kosarev updated this revision to Diff 119257.
kosarev added a comment.
- Removed renamings that complicate reviewing.
https://reviews.llvm.org/D38947
Files:
lib/CodeGen/CGExpr.cpp
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -3665,15 +3665,6 @@
LValue CodeGenFunction::EmitLValueForField(LValue base,
const FieldDecl *field) {
LValueBaseInfo BaseInfo = base.getBaseInfo();
- AlignmentSource fieldAlignSource =
- getFieldAlignmentSource(BaseInfo.getAlignmentSource());
- LValueBaseInfo FieldBaseInfo(fieldAlignSource, BaseInfo.getMayAlias());
-
- QualType type = field->getType();
- const RecordDecl *rec = field->getParent();
- if (rec->isUnion() || rec->hasAttr<MayAliasAttr>() || type->isVectorType())
- FieldBaseInfo.setMayAlias(true);
- bool mayAlias = FieldBaseInfo.getMayAlias();
if (field->isBitField()) {
const CGRecordLayout &RL =
@@ -3693,19 +3684,54 @@
QualType fieldType =
field->getType().withCVRQualifiers(base.getVRQualifiers());
+ // TODO: Support TBAA for bit fields.
+ LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource(), false);
return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo);
}
+ // Fields of may-alias structures are may-alias themselves.
+ // FIXME: this should get propagated down through anonymous structs
+ // and unions.
+ QualType FieldType = field->getType();
+ const RecordDecl *rec = field->getParent();
+ AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
+ LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource), false);
+ TBAAAccessInfo FieldTBAAInfo;
+ if (BaseInfo.getMayAlias() || rec->hasAttr<MayAliasAttr>() ||
+ FieldType->isVectorType()) {
+ FieldBaseInfo.setMayAlias(true);
+ FieldTBAAInfo = CGM.getTBAAMayAliasAccessInfo();
+ } else if (rec->isUnion()) {
+ // TODO: Support TBAA for unions.
+ FieldBaseInfo.setMayAlias(true);
+ FieldTBAAInfo = CGM.getTBAAMayAliasAccessInfo();
+ } else {
+ // If no base type been assigned for the base access, then try to generate
+ // one for this base lvalue.
+ FieldTBAAInfo = base.getTBAAInfo();
+ if (!FieldTBAAInfo.BaseType) {
+ FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
+ assert(!FieldTBAAInfo.Offset &&
+ "Nonzero offset for an access with no base type!");
+ }
+
+ // Adjust offset to be relative to the base type.
+ const ASTRecordLayout &Layout =
+ getContext().getASTRecordLayout(field->getParent());
+ unsigned CharWidth = getContext().getCharWidth();
+ if (FieldTBAAInfo.BaseType)
+ FieldTBAAInfo.Offset +=
+ Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
+
+ // Update the final access type.
+ FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
+ }
+
Address addr = base.getAddress();
unsigned cvr = base.getVRQualifiers();
- bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
if (rec->isUnion()) {
// For unions, there is no pointer adjustment.
- assert(!type->isReferenceType() && "union has reference member");
- // TODO: handle path-aware TBAA for union.
- TBAAPath = false;
-
- const auto FieldType = field->getType();
+ assert(!FieldType->isReferenceType() && "union has reference member");
if (CGM.getCodeGenOpts().StrictVTablePointers &&
hasAnyVptr(FieldType, getContext()))
// Because unions can easily skip invariant.barriers, we need to add
@@ -3717,24 +3743,18 @@
addr = emitAddrOfFieldStorage(*this, addr, field);
// If this is a reference field, load the reference right now.
- if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
+ if (const ReferenceType *refType = FieldType->getAs<ReferenceType>()) {
llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
if (cvr & Qualifiers::Volatile) load->setVolatile(true);
- // Loading the reference will disable path-aware TBAA.
- TBAAPath = false;
- TBAAAccessInfo TBAAInfo = mayAlias ? CGM.getTBAAMayAliasAccessInfo() :
- CGM.getTBAAAccessInfo(type);
- CGM.DecorateInstructionWithTBAA(load, TBAAInfo);
-
- mayAlias = false;
- type = refType->getPointeeType();
-
- CharUnits alignment =
- getNaturalTypeAlignment(type, &FieldBaseInfo, /* TBAAInfo= */ nullptr,
- /* forPointeeType= */ true);
- FieldBaseInfo.setMayAlias(false);
- addr = Address(load, alignment);
+ CGM.DecorateInstructionWithTBAA(load, FieldTBAAInfo);
+
+ FieldType = refType->getPointeeType();
+
+ CharUnits Align = getNaturalTypeAlignment(FieldType, &FieldBaseInfo,
+ &FieldTBAAInfo,
+ /* forPointeeType= */ true);
+ addr = Address(load, Align);
// Qualifiers on the struct don't apply to the referencee, and
// we'll pick up CVR from the actual type later, so reset these
@@ -3747,46 +3767,15 @@
// for both unions and structs. A union needs a bitcast, a struct element
// will need a bitcast if the LLVM type laid out doesn't match the desired
// type.
- addr = Builder.CreateElementBitCast(addr,
- CGM.getTypes().ConvertTypeForMem(type),
- field->getName());
+ addr = Builder.CreateElementBitCast(
+ addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
if (field->hasAttr<AnnotateAttr>())
addr = EmitFieldAnnotations(field, addr);
- LValue LV = MakeAddrLValue(addr, type, FieldBaseInfo,
- CGM.getTBAAAccessInfo(type));
+ LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
LV.getQuals().addCVRQualifiers(cvr);
- // Fields of may_alias structs act like 'char' for TBAA purposes.
- // FIXME: this should get propagated down through anonymous structs
- // and unions.
- if (mayAlias) {
- LV.setTBAAInfo(CGM.getTBAAMayAliasAccessInfo());
- } else if (TBAAPath) {
- // If no base type been assigned for the base access, then try to generate
- // one for this base lvalue.
- TBAAAccessInfo TBAAInfo = base.getTBAAInfo();
- if (!TBAAInfo.BaseType) {
- TBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
- assert(!TBAAInfo.Offset &&
- "Nonzero offset for an access with no base type!");
- }
-
- // Adjust offset to be relative to the base type.
- const ASTRecordLayout &Layout =
- getContext().getASTRecordLayout(field->getParent());
- unsigned CharWidth = getContext().getCharWidth();
- if (TBAAInfo.BaseType)
- TBAAInfo.Offset +=
- Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
-
- // Update the final access type.
- TBAAInfo.AccessType = LV.getTBAAInfo().AccessType;
-
- LV.setTBAAInfo(TBAAInfo);
- }
-
// __weak attribute on a field is ignored.
if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
LV.getQuals().removeObjCGCAttr();
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