mstorsjo updated this revision to Diff 549099.
mstorsjo added a comment.
Plumb the info from EmitInitializerForField through AggValueSlot and
ReturnValueSlot to EmitCall.
The fields/variables could use better names.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D157332/new/
https://reviews.llvm.org/D157332
Files:
clang/lib/CodeGen/CGCall.cpp
clang/lib/CodeGen/CGCall.h
clang/lib/CodeGen/CGClass.cpp
clang/lib/CodeGen/CGExprAgg.cpp
clang/lib/CodeGen/CGValue.h
clang/test/CodeGenCXX/ctor-empty-nounique.cpp
Index: clang/test/CodeGenCXX/ctor-empty-nounique.cpp
===================================================================
--- /dev/null
+++ clang/test/CodeGenCXX/ctor-empty-nounique.cpp
@@ -0,0 +1,43 @@
+// RUN: %clang_cc1 -triple x86_64-windows-gnu -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple powerpc64le-windows-gnu -emit-llvm -o - %s | FileCheck %s
+
+// An empty struct is handled as a struct with a dummy i8, on all targets.
+// Most targets treat an empty struct return value as essentially void - but
+// some don't. (Currently, at least x86_64-windows-* and powerpc64le-* don't
+// treat it as void.)
+//
+// When intializing a struct with such a no_unique_address member, make sure we
+// don't write the dummy i8 into the struct where there's no space allocated for
+// it.
+//
+// This can only be tested with targets that don't treat empty struct returns as
+// void.
+
+struct S {};
+S f();
+struct Z {
+ int x;
+ [[no_unique_address]] S y;
+ Z();
+};
+Z::Z() : x(111), y(f()) {}
+
+// CHECK: define {{.*}} @_ZN1ZC2Ev
+// CHECK: %call = call i8 @_Z1fv()
+// CHECK-NEXT: ret void
+
+struct S2 {
+ S2();
+};
+struct Z2 {
+ int x;
+ [[no_unique_address]] S2 y;
+ Z2();
+};
+Z2::Z2() : x(111) {}
+
+// CHECK: define {{.*}} @_ZN2Z2C2Ev(ptr {{.*}} %this)
+// CHECK: %this.addr = alloca ptr
+// CHECK: store ptr %this, ptr %this.addr
+// CHECK: %this1 = load ptr, ptr %this.addr
+// CHECK: call void @_ZN2S2C1Ev(ptr {{.*}} %this1)
Index: clang/lib/CodeGen/CGValue.h
===================================================================
--- clang/lib/CodeGen/CGValue.h
+++ clang/lib/CodeGen/CGValue.h
@@ -559,13 +559,16 @@
/// them.
bool SanitizerCheckedFlag : 1;
+ bool IsDummy : 1;
+
+public:
AggValueSlot(Address Addr, Qualifiers Quals, bool DestructedFlag,
bool ObjCGCFlag, bool ZeroedFlag, bool AliasedFlag,
- bool OverlapFlag, bool SanitizerCheckedFlag)
+ bool OverlapFlag, bool SanitizerCheckedFlag, bool IsDummy)
: Addr(Addr), Quals(Quals), DestructedFlag(DestructedFlag),
ObjCGCFlag(ObjCGCFlag), ZeroedFlag(ZeroedFlag),
AliasedFlag(AliasedFlag), OverlapFlag(OverlapFlag),
- SanitizerCheckedFlag(SanitizerCheckedFlag) {}
+ SanitizerCheckedFlag(SanitizerCheckedFlag), IsDummy(IsDummy) {}
public:
enum IsAliased_t { IsNotAliased, IsAliased };
@@ -574,6 +577,7 @@
enum Overlap_t { DoesNotOverlap, MayOverlap };
enum NeedsGCBarriers_t { DoesNotNeedGCBarriers, NeedsGCBarriers };
enum IsSanitizerChecked_t { IsNotSanitizerChecked, IsSanitizerChecked };
+ enum IsDummy_t { IsNotADummySlot, IsADummySlot };
/// ignored - Returns an aggregate value slot indicating that the
/// aggregate value is being ignored.
@@ -592,27 +596,26 @@
/// for calling destructors on this object
/// \param needsGC - true if the slot is potentially located
/// somewhere that ObjC GC calls should be emitted for
- static AggValueSlot forAddr(Address addr,
- Qualifiers quals,
- IsDestructed_t isDestructed,
- NeedsGCBarriers_t needsGC,
- IsAliased_t isAliased,
- Overlap_t mayOverlap,
- IsZeroed_t isZeroed = IsNotZeroed,
- IsSanitizerChecked_t isChecked = IsNotSanitizerChecked) {
+ static AggValueSlot
+ forAddr(Address addr, Qualifiers quals, IsDestructed_t isDestructed,
+ NeedsGCBarriers_t needsGC, IsAliased_t isAliased,
+ Overlap_t mayOverlap, IsZeroed_t isZeroed = IsNotZeroed,
+ IsSanitizerChecked_t isChecked = IsNotSanitizerChecked,
+ IsDummy_t isDummy = IsNotADummySlot) {
if (addr.isValid())
addr.setKnownNonNull();
return AggValueSlot(addr, quals, isDestructed, needsGC, isZeroed, isAliased,
- mayOverlap, isChecked);
+ mayOverlap, isChecked, isDummy);
}
static AggValueSlot
forLValue(const LValue &LV, CodeGenFunction &CGF, IsDestructed_t isDestructed,
NeedsGCBarriers_t needsGC, IsAliased_t isAliased,
Overlap_t mayOverlap, IsZeroed_t isZeroed = IsNotZeroed,
- IsSanitizerChecked_t isChecked = IsNotSanitizerChecked) {
+ IsSanitizerChecked_t isChecked = IsNotSanitizerChecked,
+ IsDummy_t isDummy = IsNotADummySlot) {
return forAddr(LV.getAddress(CGF), LV.getQuals(), isDestructed, needsGC,
- isAliased, mayOverlap, isZeroed, isChecked);
+ isAliased, mayOverlap, isZeroed, isChecked, isDummy);
}
IsDestructed_t isExternallyDestructed() const {
@@ -671,6 +674,8 @@
return SanitizerCheckedFlag;
}
+ bool isDummy() const { return IsDummy; }
+
RValue asRValue() const {
if (isIgnored()) {
return RValue::getIgnored();
Index: clang/lib/CodeGen/CGExprAgg.cpp
===================================================================
--- clang/lib/CodeGen/CGExprAgg.cpp
+++ clang/lib/CodeGen/CGExprAgg.cpp
@@ -317,7 +317,7 @@
RValue Src =
EmitCall(ReturnValueSlot(RetAddr, Dest.isVolatile(), IsResultUnused,
- Dest.isExternallyDestructed()));
+ Dest.isExternallyDestructed(), Dest.isDummy()));
if (!UseTemp)
return;
Index: clang/lib/CodeGen/CGClass.cpp
===================================================================
--- clang/lib/CodeGen/CGClass.cpp
+++ clang/lib/CodeGen/CGClass.cpp
@@ -10,6 +10,7 @@
//
//===----------------------------------------------------------------------===//
+#include "ABIInfoImpl.h"
#include "CGBlocks.h"
#include "CGCXXABI.h"
#include "CGDebugInfo.h"
@@ -695,12 +696,15 @@
EmitComplexExprIntoLValue(Init, LHS, /*isInit*/ true);
break;
case TEK_Aggregate: {
+ bool IsDummy = Field->hasAttr<NoUniqueAddressAttr>() &&
+ isEmptyRecord(getContext(), FieldType, true);
AggValueSlot Slot = AggValueSlot::forLValue(
LHS, *this, AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased,
getOverlapForFieldInit(Field), AggValueSlot::IsNotZeroed,
// Checks are made by the code that calls constructor.
- AggValueSlot::IsSanitizerChecked);
+ AggValueSlot::IsSanitizerChecked,
+ IsDummy ? AggValueSlot::IsADummySlot : AggValueSlot::IsNotADummySlot);
EmitAggExpr(Init, Slot);
break;
}
Index: clang/lib/CodeGen/CGCall.h
===================================================================
--- clang/lib/CodeGen/CGCall.h
+++ clang/lib/CodeGen/CGCall.h
@@ -359,20 +359,23 @@
unsigned IsVolatile : 1;
unsigned IsUnused : 1;
unsigned IsExternallyDestructed : 1;
+ unsigned IsDummy : 1;
public:
ReturnValueSlot()
- : IsVolatile(false), IsUnused(false), IsExternallyDestructed(false) {}
+ : IsVolatile(false), IsUnused(false), IsExternallyDestructed(false),
+ IsDummy(false) {}
ReturnValueSlot(Address Addr, bool IsVolatile, bool IsUnused = false,
- bool IsExternallyDestructed = false)
+ bool IsExternallyDestructed = false, bool IsDummy = false)
: Addr(Addr), IsVolatile(IsVolatile), IsUnused(IsUnused),
- IsExternallyDestructed(IsExternallyDestructed) {}
+ IsExternallyDestructed(IsExternallyDestructed), IsDummy(IsDummy) {}
bool isNull() const { return !Addr.isValid(); }
bool isVolatile() const { return IsVolatile; }
Address getValue() const { return Addr; }
bool isUnused() const { return IsUnused; }
bool isExternallyDestructed() const { return IsExternallyDestructed; }
+ bool isDummy() const { return IsDummy; }
};
/// Helper to add attributes to \p F according to the CodeGenOptions and
Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -5778,8 +5778,10 @@
}
// If the value is offset in memory, apply the offset now.
- Address StorePtr = emitAddressAtOffset(*this, DestPtr, RetAI);
- CreateCoercedStore(CI, StorePtr, DestIsVolatile, *this);
+ if (!ReturnValue.isDummy()) {
+ Address StorePtr = emitAddressAtOffset(*this, DestPtr, RetAI);
+ CreateCoercedStore(CI, StorePtr, DestIsVolatile, *this);
+ }
return convertTempToRValue(DestPtr, RetTy, SourceLocation());
}
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