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

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2.8 KiB
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//===--- SuspiciousSemicolonCheck.cpp - clang-tidy-------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#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 bugprone {
void SuspiciousSemicolonCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
stmt(anyOf(ifStmt(hasThen(nullStmt().bind("semi")),
unless(hasElse(stmt())),
unless(isConstexpr())),
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().hasUncompilableErrorOccurred())
return;
const auto *Semicolon = Result.Nodes.getNodeAs<NullStmt>("semi");
SourceLocation LocStart = Semicolon->getBeginLoc();
if (LocStart.isMacroID())
return;
ASTContext &Ctxt = *Result.Context;
auto Token = utils::lexer::getPreviousToken(LocStart, Ctxt.getSourceManager(),
Ctxt.getLangOpts());
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->getEndLoc();
FileID FID = SM.getFileID(LocEnd);
llvm::MemoryBufferRef Buffer = SM.getBufferOrFake(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->getBeginLoc());
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 bugprone
} // namespace tidy
} // namespace clang