forked from OSchip/llvm-project
64 lines
1.6 KiB
C++
64 lines
1.6 KiB
C++
//===--- PPCaching.cpp - Handle caching lexed tokens ----------------------===//
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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 pieces of the Preprocessor interface that manage the
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// caching of lexed tokens.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Lex/Preprocessor.h"
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using namespace clang;
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void Preprocessor::CachingLex(Token &Result) {
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if (CachedLexPos < CachedTokens.size()) {
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Result = CachedTokens[CachedLexPos++];
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return;
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}
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ExitCachingLexMode();
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Lex(Result);
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if (!CacheTokens) {
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// All cached tokens were consumed.
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CachedTokens.clear();
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CachedLexPos = 0;
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return;
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}
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// We should cache the lexed token.
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EnterCachingLexMode();
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if (Result.isNot(tok::eof)) {
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CachedTokens.push_back(Result);
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++CachedLexPos;
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}
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}
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void Preprocessor::EnterCachingLexMode() {
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if (InCachingLexMode())
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return;
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IncludeMacroStack.push_back(IncludeStackInfo(CurLexer, CurDirLookup,
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CurTokenLexer));
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CurLexer = 0;
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CurTokenLexer = 0;
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}
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const Token &Preprocessor::PeekAhead(unsigned N) {
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assert(CachedLexPos + N > CachedTokens.size() && "Confused caching.");
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ExitCachingLexMode();
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for (unsigned C = CachedLexPos + N - CachedTokens.size(); C > 0; --C) {
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CachedTokens.push_back(Token());
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Lex(CachedTokens.back());
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}
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EnterCachingLexMode();
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return CachedTokens.back();
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}
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