Fix MSVC constructor call extension after b92d290e48e9 (r353181).

The assert added to EmitCall there was triggering in Windows Chromium
builds, due to a mismatch of the return type.

The MSVC constructor call extension (`this->Foo::Foo()`) was emitting
the constructor call from 'EmitCXXMemberOrOperatorMemberCallExpr' via
calling 'EmitCXXMemberOrOperatorCall', instead of
'EmitCXXConstructorCall'. On targets where HasThisReturn is true, that
was failing to set the proper return type in the call info.

Switching to calling EmitCXXConstructorCall also allowed removing some
code e.g. the trivial copy/move support, which is already handled in
EmitCXXConstructorCall.

Ref: https://bugs.chromium.org/p/chromium/issues/detail?id=928861
Differential Revision: https://reviews.llvm.org/D57794

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@353246 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 13612d377c64031a3657e586b5eb13af6fe08678..e5cc22a119637610e26b8725aa196d4e508b77c7 100644 (file)
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -249,13 +249,25 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
     This = EmitLValue(Base);
   }
 
+  if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
+    // This is the MSVC p->Ctor::Ctor(...) extension. We assume that's
+    // constructing a new complete object of type Ctor.
+    assert(!RtlArgs);
+    assert(ReturnValue.isNull() && "Constructor shouldn't have return value");
+    CallArgList Args;
+    commonEmitCXXMemberOrOperatorCall(
+        *this, Ctor, This.getPointer(), /*ImplicitParam=*/nullptr,
+        /*ImplicitParamTy=*/QualType(), CE, Args, nullptr);
+
+    EmitCXXConstructorCall(Ctor, Ctor_Complete, /*ForVirtualBase=*/false,
+                           /*Delegating=*/false, This.getAddress(), Args,
+                           AggValueSlot::DoesNotOverlap, CE->getExprLoc(),
+                           /*NewPointerIsChecked=*/false);
+    return RValue::get(nullptr);
+  }
 
   if (MD->isTrivial() || (MD->isDefaulted() && MD->getParent()->isUnion())) {
     if (isa<CXXDestructorDecl>(MD)) return RValue::get(nullptr);
-    if (isa<CXXConstructorDecl>(MD) &&
-        cast<CXXConstructorDecl>(MD)->isDefaultConstructor())
-      return RValue::get(nullptr);
-
     if (!MD->getParent()->mayInsertExtraPadding()) {
       if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) {
         // We don't like to generate the trivial copy/move assignment operator
@@ -268,20 +280,6 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
         EmitAggregateAssign(This, RHS, CE->getType());
         return RValue::get(This.getPointer());
       }
-
-      if (isa<CXXConstructorDecl>(MD) &&
-          cast<CXXConstructorDecl>(MD)->isCopyOrMoveConstructor()) {
-        // Trivial move and copy ctor are the same.
-        assert(CE->getNumArgs() == 1 && "unexpected argcount for trivial ctor");
-        const Expr *Arg = *CE->arg_begin();
-        LValue RHS = EmitLValue(Arg);
-        LValue Dest = MakeAddrLValue(This.getAddress(), Arg->getType());
-        // This is the MSVC p->Ctor::Ctor(...) extension. We assume that's
-        // constructing a new complete object of type Ctor.
-        EmitAggregateCopy(Dest, RHS, Arg->getType(),
-                          AggValueSlot::DoesNotOverlap);
-        return RValue::get(This.getPointer());
-      }
       llvm_unreachable("unknown trivial member function");
     }
   }
@@ -293,9 +291,6 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
   if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl))
     FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
         Dtor, StructorType::Complete);
-  else if (const auto *Ctor = dyn_cast<CXXConstructorDecl>(CalleeDecl))
-    FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
-        Ctor, StructorType::Complete);
   else
     FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl);
 
@@ -318,11 +313,9 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
     if (IsImplicitObjectCXXThis || isa<DeclRefExpr>(IOA))
       SkippedChecks.set(SanitizerKind::Null, true);
   }
-  EmitTypeCheck(
-      isa<CXXConstructorDecl>(CalleeDecl) ? CodeGenFunction::TCK_ConstructorCall
-                                          : CodeGenFunction::TCK_MemberCall,
-      CallLoc, This.getPointer(), C.getRecordType(CalleeDecl->getParent()),
-      /*Alignment=*/CharUnits::Zero(), SkippedChecks);
+  EmitTypeCheck(CodeGenFunction::TCK_MemberCall, CallLoc, This.getPointer(),
+                C.getRecordType(CalleeDecl->getParent()),
+                /*Alignment=*/CharUnits::Zero(), SkippedChecks);
 
   // C++ [class.virtual]p12:
   //   Explicit qualification with the scope operator (5.1) suppresses the
@@ -366,11 +359,7 @@ RValue CodeGenFunction::EmitCXXMemberOrOperatorMemberCallExpr(
   // 'CalleeDecl' instead.
 
   CGCallee Callee;
-  if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
-    Callee = CGCallee::forDirect(
-        CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty),
-        GlobalDecl(Ctor, Ctor_Complete));
-  } else if (UseVirtualCall) {
+  if (UseVirtualCall) {
     Callee = CGCallee::forVirtual(CE, MD, This.getAddress(), Ty);
   } else {
     if (SanOpts.has(SanitizerKind::CFINVCall) &&

diff --git a/test/CodeGenCXX/constructor-direct-call.cpp b/test/CodeGenCXX/constructor-direct-call.cpp
index bcddc0fa7a496255b3bb2aba369cd02aaf9cd7b0..0ed9cd9027bc97263f2833ac88eee6d4ed305de4 100644 (file)
--- a/test/CodeGenCXX/constructor-direct-call.cpp
+++ b/test/CodeGenCXX/constructor-direct-call.cpp
@@ -1,4 +1,5 @@
-// RUN: %clang_cc1 -triple i686-pc-mingw32 -fms-extensions -Wmicrosoft %s -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 -triple i686-pc-mingw32 -fms-extensions -Wmicrosoft %s -emit-llvm -o - | FileCheck %s --check-prefix=CHECK32 --check-prefix=CHECK
+// RUN: %clang_cc1 -triple x86_64-pc-windows-msvc19.11.0 -fms-extensions -Wmicrosoft %s -emit-llvm -o - | FileCheck %s --check-prefix=CHECK64 --check-prefix=CHECK
 
 class Test1 {
 public:
@@ -9,7 +10,8 @@ void f1() {
   Test1 var;
   var.Test1::Test1();
 
-  // CHECK:   call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %{{.*}}, i8* align 4 %{{.*}}, i32 4, i1 false)
+  // CHECK32:   call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %{{.*}}, i8* align 4 %{{.*}}, i32 4, i1 false)
+  // CHECK64:   call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %{{.*}}, i8* align 4 %{{.*}}, i64 4, i1 false)
   var.Test1::Test1(var);
 }
 
@@ -22,13 +24,16 @@ public:
 
 void f2() {
   // CHECK:  %var = alloca %class.Test2, align 4
-  // CHECK-NEXT:  call x86_thiscallcc void @_ZN5Test2C1Ev(%class.Test2* %var)
+  // CHECK32-NEXT:  call x86_thiscallcc void @_ZN5Test2C1Ev(%class.Test2* %var)
+  // CHECK64-NEXT:  %call = call %class.Test2* @"??0Test2@@QEAA@XZ"(%class.Test2* %var)
   Test2 var;
 
-  // CHECK-NEXT:  call x86_thiscallcc void @_ZN5Test2C1Ev(%class.Test2* %var)
+  // CHECK32-NEXT:  call x86_thiscallcc void @_ZN5Test2C1Ev(%class.Test2* %var)
+  // CHECK64-NEXT:  %call1 = call %class.Test2* @"??0Test2@@QEAA@XZ"(%class.Test2* %var)
   var.Test2::Test2();
 
-  // CHECK:  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %{{.*}}, i8* align 4 %{{.*}}, i32 8, i1 false)
+  // CHECK32:  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 %{{.*}}, i8* align 4 %{{.*}}, i32 8, i1 false)
+  // CHECK64:  call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 %{{.*}}, i8* align 4 %{{.*}}, i64 8, i1 false)
   var.Test2::Test2(var);
 }
 
@@ -45,15 +50,19 @@ public:
 };
 
 void f3() {
-  // CHECK: call x86_thiscallcc void @_ZN5Test3C1Ev(%class.Test3* %var)
+  // CHECK32: call x86_thiscallcc void @_ZN5Test3C1Ev(%class.Test3* %var)
+  // CHECK64: %call = call %class.Test3* @"??0Test3@@QEAA@XZ"(%class.Test3* %var)
   Test3 var;
 
-  // CHECK-NEXT: call x86_thiscallcc void @_ZN5Test3C1Ev(%class.Test3* %var2)
+  // CHECK32-NEXT: call x86_thiscallcc void @_ZN5Test3C1Ev(%class.Test3* %var2)
+  // CHECK64-NEXT: %call1 = call %class.Test3* @"??0Test3@@QEAA@XZ"(%class.Test3* %var2)
   Test3 var2;
 
-  // CHECK-NEXT: call x86_thiscallcc void @_ZN5Test3C1Ev(%class.Test3* %var)
+  // CHECK32-NEXT: call x86_thiscallcc void @_ZN5Test3C1Ev(%class.Test3* %var)
+  // CHECK64-NEXT: %call2 = call %class.Test3* @"??0Test3@@QEAA@XZ"(%class.Test3* %var)
   var.Test3::Test3();
 
-  // CHECK-NEXT: call x86_thiscallcc void @_ZN5Test3C1ERKS_(%class.Test3* %var, %class.Test3* dereferenceable({{[0-9]+}}) %var2)
+  // CHECK32-NEXT: call x86_thiscallcc void @_ZN5Test3C1ERKS_(%class.Test3* %var, %class.Test3* dereferenceable({{[0-9]+}}) %var2)
+  // CHECK64-NEXT: %call3 = call %class.Test3* @"??0Test3@@QEAA@AEBV0@@Z"(%class.Test3* %var, %class.Test3* dereferenceable({{[0-9]+}}) %var2)
   var.Test3::Test3(var2);
 }