service_runtime/nacl_syscall_handlers_gen2.py

   1 #!/usr/bin/python
   2 # Copyright 2008, Google Inc.
   3 # All rights reserved.
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
   7 # met:
   8 #
   9 #     * Redistributions of source code must retain the above copyright
  10 # notice, this list of conditions and the following disclaimer.
  11 #     * Redistributions in binary form must reproduce the above
  12 # copyright notice, this list of conditions and the following disclaimer
  13 # in the documentation and/or other materials provided with the
  14 # distribution.
  15 #     * Neither the name of Google Inc. nor the names of its
  16 # contributors may be used to endorse or promote products derived from
  17 # this software without specific prior written permission.
  18 #
  19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30
  31 #
  32 #  This script extracts  "nacl syscall" prototypes from a c file
  33 #  given on stdin and then produces wrapped versions of the syscalls.
  34 #
  35 #  NOTE: Please use care to maintain python 2.3 compatibility, for
  36 #  portability.
  37 #
  38 import getopt
  39 import re
  40 import string
  41 import sys
  42
  43 AUTOGEN_COMMENT = """\
  44 /*
  45  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  46  *
  47  * Automatically generated code.  See nacl_syscall_handlers_gen.py
  48  *
  49  * NaCl Server Runtime Service Call abstractions
  50  */
  51 """
  52
  53
  54 TABLE_INITIALIZER = """\
  55
  56 /* auto generated */
  57
  58 void NaClSyscallTableInit() {
  59   int i;
  60   for (i = 0; i < NACL_MAX_SYSCALLS; ++i) {
  61      nacl_syscall[i].handler = &NotImplementedDecoder;
  62   }
  63
  64 %s
  65 }
  66 """
  67
  68
  69 IMPLEMENTATION_SKELETON = """\
  70 /* this function was automagically generated */
  71 static int32_t %(name)sDecoder(struct NaClAppThread *natp) {
  72 %(members)s\
  73   return %(name)s(natp%(arglist)s);
  74 }
  75 """
  76
  77 def FunctionNameToSyscallDefine(name):
  78   assert name.startswith("NaClSys")
  79   name = name[7:]
  80   return "NACL_sys_" + name.lower()
  81
  82 def ParamList(alist):
  83   if not alist:
  84     return ''
  85   return ', ' + ', '.join(alist)
  86
  87
  88 def ExtractVariable(decl):
  89   type_or_idents = re.findall(r'[a-zA-Z][-_a-zA-Z]*', decl)
  90   return type_or_idents[len(type_or_idents)-1]
  91
  92
  93 def ArgList(alist):
  94   if not alist:
  95     return ''
  96   # Note: although this return value might be computed more
  97   # concisely with a list comprehension, we instead use a
  98   # for statement to maintain python 2.3 compatibility.
  99   extractedargs = []
 100   for arg in alist:
 101     extractedargs += ['p.' + ExtractVariable(arg)]
 102   return ', ' + ', '.join(extractedargs)
 103
 104
 105 def MemberList(name, alist):
 106   if not alist:
 107     return ''
 108
 109   # Note: although this return value might be computed more
 110   # concisely with a list comprehension, we instead use a
 111   # for statement to maintain python 2.3 compatibility.
 112   margs = []
 113   for arg in alist:
 114     margs += ['    ' + arg]
 115   values = {
 116       'name': name,
 117       'members' : ';\n'.join(margs) + ';'
 118       }
 119
 120   return """\
 121   struct %(name)sArgs {
 122 %(members)s
 123   } p = *(struct %(name)sArgs *) natp->x_esp;
 124
 125 """ % values
 126
 127
 128 def PrintSyscallTableIntializer(protos, ostr):
 129   assign = []
 130   for name, _ in protos:
 131     syscall = FunctionNameToSyscallDefine(name)
 132     assign.append("  NaClAddSyscall(%s, &%sDecoder);" % (syscall, name))
 133   print >>ostr, TABLE_INITIALIZER % "\n".join(assign)
 134
 135
 136 def PrintImplSkel(protos, ostr):
 137   print >>ostr, AUTOGEN_COMMENT;
 138   for name, alist in protos:
 139     values = { 'name' : name,
 140                'paramlist' : ParamList(alist[1:]),
 141                'arglist' : ArgList(alist[1:]),
 142                'members' : MemberList(name, alist[1:]),
 143                }
 144     print >>ostr, IMPLEMENTATION_SKELETON % values
 145
 146
 147 def GetProtoArgs(s, fin):
 148   if "{" not in s:
 149     for line in fin:
 150       s += line
 151       if "{" in line:
 152         break
 153     else:
 154       # broken input
 155       assert 0
 156   pos = s.rfind(")")
 157   assert pos >= 0
 158   # prune stuff after )
 159   s = s[0:pos]
 160   args = [a.strip() for a in s.split(",")]
 161   return args
 162
 163
 164 def ParseFileToBeWrapped(fin, filter_regex):
 165   protos = []
 166   for line in fin:
 167     match = re.search(r"^int32_t (NaClSys[_a-zA-Z0-9]+)[(](.*)$", line)
 168     if not match:
 169       continue
 170     name = match.group(1)
 171     args = GetProtoArgs(match.group(2), fin)
 172     if filter_regex and re.search(filter_regex, name):
 173       continue
 174     protos.append( (name, args) )
 175   return protos
 176
 177
 178 def main(argv):
 179   usage='Usage: nacl_syscall_handlers_gen.py [-f regex] [-c] [-d]'
 180   filter_regex = ""
 181   mode = "dump"
 182   try:
 183     opts, pargs = getopt.getopt(argv[1:], 'hcdf:')
 184   except getopt.error, e:
 185     print >>sys.stderr, 'Illegal option:', str(e)
 186     print >>sys.stderr, usage
 187     return 1
 188
 189   for opt, val in opts:
 190     if opt == '-d':
 191       mode = "dump"
 192     elif opt == '-c':
 193       mode = "codegen"
 194     elif opt == '-f':
 195       filter_regex = val
 196     else:
 197       assert 0
 198
 199   protos = ParseFileToBeWrapped(sys.stdin, filter_regex)
 200   if mode == "dump":
 201     for f, a in  protos:
 202       print f
 203       print "\t", a
 204   elif mode == "header":
 205     PrintHeaderFile(protos, sys.stdout)
 206   elif mode == "codegen":
 207     PrintImplSkel(protos, sys.stdout)
 208     PrintSyscallTableIntializer(protos, sys.stdout)
 209
 210
 211   return 0
 212
 213
 214 if __name__ == '__main__':
 215   sys.exit(main(sys.argv))