cpython/Tools/scripts/h2py.py

172 lines
5.6 KiB
Python
Executable File

#! /usr/bin/env python3
# Read #define's and translate to Python code.
# Handle #include statements.
# Handle #define macros with one argument.
# Anything that isn't recognized or doesn't translate into valid
# Python is ignored.
# Without filename arguments, acts as a filter.
# If one or more filenames are given, output is written to corresponding
# filenames in the local directory, translated to all uppercase, with
# the extension replaced by ".py".
# By passing one or more options of the form "-i regular_expression"
# you can specify additional strings to be ignored. This is useful
# e.g. to ignore casts to u_long: simply specify "-i '(u_long)'".
# XXX To do:
# - turn trailing C comments into Python comments
# - turn C Boolean operators "&& || !" into Python "and or not"
# - what to do about #if(def)?
# - what to do about macros with multiple parameters?
import sys, re, getopt, os
p_define = re.compile(r'^[\t ]*#[\t ]*define[\t ]+([a-zA-Z0-9_]+)[\t ]+')
p_macro = re.compile(
r'^[\t ]*#[\t ]*define[\t ]+'
r'([a-zA-Z0-9_]+)\(([_a-zA-Z][_a-zA-Z0-9]*)\)[\t ]+')
p_include = re.compile(r'^[\t ]*#[\t ]*include[\t ]+<([^>\n]+)>')
p_comment = re.compile(r'/\*([^*]+|\*+[^/])*(\*+/)?')
p_cpp_comment = re.compile('//.*')
ignores = [p_comment, p_cpp_comment]
p_char = re.compile(r"'(\\.[^\\]*|[^\\])'")
p_hex = re.compile(r"0x([0-9a-fA-F]+)L?")
filedict = {}
importable = {}
try:
searchdirs=os.environ['include'].split(';')
except KeyError:
try:
searchdirs=os.environ['INCLUDE'].split(';')
except KeyError:
searchdirs=['/usr/include']
try:
searchdirs.insert(0, os.path.join('/usr/include',
os.environ['MULTIARCH']))
except KeyError:
pass
def main():
global filedict
opts, args = getopt.getopt(sys.argv[1:], 'i:')
for o, a in opts:
if o == '-i':
ignores.append(re.compile(a))
if not args:
args = ['-']
for filename in args:
if filename == '-':
sys.stdout.write('# Generated by h2py from stdin\n')
process(sys.stdin, sys.stdout)
else:
with open(filename) as fp:
outfile = os.path.basename(filename)
i = outfile.rfind('.')
if i > 0: outfile = outfile[:i]
modname = outfile.upper()
outfile = modname + '.py'
with open(outfile, 'w') as outfp:
outfp.write('# Generated by h2py from %s\n' % filename)
filedict = {}
for dir in searchdirs:
if filename[:len(dir)] == dir:
filedict[filename[len(dir)+1:]] = None # no '/' trailing
importable[filename[len(dir)+1:]] = modname
break
process(fp, outfp)
def pytify(body):
# replace ignored patterns by spaces
for p in ignores:
body = p.sub(' ', body)
# replace char literals by ord(...)
body = p_char.sub("ord('\\1')", body)
# Compute negative hexadecimal constants
start = 0
UMAX = 2*(sys.maxsize+1)
while 1:
m = p_hex.search(body, start)
if not m: break
s,e = m.span()
val = int(body[slice(*m.span(1))], 16)
if val > sys.maxsize:
val -= UMAX
body = body[:s] + "(" + str(val) + ")" + body[e:]
start = s + 1
return body
def process(fp, outfp, env = {}):
lineno = 0
while 1:
line = fp.readline()
if not line: break
lineno = lineno + 1
match = p_define.match(line)
if match:
# gobble up continuation lines
while line[-2:] == '\\\n':
nextline = fp.readline()
if not nextline: break
lineno = lineno + 1
line = line + nextline
name = match.group(1)
body = line[match.end():]
body = pytify(body)
ok = 0
stmt = '%s = %s\n' % (name, body.strip())
try:
exec(stmt, env)
except:
sys.stderr.write('Skipping: %s' % stmt)
else:
outfp.write(stmt)
match = p_macro.match(line)
if match:
macro, arg = match.group(1, 2)
body = line[match.end():]
body = pytify(body)
stmt = 'def %s(%s): return %s\n' % (macro, arg, body)
try:
exec(stmt, env)
except:
sys.stderr.write('Skipping: %s' % stmt)
else:
outfp.write(stmt)
match = p_include.match(line)
if match:
regs = match.regs
a, b = regs[1]
filename = line[a:b]
if filename in importable:
outfp.write('from %s import *\n' % importable[filename])
elif filename not in filedict:
filedict[filename] = None
inclfp = None
for dir in searchdirs:
try:
inclfp = open(dir + '/' + filename)
break
except IOError:
pass
if inclfp:
with inclfp:
outfp.write(
'\n# Included from %s\n' % filename)
process(inclfp, outfp, env)
else:
sys.stderr.write('Warning - could not find file %s\n' %
filename)
if __name__ == '__main__':
main()