[c++20] P0780R2: Support pack-expansion of init-captures.
This permits an init-capture to introduce a new pack:
template<typename ...T> auto x = [...a = T()] { /* a is a pack */ };
To support this, the mechanism for allowing ParmVarDecls to be packs has
been extended to support arbitrary local VarDecls.
llvm-svn: 361300
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index b8240d1..4480b0f 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4372,7 +4372,13 @@
llvm::FoldingSetNodeID ID;
PackExpansionType::Profile(ID, Pattern, NumExpansions);
- assert(Pattern->containsUnexpandedParameterPack() &&
+ // A deduced type can deduce to a pack, eg
+ // auto ...x = some_pack;
+ // That declaration isn't (yet) valid, but is created as part of building an
+ // init-capture pack:
+ // [...x = some_pack] {}
+ assert((Pattern->containsUnexpandedParameterPack() ||
+ Pattern->getContainedDeducedType()) &&
"Pack expansions must expand one or more parameter packs");
void *InsertPos = nullptr;
PackExpansionType *T
@@ -4872,19 +4878,20 @@
/// deduced to the given type, or to the canonical undeduced 'auto' type, or the
/// canonical deduced-but-dependent 'auto' type.
QualType ASTContext::getAutoType(QualType DeducedType, AutoTypeKeyword Keyword,
- bool IsDependent) const {
+ bool IsDependent, bool IsPack) const {
+ assert((!IsPack || IsDependent) && "only use IsPack for a dependent pack");
if (DeducedType.isNull() && Keyword == AutoTypeKeyword::Auto && !IsDependent)
return getAutoDeductType();
// Look in the folding set for an existing type.
void *InsertPos = nullptr;
llvm::FoldingSetNodeID ID;
- AutoType::Profile(ID, DeducedType, Keyword, IsDependent);
+ AutoType::Profile(ID, DeducedType, Keyword, IsDependent, IsPack);
if (AutoType *AT = AutoTypes.FindNodeOrInsertPos(ID, InsertPos))
return QualType(AT, 0);
auto *AT = new (*this, TypeAlignment)
- AutoType(DeducedType, Keyword, IsDependent);
+ AutoType(DeducedType, Keyword, IsDependent, IsPack);
Types.push_back(AT);
if (InsertPos)
AutoTypes.InsertNode(AT, InsertPos);
@@ -4946,7 +4953,7 @@
if (AutoDeductTy.isNull())
AutoDeductTy = QualType(
new (*this, TypeAlignment) AutoType(QualType(), AutoTypeKeyword::Auto,
- /*dependent*/false),
+ /*dependent*/false, /*pack*/false),
0);
return AutoDeductTy;
}
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 4e42dd7..bc0a5a4 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2397,6 +2397,10 @@
return Eval->IsICE;
}
+bool VarDecl::isParameterPack() const {
+ return isa<PackExpansionType>(getType());
+}
+
template<typename DeclT>
static DeclT *getDefinitionOrSelf(DeclT *D) {
assert(D);
@@ -2683,10 +2687,6 @@
!Init.isNull();
}
-bool ParmVarDecl::isParameterPack() const {
- return isa<PackExpansionType>(getType());
-}
-
void ParmVarDecl::setParameterIndexLarge(unsigned parameterIndex) {
getASTContext().setParameterIndex(this, parameterIndex);
ParmVarDeclBits.ParameterIndex = ParameterIndexSentinel;
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index f40896d..511925d 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -208,8 +208,8 @@
}
bool Decl::isParameterPack() const {
- if (const auto *Parm = dyn_cast<ParmVarDecl>(this))
- return Parm->isParameterPack();
+ if (const auto *Var = dyn_cast<VarDecl>(this))
+ return Var->isParameterPack();
return isTemplateParameterPack();
}
diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index 870190a..b30f785 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -1541,30 +1541,30 @@
return TemplateArgument(llvm::makeArrayRef(Arguments, NumArguments));
}
-FunctionParmPackExpr::FunctionParmPackExpr(QualType T, ParmVarDecl *ParamPack,
+FunctionParmPackExpr::FunctionParmPackExpr(QualType T, VarDecl *ParamPack,
SourceLocation NameLoc,
unsigned NumParams,
- ParmVarDecl *const *Params)
+ VarDecl *const *Params)
: Expr(FunctionParmPackExprClass, T, VK_LValue, OK_Ordinary, true, true,
true, true),
ParamPack(ParamPack), NameLoc(NameLoc), NumParameters(NumParams) {
if (Params)
std::uninitialized_copy(Params, Params + NumParams,
- getTrailingObjects<ParmVarDecl *>());
+ getTrailingObjects<VarDecl *>());
}
FunctionParmPackExpr *
FunctionParmPackExpr::Create(const ASTContext &Context, QualType T,
- ParmVarDecl *ParamPack, SourceLocation NameLoc,
- ArrayRef<ParmVarDecl *> Params) {
- return new (Context.Allocate(totalSizeToAlloc<ParmVarDecl *>(Params.size())))
+ VarDecl *ParamPack, SourceLocation NameLoc,
+ ArrayRef<VarDecl *> Params) {
+ return new (Context.Allocate(totalSizeToAlloc<VarDecl *>(Params.size())))
FunctionParmPackExpr(T, ParamPack, NameLoc, Params.size(), Params.data());
}
FunctionParmPackExpr *
FunctionParmPackExpr::CreateEmpty(const ASTContext &Context,
unsigned NumParams) {
- return new (Context.Allocate(totalSizeToAlloc<ParmVarDecl *>(NumParams)))
+ return new (Context.Allocate(totalSizeToAlloc<VarDecl *>(NumParams)))
FunctionParmPackExpr(QualType(), nullptr, SourceLocation(), 0, nullptr);
}
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 0ab4422..6207c62 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -538,6 +538,7 @@
unsigned knownArity);
void mangleCastExpression(const Expr *E, StringRef CastEncoding);
void mangleInitListElements(const InitListExpr *InitList);
+ void mangleDeclRefExpr(const NamedDecl *D);
void mangleExpression(const Expr *E, unsigned Arity = UnknownArity);
void mangleCXXCtorType(CXXCtorType T, const CXXRecordDecl *InheritedFrom);
void mangleCXXDtorType(CXXDtorType T);
@@ -3499,6 +3500,32 @@
mangleExpression(InitList->getInit(i));
}
+void CXXNameMangler::mangleDeclRefExpr(const NamedDecl *D) {
+ switch (D->getKind()) {
+ default:
+ // <expr-primary> ::= L <mangled-name> E # external name
+ Out << 'L';
+ mangle(D);
+ Out << 'E';
+ break;
+
+ case Decl::ParmVar:
+ mangleFunctionParam(cast<ParmVarDecl>(D));
+ break;
+
+ case Decl::EnumConstant: {
+ const EnumConstantDecl *ED = cast<EnumConstantDecl>(D);
+ mangleIntegerLiteral(ED->getType(), ED->getInitVal());
+ break;
+ }
+
+ case Decl::NonTypeTemplateParm:
+ const NonTypeTemplateParmDecl *PD = cast<NonTypeTemplateParmDecl>(D);
+ mangleTemplateParameter(PD->getIndex());
+ break;
+ }
+}
+
void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity) {
// <expression> ::= <unary operator-name> <expression>
// ::= <binary operator-name> <expression> <expression>
@@ -4089,37 +4116,9 @@
mangleExpression(cast<ParenExpr>(E)->getSubExpr(), Arity);
break;
- case Expr::DeclRefExprClass: {
- const NamedDecl *D = cast<DeclRefExpr>(E)->getDecl();
-
- switch (D->getKind()) {
- default:
- // <expr-primary> ::= L <mangled-name> E # external name
- Out << 'L';
- mangle(D);
- Out << 'E';
- break;
-
- case Decl::ParmVar:
- mangleFunctionParam(cast<ParmVarDecl>(D));
- break;
-
- case Decl::EnumConstant: {
- const EnumConstantDecl *ED = cast<EnumConstantDecl>(D);
- mangleIntegerLiteral(ED->getType(), ED->getInitVal());
- break;
- }
-
- case Decl::NonTypeTemplateParm: {
- const NonTypeTemplateParmDecl *PD = cast<NonTypeTemplateParmDecl>(D);
- mangleTemplateParameter(PD->getIndex());
- break;
- }
-
- }
-
+ case Expr::DeclRefExprClass:
+ mangleDeclRefExpr(cast<DeclRefExpr>(E)->getDecl());
break;
- }
case Expr::SubstNonTypeTemplateParmPackExprClass:
// FIXME: not clear how to mangle this!
@@ -4133,7 +4132,7 @@
// FIXME: not clear how to mangle this!
const FunctionParmPackExpr *FPPE = cast<FunctionParmPackExpr>(E);
Out << "v110_SUBSTPACK";
- mangleFunctionParam(FPPE->getParameterPack());
+ mangleDeclRefExpr(FPPE->getParameterPack());
break;
}
diff --git a/clang/lib/AST/JSONNodeDumper.cpp b/clang/lib/AST/JSONNodeDumper.cpp
index 8fdafd4..4b207b6 100644
--- a/clang/lib/AST/JSONNodeDumper.cpp
+++ b/clang/lib/AST/JSONNodeDumper.cpp
@@ -539,6 +539,7 @@
case VarDecl::ListInit: JOS.attribute("init", "list"); break;
}
}
+ attributeOnlyIfTrue("isParameterPack", VD->isParameterPack());
}
void JSONNodeDumper::VisitFieldDecl(const FieldDecl *FD) {
diff --git a/clang/lib/AST/TextNodeDumper.cpp b/clang/lib/AST/TextNodeDumper.cpp
index f287e96..c15713b 100644
--- a/clang/lib/AST/TextNodeDumper.cpp
+++ b/clang/lib/AST/TextNodeDumper.cpp
@@ -1366,6 +1366,8 @@
break;
}
}
+ if (D->isParameterPack())
+ OS << " pack";
}
void TextNodeDumper::VisitBindingDecl(const BindingDecl *D) {
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 101c518..e45b161 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1743,6 +1743,10 @@
Type *VisitAdjustedType(const AdjustedType *T) {
return Visit(T->getOriginalType());
}
+
+ Type *VisitPackExpansionType(const PackExpansionType *T) {
+ return Visit(T->getPattern());
+ }
};
} // namespace