Initial revision

1 files changed, 458 insertions, 0 deletions

diff --git a/Modules/cgen.py b/Modules/cgen.py
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+++ b/Modules/cgen.py
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+# Python script to parse cstubs file for gl and generate C stubs.
+# usage: python cgen <cstubs >glmodule.c
+#
+# XXX BUG return arrays generate wrong code
+# XXX need to change error returns into gotos to free mallocked arrays
+
+
+import string
+import sys
+
+
+# Function to print to stderr
+#
+def err(args):
+	savestdout = sys.stdout
+	try:
+		sys.stdout = sys.stderr
+		for i in args:
+			print i,
+		print
+	finally:
+		sys.stdout = savestdout
+
+
+# The set of digits that form a number
+#
+digits = '0123456789'
+
+
+# Function to extract a string of digits from the front of the string.
+# Returns the leading string of digits and the remaining string.
+# If no number is found, returns '' and the original string.
+#
+def getnum(s):
+	n = ''
+	while s[:1] in digits:
+		n = n + s[:1]
+		s = s[1:]
+	return n, s
+
+
+# Function to check if a string is a number
+#
+def isnum(s):
+	if not s: return 0
+	for c in s:
+		if not c in digits: return 0
+	return 1
+
+
+# Allowed function return types
+#
+return_types = ['void', 'short', 'long']
+
+
+# Allowed function argument types
+#
+arg_types = ['char', 'string', 'short', 'float', 'long', 'double']
+
+
+# Need to classify arguments as follows
+#	simple input variable
+#	simple output variable
+#	input array
+#	output array
+#	input giving size of some array
+#
+# Array dimensions can be specified as follows
+#	constant
+#	argN
+#	constant * argN
+#	retval
+#	constant * retval
+#
+# The dimensions given as constants * something are really
+# arrays of points where points are 2- 3- or 4-tuples
+#
+# We have to consider three lists:
+#	python input arguments
+#	C stub arguments (in & out)
+#	python output arguments (really return values)
+#
+# There is a mapping from python input arguments to the input arguments
+# of the C stub, and a further mapping from C stub arguments to the
+# python return values
+
+
+# Exception raised by checkarg() and generate()
+#
+arg_error = 'bad arg'
+
+
+# Function to check one argument.
+# Arguments: the type and the arg "name" (really mode plus subscript).
+# Raises arg_error if something's wrong.
+# Return type, mode, factor, rest of subscript; factor and rest may be empty.
+#
+def checkarg(type, arg):
+	#
+	# Turn "char *x" into "string x".
+	#
+	if type = 'char' and arg[0] = '*':
+		type = 'string'
+		arg = arg[1:]
+	#
+	# Check that the type is supported.
+	#
+	if type not in arg_types:
+		raise arg_error, ('bad type', type)
+	#
+	# Split it in the mode (first character) and the rest.
+	#
+	mode, rest = arg[:1], arg[1:]
+	#
+	# The mode must be 's' for send (= input) or 'r' for return argument.
+	#
+	if mode not in ('r', 's'):
+		raise arg_error, ('bad arg mode', mode)
+	#
+	# Is it a simple argument: if so, we are done.
+	#
+	if not rest:
+		return type, mode, '', ''
+	#	
+	# Not a simple argument; must be an array.
+	# The 'rest' must be a subscript enclosed in [ and ].
+	# The subscript must be one of the following forms,
+	# otherwise we don't handle it (where N is a number):
+	#	N
+	#	argN
+	#	retval
+	#	N*argN
+	#	N*retval
+	#
+	if rest[:1] <> '[' or rest[-1:] <> ']':
+		raise arg_error, ('subscript expected', rest)
+	sub = rest[1:-1]
+	#
+	# Is there a leading number?
+	#
+	num, sub = getnum(sub)
+	if num:
+		# There is a leading number
+		if not sub:
+			# The subscript is just a number
+			return type, mode, num, ''
+		if sub[:1] = '*':
+			# There is a factor prefix
+			sub = sub[1:]
+		else:
+			raise arg_error, ('\'*\' expected', sub)
+	if sub = 'retval':
+		# size is retval -- must be a reply argument
+		if mode <> 'r':
+			raise arg_error, ('non-r mode with [retval]', mode)
+	elif sub[:3] <> 'arg' or not isnum(sub[3:]):
+		raise arg_error, ('bad subscript', sub)
+	#
+	return type, mode, num, sub
+
+
+# List of functions for which we have generated stubs
+#
+functions = []
+
+
+# Generate the stub for the given function, using the database of argument
+# information build by successive calls to checkarg()
+#
+def generate(type, func, database):
+	#
+	# Check that we can handle this case:
+	# no variable size reply arrays yet
+	#
+	n_in_args = 0
+	n_out_args = 0
+	#
+	for a_type, a_mode, a_factor, a_sub in database:
+		if a_mode = 's':
+			n_in_args = n_in_args + 1
+		elif a_mode = 'r':
+			n_out_args = n_out_args + 1
+		else:
+			# Can't happen
+			raise arg_error, ('bad a_mode', a_mode)
+		if (a_mode = 'r' and a_sub) or a_sub = 'retval':
+			e = 'Function', func, 'too complicated:'
+			err(e + (a_type, a_mode, a_factor, a_sub))
+			print '/* XXX Too complicated to generate code for */'
+			return
+	#
+	functions.append(func)
+	#
+	# Stub header
+	#
+	print
+	print 'static object *'
+	print 'gl_' + func + '(self, args)'
+	print '\tobject *self;'
+	print '\tobject *args;'
+	print '{'
+	#
+	# Declare return value if any
+	#
+	if type <> 'void':
+		print '\t' + type, 'retval;'
+	#
+	# Declare arguments
+	#
+	for i in range(len(database)):
+		a_type, a_mode, a_factor, a_sub = database[i]
+		print '\t' + a_type,
+		if a_sub:
+			print '*',
+		print 'arg' + `i+1`,
+		if a_factor and not a_sub:
+			print '[', a_factor, ']',
+		print ';'
+	#
+	# Find input arguments derived from array sizes
+	#
+	for i in range(len(database)):
+		a_type, a_mode, a_factor, a_sub = database[i]
+		if a_mode = 's' and a_sub[:3] = 'arg' and isnum(a_sub[3:]):
+			# Sending a variable-length array
+			n = eval(a_sub[3:])
+			if 1 <= n <= len(database):
+			    b_type, b_mode, b_factor, b_sub = database[n-1]
+			    if b_mode = 's':
+			        database[n-1] = b_type, 'i', a_factor, `i`
+			        n_in_args = n_in_args - 1
+	#
+	# Assign argument positions in the Python argument list
+	#
+	in_pos = []
+	i_in = 0
+	for i in range(len(database)):
+		a_type, a_mode, a_factor, a_sub = database[i]
+		if a_mode = 's':
+			in_pos.append(i_in)
+			i_in = i_in + 1
+		else:
+			in_pos.append(-1)
+	#
+	# Get input arguments
+	#
+	for i in range(len(database)):
+		a_type, a_mode, a_factor, a_sub = database[i]
+		if a_mode = 'i':
+			#
+			# Implicit argument;
+			# a_factor is divisor if present,
+			# a_sub indicates which arg (`database index`)
+			#
+			j = eval(a_sub)
+			print '\tif',
+			print '(!geti' + a_type + 'arraysize(args,',
+			print `n_in_args` + ',',
+			print `in_pos[j]` + ',',
+			print '&arg' + `i+1` + '))'
+			print '\t\treturn NULL;'
+			if a_factor:
+				print '\targ' + `i+1`,
+				print '= arg' + `i+1`,
+				print '/', a_factor + ';'
+		elif a_mode = 's':
+			if a_sub: # Allocate memory for varsize array
+				print '\tif ((arg' + `i+1`, '=',
+				print 'NEW(' + a_type + ',',
+				if a_factor: print a_factor, '*',
+				print a_sub, ')) == NULL)'
+				print '\t\treturn err_nomem();'
+			print '\tif',
+			if a_factor or a_sub: # Get a fixed-size array array
+				print '(!geti' + a_type + 'array(args,',
+				print `n_in_args` + ',',
+				print `in_pos[i]` + ',',
+				if a_factor: print a_factor,
+				if a_factor and a_sub: print '*',
+				if a_sub: print a_sub,
+				print ', arg' + `i+1` + '))'
+			else: # Get a simple variable
+				print '(!geti' + a_type + 'arg(args,',
+				print `n_in_args` + ',',
+				print `in_pos[i]` + ',',
+				print '&arg' + `i+1` + '))'
+			print '\t\treturn NULL;'
+	#
+	# Begin of function call
+	#
+	if type <> 'void':
+		print '\tretval =', func + '(',
+	else:
+		print '\t' + func + '(',
+	#
+	# Argument list
+	#
+	for i in range(len(database)):
+		if i > 0: print ',',
+		a_type, a_mode, a_factor, a_sub = database[i]
+		if a_mode = 'r' and not a_factor:
+			print '&',
+		print 'arg' + `i+1`,
+	#
+	# End of function call
+	#
+	print ');'
+	#
+	# Free varsize arrays
+	#
+	for i in range(len(database)):
+		a_type, a_mode, a_factor, a_sub = database[i]
+		if a_mode = 's' and a_sub:
+			print '\tDEL(arg' + `i+1` + ');'
+	#
+	# Return
+	#
+	if n_out_args:
+		#
+		# Multiple return values -- construct a tuple
+		#
+		if type <> 'void':
+			n_out_args = n_out_args + 1
+		if n_out_args = 1:
+			for i in range(len(database)):
+				a_type, a_mode, a_factor, a_sub = database[i]
+				if a_mode = 'r':
+					break
+			else:
+				raise arg_error, 'expected r arg not found'
+			print '\treturn',
+			print mkobject(a_type, 'arg' + `i+1`) + ';'
+		else:
+			print '\t{ object *v = newtupleobject(',
+			print n_out_args, ');'
+			print '\t  if (v == NULL) return NULL;'
+			i_out = 0
+			if type <> 'void':
+				print '\t  settupleitem(v,',
+				print `i_out` + ',',
+				print mkobject(type, 'retval') + ');'
+				i_out = i_out + 1
+			for i in range(len(database)):
+				a_type, a_mode, a_factor, a_sub = database[i]
+				if a_mode = 'r':
+					print '\t  settupleitem(v,',
+					print `i_out` + ',',
+					s = mkobject(a_type, 'arg' + `i+1`)
+					print s + ');'
+					i_out = i_out + 1
+			print '\t  return v;'
+			print '\t}'
+	else:
+		#
+		# Simple function return
+		# Return None or return value
+		#
+		if type = 'void':
+			print '\tINCREF(None);'
+			print '\treturn None;'
+		else:
+			print '\treturn', mkobject(type, 'retval') + ';'
+	#
+	# Stub body closing brace
+	#
+	print '}'
+
+
+# Subroutine to return a function call to mknew<type>object(<arg>)
+#
+def mkobject(type, arg):
+	return 'mknew' + type + 'object(' + arg + ')'
+
+
+# Input line number
+lno = 0
+
+
+# Input is divided in two parts, separated by a line containing '%%'.
+#	<part1>		-- literally copied to stdout
+#	<part2>		-- stub definitions
+
+# Variable indicating the current input part.
+#
+part = 1
+
+# Main loop over the input
+#
+while 1:
+	try:
+		line = raw_input()
+	except EOFError:
+		break
+	#
+	lno = lno+1
+	words = string.split(line)
+	#
+	if part = 1:
+		#
+		# In part 1, copy everything literally
+		# except look for a line of just '%%'
+		#
+		if words = ['%%']:
+			part = part + 1
+		else:
+			#
+			# Look for names of manually written
+			# stubs: a single percent followed by the name
+			# of the function in Python.
+			# The stub name is derived by prefixing 'gl_'.
+			#
+			if words and words[0][0] = '%':
+				func = words[0][1:]
+				if (not func) and words[1:]:
+					func = words[1]
+				if func:
+					functions.append(func)
+			else:
+				print line
+	elif not words:
+		pass			# skip empty line
+	elif words[0] = '#include':
+		print line
+	elif words[0][:1] = '#':
+		pass			# ignore comment
+	elif words[0] not in return_types:
+		err('Line', lno, ': bad return type :', words[0])
+	elif len(words) < 2:
+		err('Line', lno, ': no funcname :', line)
+	else:
+		if len(words) % 2 <> 0:
+			err('Line', lno, ': odd argument list :', words[2:])
+		else:
+			database = []
+			try:
+				for i in range(2, len(words), 2):
+					x = checkarg(words[i], words[i+1])
+					database.append(x)
+				print
+				print '/*',
+				for w in words: print w,
+				print '*/'
+				generate(words[0], words[1], database)
+			except arg_error, msg:
+				err('Line', lno, ':', msg)
+
+
+print
+print 'static struct methodlist gl_methods[] = {'
+for func in functions:
+	print '\t{"' + func + '", gl_' + func + '},'
+print '\t{NULL, NULL} /* Sentinel */'
+print '};'
+print
+print 'initgl()'
+print '{'
+print '\tinitmodule("gl", gl_methods);'
+print '}'