clang-tools  3.8.0
NoexceptMoveConstructorCheck.cpp
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1 //===--- NoexceptMoveConstructorCheck.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 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 
19 void NoexceptMoveConstructorCheck::registerMatchers(MatchFinder *Finder) {
20  // Only register the matchers for C++11; the functionality currently does not
21  // provide any benefit to other languages, despite being benign.
22  if (!getLangOpts().CPlusPlus11)
23  return;
24 
25  Finder->addMatcher(
26  cxxMethodDecl(anyOf(cxxConstructorDecl(), hasOverloadedOperatorName("=")),
27  unless(isImplicit()), unless(isDeleted()))
28  .bind("decl"),
29  this);
30 }
31 
32 void NoexceptMoveConstructorCheck::check(
33  const MatchFinder::MatchResult &Result) {
34  if (const auto *Decl = Result.Nodes.getNodeAs<CXXMethodDecl>("decl")) {
35  StringRef MethodType = "assignment operator";
36  if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(Decl)) {
37  if (!Ctor->isMoveConstructor())
38  return;
39  MethodType = "constructor";
40  } else if (!Decl->isMoveAssignmentOperator()) {
41  return;
42  }
43 
44  const auto *ProtoType = Decl->getType()->getAs<FunctionProtoType>();
45  switch(ProtoType->getNoexceptSpec(*Result.Context)) {
46  case FunctionProtoType::NR_NoNoexcept:
47  diag(Decl->getLocation(), "move %0s should be marked noexcept")
48  << MethodType;
49  // FIXME: Add a fixit.
50  break;
51  case FunctionProtoType::NR_Throw:
52  // Don't complain about nothrow(false), but complain on nothrow(expr)
53  // where expr evaluates to false.
54  if (const Expr *E = ProtoType->getNoexceptExpr()) {
55  if (isa<CXXBoolLiteralExpr>(E))
56  break;
57  diag(E->getExprLoc(),
58  "noexcept specifier on the move %0 evaluates to 'false'")
59  << MethodType;
60  }
61  break;
62  case FunctionProtoType::NR_Nothrow:
63  case FunctionProtoType::NR_Dependent:
64  case FunctionProtoType::NR_BadNoexcept:
65  break;
66  }
67  }
68 }
69 
70 } // namespace tidy
71 } // namespace clang
72 
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:188
const NamedDecl * Result
Definition: USRFinder.cpp:121