[cfe-commits] r121023 - in /cfe/trunk: include/clang/AST/Decl.h include/clang/AST/DeclBase.h include/clang/AST/Redeclarable.h lib/AST/Decl.cpp lib/Serialization/ASTReaderDecl.cpp
Douglas Gregor
dgregor at apple.com
Mon Dec 6 10:36:25 PST 2010
Author: dgregor
Date: Mon Dec 6 12:36:25 2010
New Revision: 121023
URL: http://llvm.org/viewvc/llvm-project?rev=121023&view=rev
Log:
Re-implement caching for the linkage calculation of declarations.
My previous attempt at solving the compile-time problem with many
redeclarations of the same entity cached both linkage and visibility,
while this patch only tackles linkage. There are several reasons for
this difference:
- Linkage is a language concept, and is evaluated many times during
semantic analysis and codegen, while visibility is only a
code-generation concept that is evaluated only once per (unique)
declaration. Hence, we *must* optimize linkage calculations but
don't need to optimize visibility computation.
- Once we know the linkage of a declaration, subsequent
redeclarations can't change that linkage. Hence, cache
invalidation is far simpler than for visibility, where a later
redeclaration can completely change the visibility.
- We have 3 spare bits in Decl to store the linkage cache, so the
cache doesn't increase the size of declarations. With the
visibility+linkage cache, NamedDecl got larger.
Modified:
cfe/trunk/include/clang/AST/Decl.h
cfe/trunk/include/clang/AST/DeclBase.h
cfe/trunk/include/clang/AST/Redeclarable.h
cfe/trunk/lib/AST/Decl.cpp
cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
Modified: cfe/trunk/include/clang/AST/Decl.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Decl.h?rev=121023&r1=121022&r2=121023&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Decl.h (original)
+++ cfe/trunk/include/clang/AST/Decl.h Mon Dec 6 12:36:25 2010
@@ -264,7 +264,7 @@
};
/// \brief Determine what kind of linkage this entity has.
- Linkage getLinkage() const { return getLinkageAndVisibility().linkage(); }
+ Linkage getLinkage() const;
/// \brief Determines the visibility of this entity.
Visibility getVisibility() const { return getLinkageAndVisibility().visibility(); }
@@ -272,6 +272,10 @@
/// \brief Determines the linkage and visibility of this entity.
LinkageInfo getLinkageAndVisibility() const;
+ /// \brief Clear the linkage cache in response to a change
+ /// to the declaration.
+ void ClearLinkageCache() { HasCachedLinkage = 0; }
+
/// \brief Looks through UsingDecls and ObjCCompatibleAliasDecls for
/// the underlying named decl.
NamedDecl *getUnderlyingDecl();
@@ -625,6 +629,8 @@
bool NRVOVariable : 1;
friend class StmtIteratorBase;
+ friend class ASTDeclReader;
+
protected:
VarDecl(Kind DK, DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
QualType T, TypeSourceInfo *TInfo, StorageClass SC,
@@ -660,10 +666,7 @@
StorageClass getStorageClassAsWritten() const {
return (StorageClass) SClassAsWritten;
}
- void setStorageClass(StorageClass SC) {
- assert(isLegalForVariable(SC));
- SClass = SC;
- }
+ void setStorageClass(StorageClass SC);
void setStorageClassAsWritten(StorageClass SC) {
assert(isLegalForVariable(SC));
SClassAsWritten = SC;
@@ -1478,10 +1481,7 @@
}
StorageClass getStorageClass() const { return StorageClass(SClass); }
- void setStorageClass(StorageClass SC) {
- assert(isLegalForFunction(SC));
- SClass = SC;
- }
+ void setStorageClass(StorageClass SC);
StorageClass getStorageClassAsWritten() const {
return StorageClass(SClassAsWritten);
@@ -2558,6 +2558,32 @@
return DB;
}
+template<typename decl_type>
+void Redeclarable<decl_type>::setPreviousDeclaration(decl_type *PrevDecl) {
+ // Note: This routine is implemented here because we need both NamedDecl
+ // and Redeclarable to be defined.
+
+ decl_type *First;
+
+ if (PrevDecl) {
+ // Point to previous. Make sure that this is actually the most recent
+ // redeclaration, or we can build invalid chains. If the most recent
+ // redeclaration is invalid, it won't be PrevDecl, but we want it anyway.
+ RedeclLink = PreviousDeclLink(llvm::cast<decl_type>(
+ PrevDecl->getMostRecentDeclaration()));
+ First = PrevDecl->getFirstDeclaration();
+ assert(First->RedeclLink.NextIsLatest() && "Expected first");
+ } else {
+ // Make this first.
+ First = static_cast<decl_type*>(this);
+ }
+
+ // First one will point to this one as latest.
+ First->RedeclLink = LatestDeclLink(static_cast<decl_type*>(this));
+ if (NamedDecl *ND = dyn_cast<NamedDecl>(static_cast<decl_type*>(this)))
+ ND->ClearLinkageCache();
+}
+
} // end namespace clang
#endif
Modified: cfe/trunk/include/clang/AST/DeclBase.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/DeclBase.h?rev=121023&r1=121022&r2=121023&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/DeclBase.h (original)
+++ cfe/trunk/include/clang/AST/DeclBase.h Mon Dec 6 12:36:25 2010
@@ -198,7 +198,7 @@
return DeclCtx.get<DeclContext*>();
}
- /// Loc - The location that this decl.
+ /// Loc - The location of this decl.
SourceLocation Loc;
/// DeclKind - This indicates which class this is.
@@ -231,8 +231,19 @@
unsigned ChangedAfterLoad : 1;
/// IdentifierNamespace - This specifies what IDNS_* namespace this lives in.
- unsigned IdentifierNamespace : 15;
+ unsigned IdentifierNamespace : 12;
+ /// \brief Whether the \c CachedLinkage field is active.
+ ///
+ /// This field is only valid for NamedDecls subclasses.
+ mutable unsigned HasCachedLinkage : 1;
+
+ /// \brief If \c HasCachedLinkage, the linkage of this declaration.
+ ///
+ /// This field is only valid for NamedDecls subclasses.
+ mutable unsigned CachedLinkage : 2;
+
+
private:
void CheckAccessDeclContext() const;
@@ -243,7 +254,9 @@
Loc(L), DeclKind(DK), InvalidDecl(0),
HasAttrs(false), Implicit(false), Used(false),
Access(AS_none), PCHLevel(0), ChangedAfterLoad(false),
- IdentifierNamespace(getIdentifierNamespaceForKind(DK)) {
+ IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
+ HasCachedLinkage(0)
+ {
if (Decl::CollectingStats()) add(DK);
}
@@ -251,7 +264,9 @@
: NextDeclInContext(0), DeclKind(DK), InvalidDecl(0),
HasAttrs(false), Implicit(false), Used(false),
Access(AS_none), PCHLevel(0), ChangedAfterLoad(false),
- IdentifierNamespace(getIdentifierNamespaceForKind(DK)) {
+ IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
+ HasCachedLinkage(0)
+ {
if (Decl::CollectingStats()) add(DK);
}
Modified: cfe/trunk/include/clang/AST/Redeclarable.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Redeclarable.h?rev=121023&r1=121022&r2=121023&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Redeclarable.h (original)
+++ cfe/trunk/include/clang/AST/Redeclarable.h Mon Dec 6 12:36:25 2010
@@ -109,25 +109,7 @@
/// \brief Set the previous declaration. If PrevDecl is NULL, set this as the
/// first and only declaration.
- void setPreviousDeclaration(decl_type *PrevDecl) {
- decl_type *First;
-
- if (PrevDecl) {
- // Point to previous. Make sure that this is actually the most recent
- // redeclaration, or we can build invalid chains. If the most recent
- // redeclaration is invalid, it won't be PrevDecl, but we want it anyway.
- RedeclLink = PreviousDeclLink(llvm::cast<decl_type>(
- PrevDecl->getMostRecentDeclaration()));
- First = PrevDecl->getFirstDeclaration();
- assert(First->RedeclLink.NextIsLatest() && "Expected first");
- } else {
- // Make this first.
- First = static_cast<decl_type*>(this);
- }
-
- // First one will point to this one as latest.
- First->RedeclLink = LatestDeclLink(static_cast<decl_type*>(this));
- }
+ void setPreviousDeclaration(decl_type *PrevDecl);
/// \brief Iterates through all the redeclarations of the same decl.
class redecl_iterator {
Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=121023&r1=121022&r2=121023&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Mon Dec 6 12:36:25 2010
@@ -85,6 +85,15 @@
ConsiderVisibilityAttributes(true) {
}
+ /// \brief Returns a set of flags that is only useful for computing the
+ /// linkage, not the visibility, of a declaration.
+ static LVFlags CreateOnlyDeclLinkage() {
+ LVFlags F;
+ F.ConsiderGlobalVisibility = false;
+ F.ConsiderVisibilityAttributes = false;
+ return F;
+ }
+
/// Returns a set of flags, otherwise based on these, which ignores
/// off all sources of visibility except template arguments.
LVFlags onlyTemplateVisibility() const {
@@ -119,10 +128,14 @@
return LV;
}
+/// getLVForDecl - Get the linkage and visibility for the given declaration.
+static LinkageInfo getLVForDecl(const NamedDecl *D, LVFlags F);
+
/// \brief Get the most restrictive linkage for the types and
/// declarations in the given template argument list.
static LVPair getLVForTemplateArgumentList(const TemplateArgument *Args,
- unsigned NumArgs) {
+ unsigned NumArgs,
+ LVFlags &F) {
LVPair LV(ExternalLinkage, DefaultVisibility);
for (unsigned I = 0; I != NumArgs; ++I) {
@@ -140,21 +153,24 @@
// The decl can validly be null as the representation of nullptr
// arguments, valid only in C++0x.
if (Decl *D = Args[I].getAsDecl()) {
- if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
- LV = merge(LV, ND->getLinkageAndVisibility());
- if (ValueDecl *VD = dyn_cast<ValueDecl>(D))
- LV = merge(LV, VD->getLinkageAndVisibility());
+ if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
+ LinkageInfo LI = getLVForDecl(ND, F);
+ LV = merge(LV, LVPair(LI.linkage(), LI.visibility()));
+ }
}
break;
case TemplateArgument::Template:
- if (TemplateDecl *Template = Args[I].getAsTemplate().getAsTemplateDecl())
- LV = merge(LV, Template->getLinkageAndVisibility());
+ if (TemplateDecl *Template = Args[I].getAsTemplate().getAsTemplateDecl()){
+ LinkageInfo LI = getLVForDecl(Template, F);
+ LV = merge(LV, LVPair(LI.linkage(), LI.visibility()));
+ }
break;
case TemplateArgument::Pack:
LV = merge(LV, getLVForTemplateArgumentList(Args[I].pack_begin(),
- Args[I].pack_size()));
+ Args[I].pack_size(),
+ F));
break;
}
}
@@ -163,14 +179,11 @@
}
static LVPair
-getLVForTemplateArgumentList(const TemplateArgumentList &TArgs) {
- return getLVForTemplateArgumentList(TArgs.data(), TArgs.size());
+getLVForTemplateArgumentList(const TemplateArgumentList &TArgs,
+ LVFlags &F) {
+ return getLVForTemplateArgumentList(TArgs.data(), TArgs.size(), F);
}
-/// getLVForDecl - Get the cached linkage and visibility for the given
-/// declaration.
-static LinkageInfo getLVForDecl(const NamedDecl *D, LVFlags F);
-
static LinkageInfo getLVForNamespaceScopeDecl(const NamedDecl *D, LVFlags F) {
assert(D->getDeclContext()->getRedeclContext()->isFileContext() &&
"Not a name having namespace scope");
@@ -296,7 +309,7 @@
// is visible, or if the prior declaration specifies no
// linkage, then the identifier has external linkage.
if (const VarDecl *PrevVar = Var->getPreviousDeclaration()) {
- LinkageInfo PrevLV = PrevVar->getLinkageAndVisibility();
+ LinkageInfo PrevLV = getLVForDecl(PrevVar, F);
if (PrevLV.linkage()) LV.setLinkage(PrevLV.linkage());
LV.mergeVisibility(PrevLV);
}
@@ -331,7 +344,7 @@
// is visible, or if the prior declaration specifies no
// linkage, then the identifier has external linkage.
if (const FunctionDecl *PrevFunc = Function->getPreviousDeclaration()) {
- LinkageInfo PrevLV = PrevFunc->getLinkageAndVisibility();
+ LinkageInfo PrevLV = getLVForDecl(PrevFunc, F);
if (PrevLV.linkage()) LV.setLinkage(PrevLV.linkage());
LV.mergeVisibility(PrevLV);
}
@@ -342,7 +355,7 @@
LV.merge(getLVForDecl(SpecInfo->getTemplate(),
F.onlyTemplateVisibility()));
const TemplateArgumentList &TemplateArgs = *SpecInfo->TemplateArguments;
- LV.merge(getLVForTemplateArgumentList(TemplateArgs));
+ LV.merge(getLVForTemplateArgumentList(TemplateArgs, F));
}
// - a named class (Clause 9), or an unnamed class defined in a
@@ -366,7 +379,7 @@
// The arguments at which the template was instantiated.
const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
- LV.merge(getLVForTemplateArgumentList(TemplateArgs));
+ LV.merge(getLVForTemplateArgumentList(TemplateArgs, F));
}
// Consider -fvisibility unless the type has C linkage.
@@ -377,8 +390,7 @@
// - an enumerator belonging to an enumeration with external linkage;
} else if (isa<EnumConstantDecl>(D)) {
- LinkageInfo EnumLV =
- cast<NamedDecl>(D->getDeclContext())->getLinkageAndVisibility();
+ LinkageInfo EnumLV = getLVForDecl(cast<NamedDecl>(D->getDeclContext()), F);
if (!isExternalLinkage(EnumLV.linkage()))
return LinkageInfo::none();
LV.merge(EnumLV);
@@ -464,7 +476,7 @@
// the template parameters and arguments.
if (FunctionTemplateSpecializationInfo *Spec
= MD->getTemplateSpecializationInfo()) {
- LV.merge(getLVForTemplateArgumentList(*Spec->TemplateArguments));
+ LV.merge(getLVForTemplateArgumentList(*Spec->TemplateArguments, F));
LV.merge(getLVForTemplateParameterList(
Spec->getTemplate()->getTemplateParameters()));
@@ -499,7 +511,7 @@
= dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
// Merge template argument/parameter information for member
// class template specializations.
- LV.merge(getLVForTemplateArgumentList(Spec->getTemplateArgs()));
+ LV.merge(getLVForTemplateArgumentList(Spec->getTemplateArgs(), F));
LV.merge(getLVForTemplateParameterList(
Spec->getSpecializedTemplate()->getTemplateParameters()));
}
@@ -525,8 +537,27 @@
return LV;
}
+Linkage NamedDecl::getLinkage() const {
+ if (HasCachedLinkage) {
+#ifndef NDEBUG
+ assert(CachedLinkage == getLVForDecl(this,
+ LVFlags::CreateOnlyDeclLinkage()).linkage());
+#endif
+ return Linkage(CachedLinkage);
+ }
+
+ CachedLinkage = getLVForDecl(this,
+ LVFlags::CreateOnlyDeclLinkage()).linkage();
+ HasCachedLinkage = 1;
+ return Linkage(CachedLinkage);
+}
+
LinkageInfo NamedDecl::getLinkageAndVisibility() const {
- return getLVForDecl(this, LVFlags());
+ LinkageInfo LI = getLVForDecl(this, LVFlags());
+ assert(!HasCachedLinkage || (CachedLinkage == LI.linkage()));
+ HasCachedLinkage = 1;
+ CachedLinkage = LI.linkage();
+ return LI;
}
static LinkageInfo getLVForDecl(const NamedDecl *D, LVFlags Flags) {
@@ -581,11 +612,13 @@
return LinkageInfo::uniqueExternal();
LinkageInfo LV;
- if (const VisibilityAttr *VA = GetExplicitVisibility(Function))
- LV.setVisibility(GetVisibilityFromAttr(VA));
-
+ if (Flags.ConsiderVisibilityAttributes) {
+ if (const VisibilityAttr *VA = GetExplicitVisibility(Function))
+ LV.setVisibility(GetVisibilityFromAttr(VA));
+ }
+
if (const FunctionDecl *Prev = Function->getPreviousDeclaration()) {
- LinkageInfo PrevLV = Prev->getLinkageAndVisibility();
+ LinkageInfo PrevLV = getLVForDecl(Prev, Flags);
if (PrevLV.linkage()) LV.setLinkage(PrevLV.linkage());
LV.mergeVisibility(PrevLV);
}
@@ -602,11 +635,13 @@
LinkageInfo LV;
if (Var->getStorageClass() == SC_PrivateExtern)
LV.setVisibility(HiddenVisibility);
- else if (const VisibilityAttr *VA = GetExplicitVisibility(Var))
- LV.setVisibility(GetVisibilityFromAttr(VA));
-
+ else if (Flags.ConsiderVisibilityAttributes) {
+ if (const VisibilityAttr *VA = GetExplicitVisibility(Var))
+ LV.setVisibility(GetVisibilityFromAttr(VA));
+ }
+
if (const VarDecl *Prev = Var->getPreviousDeclaration()) {
- LinkageInfo PrevLV = Prev->getLinkageAndVisibility();
+ LinkageInfo PrevLV = getLVForDecl(Prev, Flags);
if (PrevLV.linkage()) LV.setLinkage(PrevLV.linkage());
LV.mergeVisibility(PrevLV);
}
@@ -878,6 +913,14 @@
return new (C) VarDecl(Var, DC, L, Id, T, TInfo, S, SCAsWritten);
}
+void VarDecl::setStorageClass(StorageClass SC) {
+ assert(isLegalForVariable(SC));
+ if (getStorageClass() != SC)
+ ClearLinkageCache();
+
+ SClass = SC;
+}
+
SourceLocation VarDecl::getInnerLocStart() const {
SourceLocation Start = getTypeSpecStartLoc();
if (Start.isInvalid())
@@ -1277,6 +1320,14 @@
return getFirstDeclaration();
}
+void FunctionDecl::setStorageClass(StorageClass SC) {
+ assert(isLegalForFunction(SC));
+ if (getStorageClass() != SC)
+ ClearLinkageCache();
+
+ SClass = SC;
+}
+
/// \brief Returns a value indicating whether this function
/// corresponds to a builtin function.
///
@@ -1787,6 +1838,7 @@
TypedefDeclOrQualifier = TDD;
if (TypeForDecl)
TypeForDecl->ClearLinkageCache();
+ ClearLinkageCache();
}
void TagDecl::startDefinition() {
Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=121023&r1=121022&r2=121023&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Mon Dec 6 12:36:25 2010
@@ -384,7 +384,7 @@
// FunctionDecl's body is handled last at ASTDeclReader::Visit,
// after everything else is read.
- FD->setStorageClass((StorageClass)Record[Idx++]);
+ FD->SClass = (StorageClass)Record[Idx++];
FD->setStorageClassAsWritten((StorageClass)Record[Idx++]);
FD->setInlineSpecified(Record[Idx++]);
FD->setVirtualAsWritten(Record[Idx++]);
@@ -651,7 +651,7 @@
void ASTDeclReader::VisitVarDecl(VarDecl *VD) {
VisitDeclaratorDecl(VD);
VisitRedeclarable(VD);
- VD->setStorageClass((StorageClass)Record[Idx++]);
+ VD->SClass = (StorageClass)Record[Idx++];
VD->setStorageClassAsWritten((StorageClass)Record[Idx++]);
VD->setThreadSpecified(Record[Idx++]);
VD->setCXXDirectInitializer(Record[Idx++]);
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