clang-tools 6.0.0

SuspiciousSemicolonCheck.cpp
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1 //===--- SuspiciousSemicolonCheck.cpp - clang-tidy-------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "SuspiciousSemicolonCheck.h"
11 #include "../utils/LexerUtils.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/ASTMatchers/ASTMatchFinder.h"
14
15 using namespace clang::ast_matchers;
16
17 namespace clang {
18 namespace tidy {
19 namespace misc {
20
21 void SuspiciousSemicolonCheck::registerMatchers(MatchFinder *Finder) {
22 Finder->addMatcher(
23 stmt(anyOf(ifStmt(hasThen(nullStmt().bind("semi")),
24 unless(hasElse(stmt()))),
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->getLocStart();
38
39 if (LocStart.isMacroID())
40 return;
41
42 ASTContext &Ctxt = *Result.Context;
43 auto Token = utils::lexer::getPreviousToken(Ctxt, LocStart);
44 auto &SM = *Result.SourceManager;
45 unsigned SemicolonLine = SM.getSpellingLineNumber(LocStart);
46
47 const auto *Statement = Result.Nodes.getNodeAs<Stmt>("stmt");
48 const bool IsIfStmt = isa<IfStmt>(Statement);
49
50 if (!IsIfStmt &&
51 SM.getSpellingLineNumber(Token.getLocation()) != SemicolonLine)
52 return;
53
54 SourceLocation LocEnd = Semicolon->getLocEnd();
55 FileID FID = SM.getFileID(LocEnd);
56 llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, LocEnd);
57 Lexer Lexer(SM.getLocForStartOfFile(FID), Ctxt.getLangOpts(),
58 Buffer->getBufferStart(), SM.getCharacterData(LocEnd) + 1,
59 Buffer->getBufferEnd());
60 if (Lexer.LexFromRawLexer(Token))
61 return;
62
63 unsigned BaseIndent = SM.getSpellingColumnNumber(Statement->getLocStart());
64 unsigned NewTokenIndent = SM.getSpellingColumnNumber(Token.getLocation());
65 unsigned NewTokenLine = SM.getSpellingLineNumber(Token.getLocation());
66
67 if (!IsIfStmt && NewTokenIndent <= BaseIndent &&
68 Token.getKind() != tok::l_brace && NewTokenLine != SemicolonLine)
69 return;
70
71 diag(LocStart, "potentially unintended semicolon")
72 << FixItHint::CreateRemoval(SourceRange(LocStart, LocEnd));
73 }
74
75 } // namespace misc
76 } // namespace tidy
77 } // namespace clang
clang::ast_matchers
Definition: ClangTidyDiagnosticConsumer.h:27
clang::tidy::utils::lexer::getPreviousToken
Token getPreviousToken(const ASTContext &Context, SourceLocation Location, bool SkipComments)
Returns previous token or tok::unknown if not found.
Definition: LexerUtils.cpp:17
clang
Definition: AndroidTidyModule.cpp:28
SuspiciousSemicolonCheck.h