clang-tools  8.0.0
AvoidGotoCheck.cpp
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1 //===--- AvoidGotoCheck.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 "AvoidGotoCheck.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 cppcoreguidelines {
19 
20 namespace {
21 AST_MATCHER(GotoStmt, isForwardJumping) {
22  return Node.getBeginLoc() < Node.getLabel()->getBeginLoc();
23 }
24 } // namespace
25 
26 void AvoidGotoCheck::registerMatchers(MatchFinder *Finder) {
27  if (!getLangOpts().CPlusPlus)
28  return;
29 
30  // TODO: This check does not recognize `IndirectGotoStmt` which is a
31  // GNU extension. These must be matched separately and an AST matcher
32  // is currently missing for them.
33 
34  // Check if the 'goto' is used for control flow other than jumping
35  // out of a nested loop.
36  auto Loop = stmt(anyOf(forStmt(), cxxForRangeStmt(), whileStmt(), doStmt()));
37  auto NestedLoop =
38  stmt(anyOf(forStmt(hasAncestor(Loop)), cxxForRangeStmt(hasAncestor(Loop)),
39  whileStmt(hasAncestor(Loop)), doStmt(hasAncestor(Loop))));
40 
41  Finder->addMatcher(gotoStmt(anyOf(unless(hasAncestor(NestedLoop)),
42  unless(isForwardJumping())))
43  .bind("goto"),
44  this);
45 }
46 
47 void AvoidGotoCheck::check(const MatchFinder::MatchResult &Result) {
48  const auto *Goto = Result.Nodes.getNodeAs<GotoStmt>("goto");
49 
50  diag(Goto->getGotoLoc(), "avoid using 'goto' for flow control")
51  << Goto->getSourceRange();
52  diag(Goto->getLabel()->getBeginLoc(), "label defined here",
53  DiagnosticIDs::Note);
54 }
55 } // namespace cppcoreguidelines
56 } // namespace tidy
57 } // namespace clang
AST_MATCHER(BinaryOperator, isAssignmentOperator)
Definition: Matchers.h:20
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//