llvm-project/clang/Lex/MacroExpander.cpp

92 lines
3.4 KiB
C++

//===--- MacroExpander.cpp - Lex from a macro expansion -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the MacroExpander interface.
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/MacroExpander.h"
#include "clang/Lex/MacroInfo.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/SourceManager.h"
using namespace llvm;
using namespace clang;
//===----------------------------------------------------------------------===//
// MacroFormalArgs Implementation
//===----------------------------------------------------------------------===//
MacroFormalArgs::MacroFormalArgs(const MacroInfo *MI) {
assert(MI->isFunctionLike() &&
"Can't have formal args for an object-like macro!");
// Reserve space for arguments to avoid reallocation.
unsigned NumArgs = MI->getNumArgs();
if (MI->isC99Varargs() || MI->isGNUVarargs())
NumArgs += 3; // Varargs can have more than this, just some guess.
ArgTokens.reserve(NumArgs);
}
//===----------------------------------------------------------------------===//
// MacroExpander Implementation
//===----------------------------------------------------------------------===//
MacroExpander::MacroExpander(LexerToken &Tok, MacroFormalArgs *Formals,
Preprocessor &pp)
: Macro(*Tok.getIdentifierInfo()->getMacroInfo()), FormalArgs(Formals),
PP(pp), CurToken(0),
InstantiateLoc(Tok.getLocation()),
AtStartOfLine(Tok.isAtStartOfLine()),
HasLeadingSpace(Tok.hasLeadingSpace()) {
}
/// Lex - Lex and return a token from this macro stream.
///
void MacroExpander::Lex(LexerToken &Tok) {
// Lexing off the end of the macro, pop this macro off the expansion stack.
if (CurToken == Macro.getNumTokens())
return PP.HandleEndOfMacro(Tok);
// Get the next token to return.
Tok = Macro.getReplacementToken(CurToken++);
// 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.
Tok.SetLocation(PP.getSourceManager().getInstantiationLoc(Tok.getLocation(),
InstantiateLoc));
// If this is the first token, set the lexical properties of the token to
// match the lexical properties of the macro identifier.
if (CurToken == 1) {
Tok.SetFlagValue(LexerToken::StartOfLine , AtStartOfLine);
Tok.SetFlagValue(LexerToken::LeadingSpace, HasLeadingSpace);
}
// Handle recursive expansion!
if (Tok.getIdentifierInfo())
return PP.HandleIdentifier(Tok);
// Otherwise, return a normal token.
}
/// 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 MacroExpander::isNextTokenLParen() const {
// Out of tokens?
if (CurToken == Macro.getNumTokens())
return 2;
return Macro.getReplacementToken(CurToken).getKind() == tok::l_paren;
}