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Move ComputeEmptySubobjectSizes to EmptySubobjectMap. 

llvm-svn: 104702
This commit is contained in:
Anders Carlsson 2010-05-26 15:54:25 +00:00
parent f58de11b61
commit c5ca1f7799
1 changed files with 65 additions and 61 deletions
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126
clang/lib/AST/RecordLayoutBuilder.cpp
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@ -31,12 +31,70 @@ class EmptySubobjectMap {
/// Class - The class whose empty entries we're keeping track of.
const CXXRecordDecl *Class;
/// ComputeEmptySubobjectSizes - Compute the size of the largest base or
/// member subobject that is empty.
void ComputeEmptySubobjectSizes();
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
/// any empty classes.
uint64_t SizeOfLargestEmptySubobject;
EmptySubobjectMap(ASTContext &Context, const CXXRecordDecl *Class)
: Context(Context), Class(Class) { }
: Context(Context), Class(Class), SizeOfLargestEmptySubobject(0) { }
};
void EmptySubobjectMap::ComputeEmptySubobjectSizes() {
// Check the bases.
for (CXXRecordDecl::base_class_const_iterator I = Class->bases_begin(),
E = Class->bases_end(); I != E; ++I) {
const CXXRecordDecl *BaseDecl =
cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
uint64_t EmptySize = 0;
const ASTRecordLayout &Layout = Context.getASTRecordLayout(BaseDecl);
if (BaseDecl->isEmpty()) {
// If the class decl is empty, get its size.
EmptySize = Layout.getSize();
} else {
// Otherwise, we get the largest empty subobject for the decl.
EmptySize = Layout.getSizeOfLargestEmptySubobject();
}
SizeOfLargestEmptySubobject = std::max(SizeOfLargestEmptySubobject,
EmptySize);
}
// Check the fields.
for (CXXRecordDecl::field_iterator I = Class->field_begin(),
E = Class->field_end(); I != E; ++I) {
const FieldDecl *FD = *I;
const RecordType *RT =
Context.getBaseElementType(FD->getType())->getAs<RecordType>();
// We only care about record types.
if (!RT)
continue;
uint64_t EmptySize = 0;
const CXXRecordDecl *MemberDecl = cast<CXXRecordDecl>(RT->getDecl());
const ASTRecordLayout &Layout = Context.getASTRecordLayout(MemberDecl);
if (MemberDecl->isEmpty()) {
// If the class decl is empty, get its size.
EmptySize = Layout.getSize();
} else {
// Otherwise, we get the largest empty subobject for the decl.
EmptySize = Layout.getSizeOfLargestEmptySubobject();
}
SizeOfLargestEmptySubobject = std::max(SizeOfLargestEmptySubobject,
EmptySize);
}
}
class RecordLayoutBuilder {
// FIXME: Remove this and make the appropriate fields public.
friend class clang::ASTContext;
@ -100,11 +158,6 @@ class RecordLayoutBuilder {
/// VisitedVirtualBases - A set of all the visited virtual bases, used to
/// avoid visiting virtual bases more than once.
llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBases;
/// SizeOfLargestEmptySubobject - When laying out C++ classes, 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 any empty classes.
uint64_t SizeOfLargestEmptySubobject;
/// EmptyClassOffsets - A map from offsets to empty record decls.
typedef std::multimap<uint64_t, const CXXRecordDecl *> EmptyClassOffsetsTy;
@ -114,8 +167,7 @@ class RecordLayoutBuilder {
: Context(Context), EmptySubobjects(0), Size(0), Alignment(8),
Packed(false), UnfilledBitsInLastByte(0), MaxFieldAlignment(0), DataSize(0),
IsUnion(false), NonVirtualSize(0), NonVirtualAlignment(8), PrimaryBase(0),
PrimaryBaseIsVirtual(false), FirstNearlyEmptyVBase(0),
SizeOfLargestEmptySubobject(0) { }
PrimaryBaseIsVirtual(false), FirstNearlyEmptyVBase(0) { }
void Layout(const RecordDecl *D);
void Layout(const CXXRecordDecl *D);
@ -198,6 +250,10 @@ class RecordLayoutBuilder {
void operator=(const RecordLayoutBuilder&); // DO NOT IMPLEMENT
public:
static const CXXMethodDecl *ComputeKeyFunction(const CXXRecordDecl *RD);
uint64_t getSizeOfLargestEmptySubobject() {
return EmptySubobjects->SizeOfLargestEmptySubobject;
}
};
} // end anonymous namespace
@ -213,56 +269,6 @@ bool RecordLayoutBuilder::IsNearlyEmpty(const CXXRecordDecl *RD) const {
return false;
}
void
RecordLayoutBuilder::ComputeEmptySubobjectSizes(const CXXRecordDecl *RD) {
// Check the bases.
for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
E = RD->bases_end(); I != E; ++I) {
const CXXRecordDecl *BaseDecl =
cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
uint64_t EmptySize = 0;
const ASTRecordLayout &Layout = Context.getASTRecordLayout(BaseDecl);
if (BaseDecl->isEmpty()) {
// If the class decl is empty, get its size.
EmptySize = Layout.getSize();
} else {
// Otherwise, we get the largest empty subobject for the decl.
EmptySize = Layout.getSizeOfLargestEmptySubobject();
}
SizeOfLargestEmptySubobject = std::max(SizeOfLargestEmptySubobject,
EmptySize);
}
// Check the fields.
for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end();
I != E; ++I) {
const FieldDecl *FD = *I;
const RecordType *RT =
Context.getBaseElementType(FD->getType())->getAs<RecordType>();
// We only care about record types.
if (!RT)
continue;
uint64_t EmptySize = 0;
const CXXRecordDecl *MemberDecl = cast<CXXRecordDecl>(RT->getDecl());
const ASTRecordLayout &Layout = Context.getASTRecordLayout(MemberDecl);
if (MemberDecl->isEmpty()) {
// If the class decl is empty, get its size.
EmptySize = Layout.getSize();
} else {
// Otherwise, we get the largest empty subobject for the decl.
EmptySize = Layout.getSizeOfLargestEmptySubobject();
}
SizeOfLargestEmptySubobject = std::max(SizeOfLargestEmptySubobject,
EmptySize);
}
}
void RecordLayoutBuilder::IdentifyPrimaryBases(const CXXRecordDecl *RD) {
const ASTRecordLayout::PrimaryBaseInfo &BaseInfo =
Context.getASTRecordLayout(RD).getPrimaryBaseInfo();
@ -780,8 +786,6 @@ void RecordLayoutBuilder::Layout(const CXXRecordDecl *RD) {
InitializeLayout(RD);
ComputeEmptySubobjectSizes(RD);
// Lay out the vtable and the non-virtual bases.
LayoutNonVirtualBases(RD);
@ -1141,7 +1145,7 @@ const ASTRecordLayout &ASTContext::getASTRecordLayout(const RecordDecl *D) {
Builder.FieldOffsets.size(),
NonVirtualSize,
Builder.NonVirtualAlignment,
Builder.SizeOfLargestEmptySubobject,
Builder.getSizeOfLargestEmptySubobject(),
Builder.PrimaryBase,
Builder.PrimaryBaseIsVirtual,
Builder.Bases, Builder.VBases);