Fix for template substitution with packs.
When we see a pack, and replace it with a template argument which is
also a pack, we want to use the pack pattern, not the expanded pack.
The caller should take care of expanding the pack afterwards.
Fixes PR16646.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186713 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index e86c742..3904daa 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -883,6 +883,16 @@
return true;
}
+static TemplateArgument
+getPackSubstitutedTemplateArgument(Sema &S, TemplateArgument Arg) {
+ assert(S.ArgumentPackSubstitutionIndex >= 0);
+ assert(S.ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
+ Arg = Arg.pack_begin()[S.ArgumentPackSubstitutionIndex];
+ if (Arg.isPackExpansion())
+ Arg = Arg.getPackExpansionPattern();
+ return Arg;
+}
+
Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) {
if (!D)
return 0;
@@ -902,10 +912,7 @@
if (TTP->isParameterPack()) {
assert(Arg.getKind() == TemplateArgument::Pack &&
"Missing argument pack");
-
- assert(getSema().ArgumentPackSubstitutionIndex >= 0);
- assert(getSema().ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
- Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
TemplateName Template = Arg.getAsTemplate();
@@ -950,8 +957,7 @@
if (getSema().ArgumentPackSubstitutionIndex == -1)
return 0;
- assert(getSema().ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
- Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
QualType T = Arg.getAsType();
@@ -1053,9 +1059,8 @@
// keep the entire argument pack.
return getSema().Context.getSubstTemplateTemplateParmPack(TTP, Arg);
}
-
- assert(getSema().ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
- Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
TemplateName Template = Arg.getAsTemplate();
@@ -1077,11 +1082,9 @@
if (getSema().ArgumentPackSubstitutionIndex == -1)
return Name;
- const TemplateArgument &ArgPack = SubstPack->getArgumentPack();
- assert(getSema().ArgumentPackSubstitutionIndex < (int)ArgPack.pack_size() &&
- "Pack substitution index out-of-range");
- return ArgPack.pack_begin()[getSema().ArgumentPackSubstitutionIndex]
- .getAsTemplate();
+ TemplateArgument Arg = SubstPack->getArgumentPack();
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
+ return Arg.getAsTemplate();
}
return inherited::TransformTemplateName(SS, Name, NameLoc, ObjectType,
@@ -1146,8 +1149,7 @@
Arg);
}
- assert(getSema().ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
- Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
return transformNonTypeTemplateParmRef(NTTP, E->getLocation(), Arg);
@@ -1160,14 +1162,6 @@
ExprResult result;
QualType type;
- // If the argument is a pack expansion, the parameter must actually be a
- // parameter pack, and we should substitute the pattern itself, producing
- // an expression which contains an unexpanded parameter pack.
- if (arg.isPackExpansion()) {
- assert(parm->isParameterPack() && "pack expansion for non-pack");
- arg = arg.getPackExpansionPattern();
- }
-
// The template argument itself might be an expression, in which
// case we just return that expression.
if (arg.getKind() == TemplateArgument::Expression) {
@@ -1233,12 +1227,9 @@
// We aren't expanding the parameter pack, so just return ourselves.
return getSema().Owned(E);
}
-
- const TemplateArgument &ArgPack = E->getArgumentPack();
- unsigned Index = (unsigned)getSema().ArgumentPackSubstitutionIndex;
- assert(Index < ArgPack.pack_size() && "Substitution index out-of-range");
-
- const TemplateArgument &Arg = ArgPack.pack_begin()[Index];
+
+ TemplateArgument Arg = E->getArgumentPack();
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
return transformNonTypeTemplateParmRef(E->getParameterPack(),
E->getParameterPackLocation(),
Arg);
@@ -1409,8 +1400,7 @@
return Result;
}
- assert(getSema().ArgumentPackSubstitutionIndex < (int)Arg.pack_size());
- Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
}
assert(Arg.getKind() == TemplateArgument::Type &&
@@ -1458,12 +1448,11 @@
NewTL.setNameLoc(TL.getNameLoc());
return TL.getType();
}
-
- const TemplateArgument &ArgPack = TL.getTypePtr()->getArgumentPack();
- unsigned Index = (unsigned)getSema().ArgumentPackSubstitutionIndex;
- assert(Index < ArgPack.pack_size() && "Substitution index out-of-range");
-
- QualType Result = ArgPack.pack_begin()[Index].getAsType();
+
+ TemplateArgument Arg = TL.getTypePtr()->getArgumentPack();
+ Arg = getPackSubstitutedTemplateArgument(getSema(), Arg);
+ QualType Result = Arg.getAsType();
+
Result = getSema().Context.getSubstTemplateTypeParmType(
TL.getTypePtr()->getReplacedParameter(),
Result);
diff --git a/test/SemaTemplate/alias-templates.cpp b/test/SemaTemplate/alias-templates.cpp
index 20ba6e0..eeb6b95 100644
--- a/test/SemaTemplate/alias-templates.cpp
+++ b/test/SemaTemplate/alias-templates.cpp
@@ -166,3 +166,26 @@
return 0;
}
}
+
+namespace PR16646 {
+ namespace test1 {
+ template <typename T> struct DefaultValue { const T value=0;};
+ template <typename ... Args> struct tuple {};
+ template <typename ... Args> using Zero = tuple<DefaultValue<Args> ...>;
+ template <typename ... Args> void f(const Zero<Args ...> &t);
+ void f() {
+ f(Zero<int,double,double>());
+ }
+ }
+
+ namespace test2 {
+ template<int x> struct X {};
+ template <template<int x> class temp> struct DefaultValue { const temp<0> value; };
+ template <typename ... Args> struct tuple {};
+ template <template<int x> class... Args> using Zero = tuple<DefaultValue<Args> ...>;
+ template <template<int x> class... Args> void f(const Zero<Args ...> &t);
+ void f() {
+ f(Zero<X,X,X>());
+ }
+ }
+}
