Handle alignas(foo...) pack expansions.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175875 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index a204532..4628f3d 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2101,7 +2101,7 @@
/// [C++11] 'alignas' '(' type-id ...[opt] ')'
/// [C++11] 'alignas' '(' assignment-expression ...[opt] ')'
void Parser::ParseAlignmentSpecifier(ParsedAttributes &Attrs,
- SourceLocation *endLoc) {
+ SourceLocation *EndLoc) {
assert((Tok.is(tok::kw_alignas) || Tok.is(tok::kw__Alignas)) &&
"Not an alignment-specifier!");
@@ -2120,19 +2120,13 @@
}
T.consumeClose();
- if (endLoc)
- *endLoc = T.getCloseLocation();
-
- // FIXME: Handle pack-expansions here.
- if (EllipsisLoc.isValid()) {
- Diag(EllipsisLoc, diag::err_alignas_pack_exp_unsupported);
- return;
- }
+ if (EndLoc)
+ *EndLoc = T.getCloseLocation();
ExprVector ArgExprs;
ArgExprs.push_back(ArgExpr.release());
Attrs.addNew(KWName, KWLoc, 0, KWLoc, 0, T.getOpenLocation(),
- ArgExprs.data(), 1, AttributeList::AS_Keyword);
+ ArgExprs.data(), 1, AttributeList::AS_Keyword, EllipsisLoc);
}
/// ParseDeclarationSpecifiers
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 1142e0d..8e2bac6 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -3315,27 +3315,28 @@
return;
}
- // FIXME: The C++11 version of this attribute should error out when it is
- // used to specify a weaker alignment, rather than being silently
- // ignored. This constraint cannot be applied until we have seen
- // all the attributes which apply to the variable.
-
if (Attr.getNumArgs() == 0) {
D->addAttr(::new (S.Context) AlignedAttr(Attr.getRange(), S.Context,
true, 0, Attr.getAttributeSpellingListIndex()));
return;
}
- S.AddAlignedAttr(Attr.getRange(), D, Attr.getArg(0),
- Attr.getAttributeSpellingListIndex());
+ Expr *E = Attr.getArg(0);
+ if (Attr.isPackExpansion() && !E->containsUnexpandedParameterPack()) {
+ S.Diag(Attr.getEllipsisLoc(),
+ diag::err_pack_expansion_without_parameter_packs);
+ return;
+ }
+
+ if (!Attr.isPackExpansion() && S.DiagnoseUnexpandedParameterPack(E))
+ return;
+
+ S.AddAlignedAttr(Attr.getRange(), D, E, Attr.getAttributeSpellingListIndex(),
+ Attr.isPackExpansion());
}
void Sema::AddAlignedAttr(SourceRange AttrRange, Decl *D, Expr *E,
- unsigned SpellingListIndex) {
- // FIXME: Handle pack-expansions here.
- if (DiagnoseUnexpandedParameterPack(E))
- return;
-
+ unsigned SpellingListIndex, bool IsPackExpansion) {
AlignedAttr TmpAttr(AttrRange, Context, true, E, SpellingListIndex);
SourceLocation AttrLoc = AttrRange.getBegin();
@@ -3379,7 +3380,9 @@
if (E->isTypeDependent() || E->isValueDependent()) {
// Save dependent expressions in the AST to be instantiated.
- D->addAttr(::new (Context) AlignedAttr(TmpAttr));
+ AlignedAttr *AA = ::new (Context) AlignedAttr(TmpAttr);
+ AA->setPackExpansion(IsPackExpansion);
+ D->addAttr(AA);
return;
}
@@ -3414,17 +3417,20 @@
}
}
- D->addAttr(::new (Context) AlignedAttr(AttrRange, Context, true,
- ICE.take(), SpellingListIndex));
+ AlignedAttr *AA = ::new (Context) AlignedAttr(AttrRange, Context, true,
+ ICE.take(), SpellingListIndex);
+ AA->setPackExpansion(IsPackExpansion);
+ D->addAttr(AA);
}
void Sema::AddAlignedAttr(SourceRange AttrRange, Decl *D, TypeSourceInfo *TS,
- unsigned SpellingListIndex) {
+ unsigned SpellingListIndex, bool IsPackExpansion) {
// FIXME: Cache the number on the Attr object if non-dependent?
// FIXME: Perform checking of type validity
- D->addAttr(::new (Context) AlignedAttr(AttrRange, Context, false, TS,
- SpellingListIndex));
- return;
+ AlignedAttr *AA = ::new (Context) AlignedAttr(AttrRange, Context, false, TS,
+ SpellingListIndex);
+ AA->setPackExpansion(IsPackExpansion);
+ D->addAttr(AA);
}
void Sema::CheckAlignasUnderalignment(Decl *D) {
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index defa968..a829070 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -60,6 +60,64 @@
// Include attribute instantiation code.
#include "clang/Sema/AttrTemplateInstantiate.inc"
+static void instantiateDependentAlignedAttr(
+ Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
+ const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
+ if (Aligned->isAlignmentExpr()) {
+ // The alignment expression is a constant expression.
+ EnterExpressionEvaluationContext Unevaluated(S, Sema::ConstantEvaluated);
+ ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
+ if (!Result.isInvalid())
+ S.AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>(),
+ Aligned->getSpellingListIndex(), IsPackExpansion);
+ } else {
+ TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
+ TemplateArgs, Aligned->getLocation(),
+ DeclarationName());
+ if (Result)
+ S.AddAlignedAttr(Aligned->getLocation(), New, Result,
+ Aligned->getSpellingListIndex(), IsPackExpansion);
+ }
+}
+
+static void instantiateDependentAlignedAttr(
+ Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
+ const AlignedAttr *Aligned, Decl *New) {
+ if (!Aligned->isPackExpansion()) {
+ instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
+ return;
+ }
+
+ SmallVector<UnexpandedParameterPack, 2> Unexpanded;
+ if (Aligned->isAlignmentExpr())
+ S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
+ Unexpanded);
+ else
+ S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
+ Unexpanded);
+ assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
+
+ // Determine whether we can expand this attribute pack yet.
+ bool Expand = true, RetainExpansion = false;
+ Optional<unsigned> NumExpansions;
+ // FIXME: Use the actual location of the ellipsis.
+ SourceLocation EllipsisLoc = Aligned->getLocation();
+ if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
+ Unexpanded, TemplateArgs, Expand,
+ RetainExpansion, NumExpansions))
+ return;
+
+ if (!Expand) {
+ Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
+ instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
+ } else {
+ for (unsigned I = 0; I != *NumExpansions; ++I) {
+ Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, I);
+ instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
+ }
+ }
+}
+
void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
const Decl *Tmpl, Decl *New,
LateInstantiatedAttrVec *LateAttrs,
@@ -69,31 +127,13 @@
const Attr *TmplAttr = *i;
// FIXME: This should be generalized to more than just the AlignedAttr.
- if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) {
- if (Aligned->isAlignmentDependent()) {
- if (Aligned->isAlignmentExpr()) {
- // The alignment expression is a constant expression.
- EnterExpressionEvaluationContext Unevaluated(*this,
- Sema::ConstantEvaluated);
-
- ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(),
- TemplateArgs);
- if (!Result.isInvalid())
- AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>(),
- Aligned->getSpellingListIndex());
- } else {
- TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(),
- TemplateArgs,
- Aligned->getLocation(),
- DeclarationName());
- if (Result)
- AddAlignedAttr(Aligned->getLocation(), New, Result,
- Aligned->getSpellingListIndex());
- }
- continue;
- }
+ const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
+ if (Aligned && Aligned->isAlignmentDependent()) {
+ instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
+ continue;
}
+ assert(!TmplAttr->isPackExpansion());
if (TmplAttr->isLateParsed() && LateAttrs) {
// Late parsed attributes must be instantiated and attached after the
// enclosing class has been instantiated. See Sema::InstantiateClass.