Allow deserialization of just the fields of a record, when we want to iterate over them,
instead of deserializing the complete declaration context of the record.
Iterating over the fields of a record is very common (e.g to determine the layout), unfortunately we needlessly deserialize every declaration
that the declaration context of the record contains; this can be bad for large C++ classes that contain a lot of methods.
Fix this by allow deserialization of just the fields when we want to iterate over them.
Progress for rdar://7260160.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116507 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index f455473..e822009 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1651,6 +1651,7 @@
HasFlexibleArrayMember = false;
AnonymousStructOrUnion = false;
HasObjectMember = false;
+ LoadedFieldsFromExternalStorage = false;
assert(classof(static_cast<Decl*>(this)) && "Invalid Kind!");
}
@@ -1673,6 +1674,13 @@
cast<RecordDecl>(getDeclContext())->getDeclName() == getDeclName();
}
+RecordDecl::field_iterator RecordDecl::field_begin() const {
+ if (hasExternalLexicalStorage() && !LoadedFieldsFromExternalStorage)
+ LoadFieldsFromExternalStorage();
+
+ return field_iterator(decl_iterator(FirstDecl));
+}
+
/// completeDefinition - Notes that the definition of this type is now
/// complete.
void RecordDecl::completeDefinition() {
@@ -1691,6 +1699,31 @@
return D;
}
+void RecordDecl::LoadFieldsFromExternalStorage() const {
+ ExternalASTSource *Source = getASTContext().getExternalSource();
+ assert(hasExternalLexicalStorage() && Source && "No external storage?");
+
+ // Notify that we have a RecordDecl doing some initialization.
+ ExternalASTSource::Deserializing TheFields(Source);
+
+ llvm::SmallVector<Decl*, 64> Decls;
+ if (Source->FindExternalLexicalDeclsBy<FieldDecl>(this, Decls))
+ return;
+
+#ifndef NDEBUG
+ // Check that all decls we got were FieldDecls.
+ for (unsigned i=0, e=Decls.size(); i != e; ++i)
+ assert(isa<FieldDecl>(Decls[i]));
+#endif
+
+ LoadedFieldsFromExternalStorage = true;
+
+ if (Decls.empty())
+ return;
+
+ llvm::tie(FirstDecl, LastDecl) = BuildDeclChain(Decls);
+}
+
//===----------------------------------------------------------------------===//
// BlockDecl Implementation
//===----------------------------------------------------------------------===//
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index ece9945..d60a067 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -599,6 +599,24 @@
}
}
+std::pair<Decl *, Decl *>
+DeclContext::BuildDeclChain(const llvm::SmallVectorImpl<Decl*> &Decls) {
+ // Build up a chain of declarations via the Decl::NextDeclInContext field.
+ Decl *FirstNewDecl = 0;
+ Decl *PrevDecl = 0;
+ for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
+ Decl *D = Decls[I];
+ if (PrevDecl)
+ PrevDecl->NextDeclInContext = D;
+ else
+ FirstNewDecl = D;
+
+ PrevDecl = D;
+ }
+
+ return std::make_pair(FirstNewDecl, PrevDecl);
+}
+
/// \brief Load the declarations within this lexical storage from an
/// external source.
void
@@ -619,26 +637,22 @@
if (Decls.empty())
return;
- // Resolve all of the declaration IDs into declarations, building up
- // a chain of declarations via the Decl::NextDeclInContext field.
- Decl *FirstNewDecl = 0;
- Decl *PrevDecl = 0;
- for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
- Decl *D = Decls[I];
- if (PrevDecl)
- PrevDecl->NextDeclInContext = D;
- else
- FirstNewDecl = D;
-
- PrevDecl = D;
- }
+ // We may have already loaded just the fields of this record, in which case
+ // don't add the decls, just replace the FirstDecl/LastDecl chain.
+ if (const RecordDecl *RD = dyn_cast<RecordDecl>(this))
+ if (RD->LoadedFieldsFromExternalStorage) {
+ llvm::tie(FirstDecl, LastDecl) = BuildDeclChain(Decls);
+ return;
+ }
// Splice the newly-read declarations into the beginning of the list
// of declarations.
- PrevDecl->NextDeclInContext = FirstDecl;
- FirstDecl = FirstNewDecl;
+ Decl *ExternalFirst, *ExternalLast;
+ llvm::tie(ExternalFirst, ExternalLast) = BuildDeclChain(Decls);
+ ExternalLast->NextDeclInContext = FirstDecl;
+ FirstDecl = ExternalFirst;
if (!LastDecl)
- LastDecl = PrevDecl;
+ LastDecl = ExternalLast;
}
DeclContext::lookup_result
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 9ee8183..23f2eaa 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -903,8 +903,8 @@
return true;
}
- Info.LexicalDecls = reinterpret_cast<const DeclID*>(Blob);
- Info.NumLexicalDecls = BlobLen / sizeof(DeclID);
+ Info.LexicalDecls = reinterpret_cast<const KindDeclIDPair*>(Blob);
+ Info.NumLexicalDecls = BlobLen / sizeof(KindDeclIDPair);
} else {
Info.LexicalDecls = 0;
Info.NumLexicalDecls = 0;
@@ -1778,8 +1778,8 @@
case TU_UPDATE_LEXICAL: {
DeclContextInfo Info = {
/* No visible information */ 0,
- reinterpret_cast<const DeclID *>(BlobStart),
- BlobLen / sizeof(DeclID)
+ reinterpret_cast<const KindDeclIDPair *>(BlobStart),
+ BlobLen / sizeof(KindDeclIDPair)
};
DeclContextOffsets[Context ? Context->getTranslationUnitDecl() : 0]
.push_back(Info);
@@ -3242,6 +3242,7 @@
}
bool ASTReader::FindExternalLexicalDecls(const DeclContext *DC,
+ bool (*isKindWeWant)(Decl::Kind),
llvm::SmallVectorImpl<Decl*> &Decls) {
assert(DC->hasExternalLexicalStorage() &&
"DeclContext has no lexical decls in storage");
@@ -3258,9 +3259,12 @@
continue;
// Load all of the declaration IDs
- for (const DeclID *ID = I->LexicalDecls, *IDE = ID + I->NumLexicalDecls;
- ID != IDE; ++ID) {
- Decl *D = GetDecl(*ID);
+ for (const KindDeclIDPair *ID = I->LexicalDecls,
+ *IDE = ID + I->NumLexicalDecls; ID != IDE; ++ID) {
+ if (isKindWeWant && !isKindWeWant((Decl::Kind)ID->first))
+ continue;
+
+ Decl *D = GetDecl(ID->second);
assert(D && "Null decl in lexical decls");
Decls.push_back(D);
}
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index eae47db..8dffe1a 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1474,14 +1474,15 @@
uint64_t Offset = Stream.GetCurrentBitNo();
RecordData Record;
Record.push_back(DECL_CONTEXT_LEXICAL);
- llvm::SmallVector<DeclID, 64> Decls;
+ llvm::SmallVector<KindDeclIDPair, 64> Decls;
for (DeclContext::decl_iterator D = DC->decls_begin(), DEnd = DC->decls_end();
D != DEnd; ++D)
- Decls.push_back(GetDeclRef(*D));
+ Decls.push_back(std::make_pair((*D)->getKind(), GetDeclRef(*D)));
++NumLexicalDeclContexts;
Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record,
- reinterpret_cast<char*>(Decls.data()), Decls.size() * sizeof(DeclID));
+ reinterpret_cast<char*>(Decls.data()),
+ Decls.size() * sizeof(KindDeclIDPair));
return Offset;
}
@@ -2471,12 +2472,12 @@
// We don't start with the translation unit, but with its decls that
// don't come from the chained PCH.
const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
- llvm::SmallVector<DeclID, 64> NewGlobalDecls;
+ llvm::SmallVector<KindDeclIDPair, 64> NewGlobalDecls;
for (DeclContext::decl_iterator I = TU->noload_decls_begin(),
E = TU->noload_decls_end();
I != E; ++I) {
if ((*I)->getPCHLevel() == 0)
- NewGlobalDecls.push_back(GetDeclRef(*I));
+ NewGlobalDecls.push_back(std::make_pair((*I)->getKind(), GetDeclRef(*I)));
else if ((*I)->isChangedSinceDeserialization())
(void)GetDeclRef(*I); // Make sure it's written, but don't record it.
}
@@ -2489,7 +2490,7 @@
Record.push_back(TU_UPDATE_LEXICAL);
Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
reinterpret_cast<const char*>(NewGlobalDecls.data()),
- NewGlobalDecls.size() * sizeof(DeclID));
+ NewGlobalDecls.size() * sizeof(KindDeclIDPair));
// And in C++, a visible updates block for the TU.
if (Context.getLangOptions().CPlusPlus) {
Abv = new llvm::BitCodeAbbrev();