llvm-project/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp

100 lines
2.9 KiB
C++

//===--- UseUsingCheck.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 "UseUsingCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace modernize {
void UseUsingCheck::registerMatchers(MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus11)
return;
Finder->addMatcher(typedefDecl().bind("typedef"), this);
}
// Checks if 'typedef' keyword can be removed - we do it only if
// it is the only declaration in a declaration chain.
static bool CheckRemoval(SourceManager &SM, SourceLocation StartLoc,
ASTContext &Context) {
assert(StartLoc.isFileID() && "StartLoc must not be in a macro");
std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(StartLoc);
StringRef File = SM.getBufferData(LocInfo.first);
const char *TokenBegin = File.data() + LocInfo.second;
Lexer DeclLexer(SM.getLocForStartOfFile(LocInfo.first), Context.getLangOpts(),
File.begin(), TokenBegin, File.end());
Token Tok;
int ParenLevel = 0;
bool FoundTypedef = false;
while (!DeclLexer.LexFromRawLexer(Tok) && !Tok.is(tok::semi)) {
switch (Tok.getKind()) {
case tok::l_brace:
case tok::r_brace:
// This might be the `typedef struct {...} T;` case.
return false;
case tok::l_paren:
ParenLevel++;
break;
case tok::r_paren:
ParenLevel--;
break;
case tok::comma:
if (ParenLevel == 0) {
// If there is comma and we are not between open parenthesis then it is
// two or more declarations in this chain.
return false;
}
break;
case tok::raw_identifier:
if (Tok.getRawIdentifier() == "typedef") {
FoundTypedef = true;
}
break;
default:
break;
}
}
// Sanity check against weird macro cases.
return FoundTypedef;
}
void UseUsingCheck::check(const MatchFinder::MatchResult &Result) {
const auto *MatchedDecl = Result.Nodes.getNodeAs<TypedefDecl>("typedef");
if (MatchedDecl->getLocation().isInvalid())
return;
auto &Context = *Result.Context;
auto &SM = *Result.SourceManager;
auto Diag =
diag(MatchedDecl->getLocStart(), "use 'using' instead of 'typedef'");
SourceLocation StartLoc = MatchedDecl->getLocStart();
if (StartLoc.isMacroID())
return;
if (CheckRemoval(SM, StartLoc, Context)) {
Diag << FixItHint::CreateReplacement(
MatchedDecl->getSourceRange(),
"using " + MatchedDecl->getNameAsString() + " = " +
MatchedDecl->getUnderlyingType().getAsString(getLangOpts()));
}
}
} // namespace modernize
} // namespace tidy
} // namespace clang