r176584 - Ensure that DIType is regenerated after we visit an implementation
David Blaikie
dblaikie at gmail.com
Sun May 4 17:18:20 PDT 2014
Oh, and just for the fun of it, this is a yak I discovered (& is
somewhat related to) while trying to fix PR19598, a memory leak in
Clang.
On Sun, May 4, 2014 at 5:09 PM, David Blaikie <dblaikie at gmail.com> wrote:
> On Wed, Mar 6, 2013 at 2:03 PM, Adrian Prantl <aprantl at apple.com> wrote:
>> Author: adrian
>> Date: Wed Mar 6 16:03:30 2013
>> New Revision: 176584
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=176584&view=rev
>> Log:
>> Ensure that DIType is regenerated after we visit an implementation
>> that adds ivars to an interface.
>>
>> Fixes rdar://13175234
>>
>> This is an update to r176116 that performs a smart caching of interfaces.
>
> *performs necromancy*
>
> So, I was looking at this code and how we've refactored type
> completion code in the last year or two (using complete type and
> requires complete type callbacks, etc) and I was going to change
> getOrCreateType to simply bail if getTypeOrNull returned non-null,
> rather than using getCompleteTypeOrNull.
>
> But that causes these 3 tests to fail, because these tests expect to
> attempt to rebuild the type every time it's referenced if it isn't
> complete. We don't need to do this for C++ types (rather than waiting
> for a use after the type becomes complete to create the complete debug
> info, we use the callback to inform us that the type is complete).
>
> I think it will simplify (marginally speed up, but I doubt that's
> relevant) the implementation of getTypeOrNull if we could do something
> similar for IVars - indeed, it would also be more correct. Try adding
> this to the end of debug-info-ivars-indirect.m:
>
>
> I *source();
>
> @interface I()
> {
> @public int c;
> }
> @end
>
> // CHECK: ; [ DW_TAG_member ] [c]
>
> void use() {
> int _c = source()->c;
> }
>
> Since we never generate debug info for the 'I' type after it is
> extended to have the 'c' member, we never generate debug info for that
> member.
>
> Is there a way we could do this in a callback fashion - thus being
> more correct and efficient?
>
> Alternatively: we could kill the callback system, make a list of types
> we've emitted declarations for, and walk that list at the end of the
> translation unit, building whichever types we need (that way we'd be
> sure to find all the ivars, for example). That depends whether it's
> worth visiting all the types to check if they need to be upgraded to
> definitions at the end.
>
>
>>
>> Added:
>> cfe/trunk/test/CodeGenObjC/debug-info-ivars-extension.m
>> cfe/trunk/test/CodeGenObjC/debug-info-ivars-indirect.m
>> cfe/trunk/test/CodeGenObjC/debug-info-ivars-private.m
>> Modified:
>> cfe/trunk/include/clang/AST/DeclObjC.h
>> cfe/trunk/lib/AST/DeclObjC.cpp
>> cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
>> cfe/trunk/lib/CodeGen/CGDebugInfo.h
>>
>> Modified: cfe/trunk/include/clang/AST/DeclObjC.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/DeclObjC.h?rev=176584&r1=176583&r2=176584&view=diff
>> ==============================================================================
>> --- cfe/trunk/include/clang/AST/DeclObjC.h (original)
>> +++ cfe/trunk/include/clang/AST/DeclObjC.h Wed Mar 6 16:03:30 2013
>> @@ -651,6 +651,10 @@ class ObjCInterfaceDecl : public ObjCCon
>> /// completed by the external AST source when required.
>> mutable bool ExternallyCompleted : 1;
>>
>> + /// \brief Indicates that the ivar cache does not yet include ivars
>> + /// declared in the implementation.
>> + mutable bool IvarListMissingImplementation : 1;
>> +
>> /// \brief The location of the superclass, if any.
>> SourceLocation SuperClassLoc;
>>
>> @@ -660,7 +664,8 @@ class ObjCInterfaceDecl : public ObjCCon
>> SourceLocation EndLoc;
>>
>> DefinitionData() : Definition(), SuperClass(), CategoryList(), IvarList(),
>> - ExternallyCompleted() { }
>> + ExternallyCompleted(),
>> + IvarListMissingImplementation(true) { }
>> };
>>
>> ObjCInterfaceDecl(DeclContext *DC, SourceLocation atLoc, IdentifierInfo *Id,
>>
>> Modified: cfe/trunk/lib/AST/DeclObjC.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/DeclObjC.cpp?rev=176584&r1=176583&r2=176584&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/AST/DeclObjC.cpp (original)
>> +++ cfe/trunk/lib/AST/DeclObjC.cpp Wed Mar 6 16:03:30 2013
>> @@ -1093,38 +1093,51 @@ namespace {
>> /// all_declared_ivar_begin - return first ivar declared in this class,
>> /// its extensions and its implementation. Lazily build the list on first
>> /// access.
>> +///
>> +/// Caveat: The list returned by this method reflects the current
>> +/// state of the parser. The cache will be updated for every ivar
>> +/// added by an extension or the implementation when they are
>> +/// encountered.
>> +/// See also ObjCIvarDecl::Create().
>> ObjCIvarDecl *ObjCInterfaceDecl::all_declared_ivar_begin() {
>> // FIXME: Should make sure no callers ever do this.
>> if (!hasDefinition())
>> return 0;
>>
>> - if (data().IvarList)
>> - return data().IvarList;
>> -
>> ObjCIvarDecl *curIvar = 0;
>> - if (!ivar_empty()) {
>> - ObjCInterfaceDecl::ivar_iterator I = ivar_begin(), E = ivar_end();
>> - data().IvarList = *I; ++I;
>> - for (curIvar = data().IvarList; I != E; curIvar = *I, ++I)
>> - curIvar->setNextIvar(*I);
>> - }
>> + if (!data().IvarList) {
>> + if (!ivar_empty()) {
>> + ObjCInterfaceDecl::ivar_iterator I = ivar_begin(), E = ivar_end();
>> + data().IvarList = *I; ++I;
>> + for (curIvar = data().IvarList; I != E; curIvar = *I, ++I)
>> + curIvar->setNextIvar(*I);
>> + }
>>
>> - for (ObjCInterfaceDecl::known_extensions_iterator
>> - Ext = known_extensions_begin(),
>> - ExtEnd = known_extensions_end();
>> - Ext != ExtEnd; ++Ext) {
>> - if (!Ext->ivar_empty()) {
>> - ObjCCategoryDecl::ivar_iterator I = Ext->ivar_begin(),E = Ext->ivar_end();
>> - if (!data().IvarList) {
>> - data().IvarList = *I; ++I;
>> - curIvar = data().IvarList;
>> + for (ObjCInterfaceDecl::known_extensions_iterator
>> + Ext = known_extensions_begin(),
>> + ExtEnd = known_extensions_end();
>> + Ext != ExtEnd; ++Ext) {
>> + if (!Ext->ivar_empty()) {
>> + ObjCCategoryDecl::ivar_iterator
>> + I = Ext->ivar_begin(),
>> + E = Ext->ivar_end();
>> + if (!data().IvarList) {
>> + data().IvarList = *I; ++I;
>> + curIvar = data().IvarList;
>> + }
>> + for ( ;I != E; curIvar = *I, ++I)
>> + curIvar->setNextIvar(*I);
>> }
>> - for ( ;I != E; curIvar = *I, ++I)
>> - curIvar->setNextIvar(*I);
>> }
>> + data().IvarListMissingImplementation = true;
>> }
>> +
>> + // cached and complete!
>> + if (!data().IvarListMissingImplementation)
>> + return data().IvarList;
>>
>> if (ObjCImplementationDecl *ImplDecl = getImplementation()) {
>> + data().IvarListMissingImplementation = false;
>> if (!ImplDecl->ivar_empty()) {
>> SmallVector<SynthesizeIvarChunk, 16> layout;
>> for (ObjCImplementationDecl::ivar_iterator I = ImplDecl->ivar_begin(),
>>
>> Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=176584&r1=176583&r2=176584&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
>> +++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Wed Mar 6 16:03:30 2013
>> @@ -1343,7 +1343,7 @@ llvm::DIType CGDebugInfo::CreateType(con
>> LexicalBlockStack.push_back(FwdDeclNode);
>> RegionMap[Ty->getDecl()] = llvm::WeakVH(FwdDecl);
>>
>> - // Add this to the completed types cache since we're completing it.
>> + // Add this to the completed-type cache while we're completing it recursively.
>> CompletedTypeCache[QualType(Ty, 0).getAsOpaquePtr()] = FwdDecl;
>>
>> // Convert all the elements.
>> @@ -1436,7 +1436,8 @@ llvm::DIType CGDebugInfo::CreateType(con
>>
>> // Otherwise, insert it into the CompletedTypeCache so that recursive uses
>> // will find it and we're emitting the complete type.
>> - CompletedTypeCache[QualType(Ty, 0).getAsOpaquePtr()] = RealDecl;
>> + QualType QualTy = QualType(Ty, 0);
>> + CompletedTypeCache[QualTy.getAsOpaquePtr()] = RealDecl;
>> // Push the struct on region stack.
>> llvm::TrackingVH<llvm::MDNode> FwdDeclNode(RealDecl);
>>
>> @@ -1561,6 +1562,12 @@ llvm::DIType CGDebugInfo::CreateType(con
>>
>> llvm::DIArray Elements = DBuilder.getOrCreateArray(EltTys);
>> FwdDeclNode->replaceOperandWith(10, Elements);
>> +
>> + // If the implementation is not yet set, we do not want to mark it
>> + // as complete. An implementation may declare additional
>> + // private ivars that we would miss otherwise.
>> + if (ID->getImplementation() == 0)
>> + CompletedTypeCache.erase(QualTy.getAsOpaquePtr());
>>
>> LexicalBlockStack.pop_back();
>> return llvm::DIType(FwdDeclNode);
>> @@ -1790,13 +1797,27 @@ llvm::DIType CGDebugInfo::getCompletedTy
>> Ty = UnwrapTypeForDebugInfo(Ty, CGM.getContext());
>>
>> // Check for existing entry.
>> + llvm::Value *V = 0;
>> llvm::DenseMap<void *, llvm::WeakVH>::iterator it =
>> CompletedTypeCache.find(Ty.getAsOpaquePtr());
>> - if (it != CompletedTypeCache.end()) {
>> - // Verify that the debug info still exists.
>> - if (llvm::Value *V = it->second)
>> - return llvm::DIType(cast<llvm::MDNode>(V));
>> - }
>> + 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;
>> + }
>> + }
>> +
>> + // Verify that any cached debug info still exists.
>> + if (V != 0)
>> + return llvm::DIType(cast<llvm::MDNode>(V));
>>
>> return llvm::DIType();
>> }
>> @@ -1824,6 +1845,16 @@ llvm::DIType CGDebugInfo::getOrCreateTyp
>> 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;
>> + }
>> +
>> // And update the type cache.
>> TypeCache[Ty.getAsOpaquePtr()] = Res;
>>
>> @@ -1833,6 +1864,26 @@ llvm::DIType CGDebugInfo::getOrCreateTyp
>> return Res;
>> }
>>
>> +/// Currently the checksum merely consists of the number of ivars.
>> +unsigned CGDebugInfo::Checksum(const ObjCInterfaceDecl
>> + *InterfaceDecl) {
>> + unsigned IvarNo = 0;
>> + for (const ObjCIvarDecl *Ivar = InterfaceDecl->all_declared_ivar_begin();
>> + Ivar != 0; Ivar = Ivar->getNextIvar()) ++IvarNo;
>> + return IvarNo;
>> +}
>> +
>> +ObjCInterfaceDecl *CGDebugInfo::getObjCInterfaceDecl(QualType Ty) {
>> + switch (Ty->getTypeClass()) {
>> + case Type::ObjCObjectPointer:
>> + return getObjCInterfaceDecl(cast<ObjCObjectPointerType>(Ty)->getPointeeType());
>> + case Type::ObjCInterface:
>> + return cast<ObjCInterfaceType>(Ty)->getDecl();
>> + default:
>> + return 0;
>> + }
>> +}
>> +
>> /// CreateTypeNode - Create a new debug type node.
>> llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
>> // Handle qualifiers, which recursively handles what they refer to.
>>
>> Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.h
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.h?rev=176584&r1=176583&r2=176584&view=diff
>> ==============================================================================
>> --- cfe/trunk/lib/CodeGen/CGDebugInfo.h (original)
>> +++ cfe/trunk/lib/CodeGen/CGDebugInfo.h Wed Mar 6 16:03:30 2013
>> @@ -32,6 +32,7 @@ namespace clang {
>> class CXXMethodDecl;
>> class VarDecl;
>> class ObjCInterfaceDecl;
>> + class ObjCIvarDecl;
>> class ClassTemplateSpecializationDecl;
>> class GlobalDecl;
>>
>> @@ -60,6 +61,11 @@ class CGDebugInfo {
>> /// TypeCache - Cache of previously constructed Types.
>> llvm::DenseMap<void *, llvm::WeakVH> TypeCache;
>>
>> + /// ObjCInterfaceCache - Cache of previously constructed interfaces
>> + /// which may change. Storing a pair of DIType and checksum.
>> + llvm::DenseMap<void *, std::pair<llvm::WeakVH, unsigned > >
>> + ObjCInterfaceCache;
>> +
>> /// CompleteTypeCache - Cache of previously constructed complete RecordTypes.
>> llvm::DenseMap<void *, llvm::WeakVH> CompletedTypeCache;
>>
>> @@ -89,6 +95,7 @@ class CGDebugInfo {
>> llvm::DenseMap<const Decl *, llvm::WeakVH> StaticDataMemberCache;
>>
>> /// Helper functions for getOrCreateType.
>> + unsigned Checksum(const ObjCInterfaceDecl *InterfaceDecl);
>> llvm::DIType CreateType(const BuiltinType *Ty);
>> llvm::DIType CreateType(const ComplexType *Ty);
>> llvm::DIType CreateQualifiedType(QualType Ty, llvm::DIFile F);
>> @@ -299,6 +306,10 @@ private:
>> /// CreateTypeNode - Create type metadata for a source language type.
>> llvm::DIType CreateTypeNode(QualType Ty, llvm::DIFile F);
>>
>> + /// getObjCInterfaceDecl - return the underlying ObjCInterfaceDecl
>> + /// if Ty is an ObjCInterface or a pointer to one.
>> + ObjCInterfaceDecl* getObjCInterfaceDecl(QualType Ty);
>> +
>> /// CreateLimitedTypeNode - Create type metadata for a source language
>> /// type, but only partial types for records.
>> llvm::DIType CreateLimitedTypeNode(QualType Ty, llvm::DIFile F);
>>
>> Added: cfe/trunk/test/CodeGenObjC/debug-info-ivars-extension.m
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/debug-info-ivars-extension.m?rev=176584&view=auto
>> ==============================================================================
>> --- cfe/trunk/test/CodeGenObjC/debug-info-ivars-extension.m (added)
>> +++ cfe/trunk/test/CodeGenObjC/debug-info-ivars-extension.m Wed Mar 6 16:03:30 2013
>> @@ -0,0 +1,28 @@
>> +// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -g %s -o - | FileCheck %s
>> +
>> +// Make sure we generate debug symbols for ivars added by a class extension.
>> +
>> + at interface I
>> +{
>> + @public int a;
>> +}
>> + at end
>> +
>> +void foo(I* pi) {
>> + // poking into pi for primary class ivars.
>> + int _a = pi->a;
>> +}
>> +
>> + at interface I()
>> +{
>> + @public int b;
>> +}
>> + at end
>> +
>> +void gorf (I* pg) {
>> + // poking into pg for ivars for class extension
>> + int _b = pg->b;
>> +}
>> +
>> +// 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]
>> +// 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]
>>
>> Added: cfe/trunk/test/CodeGenObjC/debug-info-ivars-indirect.m
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/debug-info-ivars-indirect.m?rev=176584&view=auto
>> ==============================================================================
>> --- cfe/trunk/test/CodeGenObjC/debug-info-ivars-indirect.m (added)
>> +++ cfe/trunk/test/CodeGenObjC/debug-info-ivars-indirect.m Wed Mar 6 16:03:30 2013
>> @@ -0,0 +1,32 @@
>> +// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -g %s -o - | FileCheck %s
>> +
>> +// Make sure we generate debug symbols for an indirectly referenced
>> +// extension to an interface.
>> +
>> + at interface I
>> +{
>> + @public int a;
>> +}
>> + at end
>> +
>> +void foo(I* pi) {
>> + int _a = pi->a;
>> +}
>> +
>> +// another layer of indirection
>> +struct S
>> +{
>> + I* i;
>> +};
>> +
>> + at interface I()
>> +{
>> + @public int b;
>> +}
>> + at end
>> +
>> +void gorf (struct S* s) {
>> + int _b = s->i->b;
>> +}
>> +
>> +// CHECK: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"b", metadata !{{[0-9]*}}, i32 24, i64 32, i64 32, i64 0, i32 0, metadata !{{[0-9]*}}, null} ; [ DW_TAG_member ] [b] [line 24, size 32, align 32, offset 0] [from int]
>>
>> Added: cfe/trunk/test/CodeGenObjC/debug-info-ivars-private.m
>> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjC/debug-info-ivars-private.m?rev=176584&view=auto
>> ==============================================================================
>> --- cfe/trunk/test/CodeGenObjC/debug-info-ivars-private.m (added)
>> +++ cfe/trunk/test/CodeGenObjC/debug-info-ivars-private.m Wed Mar 6 16:03:30 2013
>> @@ -0,0 +1,36 @@
>> +// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -emit-llvm -g %s -o - | FileCheck %s
>> +
>> +// Debug symbols for private ivars. This test ensures that we are
>> +// generating debug info for ivars added by the implementation.
>> +__attribute((objc_root_class)) @interface NSObject {
>> + id isa;
>> +}
>> + at end
>> +
>> + at protocol Protocol
>> + at end
>> +
>> + at interface Delegate : NSObject<Protocol> {
>> + @protected int foo;
>> +}
>> + at end
>> +
>> + at interface Delegate(NSObject)
>> +- (void)f;
>> + at end
>> +
>> + at implementation Delegate(NSObject)
>> +- (void)f { return; }
>> + at end
>> +
>> + at implementation Delegate {
>> + int bar;
>> +}
>> +
>> +- (void)g:(NSObject*) anObject {
>> + bar = foo;
>> +}
>> + at end
>> +
>> +// CHECK: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"foo", metadata !{{[0-9]*}}, i32 14, i64 32, i64 32, i64 0, i32 2, metadata !{{[0-9]*}}, null} ; [ DW_TAG_member ] [foo] [line 14, size 32, align 32, offset 0] [protected] [from int]
>> +// CHECK: metadata !{i32 {{[0-9]*}}, metadata !{{[0-9]*}}, metadata !"bar", metadata !{{[0-9]*}}, i32 27, i64 32, i64 32, i64 0, i32 1, metadata !{{[0-9]*}}, null} ; [ DW_TAG_member ] [bar] [line 27, size 32, align 32, offset 0] [private] [from int]
>>
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
More information about the cfe-commits
mailing list