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authorEd Schouten <ed@FreeBSD.org>2009-06-02 17:58:47 +0000
committerEd Schouten <ed@FreeBSD.org>2009-06-02 17:58:47 +0000
commitec2b103c267a06a66e926f62cd96767b280f5cf5 (patch)
treece7d964cbb5e39695b71481698f10cb099c23d4a /lib/Lex/TokenLexer.cpp
downloadsrc-ec2b103c267a06a66e926f62cd96767b280f5cf5.tar.gz
src-ec2b103c267a06a66e926f62cd96767b280f5cf5.zip
Import Clang, at r72732.vendor/clang/clang-r72732
Notes
Notes: svn path=/vendor/clang/dist/; revision=193326 svn path=/vendor/clang/clang-r72732/; revision=193327; tag=vendor/clang/clang-r72732
Diffstat (limited to 'lib/Lex/TokenLexer.cpp')
-rw-r--r--lib/Lex/TokenLexer.cpp542
1 files changed, 542 insertions, 0 deletions
diff --git a/lib/Lex/TokenLexer.cpp b/lib/Lex/TokenLexer.cpp
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+//===--- TokenLexer.cpp - Lex from a token stream -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the TokenLexer interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/TokenLexer.h"
+#include "MacroArgs.h"
+#include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/LexDiagnostic.h"
+#include "llvm/ADT/SmallVector.h"
+using namespace clang;
+
+
+/// Create a TokenLexer for the specified macro with the specified actual
+/// arguments. Note that this ctor takes ownership of the ActualArgs pointer.
+void TokenLexer::Init(Token &Tok, SourceLocation ILEnd, MacroArgs *Actuals) {
+ // If the client is reusing a TokenLexer, make sure to free any memory
+ // associated with it.
+ destroy();
+
+ Macro = PP.getMacroInfo(Tok.getIdentifierInfo());
+ ActualArgs = Actuals;
+ CurToken = 0;
+
+ InstantiateLocStart = Tok.getLocation();
+ InstantiateLocEnd = ILEnd;
+ AtStartOfLine = Tok.isAtStartOfLine();
+ HasLeadingSpace = Tok.hasLeadingSpace();
+ Tokens = &*Macro->tokens_begin();
+ OwnsTokens = false;
+ DisableMacroExpansion = false;
+ NumTokens = Macro->tokens_end()-Macro->tokens_begin();
+
+ // If this is a function-like macro, expand the arguments and change
+ // Tokens to point to the expanded tokens.
+ if (Macro->isFunctionLike() && Macro->getNumArgs())
+ ExpandFunctionArguments();
+
+ // Mark the macro as currently disabled, so that it is not recursively
+ // expanded. The macro must be disabled only after argument pre-expansion of
+ // function-like macro arguments occurs.
+ Macro->DisableMacro();
+}
+
+
+
+/// Create a TokenLexer for the specified token stream. This does not
+/// take ownership of the specified token vector.
+void TokenLexer::Init(const Token *TokArray, unsigned NumToks,
+ bool disableMacroExpansion, bool ownsTokens) {
+ // If the client is reusing a TokenLexer, make sure to free any memory
+ // associated with it.
+ destroy();
+
+ Macro = 0;
+ ActualArgs = 0;
+ Tokens = TokArray;
+ OwnsTokens = ownsTokens;
+ DisableMacroExpansion = disableMacroExpansion;
+ NumTokens = NumToks;
+ CurToken = 0;
+ InstantiateLocStart = InstantiateLocEnd = SourceLocation();
+ AtStartOfLine = false;
+ HasLeadingSpace = false;
+
+ // Set HasLeadingSpace/AtStartOfLine so that the first token will be
+ // returned unmodified.
+ if (NumToks != 0) {
+ AtStartOfLine = TokArray[0].isAtStartOfLine();
+ HasLeadingSpace = TokArray[0].hasLeadingSpace();
+ }
+}
+
+
+void TokenLexer::destroy() {
+ // If this was a function-like macro that actually uses its arguments, delete
+ // the expanded tokens.
+ if (OwnsTokens) {
+ delete [] Tokens;
+ Tokens = 0;
+ OwnsTokens = false;
+ }
+
+ // TokenLexer owns its formal arguments.
+ if (ActualArgs) ActualArgs->destroy();
+}
+
+/// Expand the arguments of a function-like macro so that we can quickly
+/// return preexpanded tokens from Tokens.
+void TokenLexer::ExpandFunctionArguments() {
+ llvm::SmallVector<Token, 128> ResultToks;
+
+ // Loop through 'Tokens', expanding them into ResultToks. Keep
+ // track of whether we change anything. If not, no need to keep them. If so,
+ // we install the newly expanded sequence as the new 'Tokens' list.
+ bool MadeChange = false;
+
+ // NextTokGetsSpace - When this is true, the next token appended to the
+ // output list will get a leading space, regardless of whether it had one to
+ // begin with or not. This is used for placemarker support.
+ bool NextTokGetsSpace = false;
+
+ for (unsigned i = 0, e = NumTokens; i != e; ++i) {
+ // If we found the stringify operator, get the argument stringified. The
+ // preprocessor already verified that the following token is a macro name
+ // when the #define was parsed.
+ const Token &CurTok = Tokens[i];
+ if (CurTok.is(tok::hash) || CurTok.is(tok::hashat)) {
+ int ArgNo = Macro->getArgumentNum(Tokens[i+1].getIdentifierInfo());
+ assert(ArgNo != -1 && "Token following # is not an argument?");
+
+ Token Res;
+ if (CurTok.is(tok::hash)) // Stringify
+ Res = ActualArgs->getStringifiedArgument(ArgNo, PP);
+ else {
+ // 'charify': don't bother caching these.
+ Res = MacroArgs::StringifyArgument(ActualArgs->getUnexpArgument(ArgNo),
+ PP, true);
+ }
+
+ // The stringified/charified string leading space flag gets set to match
+ // the #/#@ operator.
+ if (CurTok.hasLeadingSpace() || NextTokGetsSpace)
+ Res.setFlag(Token::LeadingSpace);
+
+ ResultToks.push_back(Res);
+ MadeChange = true;
+ ++i; // Skip arg name.
+ NextTokGetsSpace = false;
+ continue;
+ }
+
+ // Otherwise, if this is not an argument token, just add the token to the
+ // output buffer.
+ IdentifierInfo *II = CurTok.getIdentifierInfo();
+ int ArgNo = II ? Macro->getArgumentNum(II) : -1;
+ if (ArgNo == -1) {
+ // This isn't an argument, just add it.
+ ResultToks.push_back(CurTok);
+
+ if (NextTokGetsSpace) {
+ ResultToks.back().setFlag(Token::LeadingSpace);
+ NextTokGetsSpace = false;
+ }
+ continue;
+ }
+
+ // An argument is expanded somehow, the result is different than the
+ // input.
+ MadeChange = true;
+
+ // Otherwise, this is a use of the argument. Find out if there is a paste
+ // (##) operator before or after the argument.
+ bool PasteBefore =
+ !ResultToks.empty() && ResultToks.back().is(tok::hashhash);
+ bool PasteAfter = i+1 != e && Tokens[i+1].is(tok::hashhash);
+
+ // If it is not the LHS/RHS of a ## operator, we must pre-expand the
+ // argument and substitute the expanded tokens into the result. This is
+ // C99 6.10.3.1p1.
+ if (!PasteBefore && !PasteAfter) {
+ const Token *ResultArgToks;
+
+ // Only preexpand the argument if it could possibly need it. This
+ // avoids some work in common cases.
+ const Token *ArgTok = ActualArgs->getUnexpArgument(ArgNo);
+ if (ActualArgs->ArgNeedsPreexpansion(ArgTok, PP))
+ ResultArgToks = &ActualArgs->getPreExpArgument(ArgNo, PP)[0];
+ else
+ ResultArgToks = ArgTok; // Use non-preexpanded tokens.
+
+ // If the arg token expanded into anything, append it.
+ if (ResultArgToks->isNot(tok::eof)) {
+ unsigned FirstResult = ResultToks.size();
+ unsigned NumToks = MacroArgs::getArgLength(ResultArgToks);
+ ResultToks.append(ResultArgToks, ResultArgToks+NumToks);
+
+ // If any tokens were substituted from the argument, the whitespace
+ // before the first token should match the whitespace of the arg
+ // identifier.
+ ResultToks[FirstResult].setFlagValue(Token::LeadingSpace,
+ CurTok.hasLeadingSpace() ||
+ NextTokGetsSpace);
+ NextTokGetsSpace = false;
+ } else {
+ // If this is an empty argument, and if there was whitespace before the
+ // formal token, make sure the next token gets whitespace before it.
+ NextTokGetsSpace = CurTok.hasLeadingSpace();
+ }
+ continue;
+ }
+
+ // Okay, we have a token that is either the LHS or RHS of a paste (##)
+ // argument. It gets substituted as its non-pre-expanded tokens.
+ const Token *ArgToks = ActualArgs->getUnexpArgument(ArgNo);
+ unsigned NumToks = MacroArgs::getArgLength(ArgToks);
+ if (NumToks) { // Not an empty argument?
+ // If this is the GNU ", ## __VA_ARG__" extension, and we just learned
+ // that __VA_ARG__ expands to multiple tokens, avoid a pasting error when
+ // the expander trys to paste ',' with the first token of the __VA_ARG__
+ // expansion.
+ if (PasteBefore && ResultToks.size() >= 2 &&
+ ResultToks[ResultToks.size()-2].is(tok::comma) &&
+ (unsigned)ArgNo == Macro->getNumArgs()-1 &&
+ Macro->isVariadic()) {
+ // Remove the paste operator, report use of the extension.
+ PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma);
+ ResultToks.pop_back();
+ }
+
+ ResultToks.append(ArgToks, ArgToks+NumToks);
+
+ // If this token (the macro argument) was supposed to get leading
+ // whitespace, transfer this information onto the first token of the
+ // expansion.
+ //
+ // Do not do this if the paste operator occurs before the macro argument,
+ // as in "A ## MACROARG". In valid code, the first token will get
+ // smooshed onto the preceding one anyway (forming AMACROARG). In
+ // assembler-with-cpp mode, invalid pastes are allowed through: in this
+ // case, we do not want the extra whitespace to be added. For example,
+ // we want ". ## foo" -> ".foo" not ". foo".
+ if ((CurTok.hasLeadingSpace() || NextTokGetsSpace) &&
+ !PasteBefore)
+ ResultToks[ResultToks.size()-NumToks].setFlag(Token::LeadingSpace);
+
+ NextTokGetsSpace = false;
+ continue;
+ }
+
+ // If an empty argument is on the LHS or RHS of a paste, the standard (C99
+ // 6.10.3.3p2,3) calls for a bunch of placemarker stuff to occur. We
+ // implement this by eating ## operators when a LHS or RHS expands to
+ // empty.
+ NextTokGetsSpace |= CurTok.hasLeadingSpace();
+ if (PasteAfter) {
+ // Discard the argument token and skip (don't copy to the expansion
+ // buffer) the paste operator after it.
+ NextTokGetsSpace |= Tokens[i+1].hasLeadingSpace();
+ ++i;
+ continue;
+ }
+
+ // If this is on the RHS of a paste operator, we've already copied the
+ // paste operator to the ResultToks list. Remove it.
+ assert(PasteBefore && ResultToks.back().is(tok::hashhash));
+ NextTokGetsSpace |= ResultToks.back().hasLeadingSpace();
+ ResultToks.pop_back();
+
+ // If this is the __VA_ARGS__ token, and if the argument wasn't provided,
+ // and if the macro had at least one real argument, and if the token before
+ // the ## was a comma, remove the comma.
+ if ((unsigned)ArgNo == Macro->getNumArgs()-1 && // is __VA_ARGS__
+ ActualArgs->isVarargsElidedUse() && // Argument elided.
+ !ResultToks.empty() && ResultToks.back().is(tok::comma)) {
+ // Never add a space, even if the comma, ##, or arg had a space.
+ NextTokGetsSpace = false;
+ // Remove the paste operator, report use of the extension.
+ PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma);
+ ResultToks.pop_back();
+ }
+ continue;
+ }
+
+ // If anything changed, install this as the new Tokens list.
+ if (MadeChange) {
+ assert(!OwnsTokens && "This would leak if we already own the token list");
+ // This is deleted in the dtor.
+ NumTokens = ResultToks.size();
+ llvm::BumpPtrAllocator &Alloc = PP.getPreprocessorAllocator();
+ Token *Res =
+ static_cast<Token *>(Alloc.Allocate(sizeof(Token)*ResultToks.size(),
+ llvm::alignof<Token>()));
+ if (NumTokens)
+ memcpy(Res, &ResultToks[0], NumTokens*sizeof(Token));
+ Tokens = Res;
+
+ // The preprocessor bump pointer owns these tokens, not us.
+ OwnsTokens = false;
+ }
+}
+
+/// Lex - Lex and return a token from this macro stream.
+///
+void TokenLexer::Lex(Token &Tok) {
+ // Lexing off the end of the macro, pop this macro off the expansion stack.
+ if (isAtEnd()) {
+ // If this is a macro (not a token stream), mark the macro enabled now
+ // that it is no longer being expanded.
+ if (Macro) Macro->EnableMacro();
+
+ // Pop this context off the preprocessors lexer stack and get the next
+ // token. This will delete "this" so remember the PP instance var.
+ Preprocessor &PPCache = PP;
+ if (PP.HandleEndOfTokenLexer(Tok))
+ return;
+
+ // HandleEndOfTokenLexer may not return a token. If it doesn't, lex
+ // whatever is next.
+ return PPCache.Lex(Tok);
+ }
+
+ // If this is the first token of the expanded result, we inherit spacing
+ // properties later.
+ bool isFirstToken = CurToken == 0;
+
+ // Get the next token to return.
+ Tok = Tokens[CurToken++];
+
+ bool TokenIsFromPaste = false;
+
+ // If this token is followed by a token paste (##) operator, paste the tokens!
+ if (!isAtEnd() && Tokens[CurToken].is(tok::hashhash)) {
+ if (PasteTokens(Tok)) {
+ // When handling the microsoft /##/ extension, the final token is
+ // returned by PasteTokens, not the pasted token.
+ return;
+ } else {
+ TokenIsFromPaste = true;
+ }
+ }
+
+ // The token's current location indicate where the token was lexed from. We
+ // need this information to compute the spelling of the token, but any
+ // diagnostics for the expanded token should appear as if they came from
+ // InstantiationLoc. Pull this information together into a new SourceLocation
+ // that captures all of this.
+ if (InstantiateLocStart.isValid()) { // Don't do this for token streams.
+ SourceManager &SM = PP.getSourceManager();
+ Tok.setLocation(SM.createInstantiationLoc(Tok.getLocation(),
+ InstantiateLocStart,
+ InstantiateLocEnd,
+ Tok.getLength()));
+ }
+
+ // If this is the first token, set the lexical properties of the token to
+ // match the lexical properties of the macro identifier.
+ if (isFirstToken) {
+ Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
+ Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace);
+ }
+
+ // Handle recursive expansion!
+ if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != 0) {
+ // Change the kind of this identifier to the appropriate token kind, e.g.
+ // turning "for" into a keyword.
+ IdentifierInfo *II = Tok.getIdentifierInfo();
+ Tok.setKind(II->getTokenID());
+
+ // If this identifier was poisoned and from a paste, emit an error. This
+ // won't be handled by Preprocessor::HandleIdentifier because this is coming
+ // from a macro expansion.
+ if (II->isPoisoned() && TokenIsFromPaste) {
+ // We warn about __VA_ARGS__ with poisoning.
+ if (II->isStr("__VA_ARGS__"))
+ PP.Diag(Tok, diag::ext_pp_bad_vaargs_use);
+ else
+ PP.Diag(Tok, diag::err_pp_used_poisoned_id);
+ }
+
+ if (!DisableMacroExpansion && II->isHandleIdentifierCase())
+ PP.HandleIdentifier(Tok);
+ }
+
+ // Otherwise, return a normal token.
+}
+
+/// PasteTokens - Tok is the LHS of a ## operator, and CurToken is the ##
+/// operator. Read the ## and RHS, and paste the LHS/RHS together. If there
+/// are more ## after it, chomp them iteratively. Return the result as Tok.
+/// If this returns true, the caller should immediately return the token.
+bool TokenLexer::PasteTokens(Token &Tok) {
+ llvm::SmallVector<char, 128> Buffer;
+ const char *ResultTokStrPtr = 0;
+ do {
+ // Consume the ## operator.
+ SourceLocation PasteOpLoc = Tokens[CurToken].getLocation();
+ ++CurToken;
+ assert(!isAtEnd() && "No token on the RHS of a paste operator!");
+
+ // Get the RHS token.
+ const Token &RHS = Tokens[CurToken];
+
+ // Allocate space for the result token. This is guaranteed to be enough for
+ // the two tokens.
+ Buffer.resize(Tok.getLength() + RHS.getLength());
+
+ // Get the spelling of the LHS token in Buffer.
+ const char *BufPtr = &Buffer[0];
+ unsigned LHSLen = PP.getSpelling(Tok, BufPtr);
+ if (BufPtr != &Buffer[0]) // Really, we want the chars in Buffer!
+ memcpy(&Buffer[0], BufPtr, LHSLen);
+
+ BufPtr = &Buffer[LHSLen];
+ unsigned RHSLen = PP.getSpelling(RHS, BufPtr);
+ if (BufPtr != &Buffer[LHSLen]) // Really, we want the chars in Buffer!
+ memcpy(&Buffer[LHSLen], BufPtr, RHSLen);
+
+ // Trim excess space.
+ Buffer.resize(LHSLen+RHSLen);
+
+ // Plop the pasted result (including the trailing newline and null) into a
+ // scratch buffer where we can lex it.
+ Token ResultTokTmp;
+ ResultTokTmp.startToken();
+
+ // Claim that the tmp token is a string_literal so that we can get the
+ // character pointer back from CreateString.
+ ResultTokTmp.setKind(tok::string_literal);
+ PP.CreateString(&Buffer[0], Buffer.size(), ResultTokTmp);
+ SourceLocation ResultTokLoc = ResultTokTmp.getLocation();
+ ResultTokStrPtr = ResultTokTmp.getLiteralData();
+
+ // Lex the resultant pasted token into Result.
+ Token Result;
+
+ if (Tok.is(tok::identifier) && RHS.is(tok::identifier)) {
+ // Common paste case: identifier+identifier = identifier. Avoid creating
+ // a lexer and other overhead.
+ PP.IncrementPasteCounter(true);
+ Result.startToken();
+ Result.setKind(tok::identifier);
+ Result.setLocation(ResultTokLoc);
+ Result.setLength(LHSLen+RHSLen);
+ } else {
+ PP.IncrementPasteCounter(false);
+
+ assert(ResultTokLoc.isFileID() &&
+ "Should be a raw location into scratch buffer");
+ SourceManager &SourceMgr = PP.getSourceManager();
+ FileID LocFileID = SourceMgr.getFileID(ResultTokLoc);
+
+ const char *ScratchBufStart = SourceMgr.getBufferData(LocFileID).first;
+
+ // Make a lexer to lex this string from. Lex just this one token.
+ // Make a lexer object so that we lex and expand the paste result.
+ Lexer TL(SourceMgr.getLocForStartOfFile(LocFileID),
+ PP.getLangOptions(), ScratchBufStart,
+ ResultTokStrPtr, ResultTokStrPtr+LHSLen+RHSLen);
+
+ // Lex a token in raw mode. This way it won't look up identifiers
+ // automatically, lexing off the end will return an eof token, and
+ // warnings are disabled. This returns true if the result token is the
+ // entire buffer.
+ bool isInvalid = !TL.LexFromRawLexer(Result);
+
+ // If we got an EOF token, we didn't form even ONE token. For example, we
+ // did "/ ## /" to get "//".
+ isInvalid |= Result.is(tok::eof);
+
+ // If pasting the two tokens didn't form a full new token, this is an
+ // error. This occurs with "x ## +" and other stuff. Return with Tok
+ // unmodified and with RHS as the next token to lex.
+ if (isInvalid) {
+ // Test for the Microsoft extension of /##/ turning into // here on the
+ // error path.
+ if (PP.getLangOptions().Microsoft && Tok.is(tok::slash) &&
+ RHS.is(tok::slash)) {
+ HandleMicrosoftCommentPaste(Tok);
+ return true;
+ }
+
+ // Do not emit the warning when preprocessing assembler code.
+ if (!PP.getLangOptions().AsmPreprocessor) {
+ // Explicitly convert the token location to have proper instantiation
+ // information so that the user knows where it came from.
+ SourceManager &SM = PP.getSourceManager();
+ SourceLocation Loc =
+ SM.createInstantiationLoc(PasteOpLoc, InstantiateLocStart,
+ InstantiateLocEnd, 2);
+ PP.Diag(Loc, diag::err_pp_bad_paste)
+ << std::string(Buffer.begin(), Buffer.end());
+ }
+
+ // Do not consume the RHS.
+ --CurToken;
+ }
+
+ // Turn ## into 'unknown' to avoid # ## # from looking like a paste
+ // operator.
+ if (Result.is(tok::hashhash))
+ Result.setKind(tok::unknown);
+ }
+
+ // Transfer properties of the LHS over the the Result.
+ Result.setFlagValue(Token::StartOfLine , Tok.isAtStartOfLine());
+ Result.setFlagValue(Token::LeadingSpace, Tok.hasLeadingSpace());
+
+ // Finally, replace LHS with the result, consume the RHS, and iterate.
+ ++CurToken;
+ Tok = Result;
+ } while (!isAtEnd() && Tokens[CurToken].is(tok::hashhash));
+
+ // Now that we got the result token, it will be subject to expansion. Since
+ // token pasting re-lexes the result token in raw mode, identifier information
+ // isn't looked up. As such, if the result is an identifier, look up id info.
+ if (Tok.is(tok::identifier)) {
+ // Look up the identifier info for the token. We disabled identifier lookup
+ // by saying we're skipping contents, so we need to do this manually.
+ IdentifierInfo *II = PP.LookUpIdentifierInfo(Tok, ResultTokStrPtr);
+ Tok.setIdentifierInfo(II);
+ }
+ return false;
+}
+
+/// isNextTokenLParen - If the next token lexed will pop this macro off the
+/// expansion stack, return 2. If the next unexpanded token is a '(', return
+/// 1, otherwise return 0.
+unsigned TokenLexer::isNextTokenLParen() const {
+ // Out of tokens?
+ if (isAtEnd())
+ return 2;
+ return Tokens[CurToken].is(tok::l_paren);
+}
+
+
+/// HandleMicrosoftCommentPaste - In microsoft compatibility mode, /##/ pastes
+/// together to form a comment that comments out everything in the current
+/// macro, other active macros, and anything left on the current physical
+/// source line of the instantiated buffer. Handle this by returning the
+/// first token on the next line.
+void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok) {
+ // We 'comment out' the rest of this macro by just ignoring the rest of the
+ // tokens that have not been lexed yet, if any.
+
+ // Since this must be a macro, mark the macro enabled now that it is no longer
+ // being expanded.
+ assert(Macro && "Token streams can't paste comments");
+ Macro->EnableMacro();
+
+ PP.HandleMicrosoftCommentPaste(Tok);
+}