[cvs-nhc98] patch applied (cpphs): Bugfix: #undef caused an infinite loop

[Malcolm Wallace]

Thu Sep  3 02:13:25 PDT 2009  Malcolm.Wallace at cs.york.ac.uk
  * Bugfix: #undef caused an infinite loop
  Ignore-this: 449791949546c4ffa141fe22ddfa34c5
  
  Cause: #undef was being translated into a SymbolReplacement where the
  replacement is the same as the original identifier.  This used to work,
  until we switched on recursive expansion of SymbolReplacements.
  
  Fix: Introduce a different HashDefine constructor (AntiDefined) to
  handle #undef, rather than piggypacking on SymbolReplacement.

    M ./Language/Preprocessor/Cpphs/CppIfdef.hs -1 +1
    M ./Language/Preprocessor/Cpphs/HashDefine.hs -2 +6
    M ./Language/Preprocessor/Cpphs/MacroPass.hs +1
    M ./tests/runtests +1
    A ./tests/undef.hs

View patch online:
http://darcs.haskell.org/cpphs/_darcs/patches/20090903091325-6871e-3e48959fce789ef5ebdace261481464530aa8075.gz