<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Sat, Aug 22, 2015 at 1:16 AM, Vassil Vassilev <span dir="ltr"><<a href="mailto:vvasilev@cern.ch" target="_blank">vvasilev@cern.ch</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On 22/08/15 03:47, Richard Smith via cfe-commits wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Author: rsmith<br>
Date: Fri Aug 21 20:47:18 2015<br>
New Revision: 245779<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=245779&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=245779&view=rev</a><br>
Log:<br>
[modules] Rearrange how redeclaration chains are loaded, to remove a walk over<br>
all modules and reduce the number of declarations we load when loading a<br>
redeclaration chain.<br>
<br>
The new approach is:<br>
* when loading the first declaration of an entity within a module file, we<br>
first load all declarations of the entity that were imported into that<br>
module file, and then load all the other declarations of that entity from<br>
that module file and build a suitable decl chain from them<br>
* when loading any other declaration of an entity, we first load the first<br>
declaration from the same module file<br>
<br>
As before, we complete redecl chains through name lookup where necessary.<br>
<br>
To make this work, I also had to change the way that template specializations<br>
are stored -- it no longer suffices to track only canonical specializations; we<br>
now emit all "first local" declarations when emitting a list of specializations<br>
for a template.<br>
<br>
On one testcase with several thousand imported module files, this reduces the<br>
total runtime by 72%.<br>
</blockquote></span>
Very nice!<br>
Does it reduce the depth of the redecl chains when merging? I.e. does this mean memory footprint reduction too?</blockquote><div><br></div><div>I wouldn't expect any difference there, and in any case, I think this would only affect the stack depth, which is typically bounded anyway since we normally build modules on a separate thread.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Modified:<br>
cfe/trunk/include/clang/Serialization/ASTWriter.h<br>
cfe/trunk/lib/Serialization/ASTReader.cpp<br>
cfe/trunk/lib/Serialization/ASTReaderDecl.cpp<br>
cfe/trunk/lib/Serialization/ASTWriter.cpp<br>
cfe/trunk/lib/Serialization/ASTWriterDecl.cpp<br>
cfe/trunk/test/Modules/cxx-templates.cpp<br>
<br>
Modified: cfe/trunk/include/clang/Serialization/ASTWriter.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Serialization/ASTWriter.h?rev=245779&r1=245778&r2=245779&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Serialization/ASTWriter.h?rev=245779&r1=245778&r2=245779&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/include/clang/Serialization/ASTWriter.h (original)<br>
+++ cfe/trunk/include/clang/Serialization/ASTWriter.h Fri Aug 21 20:47:18 2015<br>
@@ -405,6 +405,10 @@ private:<br>
/// \brief The set of declarations that may have redeclaration chains that<br>
/// need to be serialized.<br>
llvm::SmallVector<const Decl *, 16> Redeclarations;<br>
+<br>
+ /// \brief A cache of the first local declaration for "interesting"<br>
+ /// redeclaration chains.<br>
+ llvm::DenseMap<const Decl *, const Decl *> FirstLocalDeclCache;<br>
/// \brief Statements that we've encountered while serializing a<br>
/// declaration or type.<br>
@@ -676,6 +680,10 @@ public:<br>
const ASTTemplateArgumentListInfo *ASTTemplArgList,<br>
RecordDataImpl &Record);<br>
+ /// \brief Find the first local declaration of a given local redeclarable<br>
+ /// decl.<br>
+ const Decl *getFirstLocalDecl(const Decl *D);<br>
+<br>
/// \brief Emit a reference to a declaration.<br>
void AddDeclRef(const Decl *D, RecordDataImpl &Record);<br>
@@ -857,12 +865,6 @@ public:<br>
void CompletedTagDefinition(const TagDecl *D) override;<br>
void AddedVisibleDecl(const DeclContext *DC, const Decl *D) override;<br>
void AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) override;<br>
- void AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,<br>
- const ClassTemplateSpecializationDecl *D) override;<br>
- void AddedCXXTemplateSpecialization(const VarTemplateDecl *TD,<br>
- const VarTemplateSpecializationDecl *D) override;<br>
- void AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,<br>
- const FunctionDecl *D) override;<br>
void ResolvedExceptionSpec(const FunctionDecl *FD) override;<br>
void DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) override;<br>
void ResolvedOperatorDelete(const CXXDestructorDecl *DD,<br>
<br>
Modified: cfe/trunk/lib/Serialization/ASTReader.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReader.cpp?rev=245779&r1=245778&r2=245779&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReader.cpp?rev=245779&r1=245778&r2=245779&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Serialization/ASTReader.cpp (original)<br>
+++ cfe/trunk/lib/Serialization/ASTReader.cpp Fri Aug 21 20:47:18 2015<br>
@@ -8123,11 +8123,8 @@ void ASTReader::finishPendingActions() {<br>
PendingIncompleteDeclChains.clear();<br>
// Load pending declaration chains.<br>
- for (unsigned I = 0; I != PendingDeclChains.size(); ++I) {<br>
- PendingDeclChainsKnown.erase(PendingDeclChains[I]);<br>
+ for (unsigned I = 0; I != PendingDeclChains.size(); ++I)<br>
loadPendingDeclChain(PendingDeclChains[I]);<br>
- }<br>
- assert(PendingDeclChainsKnown.empty());<br>
PendingDeclChains.clear();<br>
assert(RedeclsDeserialized.empty() && "some redecls not wired up");<br>
<br>
Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=245779&r1=245778&r2=245779&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=245779&r1=245778&r2=245779&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)<br>
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Fri Aug 21 20:47:18 2015<br>
@@ -147,12 +147,6 @@ namespace clang {<br>
}<br>
~RedeclarableResult() {<br>
- if (FirstID && Owning &&<br>
- isRedeclarableDeclKind(LoadedDecl->getKind())) {<br>
- auto Canon = Reader.GetDecl(FirstID)->getCanonicalDecl();<br>
- if (Reader.PendingDeclChainsKnown.insert(Canon).second)<br>
- Reader.PendingDeclChains.push_back(Canon);<br>
- }<br>
}<br>
/// \brief Note that a RedeclarableDecl is not actually redeclarable.<br>
@@ -2186,23 +2180,33 @@ ASTDeclReader::RedeclarableResult<br>
ASTDeclReader::VisitRedeclarable(Redeclarable<T> *D) {<br>
DeclID FirstDeclID = ReadDeclID(Record, Idx);<br>
Decl *MergeWith = nullptr;<br>
+<br>
bool IsKeyDecl = ThisDeclID == FirstDeclID;<br>
+ bool IsFirstLocalDecl = false;<br>
// 0 indicates that this declaration was the only declaration of its entity,<br>
// and is used for space optimization.<br>
if (FirstDeclID == 0) {<br>
FirstDeclID = ThisDeclID;<br>
IsKeyDecl = true;<br>
+ IsFirstLocalDecl = true;<br>
} else if (unsigned N = Record[Idx++]) {<br>
- IsKeyDecl = false;<br>
+ // This declaration was the first local declaration, but may have imported<br>
+ // other declarations.<br>
+ IsKeyDecl = N == 1;<br>
+ IsFirstLocalDecl = true;<br>
// We have some declarations that must be before us in our redeclaration<br>
// chain. Read them now, and remember that we ought to merge with one of<br>
// them.<br>
// FIXME: Provide a known merge target to the second and subsequent such<br>
// declaration.<br>
- for (unsigned I = 0; I != N; ++I)<br>
+ for (unsigned I = 0; I != N - 1; ++I)<br>
MergeWith = ReadDecl(Record, Idx/*, MergeWith*/);<br>
+ } else {<br>
+ // This declaration was not the first local declaration. Read the first<br>
+ // local declaration now, to trigger the import of other redeclarations.<br>
+ (void)ReadDecl(Record, Idx);<br>
}<br>
T *FirstDecl = cast_or_null<T>(Reader.GetDecl(FirstDeclID));<br>
@@ -2214,13 +2218,21 @@ ASTDeclReader::VisitRedeclarable(Redecla<br>
D->RedeclLink = Redeclarable<T>::PreviousDeclLink(FirstDecl);<br>
D->First = FirstDecl->getCanonicalDecl();<br>
}<br>
-<br>
+<br>
// Note that this declaration has been deserialized.<br>
- Reader.RedeclsDeserialized.insert(static_cast<T *>(D));<br>
-<br>
+ T *DAsT = static_cast<T*>(D);<br>
+ Reader.RedeclsDeserialized.insert(DAsT);<br>
+<br>
+ // Note that we need to load local redeclarations of this decl and build a<br>
+ // decl chain for them. This must happen *after* we perform the preloading<br>
+ // above; this ensures that the redeclaration chain is built in the correct<br>
+ // order.<br>
+ if (IsFirstLocalDecl)<br>
+ Reader.PendingDeclChains.push_back(DAsT);<br>
+<br>
// The result structure takes care to note that we need to load the<br>
// other declaration chains for this ID.<br>
- return RedeclarableResult(Reader, FirstDeclID, static_cast<T *>(D), MergeWith,<br>
+ return RedeclarableResult(Reader, FirstDeclID, DAsT, MergeWith,<br>
IsKeyDecl);<br>
}<br>
@@ -2330,11 +2342,8 @@ void ASTDeclReader::mergeRedeclarable(Re<br>
TemplatePatternID, Redecl.isKeyDecl());<br>
// If this declaration is a key declaration, make a note of that.<br>
- if (Redecl.isKeyDecl()) {<br>
+ if (Redecl.isKeyDecl())<br>
Reader.KeyDecls[ExistingCanon].push_back(Redecl.getFirstID());<br>
- if (Reader.PendingDeclChainsKnown.insert(ExistingCanon).second)<br>
- Reader.PendingDeclChains.push_back(ExistingCanon);<br>
- }<br>
}<br>
}<br>
@@ -3424,15 +3433,12 @@ namespace {<br>
ASTReader &Reader;<br>
SmallVectorImpl<DeclID> &SearchDecls;<br>
llvm::SmallPtrSetImpl<Decl *> &Deserialized;<br>
- GlobalDeclID CanonID;<br>
SmallVector<Decl *, 4> Chain;<br>
public:<br>
RedeclChainVisitor(ASTReader &Reader, SmallVectorImpl<DeclID> &SearchDecls,<br>
- llvm::SmallPtrSetImpl<Decl *> &Deserialized,<br>
- GlobalDeclID CanonID)<br>
- : Reader(Reader), SearchDecls(SearchDecls), Deserialized(Deserialized),<br>
- CanonID(CanonID) {<br>
+ llvm::SmallPtrSetImpl<Decl *> &Deserialized)<br>
+ : Reader(Reader), SearchDecls(SearchDecls), Deserialized(Deserialized) {<br>
assert(std::is_sorted(SearchDecls.begin(), SearchDecls.end()));<br>
}<br>
@@ -3518,10 +3524,10 @@ namespace {<br>
break;<br>
}<br>
- if (LocalSearchDeclID && LocalSearchDeclID != CanonID) {<br>
+ assert(LocalSearchDeclID);<br>
+ if (LocalSearchDeclID) {<br>
// If the search decl was from this module, add it to the chain.<br>
// Note, the chain is sorted from newest to oldest, so this goes last.<br>
- // We exclude the canonical declaration; it implicitly goes at the end.<br>
addToChain(Reader.GetDecl(LocalSearchDeclID));<br>
}<br>
@@ -3531,26 +3537,14 @@ namespace {<br>
};<br>
}<br>
-void ASTReader::loadPendingDeclChain(Decl *CanonDecl) {<br>
- // The decl might have been merged into something else after being added to<br>
- // our list. If it was, just skip it.<br>
- if (!CanonDecl->isCanonicalDecl())<br>
- return;<br>
-<br>
+void ASTReader::loadPendingDeclChain(Decl *FirstLocal) {<br>
// Determine the set of declaration IDs we'll be searching for.<br>
- SmallVector<DeclID, 16> SearchDecls;<br>
- GlobalDeclID CanonID = CanonDecl->getGlobalID();<br>
- if (CanonID)<br>
- SearchDecls.push_back(CanonDecl->getGlobalID()); // Always first.<br>
- KeyDeclsMap::iterator KeyPos = KeyDecls.find(CanonDecl);<br>
- if (KeyPos != KeyDecls.end())<br>
- SearchDecls.append(KeyPos->second.begin(), KeyPos->second.end());<br>
- llvm::array_pod_sort(SearchDecls.begin(), SearchDecls.end());<br>
+ SmallVector<DeclID, 1> SearchDecls;<br>
+ SearchDecls.push_back(FirstLocal->getGlobalID());<br>
// Build up the list of redeclarations.<br>
- RedeclChainVisitor Visitor(*this, SearchDecls, RedeclsDeserialized, CanonID);<br>
- ModuleMgr.visit(Visitor);<br>
- RedeclsDeserialized.erase(CanonDecl);<br>
+ RedeclChainVisitor Visitor(*this, SearchDecls, RedeclsDeserialized);<br>
+ Visitor(*getOwningModuleFile(FirstLocal));<br>
// Retrieve the chains.<br>
ArrayRef<Decl *> Chain = Visitor.getChain();<br>
@@ -3561,11 +3555,14 @@ void ASTReader::loadPendingDeclChain(Dec<br>
//<br>
// FIXME: We have three different dispatches on decl kind here; maybe<br>
// we should instead generate one loop per kind and dispatch up-front?<br>
+ Decl *CanonDecl = FirstLocal->getCanonicalDecl();<br>
Decl *MostRecent = ASTDeclReader::getMostRecentDecl(CanonDecl);<br>
if (!MostRecent)<br>
MostRecent = CanonDecl;<br>
for (unsigned I = 0, N = Chain.size(); I != N; ++I) {<br>
auto *D = Chain[N - I - 1];<br>
+ if (D == CanonDecl)<br>
+ continue;<br>
ASTDeclReader::attachPreviousDecl(*this, D, MostRecent, CanonDecl);<br>
MostRecent = D;<br>
}<br>
<br>
Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=245779&r1=245778&r2=245779&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=245779&r1=245778&r2=245779&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Serialization/ASTWriter.cpp (original)<br>
+++ cfe/trunk/lib/Serialization/ASTWriter.cpp Fri Aug 21 20:47:18 2015<br>
@@ -3799,41 +3799,39 @@ void ASTWriter::WriteRedeclarations() {<br>
SmallVector<serialization::LocalRedeclarationsInfo, 2> LocalRedeclsMap;<br>
for (unsigned I = 0, N = Redeclarations.size(); I != N; ++I) {<br>
- const Decl *Key = Redeclarations[I];<br>
- assert((Chain ? Chain->getKeyDeclaration(Key) == Key<br>
- : Key->isFirstDecl()) &&<br>
- "not the key declaration");<br>
+ const Decl *FirstLocal = Redeclarations[I];<br>
+ assert(!FirstLocal->isFromASTFile() &&<br>
+ (!FirstLocal->getPreviousDecl() ||<br>
+ FirstLocal->getPreviousDecl()->isFromASTFile() ||<br>
+ getDeclID(FirstLocal->getPreviousDecl()) < NUM_PREDEF_DECL_IDS) &&<br>
+ "not the first local declaration");<br>
+ assert(getDeclID(FirstLocal) >= NUM_PREDEF_DECL_IDS &&<br>
+ "should not have predefined decl as first decl");<br>
- const Decl *First = Key->getCanonicalDecl();<br>
- const Decl *MostRecent = First->getMostRecentDecl();<br>
-<br>
- assert((getDeclID(First) >= NUM_PREDEF_DECL_IDS || First == Key) &&<br>
- "should not have imported key decls for predefined decl");<br>
-<br>
- // If we only have a single declaration, there is no point in storing<br>
- // a redeclaration chain.<br>
- if (First == MostRecent)<br>
- continue;<br>
-<br>
unsigned Offset = LocalRedeclChains.size();<br>
unsigned Size = 0;<br>
LocalRedeclChains.push_back(0); // Placeholder for the size.<br>
// Collect the set of local redeclarations of this declaration, from newest<br>
// to oldest.<br>
- for (const Decl *Prev = MostRecent; Prev;<br>
- Prev = Prev->getPreviousDecl()) {<br>
- if (!Prev->isFromASTFile() && Prev != Key) {<br>
+ for (const Decl *Prev = FirstLocal->getMostRecentDecl(); Prev != FirstLocal;<br>
+ Prev = Prev->getPreviousDecl()) {<br>
+ if (!Prev->isFromASTFile()) {<br>
AddDeclRef(Prev, LocalRedeclChains);<br>
++Size;<br>
}<br>
}<br>
+ // If we only have a single local declaration, there is no point in storing<br>
+ // a redeclaration chain.<br>
+ if (LocalRedeclChains.size() == 1)<br>
+ continue;<br>
+<br>
LocalRedeclChains[Offset] = Size;<br>
// Add the mapping from the first ID from the AST to the set of local<br>
// declarations.<br>
- LocalRedeclarationsInfo Info = { getDeclID(Key), Offset };<br>
+ LocalRedeclarationsInfo Info = { getDeclID(FirstLocal), Offset };<br>
LocalRedeclsMap.push_back(Info);<br>
assert(N == Redeclarations.size() &&<br>
@@ -4145,8 +4143,6 @@ void ASTWriter::WriteASTCore(Sema &SemaR<br>
if (D) {<br>
assert(D->isCanonicalDecl() && "predefined decl is not canonical");<br>
DeclIDs[D] = ID;<br>
- if (D->getMostRecentDecl() != D)<br>
- Redeclarations.push_back(D);<br>
}<br>
};<br>
RegisterPredefDecl(Context.getTranslationUnitDecl(),<br>
@@ -5730,42 +5726,6 @@ void ASTWriter::AddedCXXImplicitMember(c<br>
DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));<br>
}<br>
-void ASTWriter::AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,<br>
- const ClassTemplateSpecializationDecl *D) {<br>
- // The specializations set is kept in the canonical template.<br>
- TD = TD->getCanonicalDecl();<br>
- if (!(!D->isFromASTFile() && TD->isFromASTFile()))<br>
- return; // Not a source specialization added to a template from PCH.<br>
-<br>
- assert(!WritingAST && "Already writing the AST!");<br>
- DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,<br>
- D));<br>
-}<br>
-<br>
-void ASTWriter::AddedCXXTemplateSpecialization(<br>
- const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {<br>
- // The specializations set is kept in the canonical template.<br>
- TD = TD->getCanonicalDecl();<br>
- if (!(!D->isFromASTFile() && TD->isFromASTFile()))<br>
- return; // Not a source specialization added to a template from PCH.<br>
-<br>
- assert(!WritingAST && "Already writing the AST!");<br>
- DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,<br>
- D));<br>
-}<br>
-<br>
-void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,<br>
- const FunctionDecl *D) {<br>
- // The specializations set is kept in the canonical template.<br>
- TD = TD->getCanonicalDecl();<br>
- if (!(!D->isFromASTFile() && TD->isFromASTFile()))<br>
- return; // Not a source specialization added to a template from PCH.<br>
-<br>
- assert(!WritingAST && "Already writing the AST!");<br>
- DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,<br>
- D));<br>
-}<br>
-<br>
void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {<br>
assert(!DoneWritingDeclsAndTypes && "Already done writing updates!");<br>
if (!Chain) return;<br>
<br>
Modified: cfe/trunk/lib/Serialization/ASTWriterDecl.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriterDecl.cpp?rev=245779&r1=245778&r2=245779&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriterDecl.cpp?rev=245779&r1=245778&r2=245779&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Serialization/ASTWriterDecl.cpp (original)<br>
+++ cfe/trunk/lib/Serialization/ASTWriterDecl.cpp Fri Aug 21 20:47:18 2015<br>
@@ -159,6 +159,19 @@ namespace clang {<br>
Writer.AddStmt(FD->getBody());<br>
}<br>
+ /// Add to the record the first declaration from each module file that<br>
+ /// provides a declaration of D. The intent is to provide a sufficient<br>
+ /// set such that reloading this set will load all current redeclarations.<br>
+ void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {<br>
+ llvm::MapVector<ModuleFile*, const Decl*> Firsts;<br>
+ // FIXME: We can skip entries that we know are implied by others.<br>
+ for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl())<br>
+ if (IncludeLocal || R->isFromASTFile())<br>
+ Firsts[Writer.Chain->getOwningModuleFile(R)] = R;<br>
+ for (const auto &F : Firsts)<br>
+ Writer.AddDeclRef(F.second, Record);<br>
+ }<br>
+<br>
/// Get the specialization decl from an entry in the specialization list.<br>
template <typename EntryType><br>
typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *<br>
@@ -194,20 +207,46 @@ namespace clang {<br>
if (auto *LS = Common->LazySpecializations)<br>
LazySpecializations = ArrayRef<DeclID>(LS + 1, LS + 1 + LS[0]);<br>
- Record.push_back(Specializations.size() +<br>
- PartialSpecializations.size() +<br>
- LazySpecializations.size());<br>
+ // Add a slot to the record for the number of specializations.<br>
+ unsigned I = Record.size();<br>
+ Record.push_back(0);<br>
+<br>
for (auto &Entry : Specializations) {<br>
auto *D = getSpecializationDecl(Entry);<br>
assert(D->isCanonicalDecl() && "non-canonical decl in set");<br>
- Writer.AddDeclRef(D, Record);<br>
+ AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);<br>
}<br>
for (auto &Entry : PartialSpecializations) {<br>
auto *D = getSpecializationDecl(Entry);<br>
assert(D->isCanonicalDecl() && "non-canonical decl in set");<br>
- Writer.AddDeclRef(D, Record);<br>
+ AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);<br>
}<br>
Record.append(LazySpecializations.begin(), LazySpecializations.end());<br>
+<br>
+ // Update the size entry we added earlier.<br>
+ Record[I] = Record.size() - I - 1;<br>
+ }<br>
+<br>
+ /// Ensure that this template specialization is associated with the specified<br>
+ /// template on reload.<br>
+ void RegisterTemplateSpecialization(const Decl *Template,<br>
+ const Decl *Specialization) {<br>
+ Template = Template->getCanonicalDecl();<br>
+<br>
+ // If the canonical template is local, we'll write out this specialization<br>
+ // when we emit it.<br>
+ // FIXME: We can do the same thing if there is any local declaration of<br>
+ // the template, to avoid emitting an update record.<br>
+ if (!Template->isFromASTFile())<br>
+ return;<br>
+<br>
+ // We only need to associate the first local declaration of the<br>
+ // specialization. The other declarations will get pulled in by it.<br>
+ if (Writer.getFirstLocalDecl(Specialization) != Specialization)<br>
+ return;<br>
+<br>
+ Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(<br>
+ UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));<br>
}<br>
};<br>
}<br>
@@ -479,6 +518,9 @@ void ASTDeclWriter::VisitFunctionDecl(Fu<br>
case FunctionDecl::TK_FunctionTemplateSpecialization: {<br>
FunctionTemplateSpecializationInfo *<br>
FTSInfo = D->getTemplateSpecializationInfo();<br>
+<br>
+ RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);<br>
+<br>
Writer.AddDeclRef(FTSInfo->getTemplate(), Record);<br>
Record.push_back(FTSInfo->getTemplateSpecializationKind());<br>
@@ -1249,6 +1291,8 @@ void ASTDeclWriter::VisitClassTemplateDe<br>
void ASTDeclWriter::VisitClassTemplateSpecializationDecl(<br>
ClassTemplateSpecializationDecl *D) {<br>
+ RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);<br>
+<br>
VisitCXXRecordDecl(D);<br>
llvm::PointerUnion<ClassTemplateDecl *,<br>
@@ -1308,6 +1352,8 @@ void ASTDeclWriter::VisitVarTemplateDecl<br>
void ASTDeclWriter::VisitVarTemplateSpecializationDecl(<br>
VarTemplateSpecializationDecl *D) {<br>
+ RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);<br>
+<br>
VisitVarDecl(D);<br>
llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *><br>
@@ -1478,48 +1524,61 @@ void ASTDeclWriter::VisitDeclContext(Dec<br>
Record.push_back(VisibleOffset);<br>
}<br>
-/// Determine whether D is the first declaration in its redeclaration chain that<br>
-/// is not from an AST file.<br>
-template <typename T><br>
-static bool isFirstLocalDecl(Redeclarable<T> *D) {<br>
- assert(D && !static_cast<T*>(D)->isFromASTFile());<br>
- do<br>
- D = D->getPreviousDecl();<br>
- while (D && static_cast<T*>(D)->isFromASTFile());<br>
- return !D;<br>
+/// \brief Is this a local declaration (that is, one that will be written to<br>
+/// our AST file)? This is the case for declarations that are neither imported<br>
+/// from another AST file nor predefined.<br>
+static bool isLocalDecl(ASTWriter &W, const Decl *D) {<br>
+ if (D->isFromASTFile())<br>
+ return false;<br>
+ return W.getDeclID(D) >= NUM_PREDEF_DECL_IDS;<br>
+}<br>
+<br>
+const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {<br>
+ assert(isLocalDecl(*this, D) && "expected a local declaration");<br>
+<br>
+ const Decl *Canon = D->getCanonicalDecl();<br>
+ if (isLocalDecl(*this, Canon))<br>
+ return Canon;<br>
+<br>
+ const Decl *&CacheEntry = FirstLocalDeclCache[Canon];<br>
+ if (CacheEntry)<br>
+ return CacheEntry;<br>
+<br>
+ for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())<br>
+ if (isLocalDecl(*this, Redecl))<br>
+ D = Redecl;<br>
+ return CacheEntry = D;<br>
}<br>
template <typename T><br>
void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {<br>
T *First = D->getFirstDecl();<br>
T *MostRecent = First->getMostRecentDecl();<br>
+ T *DAsT = static_cast<T *>(D);<br>
if (MostRecent != First) {<br>
- assert(isRedeclarableDeclKind(static_cast<T *>(D)->getKind()) &&<br>
+ assert(isRedeclarableDeclKind(DAsT->getKind()) &&<br>
"Not considered redeclarable?");<br>
Writer.AddDeclRef(First, Record);<br>
- // In a modules build, emit a list of all imported key declarations<br>
- // (excluding First, if it was imported), so that we can be sure that all<br>
- // redeclarations visible to this module are before D in the redecl chain.<br>
- unsigned I = Record.size();<br>
- Record.push_back(0);<br>
- if (Context.getLangOpts().Modules && Writer.Chain) {<br>
- if (isFirstLocalDecl(D)) {<br>
- Writer.Chain->forEachImportedKeyDecl(First, [&](const Decl *D) {<br>
- if (D != First)<br>
- Writer.AddDeclRef(D, Record);<br>
- });<br>
- Record[I] = Record.size() - I - 1;<br>
-<br>
- // Write a redeclaration chain, attached to the first key decl.<br>
- Writer.Redeclarations.push_back(Writer.Chain->getKeyDeclaration(First));<br>
- }<br>
- } else if (D == First || D->getPreviousDecl()->isFromASTFile()) {<br>
- assert(isFirstLocalDecl(D) && "imported decl after local decl");<br>
-<br>
- // Write a redeclaration chain attached to the first decl.<br>
- Writer.Redeclarations.push_back(First);<br>
+ // Write out a list of local redeclarations of this declaration if it's the<br>
+ // first local declaration in the chain.<br>
+ const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);<br>
+ if (DAsT == FirstLocal) {<br>
+ Writer.Redeclarations.push_back(DAsT);<br>
+<br>
+ // Emit a list of all imported first declarations so that we can be sure<br>
+ // that all redeclarations visible to this module are before D in the<br>
+ // redecl chain.<br>
+ unsigned I = Record.size();<br>
+ Record.push_back(0);<br>
+ if (Writer.Chain)<br>
+ AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);<br>
+ // This is the number of imported first declarations + 1.<br>
+ Record[I] = Record.size() - I;<br>
+ } else {<br>
+ Record.push_back(0);<br>
+ Writer.AddDeclRef(FirstLocal, Record);<br>
}<br>
// Make sure that we serialize both the previous and the most-recent<br>
<br>
Modified: cfe/trunk/test/Modules/cxx-templates.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/cxx-templates.cpp?rev=245779&r1=245778&r2=245779&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/cxx-templates.cpp?rev=245779&r1=245778&r2=245779&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/Modules/cxx-templates.cpp (original)<br>
+++ cfe/trunk/test/Modules/cxx-templates.cpp Fri Aug 21 20:47:18 2015<br>
@@ -187,10 +187,10 @@ namespace Std {<br>
// CHECK-DUMP: ClassTemplateDecl {{.*}} <{{.*[/\\]}}cxx-templates-common.h:1:1, {{.*}}> col:{{.*}} in cxx_templates_common SomeTemplate<br>
// CHECK-DUMP: ClassTemplateSpecializationDecl {{.*}} prev {{.*}} SomeTemplate<br>
-// CHECK-DUMP-NEXT: TemplateArgument type 'char [2]'<br>
-// CHECK-DUMP: ClassTemplateSpecializationDecl {{.*}} SomeTemplate definition<br>
-// CHECK-DUMP-NEXT: TemplateArgument type 'char [2]'<br>
-// CHECK-DUMP: ClassTemplateSpecializationDecl {{.*}} prev {{.*}} SomeTemplate<br>
// CHECK-DUMP-NEXT: TemplateArgument type 'char [1]'<br>
// CHECK-DUMP: ClassTemplateSpecializationDecl {{.*}} SomeTemplate definition<br>
// CHECK-DUMP-NEXT: TemplateArgument type 'char [1]'<br>
+// CHECK-DUMP: ClassTemplateSpecializationDecl {{.*}} prev {{.*}} SomeTemplate<br>
+// CHECK-DUMP-NEXT: TemplateArgument type 'char [2]'<br>
+// CHECK-DUMP: ClassTemplateSpecializationDecl {{.*}} SomeTemplate definition<br>
+// CHECK-DUMP-NEXT: TemplateArgument type 'char [2]'<br>
<br>
<br>
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</blockquote>
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