Before checking a template template argument against its corresponding
template template parameter, substitute any prior template arguments
into the template template parameter. This, for example, allows us to
properly check the template template argument for a class such as:
template<typename T, template<T Value> class X> struct Foo;
The actual implementation of this feature was trivial; most of the
change is dedicated to giving decent diagnostics when this
substitution goes horribly wrong. We now get a note like:
note: while substituting prior template arguments into template
template parameter 'X' [with T = float]
As part of this change, enabled some very pedantic checking when
comparing template template parameter lists, which shook out a bug in
our overly-eager checking of default arguments of template template
parameters. We now perform only minimal checking of such default
arguments when they are initially parsed.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86864 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 6c88995..b2e0751 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -2650,6 +2650,11 @@
std::string
getTemplateArgumentBindingsText(const TemplateParameterList *Params,
const TemplateArgumentList &Args);
+
+ std::string
+ getTemplateArgumentBindingsText(const TemplateParameterList *Params,
+ const TemplateArgument *Args,
+ unsigned NumArgs);
/// \brief Describes the result of template argument deduction.
///
@@ -2872,17 +2877,26 @@
/// partial specialization or a function template. The
/// Entity is either a ClassTemplatePartialSpecializationDecl or
/// a FunctionTemplateDecl.
- DeducedTemplateArgumentSubstitution
+ DeducedTemplateArgumentSubstitution,
+
+ /// We are substituting prior template arguments into a new
+ /// template parameter. The template parameter itself is either a
+ /// NonTypeTemplateParmDecl or a TemplateTemplateParmDecl.
+ PriorTemplateArgumentSubstitution
} Kind;
/// \brief The point of instantiation within the source code.
SourceLocation PointOfInstantiation;
+ /// \brief The template in which we are performing the instantiation,
+ /// for substitutions of prior template arguments.
+ TemplateDecl *Template;
+
/// \brief The entity that is being instantiated.
uintptr_t Entity;
- // \brief If this the instantiation of a default template
- // argument, the list of template arguments.
+ /// \brief The list of template arguments we are substituting, if they
+ /// are not part of the entity.
const TemplateArgument *TemplateArgs;
/// \brief The number of template arguments in TemplateArgs.
@@ -2893,8 +2907,9 @@
/// template instantiation.
SourceRange InstantiationRange;
- ActiveTemplateInstantiation() : Kind(TemplateInstantiation), Entity(0),
- TemplateArgs(0), NumTemplateArgs(0) {}
+ ActiveTemplateInstantiation()
+ : Kind(TemplateInstantiation), Template(0), Entity(0), TemplateArgs(0),
+ NumTemplateArgs(0) {}
friend bool operator==(const ActiveTemplateInstantiation &X,
const ActiveTemplateInstantiation &Y) {
@@ -2908,6 +2923,12 @@
case TemplateInstantiation:
return true;
+ case PriorTemplateArgumentSubstitution:
+ if (X.Template != Y.Template)
+ return false;
+
+ // Fall through
+
case DefaultTemplateArgumentInstantiation:
case ExplicitTemplateArgumentSubstitution:
case DeducedTemplateArgumentSubstitution:
@@ -2993,6 +3014,22 @@
unsigned NumTemplateArgs,
SourceRange InstantiationRange = SourceRange());
+ /// \brief Note that we are substituting prior template arguments into a
+ /// non-type or template template parameter.
+ InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
+ TemplateDecl *Template,
+ NonTypeTemplateParmDecl *Param,
+ const TemplateArgument *TemplateArgs,
+ unsigned NumTemplateArgs,
+ SourceRange InstantiationRange);
+
+ InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
+ TemplateDecl *Template,
+ TemplateTemplateParmDecl *Param,
+ const TemplateArgument *TemplateArgs,
+ unsigned NumTemplateArgs,
+ SourceRange InstantiationRange);
+
/// \brief Note that we have finished instantiating this template.
void Clear();
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index ce2ffc1..6770385 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -566,13 +566,21 @@
// A template-parameter shall not be used in its own default argument.
// FIXME: Implement this check! Needs a recursive walk over the types.
- // Check the well-formedness of the template argument.
+ // Check only that we have a template template argument. We don't want to
+ // try to check well-formedness now, because our template template parameter
+ // might have dependent types in its template parameters, which we wouldn't
+ // be able to match now.
+ //
+ // If none of the template template parameter's template arguments mention
+ // other template parameters, we could actually perform more checking here.
+ // However, it isn't worth doing.
TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
- if (CheckTemplateArgument(TemplateParm, DefaultArg)) {
- TemplateParm->setInvalidDecl();
+ if (DefaultArg.getArgument().getAsTemplate().isNull()) {
+ Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template)
+ << DefaultArg.getSourceRange();
return;
}
-
+
TemplateParm->setDefaultArgument(DefaultArg);
}
@@ -1739,8 +1747,8 @@
QualType NTTPType = NTTP->getType();
if (NTTPType->isDependentType()) {
// Do substitution on the type of the non-type template parameter.
- InstantiatingTemplate Inst(*this, TemplateLoc,
- Template, Converted.getFlatArguments(),
+ InstantiatingTemplate Inst(*this, TemplateLoc, Template,
+ NTTP, Converted.getFlatArguments(),
Converted.flatSize(),
SourceRange(TemplateLoc, RAngleLoc));
@@ -1850,6 +1858,30 @@
TemplateTemplateParmDecl *TempParm
= cast<TemplateTemplateParmDecl>(*Param);
+ // Substitute into the template parameter list of the template
+ // template parameter, since previously-supplied template arguments
+ // may appear within the template template parameter.
+ {
+ // Set up a template instantiation context.
+ LocalInstantiationScope Scope(*this);
+ InstantiatingTemplate Inst(*this, TemplateLoc, Template,
+ TempParm, Converted.getFlatArguments(),
+ Converted.flatSize(),
+ SourceRange(TemplateLoc, RAngleLoc));
+
+ TemplateArgumentList TemplateArgs(Context, Converted,
+ /*TakeArgs=*/false);
+ TempParm = cast_or_null<TemplateTemplateParmDecl>(
+ SubstDecl(TempParm, CurContext,
+ MultiLevelTemplateArgumentList(TemplateArgs)));
+ if (!TempParm) {
+ Invalid = true;
+ break;
+ }
+
+ // FIXME: TempParam is leaked.
+ }
+
switch (Arg.getArgument().getKind()) {
case TemplateArgument::Null:
assert(false && "Should never see a NULL template argument here");
@@ -2518,9 +2550,9 @@
NextDiag = diag::note_template_param_different_kind;
}
Diag((*NewParm)->getLocation(), NextDiag)
- << IsTemplateTemplateParm;
+ << IsTemplateTemplateParm;
Diag((*OldParm)->getLocation(), diag::note_template_prev_declaration)
- << IsTemplateTemplateParm;
+ << IsTemplateTemplateParm;
}
return false;
}
@@ -2528,21 +2560,6 @@
if (isa<TemplateTypeParmDecl>(*OldParm)) {
// Okay; all template type parameters are equivalent (since we
// know we're at the same index).
-#if 0
- // FIXME: Enable this code in debug mode *after* we properly go through
- // and "instantiate" the template parameter lists of template template
- // parameters. It's only after this instantiation that (1) any dependent
- // types within the template parameter list of the template template
- // parameter can be checked, and (2) the template type parameter depths
- // will match up.
- QualType OldParmType
- = Context.getTypeDeclType(cast<TemplateTypeParmDecl>(*OldParm));
- QualType NewParmType
- = Context.getTypeDeclType(cast<TemplateTypeParmDecl>(*NewParm));
- assert(Context.getCanonicalType(OldParmType) ==
- Context.getCanonicalType(NewParmType) &&
- "type parameter mismatch?");
-#endif
} else if (NonTypeTemplateParmDecl *OldNTTP
= dyn_cast<NonTypeTemplateParmDecl>(*OldParm)) {
// The types of non-type template parameters must agree.
@@ -2566,10 +2583,13 @@
}
return false;
}
+ assert(OldNTTP->getDepth() == NewNTTP->getDepth() &&
+ "Non-type template parameter depth mismatch");
+ assert(OldNTTP->getPosition() == NewNTTP->getPosition() &&
+ "Non-type template parameter position mismatch");
} else {
// The template parameter lists of template template
// parameters must agree.
- // FIXME: Could we perform a faster "type" comparison here?
assert(isa<TemplateTemplateParmDecl>(*OldParm) &&
"Only template template parameters handled here");
TemplateTemplateParmDecl *OldTTP
@@ -2582,6 +2602,11 @@
/*IsTemplateTemplateParm=*/true,
TemplateArgLoc))
return false;
+
+ assert(OldTTP->getDepth() == NewTTP->getDepth() &&
+ "Template template parameter depth mismatch");
+ assert(OldTTP->getPosition() == NewTTP->getPosition() &&
+ "Template template parameter position mismatch");
}
}
@@ -4594,12 +4619,24 @@
std::string
Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
const TemplateArgumentList &Args) {
+ // FIXME: For variadic templates, we'll need to get the structured list.
+ return getTemplateArgumentBindingsText(Params, Args.getFlatArgumentList(),
+ Args.flat_size());
+}
+
+std::string
+Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
+ const TemplateArgument *Args,
+ unsigned NumArgs) {
std::string Result;
- if (!Params || Params->size() == 0)
+ if (!Params || Params->size() == 0 || NumArgs == 0)
return Result;
for (unsigned I = 0, N = Params->size(); I != N; ++I) {
+ if (I >= NumArgs)
+ break;
+
if (I == 0)
Result += "[with ";
else
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 74f521e..b1e0481 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -190,26 +190,69 @@
}
Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef,
- SourceLocation PointOfInstantation,
+ SourceLocation PointOfInstantiation,
ParmVarDecl *Param,
const TemplateArgument *TemplateArgs,
unsigned NumTemplateArgs,
SourceRange InstantiationRange)
: SemaRef(SemaRef) {
- Invalid = CheckInstantiationDepth(PointOfInstantation, InstantiationRange);
+ Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
if (!Invalid) {
ActiveTemplateInstantiation Inst;
Inst.Kind
= ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation;
- Inst.PointOfInstantiation = PointOfInstantation;
+ Inst.PointOfInstantiation = PointOfInstantiation;
Inst.Entity = reinterpret_cast<uintptr_t>(Param);
Inst.TemplateArgs = TemplateArgs;
Inst.NumTemplateArgs = NumTemplateArgs;
Inst.InstantiationRange = InstantiationRange;
SemaRef.ActiveTemplateInstantiations.push_back(Inst);
- Invalid = false;
+ }
+}
+
+Sema::InstantiatingTemplate::
+InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
+ TemplateDecl *Template,
+ NonTypeTemplateParmDecl *Param,
+ const TemplateArgument *TemplateArgs,
+ unsigned NumTemplateArgs,
+ SourceRange InstantiationRange) : SemaRef(SemaRef) {
+ Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
+
+ if (!Invalid) {
+ ActiveTemplateInstantiation Inst;
+ Inst.Kind = ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution;
+ Inst.PointOfInstantiation = PointOfInstantiation;
+ Inst.Template = Template;
+ Inst.Entity = reinterpret_cast<uintptr_t>(Param);
+ Inst.TemplateArgs = TemplateArgs;
+ Inst.NumTemplateArgs = NumTemplateArgs;
+ Inst.InstantiationRange = InstantiationRange;
+ SemaRef.ActiveTemplateInstantiations.push_back(Inst);
+ }
+}
+
+Sema::InstantiatingTemplate::
+InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
+ TemplateDecl *Template,
+ TemplateTemplateParmDecl *Param,
+ const TemplateArgument *TemplateArgs,
+ unsigned NumTemplateArgs,
+ SourceRange InstantiationRange) : SemaRef(SemaRef) {
+ Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange);
+
+ if (!Invalid) {
+ ActiveTemplateInstantiation Inst;
+ Inst.Kind = ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution;
+ Inst.PointOfInstantiation = PointOfInstantiation;
+ Inst.Template = Template;
+ Inst.Entity = reinterpret_cast<uintptr_t>(Param);
+ Inst.TemplateArgs = TemplateArgs;
+ Inst.NumTemplateArgs = NumTemplateArgs;
+ Inst.InstantiationRange = InstantiationRange;
+ SemaRef.ActiveTemplateInstantiations.push_back(Inst);
}
}
@@ -331,6 +374,23 @@
break;
}
+ case ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution: {
+ NamedDecl *Parm = cast<NamedDecl>((Decl *)Active->Entity);
+ std::string Name;
+ if (!Parm->getName().empty())
+ Name = std::string(" '") + Parm->getName().str() + "'";
+
+ Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr),
+ diag::note_prior_template_arg_substitution)
+ << isa<TemplateTemplateParmDecl>(Parm)
+ << Name
+ << getTemplateArgumentBindingsText(
+ Active->Template->getTemplateParameters(),
+ Active->TemplateArgs,
+ Active->NumTemplateArgs)
+ << Active->InstantiationRange;
+ break;
+ }
}
}
}
@@ -351,8 +411,10 @@
return false;
case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation:
- // A default template argument instantiation may or may not be a
- // SFINAE context; look further up the stack.
+ case ActiveTemplateInstantiation::PriorTemplateArgumentSubstitution:
+ // A default template argument instantiation and substitution into
+ // template parameters with arguments for prior parameters may or may
+ // not be a SFINAE context; look further up the stack.
break;
case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution:
@@ -910,9 +972,9 @@
Member != MemberEnd; ++Member) {
Decl *NewMember = SubstDecl(*Member, Instantiation, TemplateArgs);
if (NewMember) {
- if (NewMember->isInvalidDecl())
+ if (NewMember->isInvalidDecl()) {
Invalid = true;
- else if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember))
+ } else if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember))
Fields.push_back(DeclPtrTy::make(Field));
else if (UsingDecl *UD = dyn_cast<UsingDecl>(NewMember))
Instantiation->addDecl(UD);
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index db797d6..ab71294 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1051,7 +1051,7 @@
PI != PE; ++PI) {
NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI));
Params.push_back(D);
- Invalid = Invalid || !D;
+ Invalid = Invalid || !D || D->isInvalidDecl();
}
// Clean up if we had an error.