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Improve the caching of debuginfo Objective C interface types. 

Generate forward declarations that are RAUW'd by finalize().
We thus avoid outputting the same type several times in multiple
stages of completion.

llvm-svn: 176820
This commit is contained in:
Adrian Prantl 2013-03-11 18:33:46 +00:00
parent e5ecf10a02
commit 73409ce90f
3 changed files with 68 additions and 27 deletions
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86
clang/lib/CodeGen/CGDebugInfo.cpp
View File

@ -1314,7 +1314,7 @@ llvm::DIType CGDebugInfo::getOrCreateInterfaceType(QualType D,
SourceLocation Loc) {
assert(CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo);
llvm::DIType T = getOrCreateType(D, getOrCreateFile(Loc));
DBuilder.retainType(T);
RetainedTypes.push_back(D.getAsOpaquePtr());
return T;
}
@ -1778,6 +1778,13 @@ llvm::DIType CGDebugInfo::getTypeOrNull(QualType Ty) {
Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
// Check for existing entry.
if (Ty->getTypeClass() == Type::ObjCInterface) {
llvm::Value *V = getCachedInterfaceTypeOrNull(Ty);
if (V)
return llvm::DIType(cast<llvm::MDNode>(V));
else return llvm::DIType();
}
llvm::DenseMap<void *, llvm::WeakVH>::iterator it =
TypeCache.find(Ty.getAsOpaquePtr());
if (it != TypeCache.end()) {
@ -1803,16 +1810,7 @@ llvm::DIType CGDebugInfo::getCompletedTypeOrNull(QualType Ty) {
if (it != CompletedTypeCache.end())
V = it->second;
else {
// Is there a cached interface that hasn't changed?
llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
::iterator it1 = ObjCInterfaceCache.find(Ty.getAsOpaquePtr());
if (it1 != ObjCInterfaceCache.end())
if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty))
if (Checksum(Decl) == it1->second.second) {
// Return cached type.
V = it1->second.first;
}
V = getCachedInterfaceTypeOrNull(Ty);
}
// Verify that any cached debug info still exists.
@ -1822,6 +1820,21 @@ llvm::DIType CGDebugInfo::getCompletedTypeOrNull(QualType Ty) {
return llvm::DIType();
}
/// getCachedInterfaceTypeOrNull - Get the type from the interface
/// cache, unless it needs to regenerated. Otherwise return null.
llvm::Value *CGDebugInfo::getCachedInterfaceTypeOrNull(QualType Ty) {
// Is there a cached interface that hasn't changed?
llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
::iterator it1 = ObjCInterfaceCache.find(Ty.getAsOpaquePtr());
if (it1 != ObjCInterfaceCache.end())
if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty))
if (Checksum(Decl) == it1->second.second)
// Return cached forward declaration.
return it1->second.first;
return 0;
}
/// getOrCreateType - Get the type from the cache or create a new
/// one if necessary.
@ -1839,27 +1852,39 @@ llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty, llvm::DIFile Unit) {
// Otherwise create the type.
llvm::DIType Res = CreateTypeNode(Ty, Unit);
void* TyPtr = Ty.getAsOpaquePtr();
// And update the type cache.
TypeCache[TyPtr] = Res;
llvm::DIType TC = getTypeOrNull(Ty);
if (TC.Verify() && TC.isForwardDecl())
ReplaceMap.push_back(std::make_pair(Ty.getAsOpaquePtr(),
static_cast<llvm::Value*>(TC)));
// Do not cache the type if it may be incomplete.
if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty)) {
// clang::ParseAST handles each TopLevelDecl immediately after it was parsed.
// A subsequent implementation may add more ivars to an interface, which is
// why we cache it together with a checksum to see if it changed.
ObjCInterfaceCache[Ty.getAsOpaquePtr()] =
std::make_pair(Res, Checksum(Decl));
return Res;
ReplaceMap.push_back(std::make_pair(TyPtr, static_cast<llvm::Value*>(TC)));
else if (ObjCInterfaceDecl* Decl = getObjCInterfaceDecl(Ty)) {
// Interface types may have elements added to them by a
// subsequent implementation or extension, so we keep them in
// the ObjCInterfaceCache together with a checksum. Instead of
// the (possibly) incomplete interace type, we return a forward
// declaration that gets RAUW'd in CGDebugInfo::finalize().
llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
::iterator it = ObjCInterfaceCache.find(TyPtr);
if (it != ObjCInterfaceCache.end())
TC = llvm::DIType(cast<llvm::MDNode>(it->second.first));
else
TC = DBuilder.createForwardDecl(llvm::dwarf::DW_TAG_structure_type,
Decl->getName(), TheCU, Unit,
getLineNumber(Decl->getLocation()),
TheCU.getLanguage());
// Store the forward declaration in the cache.
ObjCInterfaceCache[TyPtr] = std::make_pair(TC, Checksum(Decl));
// Register the type for replacement in finalize().
ReplaceMap.push_back(std::make_pair(TyPtr, static_cast<llvm::Value*>(TC)));
return TC;
}
// And update the type cache.
TypeCache[Ty.getAsOpaquePtr()] = Res;
if (!Res.isForwardDecl())
CompletedTypeCache[Ty.getAsOpaquePtr()] = Res;
CompletedTypeCache[TyPtr] = Res;
return Res;
}
@ -2929,10 +2954,17 @@ void CGDebugInfo::finalize() {
if (llvm::Value *V = it->second)
RepTy = llvm::DIType(cast<llvm::MDNode>(V));
}
if (Ty.Verify() && Ty.isForwardDecl() && RepTy.Verify()) {
Ty.replaceAllUsesWith(RepTy);
}
}
// We keep our own list of retained types, because we need to look
// up the final type in the type cache.
for (std::vector<void *>::const_iterator RI = RetainedTypes.begin(),
RE = RetainedTypes.end(); RI != RE; ++RI)
DBuilder.retainType(llvm::DIType(cast<llvm::MDNode>(TypeCache[*RI])));
DBuilder.finalize();
}

4
clang/lib/CodeGen/CGDebugInfo.h
View File

@ -66,6 +66,9 @@ class CGDebugInfo {
llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
ObjCInterfaceCache;
/// RetainedTypes - list of interfaces we want to keep even if orphaned.
std::vector<void *> RetainedTypes;
/// CompleteTypeCache - Cache of previously constructed complete RecordTypes.
llvm::DenseMap<void *, llvm::WeakVH> CompletedTypeCache;
@ -131,6 +134,7 @@ class CGDebugInfo {
const Type *Ty, QualType PointeeTy,
llvm::DIFile F);
llvm::Value *getCachedInterfaceTypeOrNull(const QualType Ty);
llvm::DIType getOrCreateStructPtrType(StringRef Name, llvm::DIType &Cache);
llvm::DISubprogram CreateCXXMemberFunction(const CXXMethodDecl *Method,

5
clang/test/CodeGenObjC/debug-info-ivars-extension.m
View File

@ -24,5 +24,10 @@ void gorf (I* pg) {
int _b = pg->b;
}
// CHECK: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"I", {{.*}}} ; [ DW_TAG_structure_type ]
// Check for "a".
// CHECK: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"a", metadata !{{[0-9]*}}, i32 7, i64 32, i64 32, i64 0, i32 0, metadata !{{[0-9]*}}, null} ; [ DW_TAG_member ] [a] [line 7, size 32, align 32, offset 0] [from int]
// Make sure we don't output the same type twice.
// CHECK-NOT: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"I", {{.*}}} ; [ DW_TAG_structure_type ]
// Check for "b".
// CHECK: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"b", metadata !{{[0-9]*}}, i32 18, i64 32, i64 32, i64 0, i32 0, metadata !{{[0-9]*}}, null} ; [ DW_TAG_member ] [b] [line 18, size 32, align 32, offset 0] [from int]