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llvm-capstone/clang/lib/Lex/TokenLexer.cpp
Simon Tatham 21401a7262 [clang] Introduce SourceLocation::[U]IntTy typedefs. 
This is part of a patch series working towards the ability to make
SourceLocation into a 64-bit type to handle larger translation units.

NFC: this patch introduces typedefs for the integer type used by
SourceLocation and makes all the boring changes to use the typedefs
everywhere, but for the moment, they are unconditionally defined to
uint32_t.

Patch originally by Mikhail Maltsev.

Reviewed By: tmatheson

Differential Revision: https://reviews.llvm.org/D105492
2021-07-21 10:45:46 +01:00

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//===- TokenLexer.cpp - Lex from a token stream ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the TokenLexer interface.
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/TokenLexer.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/Lexer.h"
#include "clang/Lex/MacroArgs.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/Token.h"
#include "clang/Lex/VariadicMacroSupport.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/iterator_range.h"
#include <cassert>
#include <cstring>
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 ELEnd, MacroInfo *MI,
MacroArgs *Actuals) {
// If the client is reusing a TokenLexer, make sure to free any memory
// associated with it.
destroy();
Macro = MI;
ActualArgs = Actuals;
CurTokenIdx = 0;
ExpandLocStart = Tok.getLocation();
ExpandLocEnd = ELEnd;
AtStartOfLine = Tok.isAtStartOfLine();
HasLeadingSpace = Tok.hasLeadingSpace();
NextTokGetsSpace = false;
Tokens = &*Macro->tokens_begin();
OwnsTokens = false;
DisableMacroExpansion = false;
IsReinject = false;
NumTokens = Macro->tokens_end()-Macro->tokens_begin();
MacroExpansionStart = SourceLocation();
SourceManager &SM = PP.getSourceManager();
MacroStartSLocOffset = SM.getNextLocalOffset();
if (NumTokens > 0) {
assert(Tokens[0].getLocation().isValid());
assert((Tokens[0].getLocation().isFileID() || Tokens[0].is(tok::comment)) &&
"Macro defined in macro?");
assert(ExpandLocStart.isValid());
// Reserve a source location entry chunk for the length of the macro
// definition. Tokens that get lexed directly from the definition will
// have their locations pointing inside this chunk. This is to avoid
// creating separate source location entries for each token.
MacroDefStart = SM.getExpansionLoc(Tokens[0].getLocation());
MacroDefLength = Macro->getDefinitionLength(SM);
MacroExpansionStart = SM.createExpansionLoc(MacroDefStart,
ExpandLocStart,
ExpandLocEnd,
MacroDefLength);
}
// If this is a function-like macro, expand the arguments and change
// Tokens to point to the expanded tokens.
if (Macro->isFunctionLike() && Macro->getNumParams())
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,
bool isReinject) {
assert(!isReinject || disableMacroExpansion);
// If the client is reusing a TokenLexer, make sure to free any memory
// associated with it.
destroy();
Macro = nullptr;
ActualArgs = nullptr;
Tokens = TokArray;
OwnsTokens = ownsTokens;
DisableMacroExpansion = disableMacroExpansion;
IsReinject = isReinject;
NumTokens = NumToks;
CurTokenIdx = 0;
ExpandLocStart = ExpandLocEnd = SourceLocation();
AtStartOfLine = false;
HasLeadingSpace = false;
NextTokGetsSpace = false;
MacroExpansionStart = SourceLocation();
// 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 = nullptr;
OwnsTokens = false;
}
// TokenLexer owns its formal arguments.
if (ActualArgs) ActualArgs->destroy(PP);
}
bool TokenLexer::MaybeRemoveCommaBeforeVaArgs(
SmallVectorImpl<Token> &ResultToks, bool HasPasteOperator, MacroInfo *Macro,
unsigned MacroArgNo, Preprocessor &PP) {
// Is the macro argument __VA_ARGS__?
if (!Macro->isVariadic() || MacroArgNo != Macro->getNumParams()-1)
return false;
// In Microsoft-compatibility mode, a comma is removed in the expansion
// of " ... , __VA_ARGS__ " if __VA_ARGS__ is empty. This extension is
// not supported by gcc.
if (!HasPasteOperator && !PP.getLangOpts().MSVCCompat)
return false;
// GCC removes the comma in the expansion of " ... , ## __VA_ARGS__ " if
// __VA_ARGS__ is empty, but not in strict C99 mode where there are no
// named arguments, where it remains. In all other modes, including C99
// with GNU extensions, it is removed regardless of named arguments.
// Microsoft also appears to support this extension, unofficially.
if (PP.getLangOpts().C99 && !PP.getLangOpts().GNUMode
&& Macro->getNumParams() < 2)
return false;
// Is a comma available to be removed?
if (ResultToks.empty() || !ResultToks.back().is(tok::comma))
return false;
// Issue an extension diagnostic for the paste operator.
if (HasPasteOperator)
PP.Diag(ResultToks.back().getLocation(), diag::ext_paste_comma);
// Remove the comma.
ResultToks.pop_back();
if (!ResultToks.empty()) {
// If the comma was right after another paste (e.g. "X##,##__VA_ARGS__"),
// then removal of the comma should produce a placemarker token (in C99
// terms) which we model by popping off the previous ##, giving us a plain
// "X" when __VA_ARGS__ is empty.
if (ResultToks.back().is(tok::hashhash))
ResultToks.pop_back();
// Remember that this comma was elided.
ResultToks.back().setFlag(Token::CommaAfterElided);
}
// Never add a space, even if the comma, ##, or arg had a space.
NextTokGetsSpace = false;
return true;
}
void TokenLexer::stringifyVAOPTContents(
SmallVectorImpl<Token> &ResultToks, const VAOptExpansionContext &VCtx,
const SourceLocation VAOPTClosingParenLoc) {
const int NumToksPriorToVAOpt = VCtx.getNumberOfTokensPriorToVAOpt();
const unsigned int NumVAOptTokens = ResultToks.size() - NumToksPriorToVAOpt;
Token *const VAOPTTokens =
NumVAOptTokens ? &ResultToks[NumToksPriorToVAOpt] : nullptr;
SmallVector<Token, 64> ConcatenatedVAOPTResultToks;
// FIXME: Should we keep track within VCtx that we did or didnot
// encounter pasting - and only then perform this loop.
// Perform token pasting (concatenation) prior to stringization.
for (unsigned int CurTokenIdx = 0; CurTokenIdx != NumVAOptTokens;
++CurTokenIdx) {
if (VAOPTTokens[CurTokenIdx].is(tok::hashhash)) {
assert(CurTokenIdx != 0 &&
"Can not have __VAOPT__ contents begin with a ##");
Token &LHS = VAOPTTokens[CurTokenIdx - 1];
pasteTokens(LHS, llvm::makeArrayRef(VAOPTTokens, NumVAOptTokens),
CurTokenIdx);
// Replace the token prior to the first ## in this iteration.
ConcatenatedVAOPTResultToks.back() = LHS;
if (CurTokenIdx == NumVAOptTokens)
break;
}
ConcatenatedVAOPTResultToks.push_back(VAOPTTokens[CurTokenIdx]);
}
ConcatenatedVAOPTResultToks.push_back(VCtx.getEOFTok());
// Get the SourceLocation that represents the start location within
// the macro definition that marks where this string is substituted
// into: i.e. the __VA_OPT__ and the ')' within the spelling of the
// macro definition, and use it to indicate that the stringified token
// was generated from that location.
const SourceLocation ExpansionLocStartWithinMacro =
getExpansionLocForMacroDefLoc(VCtx.getVAOptLoc());
const SourceLocation ExpansionLocEndWithinMacro =
getExpansionLocForMacroDefLoc(VAOPTClosingParenLoc);
Token StringifiedVAOPT = MacroArgs::StringifyArgument(
&ConcatenatedVAOPTResultToks[0], PP, VCtx.hasCharifyBefore() /*Charify*/,
ExpansionLocStartWithinMacro, ExpansionLocEndWithinMacro);
if (VCtx.getLeadingSpaceForStringifiedToken())
StringifiedVAOPT.setFlag(Token::LeadingSpace);
StringifiedVAOPT.setFlag(Token::StringifiedInMacro);
// Resize (shrink) the token stream to just capture this stringified token.
ResultToks.resize(NumToksPriorToVAOpt + 1);
ResultToks.back() = StringifiedVAOPT;
}
/// Expand the arguments of a function-like macro so that we can quickly
/// return preexpanded tokens from Tokens.
void TokenLexer::ExpandFunctionArguments() {
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;
Optional<bool> CalledWithVariadicArguments;
VAOptExpansionContext VCtx(PP);
for (unsigned I = 0, E = NumTokens; I != E; ++I) {
const Token &CurTok = Tokens[I];
// We don't want a space for the next token after a paste
// operator. In valid code, the token will get smooshed onto the
// preceding one anyway. 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 (I != 0 && !Tokens[I-1].is(tok::hashhash) && CurTok.hasLeadingSpace())
NextTokGetsSpace = true;
if (VCtx.isVAOptToken(CurTok)) {
MadeChange = true;
assert(Tokens[I + 1].is(tok::l_paren) &&
"__VA_OPT__ must be followed by '('");
++I; // Skip the l_paren
VCtx.sawVAOptFollowedByOpeningParens(CurTok.getLocation(),
ResultToks.size());
continue;
}
// We have entered into the __VA_OPT__ context, so handle tokens
// appropriately.
if (VCtx.isInVAOpt()) {
// If we are about to process a token that is either an argument to
// __VA_OPT__ or its closing rparen, then:
// 1) If the token is the closing rparen that exits us out of __VA_OPT__,
// perform any necessary stringification or placemarker processing,
// and/or skip to the next token.
// 2) else if macro was invoked without variadic arguments skip this
// token.
// 3) else (macro was invoked with variadic arguments) process the token
// normally.
if (Tokens[I].is(tok::l_paren))
VCtx.sawOpeningParen(Tokens[I].getLocation());
// Continue skipping tokens within __VA_OPT__ if the macro was not
// called with variadic arguments, else let the rest of the loop handle
// this token. Note sawClosingParen() returns true only if the r_paren matches
// the closing r_paren of the __VA_OPT__.
if (!Tokens[I].is(tok::r_paren) || !VCtx.sawClosingParen()) {
// Lazily expand __VA_ARGS__ when we see the first __VA_OPT__.
if (!CalledWithVariadicArguments.hasValue()) {
CalledWithVariadicArguments =
ActualArgs->invokedWithVariadicArgument(Macro, PP);
}
if (!*CalledWithVariadicArguments) {
// Skip this token.
continue;
}
// ... else the macro was called with variadic arguments, and we do not
// have a closing rparen - so process this token normally.
} else {
// Current token is the closing r_paren which marks the end of the
// __VA_OPT__ invocation, so handle any place-marker pasting (if
// empty) by removing hashhash either before (if exists) or after. And
// also stringify the entire contents if VAOPT was preceded by a hash,
// but do so only after any token concatenation that needs to occur
// within the contents of VAOPT.
if (VCtx.hasStringifyOrCharifyBefore()) {
// Replace all the tokens just added from within VAOPT into a single
// stringified token. This requires token-pasting to eagerly occur
// within these tokens. If either the contents of VAOPT were empty
// or the macro wasn't called with any variadic arguments, the result
// is a token that represents an empty string.
stringifyVAOPTContents(ResultToks, VCtx,
/*ClosingParenLoc*/ Tokens[I].getLocation());
} else if (/*No tokens within VAOPT*/
ResultToks.size() == VCtx.getNumberOfTokensPriorToVAOpt()) {
// Treat VAOPT as a placemarker token. Eat either the '##' before the
// RHS/VAOPT (if one exists, suggesting that the LHS (if any) to that
// hashhash was not a placemarker) or the '##'
// after VAOPT, but not both.
if (ResultToks.size() && ResultToks.back().is(tok::hashhash)) {
ResultToks.pop_back();
} else if ((I + 1 != E) && Tokens[I + 1].is(tok::hashhash)) {
++I; // Skip the following hashhash.
}
} else {
// If there's a ## before the __VA_OPT__, we might have discovered
// that the __VA_OPT__ begins with a placeholder. We delay action on
// that to now to avoid messing up our stashed count of tokens before
// __VA_OPT__.
if (VCtx.beginsWithPlaceholder()) {
assert(VCtx.getNumberOfTokensPriorToVAOpt() > 0 &&
ResultToks.size() >= VCtx.getNumberOfTokensPriorToVAOpt() &&
ResultToks[VCtx.getNumberOfTokensPriorToVAOpt() - 1].is(
tok::hashhash) &&
"no token paste before __VA_OPT__");
ResultToks.erase(ResultToks.begin() +
VCtx.getNumberOfTokensPriorToVAOpt() - 1);
}
// If the expansion of __VA_OPT__ ends with a placeholder, eat any
// following '##' token.
if (VCtx.endsWithPlaceholder() && I + 1 != E &&
Tokens[I + 1].is(tok::hashhash)) {
++I;
}
}
VCtx.reset();
// We processed __VA_OPT__'s closing paren (and the exit out of
// __VA_OPT__), so skip to the next token.
continue;
}
}
// If we found the stringify operator, get the argument stringified. The
// preprocessor already verified that the following token is a macro
// parameter or __VA_OPT__ when the #define was lexed.
if (CurTok.isOneOf(tok::hash, tok::hashat)) {
int ArgNo = Macro->getParameterNum(Tokens[I+1].getIdentifierInfo());
assert((ArgNo != -1 || VCtx.isVAOptToken(Tokens[I + 1])) &&
"Token following # is not an argument or __VA_OPT__!");
if (ArgNo == -1) {
// Handle the __VA_OPT__ case.
VCtx.sawHashOrHashAtBefore(NextTokGetsSpace,
CurTok.is(tok::hashat));
continue;
}
// Else handle the simple argument case.
SourceLocation ExpansionLocStart =
getExpansionLocForMacroDefLoc(CurTok.getLocation());
SourceLocation ExpansionLocEnd =
getExpansionLocForMacroDefLoc(Tokens[I+1].getLocation());
bool Charify = CurTok.is(tok::hashat);
const Token *UnexpArg = ActualArgs->getUnexpArgument(ArgNo);
Token Res = MacroArgs::StringifyArgument(
UnexpArg, PP, Charify, ExpansionLocStart, ExpansionLocEnd);
Res.setFlag(Token::StringifiedInMacro);
// The stringified/charified string leading space flag gets set to match
// the #/#@ operator.
if (NextTokGetsSpace)
Res.setFlag(Token::LeadingSpace);
ResultToks.push_back(Res);
MadeChange = true;
++I; // Skip arg name.
NextTokGetsSpace = false;
continue;
}
// Find out if there is a paste (##) operator before or after the token.
bool NonEmptyPasteBefore =
!ResultToks.empty() && ResultToks.back().is(tok::hashhash);
bool PasteBefore = I != 0 && Tokens[I-1].is(tok::hashhash);
bool PasteAfter = I+1 != E && Tokens[I+1].is(tok::hashhash);
bool RParenAfter = I+1 != E && Tokens[I+1].is(tok::r_paren);
assert((!NonEmptyPasteBefore || PasteBefore || VCtx.isInVAOpt()) &&
"unexpected ## in ResultToks");
// Otherwise, if this is not an argument token, just add the token to the
// output buffer.
IdentifierInfo *II = CurTok.getIdentifierInfo();
int ArgNo = II ? Macro->getParameterNum(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;
} else if (PasteBefore && !NonEmptyPasteBefore)
ResultToks.back().clearFlag(Token::LeadingSpace);
continue;
}
// An argument is expanded somehow, the result is different than the
// input.
MadeChange = true;
// Otherwise, this is a use of the argument.
// In Microsoft mode, remove the comma before __VA_ARGS__ to ensure there
// are no trailing commas if __VA_ARGS__ is empty.
if (!PasteBefore && ActualArgs->isVarargsElidedUse() &&
MaybeRemoveCommaBeforeVaArgs(ResultToks,
/*HasPasteOperator=*/false,
Macro, ArgNo, PP))
continue;
// 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)) {
size_t FirstResult = ResultToks.size();
unsigned NumToks = MacroArgs::getArgLength(ResultArgToks);
ResultToks.append(ResultArgToks, ResultArgToks+NumToks);
// In Microsoft-compatibility mode, we follow MSVC's preprocessing
// behavior by not considering single commas from nested macro
// expansions as argument separators. Set a flag on the token so we can
// test for this later when the macro expansion is processed.
if (PP.getLangOpts().MSVCCompat && NumToks == 1 &&
ResultToks.back().is(tok::comma))
ResultToks.back().setFlag(Token::IgnoredComma);
// If the '##' came from expanding an argument, turn it into 'unknown'
// to avoid pasting.
for (Token &Tok : llvm::make_range(ResultToks.begin() + FirstResult,
ResultToks.end())) {
if (Tok.is(tok::hashhash))
Tok.setKind(tok::unknown);
}
if(ExpandLocStart.isValid()) {
updateLocForMacroArgTokens(CurTok.getLocation(),
ResultToks.begin()+FirstResult,
ResultToks.end());
}
// 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,
NextTokGetsSpace);
ResultToks[FirstResult].setFlagValue(Token::StartOfLine, false);
NextTokGetsSpace = false;
} else {
// We're creating a placeholder token. Usually this doesn't matter,
// but it can affect paste behavior when at the start or end of a
// __VA_OPT__.
if (NonEmptyPasteBefore) {
// We're imagining a placeholder token is inserted here. If this is
// the first token in a __VA_OPT__ after a ##, delete the ##.
assert(VCtx.isInVAOpt() && "should only happen inside a __VA_OPT__");
VCtx.hasPlaceholderAfterHashhashAtStart();
}
if (RParenAfter)
VCtx.hasPlaceholderBeforeRParen();
}
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?
bool VaArgsPseudoPaste = false;
// If this is the GNU ", ## __VA_ARGS__" extension, and we just learned
// that __VA_ARGS__ expands to multiple tokens, avoid a pasting error when
// the expander tries to paste ',' with the first token of the __VA_ARGS__
// expansion.
if (NonEmptyPasteBefore && ResultToks.size() >= 2 &&
ResultToks[ResultToks.size()-2].is(tok::comma) &&
(unsigned)ArgNo == Macro->getNumParams()-1 &&
Macro->isVariadic()) {
VaArgsPseudoPaste = true;
// Remove the paste operator, report use of the extension.
PP.Diag(ResultToks.pop_back_val().getLocation(), diag::ext_paste_comma);
}
ResultToks.append(ArgToks, ArgToks+NumToks);
// If the '##' came from expanding an argument, turn it into 'unknown'
// to avoid pasting.
for (Token &Tok : llvm::make_range(ResultToks.end() - NumToks,
ResultToks.end())) {
if (Tok.is(tok::hashhash))
Tok.setKind(tok::unknown);
}
if (ExpandLocStart.isValid()) {
updateLocForMacroArgTokens(CurTok.getLocation(),
ResultToks.end()-NumToks, ResultToks.end());
}
// Transfer the leading whitespace information from the token
// (the macro argument) onto the first token of the
// expansion. Note that we don't do this for the GNU
// pseudo-paste extension ", ## __VA_ARGS__".
if (!VaArgsPseudoPaste) {
ResultToks[ResultToks.size() - NumToks].setFlagValue(Token::StartOfLine,
false);
ResultToks[ResultToks.size() - NumToks].setFlagValue(
Token::LeadingSpace, NextTokGetsSpace);
}
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.
if (PasteAfter) {
// Discard the argument token and skip (don't copy to the expansion
// buffer) the paste operator after it.
++I;
continue;
}
if (RParenAfter)
VCtx.hasPlaceholderBeforeRParen();
// If this is on the RHS of a paste operator, we've already copied the
// paste operator to the ResultToks list, unless the LHS was empty too.
// Remove it.
assert(PasteBefore);
if (NonEmptyPasteBefore) {
assert(ResultToks.back().is(tok::hashhash));
// Do not remove the paste operator if it is the one before __VA_OPT__
// (and we are still processing tokens within VA_OPT). We handle the case
// of removing the paste operator if __VA_OPT__ reduces to the notional
// placemarker above when we encounter the closing paren of VA_OPT.
if (!VCtx.isInVAOpt() ||
ResultToks.size() > VCtx.getNumberOfTokensPriorToVAOpt())
ResultToks.pop_back();
else
VCtx.hasPlaceholderAfterHashhashAtStart();
}
// 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. This is a GCC extension which is
// disabled when using -std=c99.
if (ActualArgs->isVarargsElidedUse())
MaybeRemoveCommaBeforeVaArgs(ResultToks,
/*HasPasteOperator=*/true,
Macro, ArgNo, PP);
}
// 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();
// The tokens will be added to Preprocessor's cache and will be removed
// when this TokenLexer finishes lexing them.
Tokens = PP.cacheMacroExpandedTokens(this, ResultToks);
// The preprocessor cache of macro expanded tokens owns these tokens,not us.
OwnsTokens = false;
}
}
/// Checks if two tokens form wide string literal.
static bool isWideStringLiteralFromMacro(const Token &FirstTok,
const Token &SecondTok) {
return FirstTok.is(tok::identifier) &&
FirstTok.getIdentifierInfo()->isStr("L") && SecondTok.isLiteral() &&
SecondTok.stringifiedInMacro();
}
/// 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 (CurTokenIdx == 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 = CurTokenIdx == 0;
// Get the next token to return.
Tok = Tokens[CurTokenIdx++];
if (IsReinject)
Tok.setFlag(Token::IsReinjected);
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[CurTokenIdx].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[CurTokenIdx])))) {
// 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;
}
bool TokenLexer::pasteTokens(Token &Tok) {
return pasteTokens(Tok, llvm::makeArrayRef(Tokens, NumTokens), CurTokenIdx);
}
/// LHSTok is the LHS of a ## operator, and CurTokenIdx 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 LHSTok.
/// If this returns true, the caller should immediately return the token.
bool TokenLexer::pasteTokens(Token &LHSTok, ArrayRef<Token> TokenStream,
unsigned int &CurIdx) {
assert(CurIdx > 0 && "## can not be the first token within tokens");
assert((TokenStream[CurIdx].is(tok::hashhash) ||
(PP.getLangOpts().MSVCCompat &&
isWideStringLiteralFromMacro(LHSTok, TokenStream[CurIdx]))) &&
"Token at this Index must be ## or part of the MSVC 'L "
"#macro-arg' pasting pair");
// MSVC: If previous token was pasted, this must be a recovery from an invalid
// paste operation. Ignore spaces before this token to mimic MSVC output.
// Required for generating valid UUID strings in some MS headers.
if (PP.getLangOpts().MicrosoftExt && (CurIdx >= 2) &&
TokenStream[CurIdx - 2].is(tok::hashhash))
LHSTok.clearFlag(Token::LeadingSpace);
SmallString<128> Buffer;
const char *ResultTokStrPtr = nullptr;
SourceLocation StartLoc = LHSTok.getLocation();
SourceLocation PasteOpLoc;
auto IsAtEnd = [&TokenStream, &CurIdx] {
return TokenStream.size() == CurIdx;
};
do {
// Consume the ## operator if any.
PasteOpLoc = TokenStream[CurIdx].getLocation();
if (TokenStream[CurIdx].is(tok::hashhash))
++CurIdx;
assert(!IsAtEnd() && "No token on the RHS of a paste operator!");
// Get the RHS token.
const Token &RHS = TokenStream[CurIdx];
// Allocate space for the result token. This is guaranteed to be enough for
// the two tokens.
Buffer.resize(LHSTok.getLength() + RHS.getLength());
// Get the spelling of the LHS token in Buffer.
const char *BufPtr = &Buffer[0];
bool Invalid = false;
unsigned LHSLen = PP.getSpelling(LHSTok, BufPtr, &Invalid);
if (BufPtr != &Buffer[0]) // Really, we want the chars in Buffer!
memcpy(&Buffer[0], BufPtr, LHSLen);
if (Invalid)
return true;
BufPtr = Buffer.data() + LHSLen;
unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid);
if (Invalid)
return true;
if (RHSLen && 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 in getLiteralData().
ResultTokTmp.setKind(tok::string_literal);
PP.CreateString(Buffer, ResultTokTmp);
SourceLocation ResultTokLoc = ResultTokTmp.getLocation();
ResultTokStrPtr = ResultTokTmp.getLiteralData();
// Lex the resultant pasted token into Result.
Token Result;
if (LHSTok.isAnyIdentifier() && RHS.isAnyIdentifier()) {
// Common paste case: identifier+identifier = identifier. Avoid creating
// a lexer and other overhead.
PP.IncrementPasteCounter(true);
Result.startToken();
Result.setKind(tok::raw_identifier);
Result.setRawIdentifierData(ResultTokStrPtr);
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);
bool Invalid = false;
const char *ScratchBufStart
= SourceMgr.getBufferData(LocFileID, &Invalid).data();
if (Invalid)
return false;
// 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.getLangOpts(), 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 LHSTok
// unmodified and with RHS as the next token to lex.
if (isInvalid) {
// Explicitly convert the token location to have proper expansion
// information so that the user knows where it came from.
SourceManager &SM = PP.getSourceManager();
SourceLocation Loc =
SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2);
// Test for the Microsoft extension of /##/ turning into // here on the
// error path.
if (PP.getLangOpts().MicrosoftExt && LHSTok.is(tok::slash) &&
RHS.is(tok::slash)) {
HandleMicrosoftCommentPaste(LHSTok, Loc);
return true;
}
// Do not emit the error when preprocessing assembler code.
if (!PP.getLangOpts().AsmPreprocessor) {
// If we're in microsoft extensions mode, downgrade this from a hard
// error to an extension that defaults to an error. This allows
// disabling it.
PP.Diag(Loc, PP.getLangOpts().MicrosoftExt ? diag::ext_pp_bad_paste_ms
: diag::err_pp_bad_paste)
<< Buffer;
}
// An error has occurred so exit loop.
break;
}
// 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 Result.
Result.setFlagValue(Token::StartOfLine , LHSTok.isAtStartOfLine());
Result.setFlagValue(Token::LeadingSpace, LHSTok.hasLeadingSpace());
// Finally, replace LHS with the result, consume the RHS, and iterate.
++CurIdx;
LHSTok = Result;
} while (!IsAtEnd() && TokenStream[CurIdx].is(tok::hashhash));
SourceLocation EndLoc = TokenStream[CurIdx - 1].getLocation();
// 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 the token was
// expanded from the full ## expression. Pull this information together into
// a new SourceLocation that captures all of this.
SourceManager &SM = PP.getSourceManager();
if (StartLoc.isFileID())
StartLoc = getExpansionLocForMacroDefLoc(StartLoc);
if (EndLoc.isFileID())
EndLoc = getExpansionLocForMacroDefLoc(EndLoc);
FileID MacroFID = SM.getFileID(MacroExpansionStart);
while (SM.getFileID(StartLoc) != MacroFID)
StartLoc = SM.getImmediateExpansionRange(StartLoc).getBegin();
while (SM.getFileID(EndLoc) != MacroFID)
EndLoc = SM.getImmediateExpansionRange(EndLoc).getEnd();
LHSTok.setLocation(SM.createExpansionLoc(LHSTok.getLocation(), StartLoc, EndLoc,
LHSTok.getLength()));
// 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 (LHSTok.is(tok::raw_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.
PP.LookUpIdentifierInfo(LHSTok);
}
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[CurTokenIdx].is(tok::l_paren);
}
/// isParsingPreprocessorDirective - Return true if we are in the middle of a
/// preprocessor directive.
bool TokenLexer::isParsingPreprocessorDirective() const {
return Tokens[NumTokens-1].is(tok::eod) && !isAtEnd();
}
/// 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 expanded buffer. Handle this by returning the
/// first token on the next line.
void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok, SourceLocation OpLoc) {
PP.Diag(OpLoc, diag::ext_comment_paste_microsoft);
// 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);
}
/// If \arg loc is a file ID and points inside the current macro
/// definition, returns the appropriate source location pointing at the
/// macro expansion source location entry, otherwise it returns an invalid
/// SourceLocation.
SourceLocation
TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const {
assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() &&
"Not appropriate for token streams");
assert(loc.isValid() && loc.isFileID());
SourceManager &SM = PP.getSourceManager();
assert(SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength) &&
"Expected loc to come from the macro definition");
SourceLocation::UIntTy relativeOffset = 0;
SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength, &relativeOffset);
return MacroExpansionStart.getLocWithOffset(relativeOffset);
}
/// Finds the tokens that are consecutive (from the same FileID)
/// creates a single SLocEntry, and assigns SourceLocations to each token that
/// point to that SLocEntry. e.g for
/// assert(foo == bar);
/// There will be a single SLocEntry for the "foo == bar" chunk and locations
/// for the 'foo', '==', 'bar' tokens will point inside that chunk.
///
/// \arg begin_tokens will be updated to a position past all the found
/// consecutive tokens.
static void updateConsecutiveMacroArgTokens(SourceManager &SM,
SourceLocation InstLoc,
Token *&begin_tokens,
Token * end_tokens) {
assert(begin_tokens < end_tokens);
SourceLocation FirstLoc = begin_tokens->getLocation();
SourceLocation CurLoc = FirstLoc;
// Compare the source location offset of tokens and group together tokens that
// are close, even if their locations point to different FileIDs. e.g.
//
// |bar | foo | cake | (3 tokens from 3 consecutive FileIDs)
// ^ ^
// |bar foo cake| (one SLocEntry chunk for all tokens)
//
// we can perform this "merge" since the token's spelling location depends
// on the relative offset.
Token *NextTok = begin_tokens + 1;
for (; NextTok < end_tokens; ++NextTok) {
SourceLocation NextLoc = NextTok->getLocation();
if (CurLoc.isFileID() != NextLoc.isFileID())
break; // Token from different kind of FileID.
SourceLocation::IntTy RelOffs;
if (!SM.isInSameSLocAddrSpace(CurLoc, NextLoc, &RelOffs))
break; // Token from different local/loaded location.
// Check that token is not before the previous token or more than 50
// "characters" away.
if (RelOffs < 0 || RelOffs > 50)
break;
if (CurLoc.isMacroID() && !SM.isWrittenInSameFile(CurLoc, NextLoc))
break; // Token from a different macro.
CurLoc = NextLoc;
}
// For the consecutive tokens, find the length of the SLocEntry to contain
// all of them.
Token &LastConsecutiveTok = *(NextTok-1);
SourceLocation::IntTy LastRelOffs = 0;
SM.isInSameSLocAddrSpace(FirstLoc, LastConsecutiveTok.getLocation(),
&LastRelOffs);
SourceLocation::UIntTy FullLength =
LastRelOffs + LastConsecutiveTok.getLength();
// Create a macro expansion SLocEntry that will "contain" all of the tokens.
SourceLocation Expansion =
SM.createMacroArgExpansionLoc(FirstLoc, InstLoc,FullLength);
// Change the location of the tokens from the spelling location to the new
// expanded location.
for (; begin_tokens < NextTok; ++begin_tokens) {
Token &Tok = *begin_tokens;
SourceLocation::IntTy RelOffs = 0;
SM.isInSameSLocAddrSpace(FirstLoc, Tok.getLocation(), &RelOffs);
Tok.setLocation(Expansion.getLocWithOffset(RelOffs));
}
}
/// Creates SLocEntries and updates the locations of macro argument
/// tokens to their new expanded locations.
///
/// \param ArgIdSpellLoc the location of the macro argument id inside the macro
/// definition.
void TokenLexer::updateLocForMacroArgTokens(SourceLocation ArgIdSpellLoc,
Token *begin_tokens,
Token *end_tokens) {
SourceManager &SM = PP.getSourceManager();
SourceLocation InstLoc =
getExpansionLocForMacroDefLoc(ArgIdSpellLoc);
while (begin_tokens < end_tokens) {
// If there's only one token just create a SLocEntry for it.
if (end_tokens - begin_tokens == 1) {
Token &Tok = *begin_tokens;
Tok.setLocation(SM.createMacroArgExpansionLoc(Tok.getLocation(),
InstLoc,
Tok.getLength()));
return;
}
updateConsecutiveMacroArgTokens(SM, InstLoc, begin_tokens, end_tokens);
}
}
void TokenLexer::PropagateLineStartLeadingSpaceInfo(Token &Result) {
AtStartOfLine = Result.isAtStartOfLine();
HasLeadingSpace = Result.hasLeadingSpace();
}
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