_INCLUDE_DIR AND CLIENT_INCLUDE_DIR)
     set(AVAHI_INCLUDE_DIRS ${COMMON_INCLUDE_DIR} ${CLIENT_INCLUDE_DIR})

cmake/FindCDDB.cmake

@@ -1,12 +1,26 @@
 # - Try to find CDDB
 # Once done this will define
 #
-#  CDDB_FOUND - system has UDev
-#  CDDB_INCLUDE_DIR - the libudev include directory
-#  CDDB_LIBS - The libudev libraries
+#  CDDB_FOUND - system has CDDB
+#  CDDB_INCLUDE_DIR - the libcddb include directory
+#  CDDB_LIBS - The libcddb libraries
 
-find_path(CDDB_INCLUDE_DIR cddb/cddb.h)
-find_library(CDDB_LIBS cddb)
+# use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+find_package(PkgConfig)
+
+if(PKG_CONFIG_FOUND)
+    pkg_check_modules(_CDDB libcddb)
+endif(PKG_CONFIG_FOUND)
+
+find_path(CDDB_INCLUDE_DIR cddb/cddb.h
+    ${_CDDB_INCLUDE_DIRS}
+)
+
+find_library(CDDB_LIBS NAMES cddb
+    PATHS
+    ${_CDDB_LIBRARY_DIRS}
+)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(CDDB DEFAULT_MSG CDDB_INCLUDE_DIR CDDB_LIBS)

cmake/FindEbur128.cmake

@@ -6,10 +6,19 @@
 #
 set(EBUR128_FOUND FALSE)
 
+# use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+find_package(PkgConfig)
+
+if(PKG_CONFIG_FOUND)
+  pkg_check_modules(_EBUR128 libebur128)
+endif(PKG_CONFIG_FOUND)
+
 find_path(EBUR128_INCLUDE_DIR ebur128.h
   HINTS
   PATH_SUFFIXES include 
   PATHS
+  ${_EBUR128_INCLUDE_DIRS}
   ~/Library/Frameworks
   /Library/Frameworks
   /usr/local/include
@@ -26,6 +35,7 @@ find_library(EBUR128_LIBRARY
   HINTS
   PATH_SUFFIXES lib64 lib
   PATHS
+  ${_EBUR128_LIBRARY_DIRS}
   /usr/local
   /usr
   /sw

cmake/FindTaglib.cmake

@@ -16,29 +16,25 @@ if(NOT TAGLIB_MIN_VERSION)
   set(TAGLIB_MIN_VERSION "1.6")
 endif(NOT TAGLIB_MIN_VERSION)
 
-if(NOT WIN32)
-    find_program(TAGLIBCONFIG_EXECUTABLE NAMES taglib-config PATHS
-       ${BIN_INSTALL_DIR}
-    )
-endif(NOT WIN32)
-
 #reset vars
 set(TAGLIB_LIBRARIES)
 set(TAGLIB_CFLAGS)
 
-# if taglib-config has been found
-if(TAGLIBCONFIG_EXECUTABLE)
+find_package(PkgConfig)
 
-  exec_program(${TAGLIBCONFIG_EXECUTABLE} ARGS --version RETURN_VALUE _return_VALUE OUTPUT_VARIABLE TAGLIB_VERSION)
+# if pkg-config has been found
+if(PKG_CONFIG_EXECUTABLE)
+
+  exec_program(${PKG_CONFIG_EXECUTABLE} ARGS --modversion taglib RETURN_VALUE _return_VALUE OUTPUT_VARIABLE TAGLIB_VERSION)
 
   if(TAGLIB_VERSION VERSION_LESS "${TAGLIB_MIN_VERSION}")
      message(STATUS "TagLib version too old: version searched :${TAGLIB_MIN_VERSION}, found ${TAGLIB_VERSION}")
      set(TAGLIB_FOUND FALSE)
   else(TAGLIB_VERSION VERSION_LESS "${TAGLIB_MIN_VERSION}")
 
-     exec_program(${TAGLIBCONFIG_EXECUTABLE} ARGS --libs RETURN_VALUE _return_VALUE OUTPUT_VARIABLE TAGLIB_LIBRARIES)
+     exec_program(${PKG_CONFIG_EXECUTABLE} ARGS --libs taglib RETURN_VALUE _return_VALUE OUTPUT_VARIABLE TAGLIB_LIBRARIES)
 
-     exec_program(${TAGLIBCONFIG_EXECUTABLE} ARGS --cflags RETURN_VALUE _return_VALUE OUTPUT_VARIABLE TAGLIB_CFLAGS)
+     exec_program(${PKG_CONFIG_EXECUTABLE} ARGS --cflags taglib RETURN_VALUE _return_VALUE OUTPUT_VARIABLE TAGLIB_CFLAGS)
 
      if(TAGLIB_LIBRARIES AND TAGLIB_CFLAGS)
         set(TAGLIB_FOUND TRUE)
@@ -47,7 +43,7 @@ if(TAGLIBCONFIG_EXECUTABLE)
   endif(TAGLIB_VERSION VERSION_LESS "${TAGLIB_MIN_VERSION}") 
   mark_as_advanced(TAGLIB_CFLAGS TAGLIB_LIBRARIES TAGLIB_INCLUDES)
 
-else(TAGLIBCONFIG_EXECUTABLE)
+else(PKG_CONFIG_EXECUTABLE)
 
   find_path(TAGLIB_INCLUDES
     NAMES
@@ -122,13 +118,13 @@ else(TAGLIBCONFIG_EXECUTABLE)
   INCLUDE(FindPackageHandleStandardArgs)
   FIND_PACKAGE_HANDLE_STANDARD_ARGS(Taglib DEFAULT_MSG TAGLIB_INCLUDES TAGLIB_LIBRARIES)
 
-endif(TAGLIBCONFIG_EXECUTABLE)
+endif(PKG_CONFIG_EXECUTABLE)
 
 
 if(TAGLIB_FOUND)
-  if(NOT Taglib_FIND_QUIETLY AND TAGLIBCONFIG_EXECUTABLE)
+  if(NOT Taglib_FIND_QUIETLY AND TAGLIB_LIBRARIES)
     message(STATUS "Taglib found: ${TAGLIB_LIBRARIES}")
-  endif(NOT Taglib_FIND_QUIETLY AND TAGLIBCONFIG_EXECUTABLE)
+  endif(NOT Taglib_FIND_QUIETLY AND TAGLIB_LIBRARIES)
 
   if(NOT WIN32)
     set(TAGLIB_INCLUDES "${TAGLIB_INCLUDES};/usr/local/include")

cmake/FindUDev.cmake

@@ -10,8 +10,19 @@
 # Redistribution and use is allowed according to the terms of the BSD license.
 # For details see the accompanying COPYING-CMAKE-SCRIPTS file.
 
-find_path(UDEV_INCLUDE_DIR libudev.h)
-find_library(UDEV_LIBS udev)
+# use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+include(FindPkgConfig)
+pkg_check_modules(_UDEV libudev)
+
+find_path(UDEV_INCLUDE_DIR libudev.h
+    ${_UDEV_INCLUDE_DIRS}
+)
+
+find_library(UDEV_LIBS NAMES udev
+    PATHS
+    ${_UDEV_LIBRARY_DIRS}
+)
 
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(UDev DEFAULT_MSG UDEV_INCLUDE_DIR UDEV_LIBS)