ENH: add second failure message parameter to

FIND_PACKAGE_HANDLE_STANDARD_ARGS(), so cmake modules can specify their own
better failure messages. If the default is ok use "DEFAULT_MSG".
Do this also for FindBoost.cmake (#5349)

Alex

1 files changed, 16 insertions, 6 deletions

diff --git a/Modules/FindPackageHandleStandardArgs.cmake b/Modules/FindPackageHandleStandardArgs.cmake
index dcb9ff4..3f5156c 100644
--- a/Modules/FindPackageHandleStandardArgs.cmake
+++ b/Modules/FindPackageHandleStandardArgs.cmake
@@ -1,20 +1,30 @@
-# FIND_PACKAGE_HANDLE_STANDARD_ARGS(NAME VAR ... )
+# FIND_PACKAGE_HANDLE_STANDARD_ARGS(NAME (DEFAULT_MSG|"Custom failure message") VAR1 ... )
 #    This macro is intended to be used in FindXXX.cmake modules files.
 #    It handles the REQUIRED and QUIET argument to FIND_PACKAGE() and
 #    it also sets the <UPPERCASED_NAME>_FOUND variable.
 #    The package is found if all variables listed are TRUE.
 #    Example:
 #
-#    FIND_PACKAGE_HANDLE_STANDARD_ARGS(LibXml2 LIBXML2_LIBRARIES LIBXML2_INCLUDE_DIR)
+#    FIND_PACKAGE_HANDLE_STANDARD_ARGS(LibXml2 DEFAULT_MSG LIBXML2_LIBRARIES LIBXML2_INCLUDE_DIR)
 #
 #    LibXml2 is considered to be found, if both LIBXML2_LIBRARIES and 
 #    LIBXML2_INCLUDE_DIR are valid. Then also LIBXML2_FOUND is set tto TRUE.
 #    If it is not found and REQUIRED was used, it fails with FATAL_ERROR, 
 #    independent whether QUIET was used or not.
-#    If it is found, the location is reported using the VAR argument, so 
+#    If it is found, the location is reported using the VAR1 argument, so 
 #    here a message "Found LibXml2: /usr/lib/libxml2.so" will be printed out.
+#    If the second argument is DEFAULT_MSG, the message in the failure case will 
+#    be "Could NOT find LibXml2", if you don't like this message you can specify
+#    your own custom failure message there.
+
+MACRO(FIND_PACKAGE_HANDLE_STANDARD_ARGS _NAME _FAIL_MSG _VAR1 )
+
+  IF("${_FAIL_MSG}" STREQUAL "DEFAULT_MSG")
+    SET(_FAIL_MESSAGE "Could NOT find ${_NAME}")
+  ELSE("${_FAIL_MSG}" STREQUAL "DEFAULT_MSG")
+    SET(_FAIL_MESSAGE "${_FAIL_MSG}")
+  ENDIF("${_FAIL_MSG}" STREQUAL "DEFAULT_MSG")
 
-MACRO(FIND_PACKAGE_HANDLE_STANDARD_ARGS _NAME _VAR1 )
   STRING(TOUPPER ${_NAME} _NAME_UPPER)
 
   SET(${_NAME_UPPER}_FOUND TRUE)
@@ -34,10 +44,10 @@ MACRO(FIND_PACKAGE_HANDLE_STANDARD_ARGS _NAME _VAR1 )
     ENDIF (NOT ${_NAME}_FIND_QUIETLY)
   ELSE (${_NAME_UPPER}_FOUND)
     IF (${_NAME}_FIND_REQUIRED)
-        MESSAGE(FATAL_ERROR "Could NOT find ${_NAME}")
+        MESSAGE(FATAL_ERROR "${_FAIL_MESSAGE}")
     ELSE (${_NAME}_FIND_REQUIRED)
       IF (NOT ${_NAME}_FIND_QUIETLY)
-        MESSAGE(STATUS "Could NOT find ${_NAME}")
+        MESSAGE(STATUS "${_FAIL_MESSAGE}")
       ENDIF (NOT ${_NAME}_FIND_QUIETLY)
     ENDIF (${_NAME}_FIND_REQUIRED)
   ENDIF (${_NAME_UPPER}_FOUND)