ref: c12e49ecbf4ae7933b13d592543c9f7c7dc03581
dir: /sys/src/cmd/python/Modules/cgen.py/
########################################################################
# Copyright (c) 2000, BeOpen.com.
# Copyright (c) 1995-2000, Corporation for National Research Initiatives.
# Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
# All rights reserved.
#
# See the file "Misc/COPYRIGHT" for information on usage and
# redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
########################################################################
# Python script to parse cstubs file for gl and generate C stubs.
# usage: python cgen.py <cstubs >glmodule.c
#
# NOTE: You must first make a python binary without the "GL" option
# before you can run this, when building Python for the first time.
# See comments in the Makefile.
#
# 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 and s[0] in digits:
n = n + s[0]
s = s[1:]
return n, s
# Function to check if a string is a number
#
def isnum(s):
if not s: return False
for c in s:
if not c in digits: return False
return True
# Allowed function return types
#
return_types = ['void', 'short', 'long']
# Allowed function argument types
#
arg_types = ['char', 'string', 'short', 'u_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)
if type[:2] == 'u_':
type = 'unsigned ' + type[2:]
#
# 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 not isnum(sub) and (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':
err('Function', func, 'too complicated:',
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 PyObject *'
print 'gl_' + func + '(self, args)'
print '\tPyObject *self;'
print '\tPyObject *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,
brac = ket = ''
if a_sub and not isnum(a_sub):
if a_factor:
brac = '('
ket = ')'
print brac + '*',
print 'arg' + repr(i+1) + ket,
if a_sub and isnum(a_sub):
print '[', a_sub, ']',
if a_factor:
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, repr(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_type[:9] == 'unsigned ':
xtype = a_type[9:]
else:
xtype = a_type
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' + xtype + 'arraysize(args,',
print repr(n_in_args) + ',',
print repr(in_pos[j]) + ',',
if xtype <> a_type:
print '('+xtype+' *)',
print '&arg' + repr(i+1) + '))'
print '\t\treturn NULL;'
if a_factor:
print '\targ' + repr(i+1),
print '= arg' + repr(i+1),
print '/', a_factor + ';'
elif a_mode == 's':
if a_sub and not isnum(a_sub):
# Allocate memory for varsize array
print '\tif ((arg' + repr(i+1), '=',
if a_factor:
print '('+a_type+'(*)['+a_factor+'])',
print 'PyMem_NEW(' + a_type, ',',
if a_factor:
print a_factor, '*',
print a_sub, ')) == NULL)'
print '\t\treturn PyErr_NoMemory();'
print '\tif',
if a_factor or a_sub: # Get a fixed-size array array
print '(!geti' + xtype + 'array(args,',
print repr(n_in_args) + ',',
print repr(in_pos[i]) + ',',
if a_factor: print a_factor,
if a_factor and a_sub: print '*',
if a_sub: print a_sub,
print ',',
if (a_sub and a_factor) or xtype <> a_type:
print '('+xtype+' *)',
print 'arg' + repr(i+1) + '))'
else: # Get a simple variable
print '(!geti' + xtype + 'arg(args,',
print repr(n_in_args) + ',',
print repr(in_pos[i]) + ',',
if xtype <> a_type:
print '('+xtype+' *)',
print '&arg' + repr(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' + repr(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 and not isnum(a_sub):
print '\tPyMem_DEL(arg' + repr(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' + repr(i+1)) + ';'
else:
print '\t{ PyObject *v = PyTuple_New(',
print n_out_args, ');'
print '\t if (v == NULL) return NULL;'
i_out = 0
if type <> 'void':
print '\t PyTuple_SetItem(v,',
print repr(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 PyTuple_SetItem(v,',
print repr(i_out) + ',',
s = mkobject(a_type, 'arg' + repr(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 '\tPy_INCREF(Py_None);'
print '\treturn Py_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):
if type[:9] == 'unsigned ':
type = type[9:]
return 'mknew' + type + 'object((' + type + ') ' + arg + ')'
return 'mknew' + type + 'object(' + arg + ')'
defined_archs = []
# usage: cgen [ -Dmach ... ] [ file ]
for arg in sys.argv[1:]:
if arg[:2] == '-D':
defined_archs.append(arg[2:])
else:
# Open optional file argument
sys.stdin = open(arg, 'r')
# 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
continue
if not words:
continue # skip empty line
elif words[0] == 'if':
# if XXX rest
# if !XXX rest
if words[1][0] == '!':
if words[1][1:] in defined_archs:
continue
elif words[1] not in defined_archs:
continue
words = words[2:]
if 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 PyMethodDef gl_methods[] = {'
for func in functions:
print '\t{"' + func + '", gl_' + func + '},'
print '\t{NULL, NULL} /* Sentinel */'
print '};'
print
print 'void'
print 'initgl()'
print '{'
print '\t(void) Py_InitModule("gl", gl_methods);'
print '}'