/// HandlePragmaPoison - Handle \#pragma GCC poison. PoisonTok is the 'poison'.
///
void Preprocessor::HandlePragmaPoison(Token &PoisonTok) {
Token Tok;
while (1) {
// Read the next token to poison. While doing this, pretend that we are
// skipping while reading the identifier to poison.
// This avoids errors on code like:
// #pragma GCC poison X
// #pragma GCC poison X
if (CurPPLexer) CurPPLexer->LexingRawMode = true;
LexUnexpandedToken(Tok);
if (CurPPLexer) CurPPLexer->LexingRawMode = false;
// If we reached the end of line, we're done.
if (Tok.is(tok::eod)) return;
// Can only poison identifiers.
if (Tok.isNot(tok::raw_identifier)) {
Diag(Tok, diag::err_pp_invalid_poison);
return;
}
// 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 = LookUpIdentifierInfo(Tok);
// Already poisoned.
if (II->isPoisoned()) continue;
// If this is a macro identifier, emit a warning.
if (II->hasMacroDefinition())
Diag(Tok, diag::pp_poisoning_existing_macro);
// Finally, poison it!
II->setIsPoisoned();
if (II->isFromAST())
II->setChangedSinceDeserialization();
}
}
/// 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);
}
SourceManager &SM = PP.getSourceManager();
// 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!
// Note that ## is a normal token when not expanding a macro.
if (!isAtEnd() && Tokens[CurToken].is(tok::hashhash) && Macro) {
// When handling the microsoft /##/ extension, the final token is
// returned by PasteTokens, not the pasted token.
if (PasteTokens(Tok))
return;
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
// ExpansionLoc. Pull this information together into a new SourceLocation
// that captures all of this.
if (ExpandLocStart.isValid() && // Don't do this for token streams.
// Check that the token's location was not already set properly.
SM.isBeforeInSLocAddrSpace(Tok.getLocation(), MacroStartSLocOffset)) {
SourceLocation instLoc;
if (Tok.is(tok::comment)) {
instLoc = SM.createExpansionLoc(Tok.getLocation(),
ExpandLocStart,
ExpandLocEnd,
Tok.getLength());
} else {
instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation());
}
Tok.setLocation(instLoc);
}
// 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) {
PP.HandlePoisonedIdentifier(Tok);
}
if (!DisableMacroExpansion && II->isHandleIdentifierCase())
PP.HandleIdentifier(Tok);
}
// Otherwise, return a normal token.
}
/// Lex - Lex and return a token from this macro stream.
///
bool 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();
Tok.startToken();
Tok.setFlagValue(Token::StartOfLine , AtStartOfLine);
Tok.setFlagValue(Token::LeadingSpace, HasLeadingSpace || NextTokGetsSpace);
if (CurToken == 0)
Tok.setFlag(Token::LeadingEmptyMacro);
return PP.HandleEndOfTokenLexer(Tok);
}
SourceManager &SM = PP.getSourceManager();
// 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!
// Note that ## is a normal token when not expanding a macro.
if (!isAtEnd() && Macro &&
(Tokens[CurToken].is(tok::hashhash) ||
// Special processing of L#x macros in -fms-compatibility mode.
// Microsoft compiler is able to form a wide string literal from
// 'L#macro_arg' construct in a function-like macro.
(PP.getLangOpts().MSVCCompat &&
isWideStringLiteralFromMacro(Tok, Tokens[CurToken])))) {
// When handling the microsoft /##/ extension, the final token is
// returned by PasteTokens, not the pasted token.
if (PasteTokens(Tok))
return true;
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
// ExpansionLoc. Pull this information together into a new SourceLocation
// that captures all of this.
if (ExpandLocStart.isValid() && // Don't do this for token streams.
// Check that the token's location was not already set properly.
SM.isBeforeInSLocAddrSpace(Tok.getLocation(), MacroStartSLocOffset)) {
SourceLocation instLoc;
if (Tok.is(tok::comment)) {
instLoc = SM.createExpansionLoc(Tok.getLocation(),
ExpandLocStart,
ExpandLocEnd,
Tok.getLength());
} else {
instLoc = getExpansionLocForMacroDefLoc(Tok.getLocation());
}
Tok.setLocation(instLoc);
}
// 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);
} else {
// If this is not the first token, we may still need to pass through
// leading whitespace if we've expanded a macro.
if (AtStartOfLine) Tok.setFlag(Token::StartOfLine);
if (HasLeadingSpace) Tok.setFlag(Token::LeadingSpace);
}
AtStartOfLine = false;
HasLeadingSpace = false;
// Handle recursive expansion!
if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != nullptr) {
// 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) {
PP.HandlePoisonedIdentifier(Tok);
}
if (!DisableMacroExpansion && II->isHandleIdentifierCase())
return PP.HandleIdentifier(Tok);
}
// Otherwise, return a normal token.
return true;
}
