From c8cb462e57ac13518a170fe52b77bb8656234b35 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Tue, 8 Jun 2010 15:56:03 +0000
Subject: [PATCH] Minor cleanups to the empty subobject map.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105608 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/AST/RecordLayoutBuilder.cpp | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index c8b1463508a..704a974a88a 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -65,11 +65,17 @@ class EmptySubobjectMap {
typedef llvm::DenseMap<uint64_t, ClassVectorTy> EmptyClassOffsetsMapTy;
EmptyClassOffsetsMapTy EmptyClassOffsets;
+ /// MaxEmptyClassOffset - The highest offset known to contain an empty
+ /// base subobject.
+ uint64_t MaxEmptyClassOffset;
+
/// ComputeEmptySubobjectSizes - Compute the size of the largest base or
/// member subobject that is empty.
void ComputeEmptySubobjectSizes();
- bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, uint64_t Offset);
+ bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD,
+ uint64_t Offset) const;
+
void AddSubobjectAtOffset(const CXXRecordDecl *RD, uint64_t Offset);
bool CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info,
@@ -79,15 +85,21 @@ class EmptySubobjectMap {
bool CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD,
const CXXRecordDecl *Class,
- uint64_t Offset);
+ uint64_t Offset) const;
bool CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD,
- uint64_t Offset);
+ uint64_t Offset) const;
void UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD,
const CXXRecordDecl *Class,
uint64_t Offset);
void UpdateEmptyFieldSubobjects(const FieldDecl *FD, uint64_t Offset);
+ /// AnyEmptySubobjectsBeyondOffset - Returns whether there are any empty
+ /// subobjects beyond the given offset.
+ bool AnyEmptySubobjectsBeyondOffset(uint64_t Offset) const {
+ return Offset <= MaxEmptyClassOffset;
+ }
+
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
@@ -103,7 +115,8 @@ public:
/// at the given offset.
/// Returns false if placing the record will result in two components
/// (direct or indirect) of the same type having the same offset.
- bool CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info, uint64_t Offset);
+ bool CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info,
+ uint64_t Offset);
/// CanPlaceFieldAtOffset - Return whether a field can be placed at the given
/// offset.
@@ -161,7 +174,7 @@ void EmptySubobjectMap::ComputeEmptySubobjectSizes() {
bool
EmptySubobjectMap::CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD,
- uint64_t Offset) {
+ uint64_t Offset) const {
// We only need to check empty bases.
if (!RD->isEmpty())
return true;
@@ -189,6 +202,9 @@ void EmptySubobjectMap::AddSubobjectAtOffset(const CXXRecordDecl *RD,
"Duplicate empty class detected!");
Classes.push_back(RD);
+
+ // Update the empty class offset.
+ MaxEmptyClassOffset = std::max(MaxEmptyClassOffset, Offset);
}
bool
@@ -273,7 +289,6 @@ bool EmptySubobjectMap::CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info,
if (!SizeOfLargestEmptySubobject)
return true;
- // FIXME: Re-enable this.
if (!CanPlaceBaseSubobjectAtOffset(Info, Offset))
return false;
@@ -286,7 +301,7 @@ bool EmptySubobjectMap::CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info,
bool
EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD,
const CXXRecordDecl *Class,
- uint64_t Offset) {
+ uint64_t Offset) const {
if (!CanPlaceSubobjectAtOffset(RD, Offset))
return false;
@@ -322,7 +337,7 @@ EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD,
}
bool EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD,
- uint64_t Offset) {
+ uint64_t Offset) const {
QualType T = FD->getType();
if (const RecordType *RT = T->getAs<RecordType>()) {
const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
--
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