When emitting an lvalue for an anonymous struct or union member during
class initialization, drill down through an arbitrary number of anonymous
records.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@104310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGClass.cpp b/lib/CodeGen/CGClass.cpp
index 72d95b8..82c7228 100644
--- a/lib/CodeGen/CGClass.cpp
+++ b/lib/CodeGen/CGClass.cpp
@@ -446,13 +446,15 @@
QualType FieldType = CGF.getContext().getCanonicalType(Field->getType());
llvm::Value *ThisPtr = CGF.LoadCXXThis();
- LValue LHS = CGF.EmitLValueForFieldInitialization(ThisPtr, Field, 0);
+ LValue LHS;
// If we are initializing an anonymous union field, drill down to the field.
if (MemberInit->getAnonUnionMember()) {
Field = MemberInit->getAnonUnionMember();
- LHS = CGF.EmitLValueForField(LHS.getAddress(), Field, 0);
+ LHS = CGF.EmitLValueForAnonRecordField(ThisPtr, Field, 0);
FieldType = Field->getType();
+ } else {
+ LHS = CGF.EmitLValueForFieldInitialization(ThisPtr, Field, 0);
}
// FIXME: If there's no initializer and the CXXBaseOrMemberInitializer
diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 80d38f2..74e64e5 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1611,6 +1611,35 @@
Field->getType().getCVRQualifiers()|CVRQualifiers);
}
+/// EmitLValueForAnonRecordField - Given that the field is a member of
+/// an anonymous struct or union buried inside a record, and given
+/// that the base value is a pointer to the enclosing record, derive
+/// an lvalue for the ultimate field.
+LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
+ const FieldDecl *Field,
+ unsigned CVRQualifiers) {
+ llvm::SmallVector<const FieldDecl *, 8> Path;
+ Path.push_back(Field);
+
+ while (Field->getParent()->isAnonymousStructOrUnion()) {
+ const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
+ if (!isa<FieldDecl>(VD)) break;
+ Field = cast<FieldDecl>(VD);
+ Path.push_back(Field);
+ }
+
+ llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
+ I = Path.rbegin(), E = Path.rend();
+ while (true) {
+ LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
+ if (++I == E) return LV;
+
+ assert(LV.isSimple());
+ BaseValue = LV.getAddress();
+ CVRQualifiers |= LV.getVRQualifiers();
+ }
+}
+
LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
const FieldDecl* Field,
unsigned CVRQualifiers) {
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 077b816..048bd09 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1052,6 +1052,9 @@
llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar);
+ LValue EmitLValueForAnonRecordField(llvm::Value* Base,
+ const FieldDecl* Field,
+ unsigned CVRQualifiers);
LValue EmitLValueForField(llvm::Value* Base, const FieldDecl* Field,
unsigned CVRQualifiers);
diff --git a/test/CodeGenCXX/anonymous-union-member-initializer.cpp b/test/CodeGenCXX/anonymous-union-member-initializer.cpp
index bd816a4..a4da2c0 100644
--- a/test/CodeGenCXX/anonymous-union-member-initializer.cpp
+++ b/test/CodeGenCXX/anonymous-union-member-initializer.cpp
@@ -52,3 +52,29 @@
// CHECK: store i32 10
// CHECK: }
}
+
+namespace test3 {
+ struct A {
+ union {
+ mutable char fibers[100];
+ struct {
+ void (*callback)(void*);
+ void *callback_value;
+ };
+ };
+
+ A();
+ };
+
+ A::A() : callback(0), callback_value(0) {}
+ // CHECK: define void @ZN5test31AC2Ev(
+ // CHECK: [[THIS:%.*]] = load
+ // CHECK-NEXT: [[UNION:%.*]] = getelementptr inbounds {{.*}} [[THIS]], i32 0, i32 0
+ // CHECK-NEXT: [[STRUCT:%.*]] = getelementptr inbounds {{.*}} [[UNION]], i32 0, i32 0
+ // CHECK-NEXT: [[CALLBACK:%.*]] = getelementptr inbounds {{.*}} [[STRUCT]], i32 0, i32 0
+ // CHECK-NEXT: store void (i8*)* null, void (i8*)** [[CALLBACK]]
+ // CHECK-NEXT: [[UNION:%.*]] = getelementptr inbounds {{.*}} [[THIS]], i32 0, i32 0
+ // CHECK-NEXT: [[STRUCT:%.*]] = getelementptr inbounds {{.*}} [[UNION]], i32 0, i32 0
+ // CHECK-NEXT: [[CVALUE:%.*]] = getelementptr inbounds {{.*}} [[STRUCT]], i32 0, i32 0
+ // CHECK-NEXT: store i8* null, void i8** [[CVALUE]]
+}