Author: ymandel Date: Thu Aug 8 10:41:44 2019 New Revision: 368319 URL: http://llvm.org/viewvc/llvm-project?rev=368319&view=rev Log: [clang] Update `ignoringElidableConstructorCall` matcher to ignore `ExprWithCleanups`.
Summary: The `ExprWithCleanups` node is added to the AST along with the elidable CXXConstructExpr. If it is the outermost node of the node being matched, ignore it as well. Reviewers: gribozavr Subscribers: cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D65944 Modified: cfe/trunk/docs/LibASTMatchersReference.html cfe/trunk/include/clang/ASTMatchers/ASTMatchers.h cfe/trunk/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp Modified: cfe/trunk/docs/LibASTMatchersReference.html URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/LibASTMatchersReference.html?rev=368319&r1=368318&r2=368319&view=diff ============================================================================== --- cfe/trunk/docs/LibASTMatchersReference.html (original) +++ cfe/trunk/docs/LibASTMatchersReference.html Thu Aug 8 10:41:44 2019 @@ -5805,14 +5805,15 @@ Example matches x (matcher = expr(hasTyp <tr><td>Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html";>Expr</a>></td><td class="name" onclick="toggle('ignoringElidableConstructorCall0')"><a name="ignoringElidableConstructorCall0Anchor">ignoringElidableConstructorCall</a></td><td>ast_matchers::Matcher<<a href="https://clang.llvm.org/doxygen/classclang_1_1Expr.html";>Expr</a>> InnerMatcher</td></tr> <tr><td colspan="4" class="doc" id="ignoringElidableConstructorCall0"><pre>Matches expressions that match InnerMatcher that are possibly wrapped in an -elidable constructor. +elidable constructor and other corresponding bookkeeping nodes. -In C++17 copy elidable constructors are no longer being -generated in the AST as it is not permitted by the standard. They are -however part of the AST in C++14 and earlier. Therefore, to write a matcher -that works in all language modes, the matcher has to skip elidable -constructor AST nodes if they appear in the AST. This matcher can be used to -skip those elidable constructors. +In C++17, elidable copy constructors are no longer being generated in the +AST as it is not permitted by the standard. They are, however, part of the +AST in C++14 and earlier. So, a matcher must abstract over these differences +to work in all language modes. This matcher skips elidable constructor-call +AST nodes, `ExprWithCleanups` nodes wrapping elidable constructor-calls and +various implicit nodes inside the constructor calls, all of which will not +appear in the C++17 AST. Given @@ -5822,10 +5823,8 @@ void f() { H D = G(); } -``varDecl(hasInitializer(any( - ignoringElidableConstructorCall(callExpr()), - exprWithCleanups(ignoringElidableConstructorCall(callExpr()))))`` -matches ``H D = G()`` +``varDecl(hasInitializer(ignoringElidableConstructorCall(callExpr())))`` +matches ``H D = G()`` in C++11 through C++17 (and beyond). </pre></td></tr> Modified: cfe/trunk/include/clang/ASTMatchers/ASTMatchers.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/ASTMatchers/ASTMatchers.h?rev=368319&r1=368318&r2=368319&view=diff ============================================================================== --- cfe/trunk/include/clang/ASTMatchers/ASTMatchers.h (original) +++ cfe/trunk/include/clang/ASTMatchers/ASTMatchers.h Thu Aug 8 10:41:44 2019 @@ -6533,14 +6533,15 @@ AST_MATCHER(FunctionDecl, hasTrailingRet } /// Matches expressions that match InnerMatcher that are possibly wrapped in an -/// elidable constructor. +/// elidable constructor and other corresponding bookkeeping nodes. /// -/// In C++17 copy elidable constructors are no longer being -/// generated in the AST as it is not permitted by the standard. They are -/// however part of the AST in C++14 and earlier. Therefore, to write a matcher -/// that works in all language modes, the matcher has to skip elidable -/// constructor AST nodes if they appear in the AST. This matcher can be used to -/// skip those elidable constructors. +/// In C++17, elidable copy constructors are no longer being generated in the +/// AST as it is not permitted by the standard. They are, however, part of the +/// AST in C++14 and earlier. So, a matcher must abstract over these differences +/// to work in all language modes. This matcher skips elidable constructor-call +/// AST nodes, `ExprWithCleanups` nodes wrapping elidable constructor-calls and +/// various implicit nodes inside the constructor calls, all of which will not +/// appear in the C++17 AST. /// /// Given /// @@ -6552,13 +6553,20 @@ AST_MATCHER(FunctionDecl, hasTrailingRet /// } /// \endcode /// -/// ``varDecl(hasInitializer(any( -/// ignoringElidableConstructorCall(callExpr()), -/// exprWithCleanups(ignoringElidableConstructorCall(callExpr()))))`` -/// matches ``H D = G()`` +/// ``varDecl(hasInitializer(ignoringElidableConstructorCall(callExpr())))`` +/// matches ``H D = G()`` in C++11 through C++17 (and beyond). AST_MATCHER_P(Expr, ignoringElidableConstructorCall, ast_matchers::internal::Matcher<Expr>, InnerMatcher) { - if (const auto *CtorExpr = dyn_cast<CXXConstructExpr>(&Node)) { + // E tracks the node that we are examining. + const Expr *E = &Node; + // If present, remove an outer `ExprWithCleanups` corresponding to the + // underlying `CXXConstructExpr`. This check won't cover all cases of added + // `ExprWithCleanups` corresponding to `CXXConstructExpr` nodes (because the + // EWC is placed on the outermost node of the expression, which this may not + // be), but, it still improves the coverage of this matcher. + if (const auto *CleanupsExpr = dyn_cast<ExprWithCleanups>(&Node)) + E = CleanupsExpr->getSubExpr(); + if (const auto *CtorExpr = dyn_cast<CXXConstructExpr>(E)) { if (CtorExpr->isElidable()) { if (const auto *MaterializeTemp = dyn_cast<MaterializeTemporaryExpr>(CtorExpr->getArg(0))) { Modified: cfe/trunk/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp?rev=368319&r1=368318&r2=368319&view=diff ============================================================================== --- cfe/trunk/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp (original) +++ cfe/trunk/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp Thu Aug 8 10:41:44 2019 @@ -671,6 +671,23 @@ TEST(Matcher, IgnoresElidableDoesNotPrev LanguageMode::Cxx11OrLater)); } +TEST(Matcher, IgnoresElidableInVarInit) { + auto matcher = + varDecl(hasInitializer(ignoringElidableConstructorCall(callExpr()))); + EXPECT_TRUE(matches("struct H {};" + "H G();" + "void f(H D = G()) {" + " return;" + "}", + matcher, LanguageMode::Cxx11OrLater)); + EXPECT_TRUE(matches("struct H {};" + "H G();" + "void f() {" + " H D = G();" + "}", + matcher, LanguageMode::Cxx11OrLater)); +} + TEST(Matcher, BindTheSameNameInAlternatives) { StatementMatcher matcher = anyOf( binaryOperator(hasOperatorName("+"), _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
