| 1 | //===--- UndelegatedConstructorCheck.cpp - clang-tidy----------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "UndelegatedConstructorCheck.h" |
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| 10 | #include "clang/AST/ASTContext.h" |
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| 11 | |
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| 12 | using namespace clang::ast_matchers; |
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| 13 | |
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| 14 | namespace clang::tidy::bugprone { |
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| 15 | |
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| 16 | namespace { |
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| 17 | AST_MATCHER_P(Stmt, ignoringTemporaryExpr, |
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| 18 | ast_matchers::internal::Matcher<Stmt>, InnerMatcher) { |
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| 19 | const Stmt *E = &Node; |
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| 20 | for (;;) { |
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| 21 | // Temporaries with non-trivial dtors. |
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| 22 | if (const auto *EWC = dyn_cast<ExprWithCleanups>(Val: E)) |
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| 23 | E = EWC->getSubExpr(); |
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| 24 | // Temporaries with zero or more than two ctor arguments. |
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| 25 | else if (const auto *BTE = dyn_cast<CXXBindTemporaryExpr>(Val: E)) |
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| 26 | E = BTE->getSubExpr(); |
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| 27 | // Temporaries with exactly one ctor argument. |
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| 28 | else if (const auto *FCE = dyn_cast<CXXFunctionalCastExpr>(Val: E)) |
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| 29 | E = FCE->getSubExpr(); |
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| 30 | else |
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| 31 | break; |
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| 32 | } |
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| 33 | |
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| 34 | return InnerMatcher.matches(Node: *E, Finder, Builder); |
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| 35 | } |
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| 36 | |
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| 37 | // Finds a node if it's a base of an already bound node. |
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| 38 | AST_MATCHER_P(CXXRecordDecl, baseOfBoundNode, std::string, ID) { |
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| 39 | return Builder->removeBindings( |
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| 40 | Predicate: [&](const ast_matchers::internal::BoundNodesMap &Nodes) { |
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| 41 | const auto *Derived = Nodes.getNodeAs<CXXRecordDecl>(ID); |
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| 42 | return Derived != &Node && !Derived->isDerivedFrom(Base: &Node); |
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| 43 | }); |
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| 44 | } |
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| 45 | } // namespace |
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| 46 | |
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| 47 | void UndelegatedConstructorCheck::registerMatchers(MatchFinder *Finder) { |
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| 48 | // We look for calls to constructors of the same type in constructors. To do |
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| 49 | // this we have to look through a variety of nodes that occur in the path, |
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| 50 | // depending on the type's destructor and the number of arguments on the |
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| 51 | // constructor call, this is handled by ignoringTemporaryExpr. Ignore template |
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| 52 | // instantiations to reduce the number of duplicated warnings. |
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| 53 | |
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| 54 | Finder->addMatcher( |
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| 55 | NodeMatch: traverse( |
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| 56 | TK: TK_AsIs, |
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| 57 | InnerMatcher: compoundStmt(hasParent(cxxConstructorDecl( |
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| 58 | ofClass(InnerMatcher: cxxRecordDecl().bind(ID: "parent" )))), |
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| 59 | forEach(ignoringTemporaryExpr( |
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| 60 | InnerMatcher: cxxConstructExpr( |
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| 61 | hasDeclaration(InnerMatcher: cxxConstructorDecl(ofClass( |
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| 62 | InnerMatcher: cxxRecordDecl(baseOfBoundNode(ID: "parent" )))))) |
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| 63 | .bind(ID: "construct" ))), |
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| 64 | unless(isInTemplateInstantiation()))), |
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| 65 | Action: this); |
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| 66 | } |
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| 67 | |
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| 68 | void UndelegatedConstructorCheck::check( |
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| 69 | const MatchFinder::MatchResult &Result) { |
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| 70 | const auto *E = Result.Nodes.getNodeAs<CXXConstructExpr>(ID: "construct" ); |
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| 71 | diag(Loc: E->getBeginLoc(), Description: "did you intend to call a delegated constructor? " |
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| 72 | "A temporary object is created here instead" ); |
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| 73 | } |
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| 74 | |
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| 75 | } // namespace clang::tidy::bugprone |
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| 76 | |
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