From 06239e42c6ca6a4107cfb2b0007c6fb7e273eb90 Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Thu, 16 Nov 2017 19:09:36 +0000 Subject: [PATCH] [MS] Apply adjustments after storing 'this' Summary: The MS ABI convention is that the 'this' pointer on entry is the address of the vfptr that was used to make the virtual method call. In other words, the pointer on entry always points to the base subobject that introduced the virtual method. Consider this hierarchy: struct A { virtual void f() = 0; }; struct B { virtual void g() = 0; }; struct C : A, B { void f() override; void g() override; }; On entry to C::g, [ER]CX will contain the address of C's B subobject, and C::g will have to subtract sizeof(A) to recover a pointer to C. Before this change, we applied this adjustment in the prologue and stored the new value into the "this" local variable alloca used for debug info. However, MSVC does not do this, presumably because it is often profitable to fold the adjustment into later field accesses. This creates a problem, because the debugger expects the variable to be unadjusted. Unfortunately, CodeView doesn't have anything like DWARF expressions for computing variables that aren't in the program anymore, so we have to declare 'this' to be the unadjusted value if we want the debugger to see the right value. This has the side benefit that, in optimized builds, the 'this' pointer will usually be available on function entry because it doesn't require any adjustment. Reviewers: hans Subscribers: aprantl, cfe-commits Differential Revision: https://reviews.llvm.org/D40109 llvm-svn: 318440 --- clang/lib/CodeGen/CGCXXABI.cpp | 11 ++- clang/lib/CodeGen/CGCXXABI.h | 14 +--- clang/lib/CodeGen/CGDecl.cpp | 18 ----- clang/lib/CodeGen/ItaniumCXXABI.cpp | 5 +- clang/lib/CodeGen/MicrosoftCXXABI.cpp | 75 ++++++++++--------- ...ft-abi-multiple-nonvirtual-inheritance.cpp | 43 ++++++----- ...soft-abi-virtual-inheritance-vtordisps.cpp | 1 + .../microsoft-abi-virtual-inheritance.cpp | 53 +++++++------ ...nonvirtual-inheritance-this-adjustment.cpp | 10 ++- 9 files changed, 116 insertions(+), 114 deletions(-) diff --git a/clang/lib/CodeGen/CGCXXABI.cpp b/clang/lib/CodeGen/CGCXXABI.cpp index 033258643ddf9..a27c3e9d27e39 100644 --- a/clang/lib/CodeGen/CGCXXABI.cpp +++ b/clang/lib/CodeGen/CGCXXABI.cpp @@ -149,12 +149,15 @@ void CGCXXABI::buildThisParam(CodeGenFunction &CGF, FunctionArgList ¶ms) { } } -void CGCXXABI::EmitThisParam(CodeGenFunction &CGF) { +llvm::Value *CGCXXABI::loadIncomingCXXThis(CodeGenFunction &CGF) { + return CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(getThisDecl(CGF)), + "this"); +} + +void CGCXXABI::setCXXABIThisValue(CodeGenFunction &CGF, llvm::Value *ThisPtr) { /// Initialize the 'this' slot. assert(getThisDecl(CGF) && "no 'this' variable for function"); - CGF.CXXABIThisValue - = CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(getThisDecl(CGF)), - "this"); + CGF.CXXABIThisValue = ThisPtr; } void CGCXXABI::EmitReturnFromThunk(CodeGenFunction &CGF, diff --git a/clang/lib/CodeGen/CGCXXABI.h b/clang/lib/CodeGen/CGCXXABI.h index 7b912e3aca576..ed5771d2ca496 100644 --- a/clang/lib/CodeGen/CGCXXABI.h +++ b/clang/lib/CodeGen/CGCXXABI.h @@ -73,9 +73,10 @@ class CGCXXABI { return CGF.CXXStructorImplicitParamValue; } - /// Perform prolog initialization of the parameter variable suitable - /// for 'this' emitted by buildThisParam. - void EmitThisParam(CodeGenFunction &CGF); + /// Loads the incoming C++ this pointer as it was passed by the caller. + llvm::Value *loadIncomingCXXThis(CodeGenFunction &CGF); + + void setCXXABIThisValue(CodeGenFunction &CGF, llvm::Value *ThisPtr); ASTContext &getContext() const { return CGM.getContext(); } @@ -358,13 +359,6 @@ class CGCXXABI { return CharUnits::Zero(); } - /// Perform ABI-specific "this" parameter adjustment in a virtual function - /// prologue. - virtual llvm::Value *adjustThisParameterInVirtualFunctionPrologue( - CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) { - return This; - } - /// Emit the ABI-specific prolog for the function. virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0; diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp index e9f58cfac681e..7350af870d2a3 100644 --- a/clang/lib/CodeGen/CGDecl.cpp +++ b/clang/lib/CodeGen/CGDecl.cpp @@ -1796,24 +1796,6 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg, setBlockContextParameter(IPD, ArgNo, Arg.getDirectValue()); return; } - - // Apply any prologue 'this' adjustments required by the ABI. Be careful to - // handle the case where 'this' is passed indirectly as part of an inalloca - // struct. - if (const CXXMethodDecl *MD = - dyn_cast_or_null(CurCodeDecl)) { - if (MD->isVirtual() && IPD == CXXABIThisDecl) { - llvm::Value *This = Arg.isIndirect() - ? Builder.CreateLoad(Arg.getIndirectAddress()) - : Arg.getDirectValue(); - This = CGM.getCXXABI().adjustThisParameterInVirtualFunctionPrologue( - *this, CurGD, This); - if (Arg.isIndirect()) - Builder.CreateStore(This, Arg.getIndirectAddress()); - else - Arg = ParamValue::forDirect(This); - } - } } Address DeclPtr = Address::invalid(); diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp index a2d303e954b78..3049383a2a67f 100644 --- a/clang/lib/CodeGen/ItaniumCXXABI.cpp +++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp @@ -1443,8 +1443,9 @@ void ItaniumCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) { if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr()) return; - /// Initialize the 'this' slot. - EmitThisParam(CGF); + /// Initialize the 'this' slot. In the Itanium C++ ABI, no prologue + /// adjustments are required, becuase they are all handled by thunks. + setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF)); /// Initialize the 'vtt' slot if needed. if (getStructorImplicitParamDecl(CGF)) { diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp index e81dedf14da01..97a7fbab9a5e3 100644 --- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp +++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp @@ -244,9 +244,6 @@ class MicrosoftCXXABI : public CGCXXABI { void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy, FunctionArgList &Params) override; - llvm::Value *adjustThisParameterInVirtualFunctionPrologue( - CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) override; - void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override; AddedStructorArgs @@ -1433,50 +1430,54 @@ void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF, } } -llvm::Value *MicrosoftCXXABI::adjustThisParameterInVirtualFunctionPrologue( - CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) { - // In this ABI, every virtual function takes a pointer to one of the - // subobjects that first defines it as the 'this' parameter, rather than a - // pointer to the final overrider subobject. Thus, we need to adjust it back - // to the final overrider subobject before use. - // See comments in the MicrosoftVFTableContext implementation for the details. - CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD); - if (Adjustment.isZero()) - return This; - - unsigned AS = cast(This->getType())->getAddressSpace(); - llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS), - *thisTy = This->getType(); - - This = CGF.Builder.CreateBitCast(This, charPtrTy); - assert(Adjustment.isPositive()); - This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This, - -Adjustment.getQuantity()); - return CGF.Builder.CreateBitCast(This, thisTy); -} - void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) { // Naked functions have no prolog. if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr()) return; - EmitThisParam(CGF); + // Overridden virtual methods of non-primary bases need to adjust the incoming + // 'this' pointer in the prologue. In this hierarchy, C::b will subtract + // sizeof(void*) to adjust from B* to C*: + // struct A { virtual void a(); }; + // struct B { virtual void b(); }; + // struct C : A, B { virtual void b(); }; + // + // Leave the value stored in the 'this' alloca unadjusted, so that the + // debugger sees the unadjusted value. Microsoft debuggers require this, and + // will apply the ThisAdjustment in the method type information. + // FIXME: Do something better for DWARF debuggers, which won't expect this, + // without making our codegen depend on debug info settings. + llvm::Value *This = loadIncomingCXXThis(CGF); + const CXXMethodDecl *MD = cast(CGF.CurGD.getDecl()); + if (!CGF.CurFuncIsThunk && MD->isVirtual()) { + CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD); + if (!Adjustment.isZero()) { + unsigned AS = cast(This->getType())->getAddressSpace(); + llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS), + *thisTy = This->getType(); + This = CGF.Builder.CreateBitCast(This, charPtrTy); + assert(Adjustment.isPositive()); + This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This, + -Adjustment.getQuantity()); + This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted"); + } + } + setCXXABIThisValue(CGF, This); - /// If this is a function that the ABI specifies returns 'this', initialize - /// the return slot to 'this' at the start of the function. - /// - /// Unlike the setting of return types, this is done within the ABI - /// implementation instead of by clients of CGCXXABI because: - /// 1) getThisValue is currently protected - /// 2) in theory, an ABI could implement 'this' returns some other way; - /// HasThisReturn only specifies a contract, not the implementation + // If this is a function that the ABI specifies returns 'this', initialize + // the return slot to 'this' at the start of the function. + // + // Unlike the setting of return types, this is done within the ABI + // implementation instead of by clients of CGCXXABI because: + // 1) getThisValue is currently protected + // 2) in theory, an ABI could implement 'this' returns some other way; + // HasThisReturn only specifies a contract, not the implementation if (HasThisReturn(CGF.CurGD)) CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue); else if (hasMostDerivedReturn(CGF.CurGD)) CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)), CGF.ReturnValue); - const CXXMethodDecl *MD = cast(CGF.CurGD.getDecl()); if (isa(MD) && MD->getParent()->getNumVBases()) { assert(getStructorImplicitParamDecl(CGF) && "no implicit parameter for a constructor with virtual bases?"); @@ -1961,7 +1962,7 @@ llvm::Function *MicrosoftCXXABI::EmitVirtualMemPtrThunk( // Start defining the function. CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo, FunctionArgs, MD->getLocation(), SourceLocation()); - EmitThisParam(CGF); + setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF)); // Load the vfptr and then callee from the vftable. The callee should have // adjusted 'this' so that the vfptr is at offset zero. @@ -3900,7 +3901,7 @@ MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD, FunctionArgs, CD->getLocation(), SourceLocation()); // Create a scope with an artificial location for the body of this function. auto AL = ApplyDebugLocation::CreateArtificial(CGF); - EmitThisParam(CGF); + setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF)); llvm::Value *This = getThisValue(CGF); llvm::Value *SrcVal = diff --git a/clang/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp b/clang/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp index f9db2680e3366..5bed69ff117f1 100644 --- a/clang/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp +++ b/clang/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp @@ -19,7 +19,7 @@ struct ChildOverride : Left, Right { extern "C" void foo(void *); void call_left_no_override(ChildNoOverride *child) { -// CHECK: define void @"\01?call_left_no_override +// CHECK-LABEL: define void @"\01?call_left_no_override // CHECK: %[[CHILD:.*]] = load %struct.ChildNoOverride child->left(); @@ -34,7 +34,8 @@ void call_left_no_override(ChildNoOverride *child) { } void ChildOverride::left() { -// CHECK: define x86_thiscallcc void @"\01?left@ChildOverride@@UAEXXZ"(%struct.ChildOverride* %[[THIS:.*]]) +// CHECK-LABEL: define x86_thiscallcc void @"\01?left@ChildOverride@@UAEXXZ" +// CHECK-SAME: (%struct.ChildOverride* %[[THIS:.*]]) // // No need to adjust 'this' as the ChildOverride's layout begins with Left. // CHECK: %[[THIS_ADDR:.*]] = alloca %struct.ChildOverride*, align 4 @@ -48,7 +49,7 @@ void ChildOverride::left() { } void call_left_override(ChildOverride *child) { -// CHECK: define void @"\01?call_left_override +// CHECK-LABEL: define void @"\01?call_left_override // CHECK: %[[CHILD:.*]] = load %struct.ChildOverride child->left(); @@ -62,7 +63,7 @@ void call_left_override(ChildOverride *child) { } void call_right_no_override(ChildNoOverride *child) { -// CHECK: define void @"\01?call_right_no_override +// CHECK-LABEL: define void @"\01?call_right_no_override // CHECK: %[[CHILD:.*]] = load %struct.ChildNoOverride child->right(); @@ -82,25 +83,27 @@ void call_right_no_override(ChildNoOverride *child) { } void ChildOverride::right() { -// CHECK: define x86_thiscallcc void @"\01?right@ChildOverride@@UAEXXZ"(i8* +// CHECK-LABEL: define x86_thiscallcc void @"\01?right@ChildOverride@@UAEXXZ"(i8* // // ChildOverride::right gets 'this' cast to Right* in ECX (i.e. this+4) so we // need to adjust 'this' before use. // // CHECK: %[[THIS_ADDR:.*]] = alloca %struct.ChildOverride*, align 4 -// CHECK: %[[THIS_i8:.*]] = getelementptr inbounds i8, i8* %[[ECX:.*]], i32 -4 -// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.ChildOverride* -// CHECK: store %struct.ChildOverride* %[[THIS]], %struct.ChildOverride** %[[THIS_ADDR]], align 4 +// CHECK: %[[THIS_INIT:.*]] = bitcast i8* %[[ECX:.*]] to %struct.ChildOverride* +// CHECK: store %struct.ChildOverride* %[[THIS_INIT]], %struct.ChildOverride** %[[THIS_ADDR]], align 4 +// CHECK: %[[THIS_RELOAD:.*]] = load %struct.ChildOverride*, %struct.ChildOverride** %[[THIS_ADDR]] +// CHECK: %[[THIS_i8:.*]] = bitcast %struct.ChildOverride* %[[THIS_RELOAD]] to i8* +// CHECK: %[[THIS_ADJUSTED:.*]] = getelementptr inbounds i8, i8* %[[THIS_i8]], i32 -4 +// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_ADJUSTED]] to %struct.ChildOverride* foo(this); -// CHECK: %[[THIS:.*]] = load %struct.ChildOverride*, %struct.ChildOverride** %[[THIS_ADDR]] // CHECK: %[[THIS_PARAM:.*]] = bitcast %struct.ChildOverride* %[[THIS]] to i8* // CHECK: call void @foo(i8* %[[THIS_PARAM]]) // CHECK: ret } void call_right_override(ChildOverride *child) { -// CHECK: define void @"\01?call_right_override +// CHECK-LABEL: define void @"\01?call_right_override // CHECK: %[[CHILD:.*]] = load %struct.ChildOverride child->right(); @@ -127,15 +130,17 @@ struct GrandchildOverride : ChildOverride { }; void GrandchildOverride::right() { -// CHECK: define x86_thiscallcc void @"\01?right@GrandchildOverride@@UAEXXZ"(i8* +// CHECK-LABEL: define x86_thiscallcc void @"\01?right@GrandchildOverride@@UAEXXZ"(i8* // // CHECK: %[[THIS_ADDR:.*]] = alloca %struct.GrandchildOverride*, align 4 -// CHECK: %[[THIS_i8:.*]] = getelementptr inbounds i8, i8* %[[ECX:.*]], i32 -4 -// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.GrandchildOverride* -// CHECK: store %struct.GrandchildOverride* %[[THIS]], %struct.GrandchildOverride** %[[THIS_ADDR]], align 4 +// CHECK: %[[THIS_INIT:.*]] = bitcast i8* %[[ECX:.*]] to %struct.GrandchildOverride* +// CHECK: store %struct.GrandchildOverride* %[[THIS_INIT]], %struct.GrandchildOverride** %[[THIS_ADDR]], align 4 +// CHECK: %[[THIS_RELOAD:.*]] = load %struct.GrandchildOverride*, %struct.GrandchildOverride** %[[THIS_ADDR]] +// CHECK: %[[THIS_i8:.*]] = bitcast %struct.GrandchildOverride* %[[THIS_RELOAD]] to i8* +// CHECK: %[[THIS_ADJUSTED:.*]] = getelementptr inbounds i8, i8* %[[THIS_i8]], i32 -4 +// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_ADJUSTED]] to %struct.GrandchildOverride* foo(this); -// CHECK: %[[THIS:.*]] = load %struct.GrandchildOverride*, %struct.GrandchildOverride** %[[THIS_ADDR]] // CHECK: %[[THIS_PARAM:.*]] = bitcast %struct.GrandchildOverride* %[[THIS]] to i8* // CHECK: call void @foo(i8* %[[THIS_PARAM]]) // CHECK: ret @@ -148,19 +153,19 @@ void call_grandchild_right(GrandchildOverride *obj) { void emit_ctors() { Left l; - // CHECK: define {{.*}} @"\01??0Left@@QAE@XZ" + // CHECK-LABEL: define {{.*}} @"\01??0Left@@QAE@XZ" // CHECK-NOT: getelementptr // CHECK: store i32 (...)** bitcast ({ [1 x i8*] }* @"\01??_7Left@@6B@" to i32 (...)**) // CHECK: ret Right r; - // CHECK: define {{.*}} @"\01??0Right@@QAE@XZ" + // CHECK-LABEL: define {{.*}} @"\01??0Right@@QAE@XZ" // CHECK-NOT: getelementptr // CHECK: store i32 (...)** bitcast ({ [1 x i8*] }* @"\01??_7Right@@6B@" to i32 (...)**) // CHECK: ret ChildOverride co; - // CHECK: define {{.*}} @"\01??0ChildOverride@@QAE@XZ" + // CHECK-LABEL: define {{.*}} @"\01??0ChildOverride@@QAE@XZ" // CHECK: %[[THIS:.*]] = load %struct.ChildOverride*, %struct.ChildOverride** // CHECK: %[[VFPTR:.*]] = bitcast %struct.ChildOverride* %[[THIS]] to i32 (...)*** // CHECK: store i32 (...)** bitcast ({ [1 x i8*] }* @"\01??_7ChildOverride@@6BLeft@@@" to i32 (...)**), i32 (...)*** %[[VFPTR]] @@ -171,7 +176,7 @@ void emit_ctors() { // CHECK: ret GrandchildOverride gc; - // CHECK: define {{.*}} @"\01??0GrandchildOverride@@QAE@XZ" + // CHECK-LABEL: define {{.*}} @"\01??0GrandchildOverride@@QAE@XZ" // CHECK: %[[THIS:.*]] = load %struct.GrandchildOverride*, %struct.GrandchildOverride** // CHECK: %[[VFPTR:.*]] = bitcast %struct.GrandchildOverride* %[[THIS]] to i32 (...)*** // CHECK: store i32 (...)** bitcast ({ [1 x i8*] }* @"\01??_7GrandchildOverride@@6BLeft@@@" to i32 (...)**), i32 (...)*** %[[VFPTR]] diff --git a/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp b/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp index bb73f8773ccb7..2f141b2a66ec8 100644 --- a/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp +++ b/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp @@ -24,6 +24,7 @@ struct D : virtual C { D::D() {} // Forces vftable emission. // CHECK-LABEL: define linkonce_odr x86_thiscallcc void @"\01?f@D@@$4PPPPPPPM@A@AEXXZ" +// Note that the vtordisp is applied before really adjusting to D*. // CHECK: %[[ECX:.*]] = load %struct.D*, %struct.D** %{{.*}} // CHECK: %[[ECX_i8:.*]] = bitcast %struct.D* %[[ECX]] to i8* // CHECK: %[[VTORDISP_PTR_i8:.*]] = getelementptr inbounds i8, i8* %[[ECX_i8]], i32 -4 diff --git a/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp b/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp index 20ecaf4316503..c9dd1dd7d8e2f 100644 --- a/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp +++ b/clang/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp @@ -1,9 +1,9 @@ -// RUN: %clang_cc1 %s -fno-rtti -triple=i386-pc-win32 -emit-llvm -o %t +// RUN: %clang_cc1 %s -fno-rtti -std=c++11 -Wno-inaccessible-base -triple=i386-pc-win32 -emit-llvm -o %t // RUN: FileCheck %s < %t // RUN: FileCheck --check-prefix=CHECK2 %s < %t // For now, just make sure x86_64 doesn't crash. -// RUN: %clang_cc1 %s -fno-rtti -triple=x86_64-pc-win32 -emit-llvm -o %t +// RUN: %clang_cc1 %s -fno-rtti -std=c++11 -Wno-inaccessible-base -triple=x86_64-pc-win32 -emit-llvm -o %t struct VBase { virtual ~VBase(); @@ -52,12 +52,14 @@ B::B() { B::~B() { // CHECK-LABEL: define x86_thiscallcc void @"\01??1B@@UAE@XZ" - // Adjust the this parameter: - // CHECK: %[[THIS_PARAM_i8:.*]] = bitcast %struct.B* {{.*}} to i8* - // CHECK: %[[THIS_i8:.*]] = getelementptr inbounds i8, i8* %[[THIS_PARAM_i8]], i32 -8 - // CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.B* - // CHECK: store %struct.B* %[[THIS]], %struct.B** %[[THIS_ADDR:.*]], align 4 - // CHECK: %[[THIS:.*]] = load %struct.B*, %struct.B** %[[THIS_ADDR]] + // Store initial this: + // CHECK: %[[THIS_ADDR:.*]] = alloca %struct.B* + // CHECK: store %struct.B* %{{.*}}, %struct.B** %[[THIS_ADDR]], align 4 + // Reload and adjust the this parameter: + // CHECK: %[[THIS_RELOAD:.*]] = load %struct.B*, %struct.B** %[[THIS_ADDR]] + // CHECK: %[[THIS_UNADJ_i8:.*]] = bitcast %struct.B* %[[THIS_RELOAD]] to i8* + // CHECK: %[[THIS_ADJ_i8:.*]] = getelementptr inbounds i8, i8* %[[THIS_UNADJ_i8]], i32 -8 + // CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_ADJ_i8]] to %struct.B* // Restore the vfptr that could have been changed by a subclass. // CHECK: %[[THIS_i8:.*]] = bitcast %struct.B* %[[THIS]] to i8* @@ -97,11 +99,11 @@ B::~B() { // CHECK2: ret // CHECK2-LABEL: define linkonce_odr x86_thiscallcc i8* @"\01??_GB@@UAEPAXI@Z" - // CHECK2: %[[THIS_PARAM_i8:.*]] = bitcast %struct.B* {{.*}} to i8* + // CHECK2: store %struct.B* %{{.*}}, %struct.B** %[[THIS_ADDR:.*]], align 4 + // CHECK2: %[[THIS:.*]] = load %struct.B*, %struct.B** %[[THIS_ADDR]] + // CHECK2: %[[THIS_PARAM_i8:.*]] = bitcast %struct.B* %[[THIS]] to i8* // CHECK2: %[[THIS_i8:.*]] = getelementptr inbounds i8, i8* %[[THIS_PARAM_i8:.*]], i32 -8 // CHECK2: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.B* - // CHECK2: store %struct.B* %[[THIS]], %struct.B** %[[THIS_ADDR:.*]], align 4 - // CHECK2: %[[THIS:.*]] = load %struct.B*, %struct.B** %[[THIS_ADDR]] // CHECK2: call x86_thiscallcc void @"\01??_DB@@QAEXXZ"(%struct.B* %[[THIS]]) // ... // CHECK2: ret @@ -113,13 +115,17 @@ void B::foo() { // B::foo gets 'this' cast to VBase* in ECX (i.e. this+8) so we // need to adjust 'this' before use. // -// CHECK: %[[THIS_ADDR:.*]] = alloca %struct.B*, align 4 -// CHECK: %[[THIS_i8:.*]] = getelementptr inbounds i8, i8* %[[ECX:.*]], i32 -8 -// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %struct.B* -// CHECK: store %struct.B* %[[THIS]], %struct.B** %[[THIS_ADDR]], align 4 +// Store initial this: +// CHECK: %[[THIS_ADDR:.*]] = alloca %struct.B* +// CHECK: store %struct.B* %{{.*}}, %struct.B** %[[THIS_ADDR]], align 4 +// +// Reload and adjust the this parameter: +// CHECK: %[[THIS_RELOAD:.*]] = load %struct.B*, %struct.B** %[[THIS_ADDR]] +// CHECK: %[[THIS_UNADJ_i8:.*]] = bitcast %struct.B* %[[THIS_RELOAD]] to i8* +// CHECK: %[[THIS_ADJ_i8:.*]] = getelementptr inbounds i8, i8* %[[THIS_UNADJ_i8]], i32 -8 +// CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_ADJ_i8]] to %struct.B* field = 42; -// CHECK: %[[THIS:.*]] = load %struct.B*, %struct.B** %[[THIS_ADDR]] // CHECK: %[[THIS8:.*]] = bitcast %struct.B* %[[THIS]] to i8* // CHECK: %[[VBPTR:.*]] = getelementptr inbounds i8, i8* %[[THIS8]], i32 0 // CHECK: %[[VBPTR8:.*]] = bitcast i8* %[[VBPTR]] to i32** @@ -284,11 +290,16 @@ struct D : virtual Z, B, C { D::~D() { // CHECK-LABEL: define x86_thiscallcc void @"\01??1D@diamond@@UAE@XZ"(%"struct.diamond::D"*{{.*}}) - // CHECK: %[[ARG_i8:.*]] = bitcast %"struct.diamond::D"* %{{.*}} to i8* - // CHECK: %[[THIS_i8:.*]] = getelementptr inbounds i8, i8* %[[ARG_i8]], i32 -24 - // CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_i8]] to %"struct.diamond::D"* - // CHECK: store %"struct.diamond::D"* %[[THIS]], %"struct.diamond::D"** %[[THIS_VAL:.*]], align 4 - // CHECK: %[[THIS:.*]] = load %"struct.diamond::D"*, %"struct.diamond::D"** %[[THIS_VAL]] + // Store initial this: + // CHECK: %[[THIS_ADDR:.*]] = alloca %"struct.diamond::D"* + // CHECK: store %"struct.diamond::D"* %{{.*}}, %"struct.diamond::D"** %[[THIS_ADDR]], align 4 + // + // Reload and adjust the this parameter: + // CHECK: %[[THIS_RELOAD:.*]] = load %"struct.diamond::D"*, %"struct.diamond::D"** %[[THIS_ADDR]] + // CHECK: %[[THIS_UNADJ_i8:.*]] = bitcast %"struct.diamond::D"* %[[THIS_RELOAD]] to i8* + // CHECK: %[[THIS_ADJ_i8:.*]] = getelementptr inbounds i8, i8* %[[THIS_UNADJ_i8]], i32 -24 + // CHECK: %[[THIS:.*]] = bitcast i8* %[[THIS_ADJ_i8]] to %"struct.diamond::D"* + // // CHECK: %[[D_i8:.*]] = bitcast %"struct.diamond::D"* %[[THIS]] to i8* // CHECK: %[[C_i8:.*]] = getelementptr inbounds i8, i8* %[[D_i8]], i32 4 // CHECK: %[[C:.*]] = bitcast i8* %[[C_i8]] to %"struct.diamond::C"* diff --git a/clang/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp b/clang/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp index b97c432f5e02b..385e9cc17b1b5 100644 --- a/clang/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp +++ b/clang/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp @@ -196,7 +196,11 @@ void C::g(NonTrivial o) { } // BITCODE-LABEL: define void @"\01?g@C@pr30293@@UAAXUNonTrivial@2@@Z"(<{ i8*, %"struct.pr30293::NonTrivial" }>* inalloca) -// BITCODE: %[[this1:[^ ]*]] = load i8*, i8** %[[thisaddr:[^ ]*]], align 4 -// BITCODE-NEXT: %[[this2:[^ ]*]] = getelementptr inbounds i8, i8* %[[this1]], i32 -4 -// BITCODE-NEXT: store i8* %[[this2]], i8** %[[thisaddr]], align 4 +// BITCODE: %[[thisaddr:[^ ]*]] = getelementptr inbounds <{ i8*, %"struct.pr30293::NonTrivial" }>, <{ i8*, %"struct.pr30293::NonTrivial" }>* {{.*}}, i32 0, i32 0 +// BITCODE: %[[thisaddr1:[^ ]*]] = bitcast i8** %[[thisaddr]] to %"struct.pr30293::C"** +// BITCODE: %[[this1:[^ ]*]] = load %"struct.pr30293::C"*, %"struct.pr30293::C"** %[[thisaddr1]], align 4 +// BITCODE: %[[this2:[^ ]*]] = bitcast %"struct.pr30293::C"* %[[this1]] to i8* +// BITCODE: %[[this3:[^ ]*]] = getelementptr inbounds i8, i8* %[[this2]], i32 -4 +// BITCODE: %[[this4:[^ ]*]] = bitcast i8* %[[this3]] to %"struct.pr30293::C"* +// BITCODE: store %"struct.pr30293::C"* %[[this4]], %"struct.pr30293::C"** @"\01?whatsthis@pr30293@@3PAUC@1@A", align 4 }