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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp b/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp new file mode 100644 index 0000000..4a40405 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp @@ -0,0 +1,362 @@ +//===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements pieces of the Preprocessor interface that manage the +// current lexer stack. +// +//===----------------------------------------------------------------------===// + +#include "clang/Lex/Preprocessor.h" +#include "clang/Lex/HeaderSearch.h" +#include "clang/Lex/MacroInfo.h" +#include "clang/Lex/LexDiagnostic.h" +#include "clang/Basic/SourceManager.h" +#include "llvm/Support/MemoryBuffer.h" +using namespace clang; + +PPCallbacks::~PPCallbacks() {} + +//===----------------------------------------------------------------------===// +// Miscellaneous Methods. +//===----------------------------------------------------------------------===// + +/// isInPrimaryFile - Return true if we're in the top-level file, not in a +/// #include. This looks through macro expansions and active _Pragma lexers. +bool Preprocessor::isInPrimaryFile() const { + if (IsFileLexer()) + return IncludeMacroStack.empty(); + + // If there are any stacked lexers, we're in a #include. + assert(IsFileLexer(IncludeMacroStack[0]) && + "Top level include stack isn't our primary lexer?"); + for (unsigned i = 1, e = IncludeMacroStack.size(); i != e; ++i) + if (IsFileLexer(IncludeMacroStack[i])) + return false; + return true; +} + +/// getCurrentLexer - Return the current file lexer being lexed from. Note +/// that this ignores any potentially active macro expansions and _Pragma +/// expansions going on at the time. +PreprocessorLexer *Preprocessor::getCurrentFileLexer() const { + if (IsFileLexer()) + return CurPPLexer; + + // Look for a stacked lexer. + for (unsigned i = IncludeMacroStack.size(); i != 0; --i) { + const IncludeStackInfo& ISI = IncludeMacroStack[i-1]; + if (IsFileLexer(ISI)) + return ISI.ThePPLexer; + } + return 0; +} + + +//===----------------------------------------------------------------------===// +// Methods for Entering and Callbacks for leaving various contexts +//===----------------------------------------------------------------------===// + +/// EnterSourceFile - Add a source file to the top of the include stack and +/// start lexing tokens from it instead of the current buffer. +void Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir, + SourceLocation Loc) { + assert(CurTokenLexer == 0 && "Cannot #include a file inside a macro!"); + ++NumEnteredSourceFiles; + + if (MaxIncludeStackDepth < IncludeMacroStack.size()) + MaxIncludeStackDepth = IncludeMacroStack.size(); + + if (PTH) { + if (PTHLexer *PL = PTH->CreateLexer(FID)) { + EnterSourceFileWithPTH(PL, CurDir); + return; + } + } + + // Get the MemoryBuffer for this FID, if it fails, we fail. + bool Invalid = false; + const llvm::MemoryBuffer *InputFile = + getSourceManager().getBuffer(FID, Loc, &Invalid); + if (Invalid) { + SourceLocation FileStart = SourceMgr.getLocForStartOfFile(FID); + Diag(Loc, diag::err_pp_error_opening_file) + << std::string(SourceMgr.getBufferName(FileStart)) << ""; + return; + } + + EnterSourceFileWithLexer(new Lexer(FID, InputFile, *this), CurDir); + return; +} + +/// EnterSourceFileWithLexer - Add a source file to the top of the include stack +/// and start lexing tokens from it instead of the current buffer. +void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer, + const DirectoryLookup *CurDir) { + + // Add the current lexer to the include stack. + if (CurPPLexer || CurTokenLexer) + PushIncludeMacroStack(); + + CurLexer.reset(TheLexer); + CurPPLexer = TheLexer; + CurDirLookup = CurDir; + + // Notify the client, if desired, that we are in a new source file. + if (Callbacks && !CurLexer->Is_PragmaLexer) { + SrcMgr::CharacteristicKind FileType = + SourceMgr.getFileCharacteristic(CurLexer->getFileLoc()); + + Callbacks->FileChanged(CurLexer->getFileLoc(), + PPCallbacks::EnterFile, FileType); + } +} + +/// EnterSourceFileWithPTH - Add a source file to the top of the include stack +/// and start getting tokens from it using the PTH cache. +void Preprocessor::EnterSourceFileWithPTH(PTHLexer *PL, + const DirectoryLookup *CurDir) { + + if (CurPPLexer || CurTokenLexer) + PushIncludeMacroStack(); + + CurDirLookup = CurDir; + CurPTHLexer.reset(PL); + CurPPLexer = CurPTHLexer.get(); + + // Notify the client, if desired, that we are in a new source file. + if (Callbacks) { + FileID FID = CurPPLexer->getFileID(); + SourceLocation EnterLoc = SourceMgr.getLocForStartOfFile(FID); + SrcMgr::CharacteristicKind FileType = + SourceMgr.getFileCharacteristic(EnterLoc); + Callbacks->FileChanged(EnterLoc, PPCallbacks::EnterFile, FileType); + } +} + +/// EnterMacro - Add a Macro to the top of the include stack and start lexing +/// tokens from it instead of the current buffer. +void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd, + MacroArgs *Args) { + PushIncludeMacroStack(); + CurDirLookup = 0; + + if (NumCachedTokenLexers == 0) { + CurTokenLexer.reset(new TokenLexer(Tok, ILEnd, Args, *this)); + } else { + CurTokenLexer.reset(TokenLexerCache[--NumCachedTokenLexers]); + CurTokenLexer->Init(Tok, ILEnd, Args); + } +} + +/// EnterTokenStream - Add a "macro" context to the top of the include stack, +/// which will cause the lexer to start returning the specified tokens. +/// +/// If DisableMacroExpansion is true, tokens lexed from the token stream will +/// not be subject to further macro expansion. Otherwise, these tokens will +/// be re-macro-expanded when/if expansion is enabled. +/// +/// If OwnsTokens is false, this method assumes that the specified stream of +/// tokens has a permanent owner somewhere, so they do not need to be copied. +/// If it is true, it assumes the array of tokens is allocated with new[] and +/// must be freed. +/// +void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks, + bool DisableMacroExpansion, + bool OwnsTokens) { + // Save our current state. + PushIncludeMacroStack(); + CurDirLookup = 0; + + // Create a macro expander to expand from the specified token stream. + if (NumCachedTokenLexers == 0) { + CurTokenLexer.reset(new TokenLexer(Toks, NumToks, DisableMacroExpansion, + OwnsTokens, *this)); + } else { + CurTokenLexer.reset(TokenLexerCache[--NumCachedTokenLexers]); + CurTokenLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens); + } +} + +/// HandleEndOfFile - This callback is invoked when the lexer hits the end of +/// the current file. This either returns the EOF token or pops a level off +/// the include stack and keeps going. +bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) { + assert(!CurTokenLexer && + "Ending a file when currently in a macro!"); + + // See if this file had a controlling macro. + if (CurPPLexer) { // Not ending a macro, ignore it. + if (const IdentifierInfo *ControllingMacro = + CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) { + // Okay, this has a controlling macro, remember in HeaderFileInfo. + if (const FileEntry *FE = + SourceMgr.getFileEntryForID(CurPPLexer->getFileID())) + HeaderInfo.SetFileControllingMacro(FE, ControllingMacro); + } + } + + // If this is a #include'd file, pop it off the include stack and continue + // lexing the #includer file. + if (!IncludeMacroStack.empty()) { + // We're done with the #included file. + RemoveTopOfLexerStack(); + + // Notify the client, if desired, that we are in a new source file. + if (Callbacks && !isEndOfMacro && CurPPLexer) { + SrcMgr::CharacteristicKind FileType = + SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation()); + Callbacks->FileChanged(CurPPLexer->getSourceLocation(), + PPCallbacks::ExitFile, FileType); + } + + // Client should lex another token. + return false; + } + + // If the file ends with a newline, form the EOF token on the newline itself, + // rather than "on the line following it", which doesn't exist. This makes + // diagnostics relating to the end of file include the last file that the user + // actually typed, which is goodness. + if (CurLexer) { + const char *EndPos = CurLexer->BufferEnd; + if (EndPos != CurLexer->BufferStart && + (EndPos[-1] == '\n' || EndPos[-1] == '\r')) { + --EndPos; + + // Handle \n\r and \r\n: + if (EndPos != CurLexer->BufferStart && + (EndPos[-1] == '\n' || EndPos[-1] == '\r') && + EndPos[-1] != EndPos[0]) + --EndPos; + } + + Result.startToken(); + CurLexer->BufferPtr = EndPos; + CurLexer->FormTokenWithChars(Result, EndPos, tok::eof); + + // We're done with the #included file. + CurLexer.reset(); + } else { + assert(CurPTHLexer && "Got EOF but no current lexer set!"); + CurPTHLexer->getEOF(Result); + CurPTHLexer.reset(); + } + + CurPPLexer = 0; + + // This is the end of the top-level file. If the diag::pp_macro_not_used + // diagnostic is enabled, look for macros that have not been used. + if (getDiagnostics().getDiagnosticLevel(diag::pp_macro_not_used) != + Diagnostic::Ignored) { + for (macro_iterator I = macro_begin(false), E = macro_end(false); + I != E; ++I) + if (!I->second->isUsed()) + Diag(I->second->getDefinitionLoc(), diag::pp_macro_not_used); + } + + return true; +} + +/// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer +/// hits the end of its token stream. +bool Preprocessor::HandleEndOfTokenLexer(Token &Result) { + assert(CurTokenLexer && !CurPPLexer && + "Ending a macro when currently in a #include file!"); + + // Delete or cache the now-dead macro expander. + if (NumCachedTokenLexers == TokenLexerCacheSize) + CurTokenLexer.reset(); + else + TokenLexerCache[NumCachedTokenLexers++] = CurTokenLexer.take(); + + // Handle this like a #include file being popped off the stack. + return HandleEndOfFile(Result, true); +} + +/// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the +/// lexer stack. This should only be used in situations where the current +/// state of the top-of-stack lexer is unknown. +void Preprocessor::RemoveTopOfLexerStack() { + assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load"); + + if (CurTokenLexer) { + // Delete or cache the now-dead macro expander. + if (NumCachedTokenLexers == TokenLexerCacheSize) + CurTokenLexer.reset(); + else + TokenLexerCache[NumCachedTokenLexers++] = CurTokenLexer.take(); + } + + PopIncludeMacroStack(); +} + +/// HandleMicrosoftCommentPaste - When the macro expander pastes together a +/// comment (/##/) in microsoft mode, this method handles updating the current +/// state, returning the token on the next source line. +void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) { + assert(CurTokenLexer && !CurPPLexer && + "Pasted comment can only be formed from macro"); + + // We handle this by scanning for the closest real lexer, switching it to + // raw mode and preprocessor mode. This will cause it to return \n as an + // explicit EOM token. + PreprocessorLexer *FoundLexer = 0; + bool LexerWasInPPMode = false; + for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) { + IncludeStackInfo &ISI = *(IncludeMacroStack.end()-i-1); + if (ISI.ThePPLexer == 0) continue; // Scan for a real lexer. + + // Once we find a real lexer, mark it as raw mode (disabling macro + // expansions) and preprocessor mode (return EOM). We know that the lexer + // was *not* in raw mode before, because the macro that the comment came + // from was expanded. However, it could have already been in preprocessor + // mode (#if COMMENT) in which case we have to return it to that mode and + // return EOM. + FoundLexer = ISI.ThePPLexer; + FoundLexer->LexingRawMode = true; + LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective; + FoundLexer->ParsingPreprocessorDirective = true; + break; + } + + // Okay, we either found and switched over the lexer, or we didn't find a + // lexer. In either case, finish off the macro the comment came from, getting + // the next token. + if (!HandleEndOfTokenLexer(Tok)) Lex(Tok); + + // Discarding comments as long as we don't have EOF or EOM. This 'comments + // out' the rest of the line, including any tokens that came from other macros + // that were active, as in: + // #define submacro a COMMENT b + // submacro c + // which should lex to 'a' only: 'b' and 'c' should be removed. + while (Tok.isNot(tok::eom) && Tok.isNot(tok::eof)) + Lex(Tok); + + // If we got an eom token, then we successfully found the end of the line. + if (Tok.is(tok::eom)) { + assert(FoundLexer && "Can't get end of line without an active lexer"); + // Restore the lexer back to normal mode instead of raw mode. + FoundLexer->LexingRawMode = false; + + // If the lexer was already in preprocessor mode, just return the EOM token + // to finish the preprocessor line. + if (LexerWasInPPMode) return; + + // Otherwise, switch out of PP mode and return the next lexed token. + FoundLexer->ParsingPreprocessorDirective = false; + return Lex(Tok); + } + + // If we got an EOF token, then we reached the end of the token stream but + // didn't find an explicit \n. This can only happen if there was no lexer + // active (an active lexer would return EOM at EOF if there was no \n in + // preprocessor directive mode), so just return EOF as our token. + assert(!FoundLexer && "Lexer should return EOM before EOF in PP mode"); +} |
