Add efacf056cd

dockerdoom/trunk/man/simplecpp

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+#!/usr/bin/env python
+#
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+# Contributors to the Freedoom project.  All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of the freedoom project nor the names of its
+#    contributors may be used to endorse or promote products derived from
+#    this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+# OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+#
+# simple cpp-style preprocessor
+#
+# Understands:
+#
+# #define NAME
+#
+# Set an option
+# You can use -D on the command line too
+#
+# #undef NAME
+#
+# Unset an option if it is set
+#
+# #if .. #endif / #ifdef .. #endif
+#
+# Specify a list of options set, eg #ifdef DOOM2 || ULTDOOM || SHAREWARE
+# The block is only displayed if one of the options is set
+#
+# #ifn .. #endif / #ifndef .. #endif
+#
+# Similarly specify a list of options
+# The block is displayed if none of the options are set
+#
+# #include "filename"
+#
+# include the contents of a file
+
+import sys
+import re
+
+debug = False
+defines = {}
+
+command_re = re.compile("\#(\w+)(\s+(.*))?")
+include_re = re.compile("\s*\"(.*)\"\s*")
+
+def debug_msg(message):
+	if debug:
+		sys.stderr.write(message)
+
+# Parse command line options
+
+def parse_cmdline():
+	for arg in sys.argv[1:]:
+		if arg.startswith("-D"):
+			name = arg[2:]
+			defines[name] = True
+
+def parse_stream(stream):
+	result = read_block(stream, False)
+
+	if result is not None:
+		raise Exception("Mismatched #if in '%s'" % stream.name)
+
+def parse_file(filename):
+	f = open(filename)
+
+	try:
+		parse_stream(f)
+	finally:
+		f.close()
+
+# #include
+
+def cmd_include(arg):
+	# Extract the filename
+
+	match = include_re.match(arg)
+
+	if not match:
+		raise Exception("Invalid 'include' command")
+
+	filename = match.group(1)
+
+	# Open the file and process it
+
+	parse_file(filename)
+
+# #define
+
+def cmd_define(arg):
+	defines[arg] = True
+
+# #undef
+
+def cmd_undef(arg):
+	if arg in defines:
+		del defines[arg]
+
+# #ifdef/#ifndef
+
+def cmd_ifdef(arg, command, stream, ignore):
+
+	# Get the define name
+	name = arg.strip()
+
+	debug_msg("%s %s >\n" % (command, arg))
+
+	# Should we ignore the contents of this block?
+
+	sub_ignore = (name not in defines)
+
+	if "n" in command:
+		sub_ignore = not sub_ignore
+
+	# Parse the block
+
+	result = read_block(stream, ignore or sub_ignore)
+
+	debug_msg("%s %s < (%s)\n" % (command, arg, result))
+
+	# There may be a second "else" block to parse:
+
+	if result == "else":
+		debug_msg("%s %s else >\n" % (command, arg))
+		result = read_block(stream, ignore or (not sub_ignore))
+		debug_msg("%s %s else < (%s)\n" % (command, arg, result))
+
+	# Should end in an endif:
+
+	if result != "endif":
+		raise Exception("'if' block did not end in an 'endif'")
+
+commands = {
+	"include" : cmd_include,
+	"define"  : cmd_define,
+	"undef"   : cmd_undef,
+	"if"      : cmd_ifdef,
+	"ifdef"   : cmd_ifdef,
+	"ifn"     : cmd_ifdef,
+	"ifndef"  : cmd_ifdef,
+}
+
+# Recursive block reading function
+# if 'ignore' argument is 1, contents are ignored
+
+def read_block(stream, ignore):
+
+	for line in stream:
+
+		# Remove newline
+
+		line = line[0:-1]
+
+		# Check if this line has a command
+
+		match = command_re.match(line)
+
+		if match:
+			command = match.group(1)
+			arg = match.group(3)
+
+			if command == "else" or command == "endif":
+				return command
+			elif command not in commands:
+				raise Exception("Unknown command: '%s'" % \
+						command)
+
+			# Get the callback function.
+
+			func = commands[command]
+
+			# Invoke the callback function. #ifdef commands
+			# are a special case and need extra arguments.
+			# Other commands are only executed if we are not
+			# ignoring this block.
+
+			if func == cmd_ifdef:
+				cmd_ifdef(arg, command=command,
+					       stream=stream,
+					       ignore=ignore)
+			elif not ignore:
+				func(arg)
+		else:
+			if not ignore:
+				print(line)
+
+parse_cmdline()
+parse_stream(sys.stdin)
+