AppPkg/Applications/Python/Python-2.7.2/Tools/bgen/bgen/bgenOutput.py

   1 """Output primitives for the binding generator classes.
   2
   3 This should really be a class, but then everybody would be passing
   4 the output object to each other.  I chose for the simpler approach
   5 of a module with a global variable.  Use SetOutputFile() or
   6 SetOutputFileName() to change the output file.
   7 """
   8
   9 _NeedClose = 0
  10
  11 def SetOutputFile(file = None, needclose = 0):
  12     """Call this with an open file object to make it the output file.
  13
  14     Call it without arguments to close the current file (if necessary)
  15     and reset it to sys.stdout.
  16     If the second argument is true, the new file will be explicitly closed
  17     on a subsequence call.
  18     """
  19     global _File, _NeedClose
  20     if _NeedClose:
  21         tmp = _File
  22         _NeedClose = 0
  23         _File = None
  24         tmp.close()
  25     if file is None:
  26         import sys
  27         file = sys.stdout
  28     _File = file
  29     _NeedClose = file and needclose
  30
  31 def SetOutputFileName(filename = None):
  32     """Call this with a filename to make it the output file.
  33
  34     Call it without arguments to close the current file (if necessary)
  35     and reset it to sys.stdout.
  36     """
  37     SetOutputFile()
  38     if filename:
  39         SetOutputFile(open(filename, 'w'), 1)
  40
  41 SetOutputFile() # Initialize _File
  42
  43 _Level = 0      # Indentation level
  44
  45 def GetLevel():
  46     """Return the current indentation level."""
  47     return _Level
  48
  49 def SetLevel(level):
  50     """Set the current indentation level.
  51
  52     This does no type or range checking -- use at own risk.
  53     """
  54     global _Level
  55     _Level = level
  56
  57 def Output(format = "", *args):
  58     VaOutput(format, args)
  59
  60 def VaOutput(format, args):
  61     """Call this with a format string and argument tuple for the format.
  62
  63     A newline is always added.  Each line in the output is indented
  64     to the proper indentation level -- even if the result of the
  65     format expansion contains embedded newlines.  Exception: lines
  66     beginning with '#' are not indented -- these are assumed to be
  67     C preprprocessor lines.
  68     """
  69     text = format % args
  70     if _Level > 0:
  71         indent = '\t' * _Level
  72         lines = text.split('\n')
  73         for i in range(len(lines)):
  74             if lines[i] and lines[i][0] != '#':
  75                 lines[i] = indent + lines[i]
  76         text = '\n'.join(lines)
  77     _File.write(text + '\n')
  78
  79 def IndentLevel(by = 1):
  80     """Increment the indentation level by one.
  81
  82     When called with an argument, adds it to the indentation level.
  83     """
  84     global _Level
  85     if _Level+by < 0:
  86         raise Error, "indentation underflow (internal error)"
  87     _Level = _Level + by
  88
  89 def DedentLevel(by = 1):
  90     """Decrement the indentation level by one.
  91
  92     When called with an argument, subtracts it from the indentation level.
  93     """
  94     IndentLevel(-by)
  95
  96 def OutIndent(format = "", *args):
  97     """Combine Output() followed by IndentLevel().
  98
  99     If no text is given, acts like lone IndentLevel().
 100     """
 101     if format: VaOutput(format, args)
 102     IndentLevel()
 103
 104 def OutDedent(format = "", *args):
 105     """Combine Output() followed by DedentLevel().
 106
 107     If no text is given, acts like loneDedentLevel().
 108     """
 109     if format: VaOutput(format, args)
 110     DedentLevel()
 111
 112 def OutLbrace(format = "", *args):
 113     """Like Output, but add a '{' and increase the indentation level.
 114
 115     If no text is given a lone '{' is output.
 116     """
 117     if format:
 118         format = format + " {"
 119     else:
 120         format = "{"
 121     VaOutput(format, args)
 122     IndentLevel()
 123
 124 def OutRbrace():
 125     """Decrease the indentation level and output a '}' on a line by itself."""
 126     DedentLevel()
 127     Output("}")
 128
 129 def OutHeader(text, dash):
 130     """Output a header comment using a given dash character."""
 131     n = 64 - len(text)
 132     Output()
 133     Output("/* %s %s %s */", dash * (n/2), text, dash * (n - n/2))
 134     Output()
 135
 136 def OutHeader1(text):
 137     """Output a level 1 header comment (uses '=' dashes)."""
 138     OutHeader(text, "=")
 139
 140 def OutHeader2(text):
 141     """Output a level 2 header comment (uses '-' dashes)."""
 142     OutHeader(text, "-")
 143
 144 def Out(text):
 145     """Output multiline text that's internally indented.
 146
 147     Pass this a multiline character string.  The whitespace before the
 148     first nonblank line of the string will be subtracted from all lines.
 149     The lines are then output using Output(), but without interpretation
 150     of formatting (if you need formatting you can do it before the call).
 151     Recommended use:
 152
 153         Out('''
 154             int main(argc, argv)
 155                 int argc;
 156                 char *argv;
 157             {
 158                 printf("Hello, world\\n");
 159                 exit(0);
 160             }
 161         ''')
 162
 163     Caveat: the indentation must be consistent -- if you use three tabs
 164     in the first line, (up to) three tabs are removed from following lines,
 165     but a line beginning with 24 spaces is not trimmed at all.  Don't use
 166     this as a feature.
 167     """
 168     # (Don't you love using triple quotes *inside* triple quotes? :-)
 169
 170     lines = text.split('\n')
 171     indent = ""
 172     for line in lines:
 173         if line.strip():
 174             for c in line:
 175                 if not c.isspace():
 176                     break
 177                 indent = indent + c
 178             break
 179     n = len(indent)
 180     for line in lines:
 181         if line[:n] == indent:
 182             line = line[n:]
 183         else:
 184             for c in indent:
 185                 if line[:1] <> c: break
 186                 line = line[1:]
 187         VaOutput("%s", line)
 188
 189
 190 def _test():
 191     """Test program.  Run when the module is run as a script."""
 192     OutHeader1("test bgenOutput")
 193     Out("""
 194         #include <Python.h>
 195         #include <stdio.h>
 196
 197         main(argc, argv)
 198             int argc;
 199             char **argv;
 200         {
 201             int i;
 202     """)
 203     IndentLevel()
 204     Output("""\
 205 /* Here are a few comment lines.
 206    Just to test indenting multiple lines.
 207
 208    End of the comment lines. */
 209 """)
 210     Output("for (i = 0; i < argc; i++)")
 211     OutLbrace()
 212     Output('printf("argv[%%d] = %%s\\n", i, argv[i]);')
 213     OutRbrace()
 214     Output("exit(0)")
 215     OutRbrace()
 216     OutHeader2("end test")
 217
 218 if __name__ == '__main__':
 219     _test()