314 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			314 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===--- TokenLexer.cpp - Lex from a token stream -------------------------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file implements the TokenLexer interface.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "clang/Lex/MacroArgs.h"
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| #include "clang/Lex/LexDiagnostic.h"
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| #include "clang/Lex/MacroInfo.h"
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| #include "clang/Lex/Preprocessor.h"
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| #include "llvm/ADT/SmallString.h"
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| #include "llvm/Support/SaveAndRestore.h"
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| #include <algorithm>
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| 
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| using namespace clang;
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| 
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| /// MacroArgs ctor function - This destroys the vector passed in.
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| MacroArgs *MacroArgs::create(const MacroInfo *MI,
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|                              ArrayRef<Token> UnexpArgTokens,
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|                              bool VarargsElided, Preprocessor &PP) {
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|   assert(MI->isFunctionLike() &&
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|          "Can't have args for an object-like macro!");
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|   MacroArgs **ResultEnt = 0;
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|   unsigned ClosestMatch = ~0U;
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|   
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|   // See if we have an entry with a big enough argument list to reuse on the
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|   // free list.  If so, reuse it.
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|   for (MacroArgs **Entry = &PP.MacroArgCache; *Entry;
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|        Entry = &(*Entry)->ArgCache)
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|     if ((*Entry)->NumUnexpArgTokens >= UnexpArgTokens.size() &&
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|         (*Entry)->NumUnexpArgTokens < ClosestMatch) {
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|       ResultEnt = Entry;
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|       
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|       // If we have an exact match, use it.
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|       if ((*Entry)->NumUnexpArgTokens == UnexpArgTokens.size())
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|         break;
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|       // Otherwise, use the best fit.
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|       ClosestMatch = (*Entry)->NumUnexpArgTokens;
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|     }
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|   
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|   MacroArgs *Result;
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|   if (ResultEnt == 0) {
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|     // Allocate memory for a MacroArgs object with the lexer tokens at the end.
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|     Result = (MacroArgs*)malloc(sizeof(MacroArgs) + 
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|                                 UnexpArgTokens.size() * sizeof(Token));
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|     // Construct the MacroArgs object.
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|     new (Result) MacroArgs(UnexpArgTokens.size(), VarargsElided);
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|   } else {
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|     Result = *ResultEnt;
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|     // Unlink this node from the preprocessors singly linked list.
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|     *ResultEnt = Result->ArgCache;
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|     Result->NumUnexpArgTokens = UnexpArgTokens.size();
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|     Result->VarargsElided = VarargsElided;
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|   }
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| 
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|   // Copy the actual unexpanded tokens to immediately after the result ptr.
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|   if (!UnexpArgTokens.empty())
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|     std::copy(UnexpArgTokens.begin(), UnexpArgTokens.end(), 
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|               const_cast<Token*>(Result->getUnexpArgument(0)));
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| 
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|   return Result;
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| }
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| 
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| /// destroy - Destroy and deallocate the memory for this object.
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| ///
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| void MacroArgs::destroy(Preprocessor &PP) {
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|   StringifiedArgs.clear();
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| 
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|   // Don't clear PreExpArgTokens, just clear the entries.  Clearing the entries
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|   // would deallocate the element vectors.
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|   for (unsigned i = 0, e = PreExpArgTokens.size(); i != e; ++i)
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|     PreExpArgTokens[i].clear();
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|   
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|   // Add this to the preprocessor's free list.
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|   ArgCache = PP.MacroArgCache;
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|   PP.MacroArgCache = this;
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| }
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| 
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| /// deallocate - This should only be called by the Preprocessor when managing
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| /// its freelist.
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| MacroArgs *MacroArgs::deallocate() {
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|   MacroArgs *Next = ArgCache;
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|   
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|   // Run the dtor to deallocate the vectors.
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|   this->~MacroArgs();
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|   // Release the memory for the object.
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|   free(this);
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|   
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|   return Next;
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| }
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| 
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| 
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| /// getArgLength - Given a pointer to an expanded or unexpanded argument,
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| /// return the number of tokens, not counting the EOF, that make up the
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| /// argument.
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| unsigned MacroArgs::getArgLength(const Token *ArgPtr) {
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|   unsigned NumArgTokens = 0;
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|   for (; ArgPtr->isNot(tok::eof); ++ArgPtr)
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|     ++NumArgTokens;
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|   return NumArgTokens;
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| }
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| 
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| 
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| /// getUnexpArgument - Return the unexpanded tokens for the specified formal.
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| ///
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| const Token *MacroArgs::getUnexpArgument(unsigned Arg) const {
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|   // The unexpanded argument tokens start immediately after the MacroArgs object
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|   // in memory.
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|   const Token *Start = (const Token *)(this+1);
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|   const Token *Result = Start;
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|   // Scan to find Arg.
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|   for (; Arg; ++Result) {
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|     assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
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|     if (Result->is(tok::eof))
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|       --Arg;
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|   }
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|   assert(Result < Start+NumUnexpArgTokens && "Invalid arg #");
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|   return Result;
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| }
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| 
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| 
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| /// ArgNeedsPreexpansion - If we can prove that the argument won't be affected
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| /// by pre-expansion, return false.  Otherwise, conservatively return true.
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| bool MacroArgs::ArgNeedsPreexpansion(const Token *ArgTok,
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|                                      Preprocessor &PP) const {
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|   // If there are no identifiers in the argument list, or if the identifiers are
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|   // known to not be macros, pre-expansion won't modify it.
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|   for (; ArgTok->isNot(tok::eof); ++ArgTok)
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|     if (IdentifierInfo *II = ArgTok->getIdentifierInfo()) {
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|       if (II->hasMacroDefinition() && PP.getMacroInfo(II)->isEnabled())
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|         // Return true even though the macro could be a function-like macro
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|         // without a following '(' token.
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|         return true;
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|     }
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|   return false;
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| }
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| 
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| /// getPreExpArgument - Return the pre-expanded form of the specified
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| /// argument.
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| const std::vector<Token> &
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| MacroArgs::getPreExpArgument(unsigned Arg, const MacroInfo *MI, 
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|                              Preprocessor &PP) {
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|   assert(Arg < MI->getNumArgs() && "Invalid argument number!");
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| 
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|   // If we have already computed this, return it.
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|   if (PreExpArgTokens.size() < MI->getNumArgs())
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|     PreExpArgTokens.resize(MI->getNumArgs());
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|   
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|   std::vector<Token> &Result = PreExpArgTokens[Arg];
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|   if (!Result.empty()) return Result;
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| 
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|   SaveAndRestore<bool> PreExpandingMacroArgs(PP.InMacroArgPreExpansion, true);
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| 
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|   const Token *AT = getUnexpArgument(Arg);
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|   unsigned NumToks = getArgLength(AT)+1;  // Include the EOF.
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| 
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|   // Otherwise, we have to pre-expand this argument, populating Result.  To do
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|   // this, we set up a fake TokenLexer to lex from the unexpanded argument
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|   // list.  With this installed, we lex expanded tokens until we hit the EOF
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|   // token at the end of the unexp list.
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|   PP.EnterTokenStream(AT, NumToks, false /*disable expand*/,
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|                       false /*owns tokens*/);
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| 
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|   // Lex all of the macro-expanded tokens into Result.
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|   do {
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|     Result.push_back(Token());
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|     Token &Tok = Result.back();
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|     PP.Lex(Tok);
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|   } while (Result.back().isNot(tok::eof));
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| 
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|   // Pop the token stream off the top of the stack.  We know that the internal
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|   // pointer inside of it is to the "end" of the token stream, but the stack
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|   // will not otherwise be popped until the next token is lexed.  The problem is
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|   // that the token may be lexed sometime after the vector of tokens itself is
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|   // destroyed, which would be badness.
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|   if (PP.InCachingLexMode())
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|     PP.ExitCachingLexMode();
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|   PP.RemoveTopOfLexerStack();
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|   return Result;
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| }
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| 
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| 
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| /// StringifyArgument - Implement C99 6.10.3.2p2, converting a sequence of
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| /// tokens into the literal string token that should be produced by the C #
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| /// preprocessor operator.  If Charify is true, then it should be turned into
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| /// a character literal for the Microsoft charize (#@) extension.
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| ///
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| Token MacroArgs::StringifyArgument(const Token *ArgToks,
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|                                    Preprocessor &PP, bool Charify,
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|                                    SourceLocation ExpansionLocStart,
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|                                    SourceLocation ExpansionLocEnd) {
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|   Token Tok;
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|   Tok.startToken();
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|   Tok.setKind(Charify ? tok::char_constant : tok::string_literal);
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| 
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|   const Token *ArgTokStart = ArgToks;
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| 
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|   // Stringify all the tokens.
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|   SmallString<128> Result;
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|   Result += "\"";
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| 
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|   bool isFirst = true;
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|   for (; ArgToks->isNot(tok::eof); ++ArgToks) {
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|     const Token &Tok = *ArgToks;
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|     if (!isFirst && (Tok.hasLeadingSpace() || Tok.isAtStartOfLine()))
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|       Result += ' ';
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|     isFirst = false;
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| 
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|     // If this is a string or character constant, escape the token as specified
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|     // by 6.10.3.2p2.
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|     if (tok::isStringLiteral(Tok.getKind()) || // "foo", u8R"x(foo)x"_bar, etc.
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|         Tok.is(tok::char_constant) ||          // 'x'
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|         Tok.is(tok::wide_char_constant) ||     // L'x'.
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|         Tok.is(tok::utf16_char_constant) ||    // u'x'.
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|         Tok.is(tok::utf32_char_constant)) {    // U'x'.
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|       bool Invalid = false;
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|       std::string TokStr = PP.getSpelling(Tok, &Invalid);
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|       if (!Invalid) {
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|         std::string Str = Lexer::Stringify(TokStr);
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|         Result.append(Str.begin(), Str.end());
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|       }
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|     } else if (Tok.is(tok::code_completion)) {
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|       PP.CodeCompleteNaturalLanguage();
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|     } else {
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|       // Otherwise, just append the token.  Do some gymnastics to get the token
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|       // in place and avoid copies where possible.
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|       unsigned CurStrLen = Result.size();
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|       Result.resize(CurStrLen+Tok.getLength());
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|       const char *BufPtr = &Result[CurStrLen];
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|       bool Invalid = false;
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|       unsigned ActualTokLen = PP.getSpelling(Tok, BufPtr, &Invalid);
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| 
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|       if (!Invalid) {
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|         // If getSpelling returned a pointer to an already uniqued version of
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|         // the string instead of filling in BufPtr, memcpy it onto our string.
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|         if (BufPtr != &Result[CurStrLen])
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|           memcpy(&Result[CurStrLen], BufPtr, ActualTokLen);
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| 
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|         // If the token was dirty, the spelling may be shorter than the token.
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|         if (ActualTokLen != Tok.getLength())
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|           Result.resize(CurStrLen+ActualTokLen);
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|       }
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|     }
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|   }
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| 
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|   // If the last character of the string is a \, and if it isn't escaped, this
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|   // is an invalid string literal, diagnose it as specified in C99.
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|   if (Result.back() == '\\') {
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|     // Count the number of consequtive \ characters.  If even, then they are
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|     // just escaped backslashes, otherwise it's an error.
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|     unsigned FirstNonSlash = Result.size()-2;
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|     // Guaranteed to find the starting " if nothing else.
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|     while (Result[FirstNonSlash] == '\\')
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|       --FirstNonSlash;
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|     if ((Result.size()-1-FirstNonSlash) & 1) {
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|       // Diagnose errors for things like: #define F(X) #X   /   F(\)
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|       PP.Diag(ArgToks[-1], diag::pp_invalid_string_literal);
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|       Result.pop_back();  // remove one of the \'s.
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|     }
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|   }
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|   Result += '"';
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| 
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|   // If this is the charify operation and the result is not a legal character
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|   // constant, diagnose it.
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|   if (Charify) {
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|     // First step, turn double quotes into single quotes:
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|     Result[0] = '\'';
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|     Result[Result.size()-1] = '\'';
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| 
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|     // Check for bogus character.
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|     bool isBad = false;
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|     if (Result.size() == 3)
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|       isBad = Result[1] == '\'';   // ''' is not legal. '\' already fixed above.
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|     else
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|       isBad = (Result.size() != 4 || Result[1] != '\\');  // Not '\x'
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| 
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|     if (isBad) {
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|       PP.Diag(ArgTokStart[0], diag::err_invalid_character_to_charify);
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|       Result = "' '";  // Use something arbitrary, but legal.
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|     }
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|   }
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| 
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|   PP.CreateString(Result, Tok,
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|                   ExpansionLocStart, ExpansionLocEnd);
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|   return Tok;
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| }
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| 
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| /// getStringifiedArgument - Compute, cache, and return the specified argument
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| /// that has been 'stringified' as required by the # operator.
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| const Token &MacroArgs::getStringifiedArgument(unsigned ArgNo,
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|                                                Preprocessor &PP,
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|                                                SourceLocation ExpansionLocStart,
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|                                                SourceLocation ExpansionLocEnd) {
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|   assert(ArgNo < NumUnexpArgTokens && "Invalid argument number!");
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|   if (StringifiedArgs.empty()) {
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|     StringifiedArgs.resize(getNumArguments());
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|     memset((void*)&StringifiedArgs[0], 0,
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|            sizeof(StringifiedArgs[0])*getNumArguments());
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|   }
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|   if (StringifiedArgs[ArgNo].isNot(tok::string_literal))
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|     StringifiedArgs[ArgNo] = StringifyArgument(getUnexpArgument(ArgNo), PP,
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|                                                /*Charify=*/false,
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|                                                ExpansionLocStart,
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|                                                ExpansionLocEnd);
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|   return StringifiedArgs[ArgNo];
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| }
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