[Python-checkins] CVS: distutils/distutils sysconfig.py,1.27,1.28

[Greg Ward]

Update of /cvsroot/python/distutils/distutils
In directory slayer.i.sourceforge.net:/tmp/cvs-serv8403

Modified Files:
	sysconfig.py 
Log Message:
Added 'expand_makefile_vars()' to (duh) expand make-style variables
  in a string (gives you something to do with the dictionary returned
  by 'parse_makefile()').
Pulled the regexes in 'parse_makefile()' out -- they're now globals,
  as 'expand_makefile_vars()' needs (two of) them.
Cosmetic tweaks to 'parse_makefile()'.


Index: sysconfig.py
===================================================================
RCS file: /cvsroot/python/distutils/distutils/sysconfig.py,v
retrieving revision 1.27
retrieving revision 1.28
diff -C2 -r1.27 -r1.28
*** sysconfig.py	2000/09/15 01:15:08	1.27
--- sysconfig.py	2000/09/17 00:53:02	1.28
***************
*** 158,161 ****
--- 158,168 ----
      return g
  
+ 
+ # Regexes needed for parsing Makefile (and similar syntaxes,
+ # like old-style Setup files).
+ _variable_rx = re.compile("([a-zA-Z][a-zA-Z0-9_]+)\s*=\s*(.*)")
+ _findvar1_rx = re.compile(r"\$\(([A-Za-z][A-Za-z0-9_]*)\)")
+ _findvar2_rx = re.compile(r"\${([A-Za-z][A-Za-z0-9_]*)}")
+ 
  def parse_makefile(fn, g=None):
      """Parse a Makefile-style file.
***************
*** 167,175 ****
      """
      from distutils.text_file import TextFile
!     fp = TextFile(fn, strip_comments=1, join_lines=1)
  
      if g is None:
          g = {}
-     variable_rx = re.compile("([a-zA-Z][a-zA-Z0-9_]+)\s*=\s*(.*)")
      done = {}
      notdone = {}
--- 174,181 ----
      """
      from distutils.text_file import TextFile
!     fp = TextFile(fn, strip_comments=1, skip_blanks=1, join_lines=1)
  
      if g is None:
          g = {}
      done = {}
      notdone = {}
***************
*** 177,183 ****
      while 1:
          line = fp.readline()
!         if line is None:
              break
!         m = variable_rx.match(line)
          if m:
              n, v = m.group(1, 2)
--- 183,189 ----
      while 1:
          line = fp.readline()
!         if line is None:                # eof
              break
!         m = _variable_rx.match(line)
          if m:
              n, v = m.group(1, 2)
***************
*** 191,202 ****
  
      # do variable interpolation here
-     findvar1_rx = re.compile(r"\$\(([A-Za-z][A-Za-z0-9_]*)\)")
-     findvar2_rx = re.compile(r"\${([A-Za-z][A-Za-z0-9_]*)}")
      while notdone:
          for name in notdone.keys():
              value = notdone[name]
!             m = findvar1_rx.search(value)
!             if not m:
!                 m = findvar2_rx.search(value)
              if m:
                  n = m.group(1)
--- 197,204 ----
  
      # do variable interpolation here
      while notdone:
          for name in notdone.keys():
              value = notdone[name]
!             m = _findvar1_rx.search(value) or _findvar2_rx.search(value)
              if m:
                  n = m.group(1)
***************
*** 229,235 ****
--- 231,265 ----
                  del notdone[name]
  
+     fp.close()
+ 
      # save the results in the global dictionary
      g.update(done)
      return g
+ 
+ 
+ def expand_makefile_vars(s, vars):
+     """Expand Makefile-style variables -- "${foo}" or "$(foo)" -- in
+     'string' according to 'vars' (a dictionary mapping variable names to
+     values).  Variables not present in 'vars' are silently expanded to the
+     empty string.  The variable values in 'vars' should not contain further
+     variable expansions; if 'vars' is the output of 'parse_makefile()',
+     you're fine.  Returns a variable-expanded version of 's'.
+     """
+ 
+     # This algorithm does multiple expansion, so if vars['foo'] contains
+     # "${bar}", it will expand ${foo} to ${bar}, and then expand
+     # ${bar}... and so forth.  This is fine as long as 'vars' comes from
+     # 'parse_makefile()', which takes care of such expansions eagerly,
+     # according to make's variable expansion semantics.
+ 
+     while 1:
+         m = _findvar1_rx.search(s) or _findvar2_rx.search(s)
+         if m:
+             name = m.group(1)
+             (beg, end) = m.span()
+             s = s[0:beg] + vars.get(m.group(1)) + s[end:]
+         else:
+             break
+     return s