/Tools/scripts/h2py.py

  1#! /usr/bin/env python
  2
  3# Read #define's and translate to Python code.
  4# Handle #include statements.
  5# Handle #define macros with one argument.
  6# Anything that isn't recognized or doesn't translate into valid
  7# Python is ignored.
  8
  9# Without filename arguments, acts as a filter.
 10# If one or more filenames are given, output is written to corresponding
 11# filenames in the local directory, translated to all uppercase, with
 12# the extension replaced by ".py".
 13
 14# By passing one or more options of the form "-i regular_expression"
 15# you can specify additional strings to be ignored.  This is useful
 16# e.g. to ignore casts to u_long: simply specify "-i '(u_long)'".
 17
 18# XXX To do:
 19# - turn trailing C comments into Python comments
 20# - turn C Boolean operators "&& || !" into Python "and or not"
 21# - what to do about #if(def)?
 22# - what to do about macros with multiple parameters?
 23
 24import sys, re, getopt, os
 25
 26p_define = re.compile('^[\t ]*#[\t ]*define[\t ]+([a-zA-Z0-9_]+)[\t ]+')
 27
 28p_macro = re.compile(
 29  '^[\t ]*#[\t ]*define[\t ]+'
 30  '([a-zA-Z0-9_]+)\(([_a-zA-Z][_a-zA-Z0-9]*)\)[\t ]+')
 31
 32p_include = re.compile('^[\t ]*#[\t ]*include[\t ]+<([a-zA-Z0-9_/\.]+)')
 33
 34p_comment = re.compile(r'/\*([^*]+|\*+[^/])*(\*+/)?')
 35p_cpp_comment = re.compile('//.*')
 36
 37ignores = [p_comment, p_cpp_comment]
 38
 39p_char = re.compile(r"'(\\.[^\\]*|[^\\])'")
 40
 41p_hex = re.compile(r"0x([0-9a-fA-F]+)L?")
 42
 43filedict = {}
 44importable = {}
 45
 46try:
 47    searchdirs=os.environ['include'].split(';')
 48except KeyError:
 49    try:
 50        searchdirs=os.environ['INCLUDE'].split(';')
 51    except KeyError:
 52        try:
 53            if  sys.platform.find("beos") == 0:
 54                searchdirs=os.environ['BEINCLUDES'].split(';')
 55            elif sys.platform.startswith("atheos"):
 56                searchdirs=os.environ['C_INCLUDE_PATH'].split(':')
 57            else:
 58                raise KeyError
 59        except KeyError:
 60            searchdirs=['/usr/include']
 61
 62def main():
 63    global filedict
 64    opts, args = getopt.getopt(sys.argv[1:], 'i:')
 65    for o, a in opts:
 66        if o == '-i':
 67            ignores.append(re.compile(a))
 68    if not args:
 69        args = ['-']
 70    for filename in args:
 71        if filename == '-':
 72            sys.stdout.write('# Generated by h2py from stdin\n')
 73            process(sys.stdin, sys.stdout)
 74        else:
 75            fp = open(filename, 'r')
 76            outfile = os.path.basename(filename)
 77            i = outfile.rfind('.')
 78            if i > 0: outfile = outfile[:i]
 79            modname = outfile.upper()
 80            outfile = modname + '.py'
 81            outfp = open(outfile, 'w')
 82            outfp.write('# Generated by h2py from %s\n' % filename)
 83            filedict = {}
 84            for dir in searchdirs:
 85                if filename[:len(dir)] == dir:
 86                    filedict[filename[len(dir)+1:]] = None  # no '/' trailing
 87                    importable[filename[len(dir)+1:]] = modname
 88                    break
 89            process(fp, outfp)
 90            outfp.close()
 91            fp.close()
 92
 93def pytify(body):
 94    # replace ignored patterns by spaces
 95    for p in ignores:
 96        body = p.sub(' ', body)
 97    # replace char literals by ord(...)
 98    body = p_char.sub('ord(\\0)', body)
 99    # Compute negative hexadecimal constants
100    start = 0
101    UMAX = 2*(sys.maxint+1)
102    while 1:
103        m = p_hex.search(body, start)
104        if not m: break
105        s,e = m.span()
106        val = long(body[slice(*m.span(1))], 16)
107        if val > sys.maxint:
108            val -= UMAX
109            body = body[:s] + "(" + str(val) + ")" + body[e:]
110        start = s + 1
111    return body
112
113def process(fp, outfp, env = {}):
114    lineno = 0
115    while 1:
116        line = fp.readline()
117        if not line: break
118        lineno = lineno + 1
119        match = p_define.match(line)
120        if match:
121            # gobble up continuation lines
122            while line[-2:] == '\\\n':
123                nextline = fp.readline()
124                if not nextline: break
125                lineno = lineno + 1
126                line = line + nextline
127            name = match.group(1)
128            body = line[match.end():]
129            body = pytify(body)
130            ok = 0
131            stmt = '%s = %s\n' % (name, body.strip())
132            try:
133                exec stmt in env
134            except:
135                sys.stderr.write('Skipping: %s' % stmt)
136            else:
137                outfp.write(stmt)
138        match = p_macro.match(line)
139        if match:
140            macro, arg = match.group(1, 2)
141            body = line[match.end():]
142            body = pytify(body)
143            stmt = 'def %s(%s): return %s\n' % (macro, arg, body)
144            try:
145                exec stmt in env
146            except:
147                sys.stderr.write('Skipping: %s' % stmt)
148            else:
149                outfp.write(stmt)
150        match = p_include.match(line)
151        if match:
152            regs = match.regs
153            a, b = regs[1]
154            filename = line[a:b]
155            if importable.has_key(filename):
156                outfp.write('from %s import *\n' % importable[filename])
157            elif not filedict.has_key(filename):
158                filedict[filename] = None
159                inclfp = None
160                for dir in searchdirs:
161                    try:
162                        inclfp = open(dir + '/' + filename)
163                        break
164                    except IOError:
165                        pass
166                if inclfp:
167                    outfp.write(
168                            '\n# Included from %s\n' % filename)
169                    process(inclfp, outfp, env)
170                else:
171                    sys.stderr.write('Warning - could not find file %s\n' %
172                                     filename)
173
174if __name__ == '__main__':
175    main()