clang-tools  9.0.0
NoexceptMoveConstructorCheck.cpp
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1 //===--- NoexceptMoveConstructorCheck.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 
13 using namespace clang::ast_matchers;
14 
15 namespace clang {
16 namespace tidy {
17 namespace performance {
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 
46  if (isUnresolvedExceptionSpec(ProtoType->getExceptionSpecType()))
47  return;
48 
49  if (!isNoexceptExceptionSpec(ProtoType->getExceptionSpecType())) {
50  diag(Decl->getLocation(), "move %0s should be marked noexcept")
51  << MethodType;
52  // FIXME: Add a fixit.
53  return;
54  }
55 
56  // Don't complain about nothrow(false), but complain on nothrow(expr)
57  // where expr evaluates to false.
58  if (ProtoType->canThrow() == CT_Can) {
59  Expr *E = ProtoType->getNoexceptExpr();
60  E = E->IgnoreImplicit();
61  if (!isa<CXXBoolLiteralExpr>(E)) {
62  diag(E->getExprLoc(),
63  "noexcept specifier on the move %0 evaluates to 'false'")
64  << MethodType;
65  }
66  }
67  }
68 }
69 
70 } // namespace performance
71 } // namespace tidy
72 } // namespace clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
llvm::Optional< llvm::Expected< tooling::AtomicChanges > > Result
Definition: Rename.cpp:36