llvm-project/clang-tools-extra/clang-tidy/misc/SuspiciousSemicolonCheck.cpp

78 lines
2.6 KiB
C++

//===--- SuspiciousSemicolonCheck.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 "SuspiciousSemicolonCheck.h"
#include "../utils/LexerUtils.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace misc {
void SuspiciousSemicolonCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
stmt(anyOf(ifStmt(hasThen(nullStmt().bind("semi")),
unless(hasElse(stmt()))),
forStmt(hasBody(nullStmt().bind("semi"))),
cxxForRangeStmt(hasBody(nullStmt().bind("semi"))),
whileStmt(hasBody(nullStmt().bind("semi")))))
.bind("stmt"),
this);
}
void SuspiciousSemicolonCheck::check(const MatchFinder::MatchResult &Result) {
if (Result.Context->getDiagnostics().hasErrorOccurred())
return;
const auto *Semicolon = Result.Nodes.getNodeAs<NullStmt>("semi");
SourceLocation LocStart = Semicolon->getLocStart();
if (LocStart.isMacroID())
return;
ASTContext &Ctxt = *Result.Context;
auto Token = utils::lexer::getPreviousNonCommentToken(Ctxt, LocStart);
auto &SM = *Result.SourceManager;
unsigned SemicolonLine = SM.getSpellingLineNumber(LocStart);
const auto *Statement = Result.Nodes.getNodeAs<Stmt>("stmt");
const bool IsIfStmt = isa<IfStmt>(Statement);
if (!IsIfStmt &&
SM.getSpellingLineNumber(Token.getLocation()) != SemicolonLine)
return;
SourceLocation LocEnd = Semicolon->getLocEnd();
FileID FID = SM.getFileID(LocEnd);
llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, LocEnd);
Lexer Lexer(SM.getLocForStartOfFile(FID), Ctxt.getLangOpts(),
Buffer->getBufferStart(), SM.getCharacterData(LocEnd) + 1,
Buffer->getBufferEnd());
if (Lexer.LexFromRawLexer(Token))
return;
unsigned BaseIndent = SM.getSpellingColumnNumber(Statement->getLocStart());
unsigned NewTokenIndent = SM.getSpellingColumnNumber(Token.getLocation());
unsigned NewTokenLine = SM.getSpellingLineNumber(Token.getLocation());
if (!IsIfStmt && NewTokenIndent <= BaseIndent &&
Token.getKind() != tok::l_brace && NewTokenLine != SemicolonLine)
return;
diag(LocStart, "potentially unintended semicolon")
<< FixItHint::CreateRemoval(SourceRange(LocStart, LocEnd));
}
} // namespace misc
} // namespace tidy
} // namespace clang