clang-tools 10.0.0

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
9 #include "NoexceptMoveConstructorCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Tooling/FixIt.h"
13
14 using namespace clang::ast_matchers;
15
16 namespace clang {
17 namespace tidy {
18 namespace performance {
19
20 void NoexceptMoveConstructorCheck::registerMatchers(MatchFinder *Finder) {
21 // Only register the matchers for C++11; the functionality currently does not
22 // provide any benefit to other languages, despite being benign.
23 if (!getLangOpts().CPlusPlus11)
24 return;
25
26 Finder->addMatcher(
27 cxxMethodDecl(anyOf(cxxConstructorDecl(), hasOverloadedOperatorName("=")),
28 unless(isImplicit()), unless(isDeleted()))
29 .bind("decl"),
30 this);
31 }
32
33 void NoexceptMoveConstructorCheck::check(
34 const MatchFinder::MatchResult &Result) {
35 if (const auto *Decl = Result.Nodes.getNodeAs<CXXMethodDecl>("decl")) {
36 StringRef MethodType = "assignment operator";
37 if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(Decl)) {
38 if (!Ctor->isMoveConstructor())
39 return;
40 MethodType = "constructor";
41 } else if (!Decl->isMoveAssignmentOperator()) {
42 return;
43 }
44
45 const auto *ProtoType = Decl->getType()->getAs<FunctionProtoType>();
46
47 if (isUnresolvedExceptionSpec(ProtoType->getExceptionSpecType()))
48 return;
49
50 if (!isNoexceptExceptionSpec(ProtoType->getExceptionSpecType())) {
51 auto Diag =
52 diag(Decl->getLocation(), "move %0s should be marked noexcept")
53 << MethodType;
54 // Add FixIt hints.
55 SourceManager &SM = *Result.SourceManager;
56 assert(Decl->getNumParams() > 0);
57 SourceLocation NoexceptLoc = Decl->getParamDecl(Decl->getNumParams() - 1)
58 ->getSourceRange()
59 .getEnd();
60 if (NoexceptLoc.isValid())
61 NoexceptLoc = Lexer::findLocationAfterToken(
62 NoexceptLoc, tok::r_paren, SM, Result.Context->getLangOpts(), true);
63 if (NoexceptLoc.isValid())
64 Diag << FixItHint::CreateInsertion(NoexceptLoc, " noexcept ");
65 return;
66 }
67
68 // Don't complain about nothrow(false), but complain on nothrow(expr)
69 // where expr evaluates to false.
70 if (ProtoType->canThrow() == CT_Can) {
71 Expr *E = ProtoType->getNoexceptExpr();
72 E = E->IgnoreImplicit();
73 if (!isa<CXXBoolLiteralExpr>(E)) {
74 diag(E->getExprLoc(),
75 "noexcept specifier on the move %0 evaluates to 'false'")
76 << MethodType;
77 }
78 }
79 }
80 }
81
82 } // namespace performance
83 } // namespace tidy
84 } // namespace clang
clang::ast_matchers
Definition: AbseilMatcher.h:14
Decl
const FunctionDecl * Decl
Definition: AvoidBindCheck.cpp:93
NoexceptMoveConstructorCheck.h
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
E
const Expr * E
Definition: AvoidBindCheck.cpp:82