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      1 //===--- MacroArgs.h - Formal argument info for Macros ----------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the MacroArgs interface.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CLANG_MACROARGS_H
     15 #define LLVM_CLANG_MACROARGS_H
     16 
     17 #include "clang/Basic/LLVM.h"
     18 #include "llvm/ADT/ArrayRef.h"
     19 #include <vector>
     20 
     21 namespace clang {
     22   class MacroInfo;
     23   class Preprocessor;
     24   class Token;
     25   class SourceLocation;
     26 
     27 /// MacroArgs - An instance of this class captures information about
     28 /// the formal arguments specified to a function-like macro invocation.
     29 class MacroArgs {
     30   /// NumUnexpArgTokens - The number of raw, unexpanded tokens for the
     31   /// arguments.  All of the actual argument tokens are allocated immediately
     32   /// after the MacroArgs object in memory.  This is all of the arguments
     33   /// concatenated together, with 'EOF' markers at the end of each argument.
     34   unsigned NumUnexpArgTokens;
     35 
     36   /// VarargsElided - True if this is a C99 style varargs macro invocation and
     37   /// there was no argument specified for the "..." argument.  If the argument
     38   /// was specified (even empty) or this isn't a C99 style varargs function, or
     39   /// if in strict mode and the C99 varargs macro had only a ... argument, this
     40   /// is false.
     41   bool VarargsElided;
     42 
     43   /// PreExpArgTokens - Pre-expanded tokens for arguments that need them.  Empty
     44   /// if not yet computed.  This includes the EOF marker at the end of the
     45   /// stream.
     46   std::vector<std::vector<Token> > PreExpArgTokens;
     47 
     48   /// StringifiedArgs - This contains arguments in 'stringified' form.  If the
     49   /// stringified form of an argument has not yet been computed, this is empty.
     50   std::vector<Token> StringifiedArgs;
     51 
     52   /// ArgCache - This is a linked list of MacroArgs objects that the
     53   /// Preprocessor owns which we use to avoid thrashing malloc/free.
     54   MacroArgs *ArgCache;
     55 
     56   MacroArgs(unsigned NumToks, bool varargsElided)
     57     : NumUnexpArgTokens(NumToks), VarargsElided(varargsElided), ArgCache(0) {}
     58   ~MacroArgs() {}
     59 public:
     60   /// MacroArgs ctor function - Create a new MacroArgs object with the specified
     61   /// macro and argument info.
     62   static MacroArgs *create(const MacroInfo *MI,
     63                            ArrayRef<Token> UnexpArgTokens,
     64                            bool VarargsElided, Preprocessor &PP);
     65 
     66   /// destroy - Destroy and deallocate the memory for this object.
     67   ///
     68   void destroy(Preprocessor &PP);
     69 
     70   /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
     71   /// by pre-expansion, return false.  Otherwise, conservatively return true.
     72   bool ArgNeedsPreexpansion(const Token *ArgTok, Preprocessor &PP) const;
     73 
     74   /// getUnexpArgument - Return a pointer to the first token of the unexpanded
     75   /// token list for the specified formal.
     76   ///
     77   const Token *getUnexpArgument(unsigned Arg) const;
     78 
     79   /// getArgLength - Given a pointer to an expanded or unexpanded argument,
     80   /// return the number of tokens, not counting the EOF, that make up the
     81   /// argument.
     82   static unsigned getArgLength(const Token *ArgPtr);
     83 
     84   /// getPreExpArgument - Return the pre-expanded form of the specified
     85   /// argument.
     86   const std::vector<Token> &
     87     getPreExpArgument(unsigned Arg, const MacroInfo *MI, Preprocessor &PP);
     88 
     89   /// getStringifiedArgument - Compute, cache, and return the specified argument
     90   /// that has been 'stringified' as required by the # operator.
     91   const Token &getStringifiedArgument(unsigned ArgNo, Preprocessor &PP,
     92                                       SourceLocation ExpansionLocStart,
     93                                       SourceLocation ExpansionLocEnd);
     94 
     95   /// getNumArguments - Return the number of arguments passed into this macro
     96   /// invocation.
     97   unsigned getNumArguments() const { return NumUnexpArgTokens; }
     98 
     99 
    100   /// isVarargsElidedUse - Return true if this is a C99 style varargs macro
    101   /// invocation and there was no argument specified for the "..." argument.  If
    102   /// the argument was specified (even empty) or this isn't a C99 style varargs
    103   /// function, or if in strict mode and the C99 varargs macro had only a ...
    104   /// argument, this returns false.
    105   bool isVarargsElidedUse() const { return VarargsElided; }
    106 
    107   /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
    108   /// tokens into the literal string token that should be produced by the C #
    109   /// preprocessor operator.  If Charify is true, then it should be turned into
    110   /// a character literal for the Microsoft charize (#@) extension.
    111   ///
    112   static Token StringifyArgument(const Token *ArgToks,
    113                                  Preprocessor &PP, bool Charify,
    114                                  SourceLocation ExpansionLocStart,
    115                                  SourceLocation ExpansionLocEnd);
    116 
    117 
    118   /// deallocate - This should only be called by the Preprocessor when managing
    119   /// its freelist.
    120   MacroArgs *deallocate();
    121 };
    122 
    123 }  // end namespace clang
    124 
    125 #endif
    126