toolkit/src2xml/source/macroparser.py

   1
   2 import sys
   3 from globals import *
   4 import srclexer
   5
   6 class MacroParser(object):
   7
   8     def __init__ (self, buf):
   9         self.buffer = buf
  10         self.macro = None
  11         self.debug = False
  12
  13     def parse (self):
  14         """
  15 A macro with arguments must have its open paren immediately following
  16 its name without any whitespace.
  17 """
  18         if self.debug:
  19             print "-"*68
  20             print "parsing '%s'"%self.buffer
  21
  22         i = 0
  23         bufSize = len(self.buffer)
  24         name, buf = '', ''
  25         while i < bufSize:
  26             c = self.buffer[i]
  27             if c in [' ', "\t"] and len(name) == 0:
  28                 # This is a simple macro with no arguments.
  29                 name = buf
  30                 vars = []
  31                 content = self.buffer[i:]
  32                 self.setMacro(name, vars, content)
  33                 return
  34             elif c == '(' and len(name) == 0:
  35                 # This one has arguments.
  36                 name = buf
  37                 buf = self.buffer[i:]
  38                 vars, content = self.parseArgs(buf)
  39                 self.setMacro(name, vars, content)
  40                 return
  41             else:
  42                 buf += c
  43                 i += 1
  44
  45     def parseArgs (self, buffer):
  46         """Parse arguments.
  47
  48 The buffer is expected to be formatted like '(a, b, c)' where the first
  49 character is the open paren.
  50 """
  51         scope = 0
  52         buf = ''
  53         vars = []
  54         content = ''
  55         bufSize = len(buffer)
  56         i = 0
  57         while i < bufSize:
  58             c = buffer[i]
  59             if c == '(':
  60                 scope += 1
  61             elif c == ')':
  62                 scope -= 1
  63                 if len(buf) > 0:
  64                     vars.append(buf)
  65                 if scope == 0:
  66                     break
  67             elif c == ',':
  68                 if len(buf) == 0:
  69                     raise globals.ParseError ('')
  70                 vars.append(buf)
  71                 buf = ''
  72             elif c in " \t" and scope > 0:
  73                 pass
  74             else:
  75                 buf += c
  76
  77             i += 1
  78
  79         if scope > 0:
  80             raise globals.ParseError ('')
  81
  82         return vars, buffer[i+1:]
  83
  84
  85     def setMacro (self, name, vars, content):
  86         if self.debug:
  87             print "-"*68
  88             print "name: %s"%name
  89             for var in vars:
  90                 print "var: %s"%var
  91             if len(vars) == 0:
  92                 print "no vars"
  93             print "content: '%s'"%content
  94
  95         if len(content) > 0:
  96             self.macro = Macro(name)
  97             for i in xrange(0, len(vars)):
  98                 self.macro.vars[vars[i]] = i
  99
 100             # tokinize it using lexer.
 101             mclexer = srclexer.SrcLexer(content)
 102             mclexer.expandHeaders = False
 103             mclexer.inMacroDefine = True
 104             mclexer.tokenize()
 105             self.macro.tokens = mclexer.getTokens()
 106             if self.debug:
 107                 print self.macro.tokens
 108
 109             if not self.isValidMacro(self.macro):
 110                 self.macro = None
 111
 112         if self.debug:
 113             if self.macro != None:
 114                 print "macro registered!"
 115             else:
 116                 print "macro not registered"
 117
 118     def isValidMacro (self, macro):
 119
 120         n = len(macro.tokens)
 121         if n == 0:
 122             return False
 123         elif len(macro.name) > 4 and macro.name[1:4] == 'ID_':
 124             # We don't want to expand macros like HID_, SID_, WID_, etc.
 125             return False
 126         return True
 127
 128
 129     def getMacro (self):
 130         return self.macro