Add partial semantic checking of template arguments that are meant for
non-type template parameters of pointer-to-object and
pointer-to-function type. The most fun part of this is the use of
overload resolution to pick a function from the set of overloaded
functions that comes in as a template argument.
Also, fixed two minor bugs in this area:
- We were allowing non-type template parameters of type pointer to
void.
- We weren't patching up an expression that refers to an overloaded
function set via "&f" properly.
We're still not performing complete checking of the expression to be
sure that it is referring to an object or function with external
linkage (C++ [temp.arg.nontype]p1).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64266 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 7aab4a5..c78d887 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -192,7 +192,9 @@
// -- integral or enumeration type,
if (T->isIntegralType() || T->isEnumeralType() ||
// -- pointer to object or pointer to function,
- T->isPointerType() ||
+ (T->isPointerType() &&
+ (T->getAsPointerType()->getPointeeType()->isObjectType() ||
+ T->getAsPointerType()->getPointeeType()->isFunctionType())) ||
// -- reference to object or reference to function,
T->isReferenceType() ||
// -- pointer to member.
@@ -844,9 +846,8 @@
// enumeration type, integral promotions (4.5) and integral
// conversions (4.7) are applied.
QualType ParamType = Param->getType();
+ QualType ArgType = Arg->getType();
if (ParamType->isIntegralType() || ParamType->isEnumeralType()) {
- QualType ArgType = Arg->getType();
-
// C++ [temp.arg.nontype]p1:
// A template-argument for a non-type, non-template
// template-parameter shall be one of:
@@ -894,6 +895,71 @@
return false;
}
+
+ if (const PointerType *ParamPtrType = ParamType->getAsPointerType()) {
+ // -- for a non-type template-parameter of type pointer to
+ // object, qualification conversions (4.4) and the
+ // array-to-pointer conversion (4.2) are applied.
+ if (ParamPtrType->getPointeeType()->isObjectType()) {
+ if (ArgType->isArrayType()) {
+ ArgType = Context.getArrayDecayedType(ArgType);
+ ImpCastExprToType(Arg, ArgType);
+ }
+
+ if (IsQualificationConversion(ArgType, ParamType)) {
+ ArgType = ParamType;
+ ImpCastExprToType(Arg, ParamType);
+ }
+
+ if (!hasSameUnqualifiedType(ArgType, ParamType)) {
+ // We can't perform this conversion.
+ Diag(Arg->getSourceRange().getBegin(),
+ diag::err_template_arg_not_convertible)
+ << Arg->getType() << Param->getType() << Arg->getSourceRange();
+ Diag(Param->getLocation(), diag::note_template_param_here);
+ return true;
+ }
+
+ // FIXME: Check the restrictions in p1!
+ return false;
+ }
+
+ assert(ParamPtrType->getPointeeType()->isFunctionType() &&
+ "Only function pointers remain");
+ // -- For a non-type template-parameter of type pointer to
+ // function, only the function-to-pointer conversion (4.3) is
+ // applied. If the template-argument represents a set of
+ // overloaded functions (or a pointer to such), the matching
+ // function is selected from the set (13.4).
+ if (hasSameUnqualifiedType(ArgType, ParamType)) {
+ // We don't have to do anything: the types already match.
+ }
+ else if (ArgType->isFunctionType()) {
+ ArgType = Context.getPointerType(ArgType);
+ ImpCastExprToType(Arg, ArgType);
+ } else if (FunctionDecl *Fn
+ = ResolveAddressOfOverloadedFunction(Arg, ParamType, true)) {
+ FixOverloadedFunctionReference(Arg, Fn);
+ ArgType = Arg->getType();
+ if (ArgType->isFunctionType()) {
+ ArgType = Context.getPointerType(Arg->getType());
+ ImpCastExprToType(Arg, ArgType);
+ }
+ }
+
+ if (!hasSameUnqualifiedType(ArgType, ParamType)) {
+ // We can't perform this conversion.
+ Diag(Arg->getSourceRange().getBegin(),
+ diag::err_template_arg_not_convertible)
+ << Arg->getType() << Param->getType() << Arg->getSourceRange();
+ Diag(Param->getLocation(), diag::note_template_param_here);
+ return true;
+ }
+
+ // FIXME: Check the restrictions in p1!
+ return false;
+ }
+
// FIXME: p5 has a lot more checks to perform!
return false;