Author: vedantk Date: Thu Sep 13 16:28:25 2018 New Revision: 342194 URL: http://llvm.org/viewvc/llvm-project?rev=342194&view=rev Log: [Sema] Remove location from implicit capture init expr
A lambda's closure is initialized when the lambda is declared. For implicit captures, the initialization code emitted from EmitLambdaExpr references source locations *within the lambda body* in the function containing the lambda. This results in a poor debugging experience: we step to the line containing the lambda, then into lambda, out again, over and over, until every capture's field is initialized. To improve stepping behavior, assign the starting location of the lambda to expressions which initialize an implicit capture within it. rdar://39807527 Differential Revision: https://reviews.llvm.org/D50927 Added: cfe/trunk/test/CodeGenCXX/debug-info-lambda.cpp Modified: cfe/trunk/lib/Sema/SemaLambda.cpp cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/p14.cpp cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp cfe/trunk/test/SemaCXX/uninitialized.cpp cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/DeclRefExpr.cpp Modified: cfe/trunk/lib/Sema/SemaLambda.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=342194&r1=342193&r2=342194&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaLambda.cpp (original) +++ cfe/trunk/lib/Sema/SemaLambda.cpp Thu Sep 13 16:28:25 2018 @@ -1392,13 +1392,14 @@ static void addBlockPointerConversion(Se Class->addDecl(Conversion); } -static ExprResult performLambdaVarCaptureInitialization(Sema &S, - const Capture &Capture, - FieldDecl *Field) { +static ExprResult performLambdaVarCaptureInitialization( + Sema &S, const Capture &Capture, FieldDecl *Field, + SourceLocation ImplicitCaptureLoc, bool IsImplicitCapture) { assert(Capture.isVariableCapture() && "not a variable capture"); auto *Var = Capture.getVariable(); - SourceLocation Loc = Capture.getLocation(); + SourceLocation Loc = + IsImplicitCapture ? ImplicitCaptureLoc : Capture.getLocation(); // C++11 [expr.prim.lambda]p21: // When the lambda-expression is evaluated, the entities that @@ -1607,8 +1608,8 @@ ExprResult Sema::BuildLambdaExpr(SourceL Var, From.getEllipsisLoc())); Expr *Init = From.getInitExpr(); if (!Init) { - auto InitResult = - performLambdaVarCaptureInitialization(*this, From, *CurField); + auto InitResult = performLambdaVarCaptureInitialization( + *this, From, *CurField, CaptureDefaultLoc, IsImplicit); if (InitResult.isInvalid()) return ExprError(); Init = InitResult.get(); Modified: cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/p14.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/p14.cpp?rev=342194&r1=342193&r2=342194&view=diff ============================================================================== --- cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/p14.cpp (original) +++ cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/p14.cpp Thu Sep 13 16:28:25 2018 @@ -15,8 +15,8 @@ public: void capture_by_copy(NonCopyable nc, NonCopyable &ncr, const NonConstCopy nco) { (void)[nc] { }; // expected-error{{capture of variable 'nc' as type 'NonCopyable' calls private copy constructor}} - (void)[=] { - ncr.foo(); // expected-error{{capture of variable 'ncr' as type 'NonCopyable' calls private copy constructor}} + (void)[=] { // expected-error{{capture of variable 'ncr' as type 'NonCopyable' calls private copy constructor}} + ncr.foo(); }(); [nco] {}(); // expected-error{{no matching constructor for initialization of 'const NonConstCopy'}} Modified: cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp?rev=342194&r1=342193&r2=342194&view=diff ============================================================================== --- cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp (original) +++ cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/templates.cpp Thu Sep 13 16:28:25 2018 @@ -88,8 +88,8 @@ namespace p2 { template<typename R, typename T> void odr_used2(R &r, Boom<T> boom) { const std::type_info &ti - = typeid([=,&r] () -> R& { - boom.tickle(); // expected-note{{in instantiation of member function}} + = typeid([=,&r] () -> R& { // expected-note{{in instantiation of member function 'p2::Boom<float>::Boom' requested here}} + boom.tickle(); return r; }()); } Added: cfe/trunk/test/CodeGenCXX/debug-info-lambda.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-lambda.cpp?rev=342194&view=auto ============================================================================== --- cfe/trunk/test/CodeGenCXX/debug-info-lambda.cpp (added) +++ cfe/trunk/test/CodeGenCXX/debug-info-lambda.cpp Thu Sep 13 16:28:25 2018 @@ -0,0 +1,16 @@ +// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm \ +// RUN: -debug-info-kind=line-tables-only -dwarf-column-info -std=c++11 %s -o - | FileCheck %s + +// CHECK-LABEL: define{{.*}}lambda_in_func +void lambda_in_func(int &ref) { + // CHECK: [[ref_slot:%.*]] = getelementptr inbounds %class.anon, %class.anon* {{.*}}, i32 0, i32 0, !dbg [[lambda_decl_loc:![0-9]+]] + // CHECK-NEXT: %1 = load i32*, i32** %ref.addr, align 8, !dbg [[capture_init_loc:![0-9]+]] + // CHECK-NEXT: store i32* %1, i32** %0, align 8, !dbg [[lambda_decl_loc]] + // CHECK-NEXT: call void {{.*}}, !dbg [[lambda_call_loc:![0-9]+]] + + auto helper = [ // CHECK: [[lambda_decl_loc]] = !DILocation(line: [[@LINE]], column: 17 + &]() { // CHECK: [[capture_init_loc]] = !DILocation(line: [[@LINE]], column: 18 + ++ref; + }; + helper(); // CHECK: [[lambda_call_loc]] = !DILocation(line: [[@LINE]] +} Modified: cfe/trunk/test/SemaCXX/uninitialized.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/uninitialized.cpp?rev=342194&r1=342193&r2=342194&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/uninitialized.cpp (original) +++ cfe/trunk/test/SemaCXX/uninitialized.cpp Thu Sep 13 16:28:25 2018 @@ -884,8 +884,10 @@ namespace lambdas { int x; }; A a0([] { return a0.x; }); // ok - void f() { - A a1([=] { return a1.x; }); // expected-warning{{variable 'a1' is uninitialized when used within its own initialization}} + void f() { + A a1([=] { // expected-warning{{variable 'a1' is uninitialized when used within its own initialization}} + return a1.x; + }); A a2([&] { return a2.x; }); // ok } } Modified: cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/DeclRefExpr.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/DeclRefExpr.cpp?rev=342194&r1=342193&r2=342194&view=diff ============================================================================== --- cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/DeclRefExpr.cpp (original) +++ cfe/trunk/unittests/Tooling/RecursiveASTVisitorTests/DeclRefExpr.cpp Thu Sep 13 16:28:25 2018 @@ -75,11 +75,11 @@ TEST(RecursiveASTVisitor, VisitsUseOfImp TEST(RecursiveASTVisitor, VisitsImplicitLambdaCaptureInit) { DeclRefExprVisitor Visitor; Visitor.setShouldVisitImplicitCode(true); - // We're expecting the "i" in the lambda to be visited twice: - // - Once for the DeclRefExpr in the lambda capture initialization (whose - // source code location is set to the first use of the variable). - // - Once for the DeclRefExpr for the use of "i" inside the lambda. - Visitor.ExpectMatch("i", 1, 24, /*Times=*/2); + // We're expecting "i" to be visited twice: once for the initialization expr + // for the captured variable "i" outside of the lambda body, and again for + // the use of "i" inside the lambda. + Visitor.ExpectMatch("i", 1, 20, /*Times=*/1); + Visitor.ExpectMatch("i", 1, 24, /*Times=*/1); EXPECT_TRUE(Visitor.runOver( "void f() { int i; [=]{ i; }; }", DeclRefExprVisitor::Lang_CXX11)); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
