ENH: better backwards compatibility, and deprecate PKGCONFIG

Modules/FindPkgConfig.cmake

@@ -355,31 +355,6 @@ macro(pkg_search_module _prefix _module0)
   endif(NOT DEFINED __pkg_config_checked_${_prefix} OR __pkg_config_checked_${_prefix} LESS ${PKG_CONFIG_VERSION})  
 endmacro(pkg_search_module)
 
-### 
-macro(PKGCONFIG _package _include_DIR _link_DIR _link_FLAGS _cflags)
-  message(STATUS "WARNING: you are using the obsolete 'PKGCONFIG' macro")
-  _pkg_check_modules_internal(0 0 _PKGCONFIG_TMP "${_package}")
-  if (_PKGCONFIG_TMP_FOUND)
-    # To be compatible with obsolete module must return blank-delimited strings.
-    # Also, lead with a blank (for TRUE/FALSE compatibility, 2.4.4 appears to
-    # have returned a blank sometimes followed by nl for the situation
-    # where the pkg-config  module has been found [e.g., _PKGCONFIG_TMP_FOUND]
-    # but does not define the desired quantity.
-    string(REGEX REPLACE ";" " " ${_include_DIR} " ${_PKGCONFIG_TMP_INCLUDE_DIRS}")
-    string(REGEX REPLACE ";" " " ${_link_DIR}    " ${_PKGCONFIG_TMP_LIBRARY_DIRS}")
-    string(REGEX REPLACE ";" " " ${_link_FLAGS}  " ${_PKGCONFIG_TMP_LDFLAGS}")
-    string(REGEX REPLACE ";" " " ${_cflags}      " ${_PKGCONFIG_TMP_CFLAGS}")
-    set(_return_VALUE 0)
-  else(_PKGCONFIG_TMP_FOUND)
-    set(${_include_DIR})
-    set(${_link_DIR})
-    set(${_link_FLAGS})
-    set(${_cflags})
-    set(_return_VALUE 1)
-  endif(_PKGCONFIG_TMP_FOUND)
-endmacro(PKGCONFIG)
-
-
 ### Local Variables:
 ### mode: cmake
 ### End:

Modules/UsePkgConfig.cmake

@@ -1,6 +1,6 @@
 # - obsolete pkg-config module for CMake
 #
-# Includes FindPkgConfig.cmake which defines 
+# Defines the following macros:
 #
 # PKGCONFIG(package includedir libdir linkflags cflags)
 #
@@ -10,11 +10,39 @@
 # variable will be empty when the function returns, otherwise they will contain the respective information
 #
 
-INCLUDE(FindPkgConfig)
-# Retain backwards compatibility with old PKGCONFIG_EXECUTABLE name.
-IF(PKG_CONFIG_EXECUTABLE)
-  SET(PKGCONFIG_EXECUTABLE ${PKG_CONFIG_EXECUTABLE})
-ELSE(PKG_CONFIG_EXECUTABLE)
-  SET(PKGCONFIG_EXECUTABLE PKGCONFIG_EXECUTABLE-NOTFOUND)
-ENDIF(PKG_CONFIG_EXECUTABLE)
 
+
+FIND_PROGRAM(PKGCONFIG_EXECUTABLE NAMES pkg-config PATHS /usr/local/bin )
+
+MACRO(PKGCONFIG _package _include_DIR _link_DIR _link_FLAGS _cflags)
+  message(STATUS
+    "WARNING: you are using the obsolete 'PKGCONFIG' macro use FindPkgConfig")
+# reset the variables at the beginning
+  SET(${_include_DIR})
+  SET(${_link_DIR})
+  SET(${_link_FLAGS})
+  SET(${_cflags})
+
+  # if pkg-config has been found
+  IF(PKGCONFIG_EXECUTABLE)
+
+    EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --exists RETURN_VALUE _return_VALUE OUTPUT_VARIABLE _pkgconfigDevNull )
+
+    # and if the package of interest also exists for pkg-config, then get the information
+    IF(NOT _return_VALUE)
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --variable=includedir OUTPUT_VARIABLE ${_include_DIR} )
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --variable=libdir OUTPUT_VARIABLE ${_link_DIR} )
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --libs OUTPUT_VARIABLE ${_link_FLAGS} )
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --cflags OUTPUT_VARIABLE ${_cflags} )
+
+    ENDIF(NOT _return_VALUE)
+
+  ENDIF(PKGCONFIG_EXECUTABLE)
+
+ENDMACRO(PKGCONFIG _include_DIR _link_DIR _link_FLAGS _cflags)
+
+MARK_AS_ADVANCED(PKGCONFIG_EXECUTABLE)