clang-tools  9.0.0
RedundantControlFlowCheck.cpp
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1 //===--- RedundantControlFlowCheck.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 "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Lex/Lexer.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace readability {
19 
20 namespace {
21 
22 const char *const RedundantReturnDiag = "redundant return statement at the end "
23  "of a function with a void return type";
24 const char *const RedundantContinueDiag = "redundant continue statement at the "
25  "end of loop statement";
26 
27 bool isLocationInMacroExpansion(const SourceManager &SM, SourceLocation Loc) {
28  return SM.isMacroBodyExpansion(Loc) || SM.isMacroArgExpansion(Loc);
29 }
30 
31 } // namespace
32 
33 void RedundantControlFlowCheck::registerMatchers(MatchFinder *Finder) {
34  Finder->addMatcher(
35  functionDecl(
36  isDefinition(), returns(voidType()),
37  has(compoundStmt(hasAnySubstatement(returnStmt(unless(has(expr())))))
38  .bind("return"))),
39  this);
40  auto CompoundContinue =
41  has(compoundStmt(hasAnySubstatement(continueStmt())).bind("continue"));
42  Finder->addMatcher(
43  stmt(anyOf(forStmt(), cxxForRangeStmt(), whileStmt(), doStmt()),
44  CompoundContinue),
45  this);
46 }
47 
48 void RedundantControlFlowCheck::check(const MatchFinder::MatchResult &Result) {
49  if (const auto *Return = Result.Nodes.getNodeAs<CompoundStmt>("return"))
50  checkRedundantReturn(Result, Return);
51  else if (const auto *Continue =
52  Result.Nodes.getNodeAs<CompoundStmt>("continue"))
53  checkRedundantContinue(Result, Continue);
54 }
55 
56 void RedundantControlFlowCheck::checkRedundantReturn(
57  const MatchFinder::MatchResult &Result, const CompoundStmt *Block) {
58  CompoundStmt::const_reverse_body_iterator last = Block->body_rbegin();
59  if (const auto *Return = dyn_cast<ReturnStmt>(*last))
60  issueDiagnostic(Result, Block, Return->getSourceRange(),
61  RedundantReturnDiag);
62 }
63 
64 void RedundantControlFlowCheck::checkRedundantContinue(
65  const MatchFinder::MatchResult &Result, const CompoundStmt *Block) {
66  CompoundStmt::const_reverse_body_iterator last = Block->body_rbegin();
67  if (const auto *Continue = dyn_cast<ContinueStmt>(*last))
68  issueDiagnostic(Result, Block, Continue->getSourceRange(),
69  RedundantContinueDiag);
70 }
71 
72 void RedundantControlFlowCheck::issueDiagnostic(
73  const MatchFinder::MatchResult &Result, const CompoundStmt *const Block,
74  const SourceRange &StmtRange, const char *const Diag) {
75  SourceManager &SM = *Result.SourceManager;
76  if (isLocationInMacroExpansion(SM, StmtRange.getBegin()))
77  return;
78 
79  CompoundStmt::const_reverse_body_iterator Previous = ++Block->body_rbegin();
80  SourceLocation Start;
81  if (Previous != Block->body_rend())
82  Start = Lexer::findLocationAfterToken(
83  dyn_cast<Stmt>(*Previous)->getEndLoc(), tok::semi, SM, getLangOpts(),
84  /*SkipTrailingWhitespaceAndNewLine=*/true);
85  if (!Start.isValid())
86  Start = StmtRange.getBegin();
87  auto RemovedRange = CharSourceRange::getCharRange(
88  Start, Lexer::findLocationAfterToken(
89  StmtRange.getEnd(), tok::semi, SM, getLangOpts(),
90  /*SkipTrailingWhitespaceAndNewLine=*/true));
91 
92  diag(StmtRange.getBegin(), Diag) << FixItHint::CreateRemoval(RemovedRange);
93 }
94 
95 } // namespace readability
96 } // namespace tidy
97 } // namespace clang
SourceLocation Loc
&#39;#&#39; location in the include directive
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: Rename.cpp:36