llvm-project/clang-tools-extra/clang-tidy/utils/LexerUtils.cpp

//===--- LexerUtils.cpp - clang-tidy---------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "LexerUtils.h"

namespace clang {
namespace tidy {
namespace utils {
namespace lexer {

Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
                       const LangOptions &LangOpts, bool SkipComments) {
  Token Token;
  Token.setKind(tok::unknown);
  Location = Location.getLocWithOffset(-1);
  auto StartOfFile = SM.getLocForStartOfFile(SM.getFileID(Location));
  while (Location != StartOfFile) {
    Location = Lexer::GetBeginningOfToken(Location, SM, LangOpts);
    if (!Lexer::getRawToken(Location, Token, SM, LangOpts) &&
        (!SkipComments || !Token.is(tok::comment))) {
      break;
    }
    Location = Location.getLocWithOffset(-1);
  }
  return Token;
}

SourceLocation findPreviousTokenStart(SourceLocation Start,
                                      const SourceManager &SM,
                                      const LangOptions &LangOpts) {
  if (Start.isInvalid() || Start.isMacroID())
    return SourceLocation();

  SourceLocation BeforeStart = Start.getLocWithOffset(-1);
  if (BeforeStart.isInvalid() || BeforeStart.isMacroID())
    return SourceLocation();

  return Lexer::GetBeginningOfToken(BeforeStart, SM, LangOpts);
}

SourceLocation findPreviousTokenKind(SourceLocation Start,
                                     const SourceManager &SM,
                                     const LangOptions &LangOpts,
                                     tok::TokenKind TK) {
  while (true) {
    SourceLocation L = findPreviousTokenStart(Start, SM, LangOpts);
    if (L.isInvalid() || L.isMacroID())
      return SourceLocation();

    Token T;
    if (Lexer::getRawToken(L, T, SM, LangOpts, /*IgnoreWhiteSpace=*/true))
      return SourceLocation();

    if (T.is(TK))
      return T.getLocation();

    Start = L;
  }
}

SourceLocation findNextTerminator(SourceLocation Start, const SourceManager &SM,
                                  const LangOptions &LangOpts) {
  return findNextAnyTokenKind(Start, SM, LangOpts, tok::comma, tok::semi);
}

bool rangeContainsExpansionsOrDirectives(SourceRange Range,
                                         const SourceManager &SM,
                                         const LangOptions &LangOpts) {
  assert(Range.isValid() && "Invalid Range for relexing provided");
  SourceLocation Loc = Range.getBegin();

  while (Loc < Range.getEnd()) {
    if (Loc.isMacroID())
      return true;

    llvm::Optional<Token> Tok = Lexer::findNextToken(Loc, SM, LangOpts);

    if (!Tok)
      return true;

    if (Tok->is(tok::hash))
      return true;

    Loc = Lexer::getLocForEndOfToken(Loc, 0, SM, LangOpts).getLocWithOffset(1);
  }

  return false;
}
} // namespace lexer
} // namespace utils
} // namespace tidy
} // namespace clang