Implement support for C++ Substitution Failure Is Not An Error
(SFINAE), which says that errors that occur during template argument
deduction do *not* produce diagnostics and do not necessarily make a
program ill-formed. Instead, template argument deduction silently
fails. This is currently implemented for template argument deduction
during matching of class template partial specializations, although
the mechanism will also apply to template argument deduction for
function templates. The scheme is simple:
- If we are in a template argument deduction context, any diagnostic
that is considered a SFINAE error (or warning) will be
suppressed. The error will be propagated up the call stack via the
normal means.
- By default, all warnings and errors are SFINAE errors. Add the
NoSFINAE class to a diagnostic in the .td file to make it a hard
error (e.g., for access-control violations).
Note that, to make this fully work, every place in Sema that emits an
error *and then immediately recovers* will need to check
Sema::isSFINAEContext() to determine whether it must immediately
return an error rather than recovering.
llvm-svn: 73332
specialization's arguments are identical to the implicit template
arguments of the primary template. Typically, this is meant to be a
declaration/definition of the primary template, so we give that
advice.
llvm-svn: 73259
still aren't instantiating the definitions of class template members,
and core issues 275 and 259 will both affect the checking that we do
for explicit instantiations (but are not yet implemented).
llvm-svn: 71613
template class X<int>;
This also cleans up the propagation of template information through
declaration parsing, which is used to improve some diagnostics.
llvm-svn: 71608
- Support initialization of reference members; complain if any
reference members are left uninitialized.
- Use C++ copy-initialization for initializing each element (falls
back to constraint checking in C)
- Make sure we diagnose when one tries to provide an initializer
list for a non-aggregate.
- Don't complain about empty initializers in C++ (they are permitted)
- Unrelated but necessary: don't bother trying to convert the
decl-specifier-seq to a type when we're dealing with a C++
constructor, destructor, or conversion operator; it results in
spurious warnings.
llvm-svn: 63431
Fix a stupid mistake in UnwrapSimilarPointers that made any two member pointers compatible as long as the pointee was the same.
Make a few style corrections as suggested by Chris.
llvm-svn: 63215
Small cleanup in the handling of user-defined conversions.
Also, implement an optimization when constructing a call. We avoid
recomputing implicit conversion sequences and instead use those
conversion sequences that we computed as part of overload resolution.
llvm-svn: 62231
Duplicate-member checking within classes is still a little messy, and
anonymous unions are still completely broken in C. We'll need to unify
the handling of fields in C and C++ to make this code applicable in
both languages.
llvm-svn: 61878
Douglas Gregor