clang-tools  8.0.0
RedundantControlFlowCheck.cpp
Go to the documentation of this file.
1 //===--- RedundantControlFlowCheck.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 
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace readability {
20 
21 namespace {
22 
23 const char *const RedundantReturnDiag = "redundant return statement at the end "
24  "of a function with a void return type";
25 const char *const RedundantContinueDiag = "redundant continue statement at the "
26  "end of loop statement";
27 
28 bool isLocationInMacroExpansion(const SourceManager &SM, SourceLocation Loc) {
29  return SM.isMacroBodyExpansion(Loc) || SM.isMacroArgExpansion(Loc);
30 }
31 
32 } // namespace
33 
34 void RedundantControlFlowCheck::registerMatchers(MatchFinder *Finder) {
35  Finder->addMatcher(
36  functionDecl(
37  isDefinition(), returns(voidType()),
38  has(compoundStmt(hasAnySubstatement(returnStmt(unless(has(expr())))))
39  .bind("return"))),
40  this);
41  auto CompoundContinue =
42  has(compoundStmt(hasAnySubstatement(continueStmt())).bind("continue"));
43  Finder->addMatcher(
44  stmt(anyOf(forStmt(), cxxForRangeStmt(), whileStmt(), doStmt()),
45  CompoundContinue),
46  this);
47 }
48 
49 void RedundantControlFlowCheck::check(const MatchFinder::MatchResult &Result) {
50  if (const auto *Return = Result.Nodes.getNodeAs<CompoundStmt>("return"))
51  checkRedundantReturn(Result, Return);
52  else if (const auto *Continue =
53  Result.Nodes.getNodeAs<CompoundStmt>("continue"))
54  checkRedundantContinue(Result, Continue);
55 }
56 
57 void RedundantControlFlowCheck::checkRedundantReturn(
58  const MatchFinder::MatchResult &Result, const CompoundStmt *Block) {
59  CompoundStmt::const_reverse_body_iterator last = Block->body_rbegin();
60  if (const auto *Return = dyn_cast<ReturnStmt>(*last))
61  issueDiagnostic(Result, Block, Return->getSourceRange(),
62  RedundantReturnDiag);
63 }
64 
65 void RedundantControlFlowCheck::checkRedundantContinue(
66  const MatchFinder::MatchResult &Result, const CompoundStmt *Block) {
67  CompoundStmt::const_reverse_body_iterator last = Block->body_rbegin();
68  if (const auto *Continue = dyn_cast<ContinueStmt>(*last))
69  issueDiagnostic(Result, Block, Continue->getSourceRange(),
70  RedundantContinueDiag);
71 }
72 
73 void RedundantControlFlowCheck::issueDiagnostic(
74  const MatchFinder::MatchResult &Result, const CompoundStmt *const Block,
75  const SourceRange &StmtRange, const char *const Diag) {
76  SourceManager &SM = *Result.SourceManager;
77  if (isLocationInMacroExpansion(SM, StmtRange.getBegin()))
78  return;
79 
80  CompoundStmt::const_reverse_body_iterator Previous = ++Block->body_rbegin();
81  SourceLocation Start;
82  if (Previous != Block->body_rend())
83  Start = Lexer::findLocationAfterToken(
84  dyn_cast<Stmt>(*Previous)->getEndLoc(), tok::semi, SM, getLangOpts(),
85  /*SkipTrailingWhitespaceAndNewLine=*/true);
86  if (!Start.isValid())
87  Start = StmtRange.getBegin();
88  auto RemovedRange = CharSourceRange::getCharRange(
89  Start, Lexer::findLocationAfterToken(
90  StmtRange.getEnd(), tok::semi, SM, getLangOpts(),
91  /*SkipTrailingWhitespaceAndNewLine=*/true));
92 
93  diag(StmtRange.getBegin(), Diag) << FixItHint::CreateRemoval(RemovedRange);
94 }
95 
96 } // namespace readability
97 } // namespace tidy
98 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//