Merge pull request #21 from Bagira80/additions_to_fix_for_issue11224

Addition to fix / workaround for issue #11224.

preprocessed/README.txt

@@ -2,14 +2,19 @@ Pre-processing of MPL-containers
 --------------------------------
 
 Pre-processing of MPL-containers can be accomplished using the script
-"boost_mpl_preprocess.py". In the simplest case call it with a single
+"boost_mpl_preprocess.py". In the simple case call it with a single
 argument which is the path to the source-directory of Boost.
 
   python boost_mpl_preprocess.py <path-to-boost-sourcedir>
 
-This will pre-process all four MPL-container types (vector, list, set,
+If the Boost source-directory is the one this script resides in, you
-map) and makes them able to hold up to 100 elements. They can be used
+can just call it without any arguments.
-either in their 'numbered' or their 'variadic' form.
+
+  python boost_mpl_preprocess.py
+
+Either way, this will pre-process all four MPL-container types (vector,
+list, set, map) and makes them able to hold up to 100 elements. They can
+be used either in their 'numbered' or their 'variadic' form.
 
 Additionally, the script also allows more fine-grained pre-processing.
 The maximal number of elements an MPL-container type is able to hold can
@@ -31,8 +36,8 @@ input source-files prior to pre-processing (by implicitly calling script
 "fix_boost_mpl_preprocess.py" with the chosen settings). It only patches
 the source-files needed for pre-processing the selected MPL-container
 types and their selected form ('numbered' or 'variadic').
-If calling it with a single argument (as in the former section) all input
+If calling it with a single (or no) argument (as in the former section)
-source-files will be patched automatically.
+all input source-files will be patched automatically.
 
 Instead of fixing the input-files implicitly during pre-processing one
 can also fix them explicitly by calling "fix_boost_mpl_preprocess.py"

preprocessed/boost_mpl_preprocess.py

@@ -72,6 +72,21 @@ def adjust_container_limits_for_variadic_sequences(headerDir, containers, maxEle
             print(line)
 
 
+def current_boost_dir():
+    """Returns the (relative) path to the Boost source-directory this file is located in (if any)."""
+    # Path to directory containing this script.
+    path = os.path.dirname( os.path.realpath(__file__) )
+    # Making sure it is located in "${boost-dir}/libs/mpl/preprocessed".
+    for directory in reversed( ["libs", "mpl", "preprocessed"] ):
+        (head, tail) = os.path.split(path)
+        if tail == directory:
+            path = head
+        else:
+            return None
+    return os.path.relpath( path )
+    
+
+
 def to_positive_multiple_of_10(string):
     """Converts a string into its encoded positive integer (greater zero) or throws an exception."""
     try:
@@ -96,7 +111,12 @@ def to_existing_absolute_path(string):
 
 def main():
     """The main function."""
-
+    
+    # Find the current Boost source-directory in which this script is located.
+    sourceDir = current_boost_dir()
+    if sourceDir == None:
+        sourceDir = ""
+    
     # Prepare and run cmdline-parser.
     cmdlineParser = argparse.ArgumentParser(description="A generator-script for pre-processed Boost.MPL headers.")
     cmdlineParser.add_argument("-v", "--verbose", dest='verbose', action='store_true',
@@ -117,9 +137,9 @@ def main():
     cmdlineParser.add_argument("--num-elements", dest='numElements', metavar="<num-elements>",
                                type=to_positive_multiple_of_10, default=100,
                                help="The maximal number of elements per container sequence. (Default=100)")
-    cmdlineParser.add_argument(dest='sourceDir', metavar="<source-dir>",
+    cmdlineParser.add_argument(dest='sourceDir', metavar="<source-dir>", default=current_boost_dir(), nargs='?',
                                type=to_existing_absolute_path,
-                               help="The source-directory of Boost.")
+                               help="The source-directory of Boost. (Default=\"" + sourceDir + "\")")
     args = cmdlineParser.parse_args()
 
     # Some verbose debug output.
@@ -134,7 +154,12 @@ def main():
         print "  want: set        = ", args.want_set
         print "  want: map        = ", args.want_map
 
-    # The directories for header- and source files of Boost.MPL.    
+    # Verify that we received any source-directory.
+    if args.sourceDir == None:
+        print "You should specify a valid path to the Boost source-directory."
+        sys.exit(0)
+
+    # The directories for header- and source files of Boost.MPL.
     # NOTE: Assuming 'args.sourceDir' is the source-directory of the entire boost project.
     headerDir = os.path.join( args.sourceDir, "boost", "mpl" )
     sourceDir = os.path.join( args.sourceDir, "libs", "mpl", "preprocessed" )