clang-tools  14.0.0git
SuspiciousSemicolonCheck.cpp
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1 //===--- SuspiciousSemicolonCheck.cpp - clang-tidy-------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
10 #include "../utils/LexerUtils.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace bugprone {
19 
20 void SuspiciousSemicolonCheck::registerMatchers(MatchFinder *Finder) {
21  Finder->addMatcher(
22  stmt(anyOf(ifStmt(hasThen(nullStmt().bind("semi")),
23  unless(hasElse(stmt())),
24  unless(isConstexpr())),
25  forStmt(hasBody(nullStmt().bind("semi"))),
26  cxxForRangeStmt(hasBody(nullStmt().bind("semi"))),
27  whileStmt(hasBody(nullStmt().bind("semi")))))
28  .bind("stmt"),
29  this);
30 }
31 
32 void SuspiciousSemicolonCheck::check(const MatchFinder::MatchResult &Result) {
33  if (Result.Context->getDiagnostics().hasUncompilableErrorOccurred())
34  return;
35 
36  const auto *Semicolon = Result.Nodes.getNodeAs<NullStmt>("semi");
37  SourceLocation LocStart = Semicolon->getBeginLoc();
38 
39  if (LocStart.isMacroID())
40  return;
41 
42  ASTContext &Ctxt = *Result.Context;
43  auto Token = utils::lexer::getPreviousToken(LocStart, Ctxt.getSourceManager(),
44  Ctxt.getLangOpts());
45  auto &SM = *Result.SourceManager;
46  unsigned SemicolonLine = SM.getSpellingLineNumber(LocStart);
47 
48  const auto *Statement = Result.Nodes.getNodeAs<Stmt>("stmt");
49  const bool IsIfStmt = isa<IfStmt>(Statement);
50 
51  if (!IsIfStmt &&
52  SM.getSpellingLineNumber(Token.getLocation()) != SemicolonLine)
53  return;
54 
55  SourceLocation LocEnd = Semicolon->getEndLoc();
56  FileID FID = SM.getFileID(LocEnd);
57  llvm::MemoryBufferRef Buffer = SM.getBufferOrFake(FID, LocEnd);
58  Lexer Lexer(SM.getLocForStartOfFile(FID), Ctxt.getLangOpts(),
59  Buffer.getBufferStart(), SM.getCharacterData(LocEnd) + 1,
60  Buffer.getBufferEnd());
61  if (Lexer.LexFromRawLexer(Token))
62  return;
63 
64  unsigned BaseIndent = SM.getSpellingColumnNumber(Statement->getBeginLoc());
65  unsigned NewTokenIndent = SM.getSpellingColumnNumber(Token.getLocation());
66  unsigned NewTokenLine = SM.getSpellingLineNumber(Token.getLocation());
67 
68  if (!IsIfStmt && NewTokenIndent <= BaseIndent &&
69  Token.getKind() != tok::l_brace && NewTokenLine != SemicolonLine)
70  return;
71 
72  diag(LocStart, "potentially unintended semicolon")
73  << FixItHint::CreateRemoval(SourceRange(LocStart, LocEnd));
74 }
75 
76 } // namespace bugprone
77 } // namespace tidy
78 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::tidy::utils::lexer::getPreviousToken
Token getPreviousToken(SourceLocation Location, const SourceManager &SM, const LangOptions &LangOpts, bool SkipComments)
Returns previous token or tok::unknown if not found.
Definition: LexerUtils.cpp:18
clang::clangd::check
bool check(llvm::StringRef File, llvm::function_ref< bool(const Position &)> ShouldCheckLine, const ThreadsafeFS &TFS, const ClangdLSPServer::Options &Opts, bool EnableCodeCompletion)
Definition: Check.cpp:259
SuspiciousSemicolonCheck.h
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
SM
const SourceManager & SM
Definition: IncludeCleaner.cpp:140