r318440 - [MS] Apply adjustments after storing 'this'

Reid Kleckner via cfe-commits cfe-commits at lists.llvm.org
Thu Nov 16 11:09:36 PST 2017


Author: rnk
Date: Thu Nov 16 11:09:36 2017
New Revision: 318440

URL: http://llvm.org/viewvc/llvm-project?rev=318440&view=rev
Log:
[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

Modified:
    cfe/trunk/lib/CodeGen/CGCXXABI.cpp
    cfe/trunk/lib/CodeGen/CGCXXABI.h
    cfe/trunk/lib/CodeGen/CGDecl.cpp
    cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
    cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
    cfe/trunk/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp
    cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp
    cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp
    cfe/trunk/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp

Modified: cfe/trunk/lib/CodeGen/CGCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXXABI.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCXXABI.cpp Thu Nov 16 11:09:36 2017
@@ -149,12 +149,15 @@ void CGCXXABI::buildThisParam(CodeGenFun
   }
 }
 
-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,

Modified: cfe/trunk/lib/CodeGen/CGCXXABI.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXXABI.h?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXXABI.h (original)
+++ cfe/trunk/lib/CodeGen/CGCXXABI.h Thu Nov 16 11:09:36 2017
@@ -73,9 +73,10 @@ protected:
     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 @@ public:
     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;
 

Modified: cfe/trunk/lib/CodeGen/CGDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDecl.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDecl.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDecl.cpp Thu Nov 16 11:09:36 2017
@@ -1796,24 +1796,6 @@ void CodeGenFunction::EmitParmDecl(const
       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<CXXMethodDecl>(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();

Modified: cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/ItaniumCXXABI.cpp Thu Nov 16 11:09:36 2017
@@ -1443,8 +1443,9 @@ void ItaniumCXXABI::EmitInstanceFunction
   if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
     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)) {

Modified: cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp (original)
+++ cfe/trunk/lib/CodeGen/MicrosoftCXXABI.cpp Thu Nov 16 11:09:36 2017
@@ -244,9 +244,6 @@ public:
   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::addImplicitStructo
   }
 }
 
-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<llvm::PointerType>(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<NakedAttr>())
     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<CXXMethodDecl>(CGF.CurGD.getDecl());
+  if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
+    CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
+    if (!Adjustment.isZero()) {
+      unsigned AS = cast<llvm::PointerType>(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<CXXMethodDecl>(CGF.CurGD.getDecl());
   if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
     assert(getStructorImplicitParamDecl(CGF) &&
            "no implicit parameter for a constructor with virtual bases?");
@@ -1961,7 +1962,7 @@ llvm::Function *MicrosoftCXXABI::EmitVir
   // 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
                     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 =

Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-multiple-nonvirtual-inheritance.cpp Thu Nov 16 11:09:36 2017
@@ -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(ChildNoOverri
 }
 
 void ChildOverride::left() {
-// CHECK: define x86_thiscallcc void @"\01?left at ChildOverride@@UAEXXZ"(%struct.ChildOverride* %[[THIS:.*]])
+// CHECK-LABEL: define x86_thiscallcc void @"\01?left at 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 *c
 }
 
 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(ChildNoOverr
 }
 
 void ChildOverride::right() {
-// CHECK: define x86_thiscallcc void @"\01?right at ChildOverride@@UAEXXZ"(i8*
+// CHECK-LABEL: define x86_thiscallcc void @"\01?right at 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 : ChildOverrid
 };
 
 void GrandchildOverride::right() {
-// CHECK: define x86_thiscallcc void @"\01?right at GrandchildOverride@@UAEXXZ"(i8*
+// CHECK-LABEL: define x86_thiscallcc void @"\01?right at 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(GrandchildOve
 
 void emit_ctors() {
   Left l;
-  // CHECK: define {{.*}} @"\01??0Left@@QAE at XZ"
+  // CHECK-LABEL: define {{.*}} @"\01??0Left@@QAE at 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 at XZ"
+  // CHECK-LABEL: define {{.*}} @"\01??0Right@@QAE at 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 at XZ"
+  // CHECK-LABEL: define {{.*}} @"\01??0ChildOverride@@QAE at 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 at XZ"
+  // CHECK-LABEL: define {{.*}} @"\01??0GrandchildOverride@@QAE at 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]]

Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance-vtordisps.cpp Thu Nov 16 11:09:36 2017
@@ -24,6 +24,7 @@ struct D : virtual C {
 D::D() {}  // Forces vftable emission.
 
 // CHECK-LABEL: define linkonce_odr x86_thiscallcc void @"\01?f at D@@$4PPPPPPPM at 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

Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-virtual-inheritance.cpp Thu Nov 16 11:09:36 2017
@@ -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 at 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 at 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 at diamond@@UAE at 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"*

Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp?rev=318440&r1=318439&r2=318440&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/microsoft-abi-vtables-multiple-nonvirtual-inheritance-this-adjustment.cpp Thu Nov 16 11:09:36 2017
@@ -196,7 +196,11 @@ void C::g(NonTrivial o) {
 }
 
 // BITCODE-LABEL: define void @"\01?g at C@pr30293@@UAAXUNonTrivial at 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 at pr30293@@3PAUC at 1@A", align 4
 }




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