From 90fced054ef040dd4bdcb83b0cedc1a1045435cb Mon Sep 17 00:00:00 2001
From: felix schwitzer <felix.schwitzer@gmx.at>
Date: Wed, 28 Mar 2012 23:24:39 +0200
Subject: [PATCH] UseSWIG: adjust module name for ruby

adjust the file name for swig generated ruby modules to match the module name
without library prefix; see issue #0012184.
Use the ruby interpreter for module suffix since it is platform dependent.
---
 Modules/UseSWIG.cmake |   42 +++++++++++++++++++++++++++++++++++++-----
 1 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/Modules/UseSWIG.cmake b/Modules/UseSWIG.cmake
index ef76724..22ad8a4 100644
--- a/Modules/UseSWIG.cmake
+++ b/Modules/UseSWIG.cmake
@@ -10,7 +10,7 @@
 # Set Source files properties such as CPLUSPLUS and SWIG_FLAGS to specify
 # special behavior of SWIG. Also global CMAKE_SWIG_FLAGS can be used to add
 # special flags to all swig calls.
-# Another special variable is CMAKE_SWIG_OUTDIR, it allows one to specify 
+# Another special variable is CMAKE_SWIG_OUTDIR, it allows one to specify
 # where to write all the swig generated module (swig -outdir option)
 # The name-specific variable SWIG_MODULE_<name>_EXTRA_DEPS may be used
 # to specify extra dependencies for the generated modules.
@@ -52,7 +52,7 @@ MACRO(SWIG_MODULE_INITIALIZE name language)
     MESSAGE(FATAL_ERROR "SWIG Error: Language \"${language}\" not found")
   ELSEIF("${SWIG_MODULE_${name}_LANGUAGE}" STREQUAL "PYTHON")
     # when swig is used without the -interface it will produce in the module.py
-    # a 'import _modulename' statement, which implies having a corresponding 
+    # a 'import _modulename' statement, which implies having a corresponding
     # _modulename.so (*NIX), _modulename.pyd (Win32).
     SET(SWIG_MODULE_${name}_REAL_NAME "_${name}")
   ELSEIF("${SWIG_MODULE_${name}_LANGUAGE}" STREQUAL "PERL")
@@ -93,13 +93,13 @@ MACRO(SWIG_ADD_SOURCE_TO_MODULE name outfiles infile)
   ENDIF("${swig_source_file_flags}" STREQUAL "NOTFOUND")
   SET(swig_source_file_fullname "${infile}")
   IF(${swig_source_file_path} MATCHES "^${CMAKE_CURRENT_SOURCE_DIR}")
-    STRING(REGEX REPLACE 
+    STRING(REGEX REPLACE
       "^${CMAKE_CURRENT_SOURCE_DIR}" ""
       swig_source_file_relative_path
       "${swig_source_file_path}")
   ELSE(${swig_source_file_path} MATCHES "^${CMAKE_CURRENT_SOURCE_DIR}")
     IF(${swig_source_file_path} MATCHES "^${CMAKE_CURRENT_BINARY_DIR}")
-      STRING(REGEX REPLACE 
+      STRING(REGEX REPLACE
         "^${CMAKE_CURRENT_BINARY_DIR}" ""
         swig_source_file_relative_path
         "${swig_source_file_path}")
@@ -178,13 +178,38 @@ MACRO(SWIG_ADD_SOURCE_TO_MODULE name outfiles infile)
     "${swig_source_file_fullname}"
     MAIN_DEPENDENCY "${swig_source_file_fullname}"
     DEPENDS ${SWIG_MODULE_${name}_EXTRA_DEPS}
-    COMMENT "Swig source") 
+    COMMENT "Swig source")
   SET_SOURCE_FILES_PROPERTIES("${swig_generated_file_fullname}" ${swig_extra_generated_files}
     PROPERTIES GENERATED 1)
   SET(${outfiles} "${swig_generated_file_fullname}" ${swig_extra_generated_files})
 ENDMACRO(SWIG_ADD_SOURCE_TO_MODULE)
 
 #
+# Determine the appropriate ruby module suffix
+# This is platform dependend, therefore use the ruby interpreter to get it
+#
+MACRO(SWIG_RUBY_MODULE_SUFFIX)
+  FIND_PACKAGE(Ruby QUIET)
+  IF(NOT RUBY_EXECUTABLE)
+    MESSAGE(SEND_ERROR "cant find ruby interpreter, skip generating module")
+  ENDIF(NOT RUBY_EXECUTABLE)
+  IF(RUBY_VERSION VERSION_LESS "1.9")
+    # starting with 1.9 Config is deprecated, use RbConfig instead
+    SET(_RUBY_CONFIG_MODULENAME "Config")
+  ELSE(RUBY_VERSION VERSION_LESS "1.9")
+    SET(_RUBY_CONFIG_MODULENAME "RbConfig")
+  ENDIF(RUBY_VERSION VERSION_LESS "1.9")
+  EXECUTE_PROCESS(
+    COMMAND ${RUBY_EXECUTABLE} -rrbconfig -e "print ${_RUBY_CONFIG_MODULENAME}::CONFIG['DLEXT']"
+    RESULT_VARIABLE _res
+    OUTPUT_VARIABLE _ext)
+  IF(_res)
+    MESSAGE(SEND_ERROR "cant find ruby interpreter, skip generating module")
+  ENDIF(_res)
+  SET(SWIG_RUBY_MODULE_SUFFIX ".${_ext}")
+ENDMACRO(SWIG_RUBY_MODULE_SUFFIX)
+
+#
 # Create Swig module
 #
 MACRO(SWIG_ADD_MODULE name language)
@@ -238,6 +263,13 @@ MACRO(SWIG_ADD_MODULE name language)
       SET_TARGET_PROPERTIES(${SWIG_MODULE_${name}_REAL_NAME} PROPERTIES SUFFIX ".pyd")
     ENDIF(WIN32 AND NOT CYGWIN)
   ENDIF ("${swig_lowercase_language}" STREQUAL "python")
+  IF ("${swig_lowercase_language}" STREQUAL "ruby")
+    # Swig generates a shared object that ruby loads directly, but this requires
+    # that the so must be named exactly as the module
+    SWIG_RUBY_MODULE_SUFFIX()
+    SET_TARGET_PROPERTIES(${SWIG_MODULE_${name}_REAL_NAME} PROPERTIES
+      PREFIX "" SUFFIX ${SWIG_RUBY_MODULE_SUFFIX})
+  ENDIF ("${swig_lowercase_language}" STREQUAL "ruby")
 ENDMACRO(SWIG_ADD_MODULE)
 
 #
-- 
1.7.5.4