Commit r191484 treated constexpr function templates as normal function
templates with respect to delaying their parsing. However, this is
unnecessarily restrictive because there is no compatibility concern with
constexpr, MSVC doesn't support it.
Instead, simply disable delayed template parsing for constexpr function
templates. This largely reverts the changes made in r191484 but keeps
it's unit test.
This fixes PR17661.
llvm-svn: 193274
Functions declared as constexpr must have their parsing delayed in
-fdelayed-template-parsing mode so as not to upset later template
instantiation.
N.B. My reading of the standard makes it seem like delayed template
parsing is at odds with constexpr. We may want to make refinements in
other places in clang to make constexpr play nicer with this feature.
This fixes PR17334.
llvm-svn: 191484
Sema::MergeFunctionDecl attempts merging two decls even if the old decl
is invalid. This can lead to interesting circumstances where we
successfully merge the decls but the result makes no sense.
Take the following for example:
template <typename T>
int main(void);
int main(void);
Sema will not consider these to be overloads of the same name because
main can't be overloaded, which means that this must be a redeclaration.
In this case the templated decl is compatible with the non-templated
decl allowing the Sema::CheckFunctionDeclaration machinery to move on
and do bizarre things like setting the previous decl of a non-templated
decl to a templated decl!
The way I see it, we should just bail from MergeFunctionDecl if the old
decl is invalid.
This fixes PR16531.
llvm-svn: 185779
The solution is to create a new ParseScope(Scope::TemplateParamScope) for each template scope that we want to reenter. (from the outmost to the innermost scope)
This fixes some errors when parsing MFC code with clang.
llvm-svn: 140344
Richard Smith