[cfe-commits] r104861 - /cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
Anders Carlsson
andersca at mac.com
Thu May 27 11:20:57 PDT 2010
Author: andersca
Date: Thu May 27 13:20:57 2010
New Revision: 104861
URL: http://llvm.org/viewvc/llvm-project?rev=104861&view=rev
Log:
More work on the empty subobject map. This code is not yet used.
Modified:
cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
Modified: cfe/trunk/lib/AST/RecordLayoutBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/RecordLayoutBuilder.cpp?rev=104861&r1=104860&r2=104861&view=diff
==============================================================================
--- cfe/trunk/lib/AST/RecordLayoutBuilder.cpp (original)
+++ cfe/trunk/lib/AST/RecordLayoutBuilder.cpp Thu May 27 13:20:57 2010
@@ -57,9 +57,23 @@
const BaseInfo *Derived);
void ComputeBaseInfo();
+ bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, uint64_t Offset);
+ void AddSubobjectAtOffset(const CXXRecordDecl *RD, uint64_t Offset);
+
bool CanPlaceBaseSubobjectAtOffset(const BaseInfo *Info, uint64_t Offset);
void UpdateEmptyBaseSubobjects(const BaseInfo *Info, uint64_t Offset);
+ bool CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD,
+ const CXXRecordDecl *Class,
+ uint64_t Offset);
+ bool CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD,
+ uint64_t Offset);
+
+ void UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD,
+ const CXXRecordDecl *Class,
+ uint64_t Offset);
+ void UpdateEmptyFieldSubobjects(const FieldDecl *FD, uint64_t Offset);
+
public:
/// This holds the size of the largest empty subobject (either a base
/// or a member). Will be zero if the record being built doesn't contain
@@ -79,6 +93,10 @@
/// (direct or indirect) of the same type having the same offset.
bool CanPlaceBaseAtOffset(const CXXRecordDecl *RD, bool BaseIsVirtual,
uint64_t Offset);
+
+ /// CanPlaceFieldAtOffset - Return whether a field can be placed at the given
+ /// offset.
+ bool CanPlaceFieldAtOffset(const FieldDecl *FD, uint64_t Offset);
};
void EmptySubobjectMap::ComputeEmptySubobjectSizes() {
@@ -198,8 +216,43 @@
}
bool
+EmptySubobjectMap::CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD,
+ uint64_t Offset) {
+ // We only need to check empty bases.
+ if (!RD->isEmpty())
+ return true;
+
+ EmptyClassOffsetsMapTy::const_iterator I = EmptyClassOffsets.find(Offset);
+ if (I == EmptyClassOffsets.end())
+ return true;
+
+ const ClassVectorTy& Classes = I->second;
+ if (std::find(Classes.begin(), Classes.end(), RD) == Classes.end())
+ return true;
+
+ // There is already an empty class of the same type at this offset.
+ return false;
+}
+
+void EmptySubobjectMap::AddSubobjectAtOffset(const CXXRecordDecl *RD,
+ uint64_t Offset) {
+ // We only care about empty bases.
+ if (!RD->isEmpty())
+ return;
+
+ ClassVectorTy& Classes = EmptyClassOffsets[Offset];
+ assert(std::find(Classes.begin(), Classes.end(), RD) == Classes.end() &&
+ "Duplicate empty class detected!");
+
+ Classes.push_back(RD);
+}
+
+bool
EmptySubobjectMap::CanPlaceBaseSubobjectAtOffset(const BaseInfo *Info,
uint64_t Offset) {
+ if (!CanPlaceSubobjectAtOffset(Info->Class, Offset))
+ return false;
+
// Traverse all non-virtual bases.
for (unsigned I = 0, E = Info->Bases.size(); I != E; ++I) {
BaseInfo* Base = Info->Bases[I];
@@ -224,15 +277,26 @@
}
}
- // FIXME: Member variables.
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class);
+
+ // Traverse all member variables.
+ unsigned FieldNo = 0;
+ for (CXXRecordDecl::field_iterator I = Info->Class->field_begin(),
+ E = Info->Class->field_end(); I != E; ++I, ++FieldNo) {
+ const FieldDecl *FD = *I;
+
+ uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo);
+
+ if (!CanPlaceFieldSubobjectAtOffset(FD, FieldOffset))
+ return false;
+ }
+
return true;
}
void EmptySubobjectMap::UpdateEmptyBaseSubobjects(const BaseInfo *Info,
uint64_t Offset) {
- if (Info->Class->isEmpty()) {
- // FIXME: Record that there is an empty class at this offset.
- }
+ AddSubobjectAtOffset(Info->Class, Offset);
// Traverse all non-virtual bases.
for (unsigned I = 0, E = Info->Bases.size(); I != E; ++I) {
@@ -254,8 +318,19 @@
if (Info == PrimaryVirtualBaseInfo->Derived)
UpdateEmptyBaseSubobjects(PrimaryVirtualBaseInfo, Offset);
}
-
- // FIXME: Member variables.
+
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class);
+
+ // Traverse all member variables.
+ unsigned FieldNo = 0;
+ for (CXXRecordDecl::field_iterator I = Info->Class->field_begin(),
+ E = Info->Class->field_end(); I != E; ++I, ++FieldNo) {
+ const FieldDecl *FD = *I;
+
+ uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo);
+
+ UpdateEmptyFieldSubobjects(FD, FieldOffset);
+ }
}
bool EmptySubobjectMap::CanPlaceBaseAtOffset(const CXXRecordDecl *RD,
@@ -275,11 +350,154 @@
if (!CanPlaceBaseSubobjectAtOffset(Info, Offset))
return false;
-
+
+ // We are able to place the base at this offset. Make sure to update the
+ // empty base subobject map.
UpdateEmptyBaseSubobjects(Info, Offset);
return true;
}
+bool
+EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD,
+ const CXXRecordDecl *Class,
+ uint64_t Offset) {
+ if (!CanPlaceSubobjectAtOffset(RD, Offset))
+ return false;
+
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+ // Traverse all non-virtual bases.
+ for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
+ E = RD->bases_end(); I != E; ++I) {
+ if (I->isVirtual())
+ continue;
+
+ const CXXRecordDecl *BaseDecl =
+ cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
+
+ uint64_t BaseOffset = Offset + Layout.getBaseClassOffset(BaseDecl);
+ if (!CanPlaceFieldSubobjectAtOffset(BaseDecl, Class, BaseOffset))
+ return false;
+ }
+
+ // Traverse all member variables.
+ unsigned FieldNo = 0;
+ for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
+ I != E; ++I, ++FieldNo) {
+ const FieldDecl *FD = *I;
+
+ uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo);
+
+ if (!CanPlaceFieldSubobjectAtOffset(FD, FieldOffset))
+ return false;
+ }
+
+ return true;
+}
+
+bool EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD,
+ uint64_t Offset) {
+ QualType T = FD->getType();
+ if (const RecordType *RT = T->getAs<RecordType>()) {
+ const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+ return CanPlaceFieldSubobjectAtOffset(RD, RD, Offset);
+ }
+
+ // If we have an array type we need to look at every element.
+ if (const ConstantArrayType *AT = Context.getAsConstantArrayType(T)) {
+ QualType ElemTy = Context.getBaseElementType(AT);
+ const RecordType *RT = ElemTy->getAs<RecordType>();
+ if (!RT)
+ return true;
+
+ const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+ uint64_t NumElements = Context.getConstantArrayElementCount(AT);
+ uint64_t ElementOffset = Offset;
+ for (uint64_t I = 0; I != NumElements; ++I) {
+ if (!CanPlaceFieldSubobjectAtOffset(RD, RD, ElementOffset))
+ return false;
+
+ ElementOffset += Layout.getSize();
+ }
+ }
+
+ return true;
+}
+
+bool
+EmptySubobjectMap::CanPlaceFieldAtOffset(const FieldDecl *FD, uint64_t Offset) {
+ if (!CanPlaceFieldSubobjectAtOffset(FD, Offset))
+ return false;
+
+ // We are able to place the member variable at this offset.
+ // Make sure to update the empty base subobject map.
+ UpdateEmptyFieldSubobjects(FD, Offset);
+ return true;
+}
+
+void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD,
+ const CXXRecordDecl *Class,
+ uint64_t Offset) {
+ AddSubobjectAtOffset(RD, Offset);
+
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+ // Traverse all non-virtual bases.
+ for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
+ E = RD->bases_end(); I != E; ++I) {
+ if (I->isVirtual())
+ continue;
+
+ const CXXRecordDecl *BaseDecl =
+ cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
+
+ uint64_t BaseOffset = Offset + Layout.getBaseClassOffset(BaseDecl);
+ UpdateEmptyFieldSubobjects(BaseDecl, Class, BaseOffset);
+ }
+
+ // Traverse all member variables.
+ unsigned FieldNo = 0;
+ for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
+ I != E; ++I, ++FieldNo) {
+ const FieldDecl *FD = *I;
+
+ uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo);
+
+ UpdateEmptyFieldSubobjects(FD, FieldOffset);
+ }
+}
+
+void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const FieldDecl *FD,
+ uint64_t Offset) {
+ QualType T = FD->getType();
+ if (const RecordType *RT = T->getAs<RecordType>()) {
+ const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+ UpdateEmptyFieldSubobjects(RD, RD, Offset);
+ return;
+ }
+
+ // If we have an array type we need to update every element.
+ if (const ConstantArrayType *AT = Context.getAsConstantArrayType(T)) {
+ QualType ElemTy = Context.getBaseElementType(AT);
+ const RecordType *RT = ElemTy->getAs<RecordType>();
+ if (!RT)
+ return;
+
+ const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+ uint64_t NumElements = Context.getConstantArrayElementCount(AT);
+ uint64_t ElementOffset = Offset;
+
+ for (uint64_t I = 0; I != NumElements; ++I) {
+ UpdateEmptyFieldSubobjects(RD, RD, ElementOffset);
+ ElementOffset += Layout.getSize();
+ }
+ }
+}
+
class RecordLayoutBuilder {
// FIXME: Remove this and make the appropriate fields public.
friend class clang::ASTContext;
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