dzhidzhoev updated this revision to Diff 483519.
dzhidzhoev added a comment.
Ignore union fields.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D139741/new/
https://reviews.llvm.org/D139741
Files:
clang/include/clang/AST/Decl.h
clang/lib/AST/Decl.cpp
clang/lib/AST/RecordLayoutBuilder.cpp
clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
clang/test/CodeGenCXX/no-unique-address-3.cpp
Index: clang/test/CodeGenCXX/no-unique-address-3.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/no-unique-address-3.cpp
@@ -0,0 +1,133 @@
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -emit-llvm -fdump-record-layouts -std=c++17 %s -o %t | FileCheck %s
+
+// CHECK-LABEL: 0 | class Empty (empty)
+// CHECK-NEXT: | [sizeof=1, dsize=1, align=1,
+// CHECK-NEXT: | nvsize=1, nvalign=1]
+// CHECK-LABEL: 0 | class Second
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 0:0-0 | short A
+// CHECK-NEXT: | [sizeof=2, dsize=1, align=2,
+// CHECK-NEXT: | nvsize=1, nvalign=2]
+// CHECK-LABEL: 0 | class Foo
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 2 | class Second NZNoUnique
+// CHECK-NEXT: 2 | class Empty (base) (empty)
+// CHECK-NEXT: 2:0-0 | short A
+// CHECK-NEXT: 3 | char B
+// CHECK-NEXT: | [sizeof=4, dsize=4, align=2,
+// CHECK-NEXT: | nvsize=4, nvalign=2]
+
+class Empty {};
+
+// CHECK-LABEL: LLVMType:%class.Second = type { i8, i8 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.Second.base = type { i8 }
+class Second : Empty {
+ short A : 1;
+};
+
+// CHECK-LABEL: LLVMType:%class.Foo = type { [2 x i8], %class.Second.base, i8 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.Foo = type { [2 x i8], %class.Second.base, i8 }
+class Foo : Empty {
+ [[no_unique_address]] Second NZNoUnique;
+ char B;
+};
+Foo I;
+
+// CHECK-LABEL: 0 | class SecondEmpty (empty)
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: | [sizeof=1, dsize=0, align=1,
+// CHECK-NEXT: | nvsize=1, nvalign=1]
+class SecondEmpty: Empty {
+};
+
+// CHECK-LABEL: 0 | class Bar
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 1 | class SecondEmpty ZNoUnique (empty)
+// CHECK-NEXT: 1 | class Empty (base) (empty)
+// CHECK-NEXT: 0 | char C
+// CHECK-NEXT: | [sizeof=2, dsize=1, align=1,
+// CHECK-NEXT: | nvsize=2, nvalign=1]
+
+// CHECK-LABEL: LLVMType:%class.Bar = type { i8, i8 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.Bar = type { i8, i8 }
+class Bar : Empty {
+ [[no_unique_address]] SecondEmpty ZNoUnique;
+ char C;
+};
+Bar J;
+
+// CHECK-LABEL: 0 | class IntFieldClass
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 2 | class Second Field
+// CHECK-NEXT: 2 | class Empty (base) (empty)
+// CHECK-NEXT: 2:0-0 | short A
+// CHECK-NEXT: 4 | int C
+// CHECK-NEXT: | [sizeof=8, dsize=8, align=4,
+// CHECK-NEXT: | nvsize=8, nvalign=4]
+
+// CHECK-LABEL: LLVMType:%class.IntFieldClass = type { [2 x i8], %class.Second.base, i32 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.IntFieldClass = type { [2 x i8], %class.Second.base, i32 }
+class IntFieldClass : Empty {
+ [[no_unique_address]] Second Field;
+ int C;
+};
+IntFieldClass K;
+
+// CHECK-LABEL: 0 | class UnionClass
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 0 | union UnionClass
+// CHECK-NEXT: 0 | int I
+// CHECK-NEXT: 0 | char C
+// CHECK-NEXT: 4 | int C
+// CHECK-NEXT: | [sizeof=8, dsize=8, align=4,
+// CHECK-NEXT: | nvsize=8, nvalign=4]
+
+// CHECK-LABEL: LLVMType:%class.UnionClass = type { %union.anon, i32 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.UnionClass = type { %union.anon, i32 }
+// CHECK-NEXT: IsZeroInitializable:1
+// CHECK-NEXT: BitFields:[
+// CHECK-NEXT: ]>
+class UnionClass : Empty {
+ [[no_unique_address]] union {
+ int I;
+ char C;
+ } U;
+ int C;
+};
+UnionClass L;
+
+// CHECK-LABEL: 0 | class EnumClass
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 0 | enum E A
+// CHECK-NEXT: 4 | int C
+// CHECK-NEXT: | [sizeof=8, dsize=8, align=4,
+// CHECK-NEXT: | nvsize=8, nvalign=4]
+
+// CHECK-LABEL: LLVMType:%class.EnumClass = type { i32, i32 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.EnumClass = type { i32, i32 }
+// CHECK-NEXT: IsZeroInitializable:1
+// CHECK-NEXT: BitFields:[
+// CHECK-NEXT: ]>
+class EnumClass : Empty {
+ [[no_unique_address]] enum class E { X, Y, Z } A;
+ int C;
+};
+EnumClass M;
+
+// CHECK-LABEL: 0 | class NoBaseField
+// CHECK-NEXT: 0 | class Empty (base) (empty)
+// CHECK-NEXT: 1 | class Empty A (empty)
+// CHECK-NEXT: 0 | int B
+// CHECK-NEXT: | [sizeof=4, dsize=4, align=4,
+// CHECK-NEXT: | nvsize=4, nvalign=4]
+
+// CHECK-LABEL: LLVMType:%class.NoBaseField = type { i32 }
+// CHECK-NEXT: NonVirtualBaseLLVMType:%class.NoBaseField = type { i32 }
+// CHECK-NEXT: IsZeroInitializable:1
+// CHECK-NEXT: BitFields:[
+// CHECK-NEXT: ]>
+class NoBaseField : Empty {
+ [[no_unique_address]] Empty A;
+ int B;
+};
+NoBaseField N;
Index: clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
===================================================================
--- clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -379,9 +379,14 @@
for (++Field; Field != FieldEnd && Field->isBitField(); ++Field);
accumulateBitFields(Start, Field);
} else if (!Field->isZeroSize(Context)) {
+ // Use base subobject layout for the potentially-overlapping field,
+ // as it is done in RecordLayoutBuilder
Members.push_back(MemberInfo(
bitsToCharUnits(getFieldBitOffset(*Field)), MemberInfo::Field,
- getStorageType(*Field), *Field));
+ Field->isPotentiallyOverlapping() && !Field->getType()->isUnionType()
+ ? getStorageType(Field->getType()->getAsCXXRecordDecl())
+ : getStorageType(*Field),
+ *Field));
++Field;
} else {
++Field;
Index: clang/lib/AST/RecordLayoutBuilder.cpp
===================================================================
--- clang/lib/AST/RecordLayoutBuilder.cpp
+++ clang/lib/AST/RecordLayoutBuilder.cpp
@@ -1853,9 +1853,8 @@
void ItaniumRecordLayoutBuilder::LayoutField(const FieldDecl *D,
bool InsertExtraPadding) {
auto *FieldClass = D->getType()->getAsCXXRecordDecl();
- bool PotentiallyOverlapping = D->hasAttr<NoUniqueAddressAttr>() && FieldClass;
bool IsOverlappingEmptyField =
- PotentiallyOverlapping && FieldClass->isEmpty();
+ D->isPotentiallyOverlapping() && FieldClass->isEmpty();
CharUnits FieldOffset =
(IsUnion || IsOverlappingEmptyField) ? CharUnits::Zero() : getDataSize();
@@ -1916,7 +1915,7 @@
// A potentially-overlapping field occupies its dsize or nvsize, whichever
// is larger.
- if (PotentiallyOverlapping) {
+ if (D->isPotentiallyOverlapping()) {
const ASTRecordLayout &Layout = Context.getASTRecordLayout(FieldClass);
EffectiveFieldSize =
std::max(Layout.getNonVirtualSize(), Layout.getDataSize());
Index: clang/lib/AST/Decl.cpp
===================================================================
--- clang/lib/AST/Decl.cpp
+++ clang/lib/AST/Decl.cpp
@@ -4339,6 +4339,10 @@
return true;
}
+bool FieldDecl::isPotentiallyOverlapping() const {
+ return hasAttr<NoUniqueAddressAttr>() && getType()->getAsCXXRecordDecl();
+}
+
unsigned FieldDecl::getFieldIndex() const {
const FieldDecl *Canonical = getCanonicalDecl();
if (Canonical != this)
Index: clang/include/clang/AST/Decl.h
===================================================================
--- clang/include/clang/AST/Decl.h
+++ clang/include/clang/AST/Decl.h
@@ -3062,6 +3062,10 @@
/// [[no_unique_address]] attribute.
bool isZeroSize(const ASTContext &Ctx) const;
+ /// Determine if this field is of potentially-overlapping class type, that
+ /// is, subobject with the [[no_unique_address]] attribute
+ bool isPotentiallyOverlapping() const;
+
/// Get the kind of (C++11) default member initializer that this field has.
InClassInitStyle getInClassInitStyle() const {
InitStorageKind storageKind = InitStorage.getInt();
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