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

foo has a constant address.

llvm-svn: 73321

preprocessor and initialize it early in clang-cc.  This
ensures that __has_builtin works in all modes, not just
when ASTContext is around.

llvm-svn: 73319

fixes a layering violation in lib/Basic/Targets.cpp.

llvm-svn: 73318

llvm-svn: 73317

llvm-svn: 73316

ExpectAndConsume instead of custom diag logic.  This gets us an
insertion hint and positions the ; at the end of the line 
instead of on the next token.  Before:

t.c:5:1: error: expected ';' after return statement
}
^

after:

t.c:4:11: error: expected ';' after return statement
  return 4
          ^
          ;

llvm-svn: 73315

diagnostics in some cases.

llvm-svn: 73314

the check for extern "c" system headers, which should prevent functiondecls
from being mangled.

llvm-svn: 73311

x86-32.  This is slightly messy, but I think it's consistent with gcc.

llvm-svn: 73306

Have CheckClassTemplatePartialSpecializationArgs take a TemplateArgumentListBuilder. No functionality change.

llvm-svn: 73297

of the elements.  Issue reported on cfe-dev by Mattias Holm.

llvm-svn: 73292

builtin preprocessor macro.  This appears to work with two caveats:
1) builtins are registered in -E mode, and 2) target-specific builtins
are unconditionally registered even if they aren't supported by the
target (e.g. SSE4 builtin when only SSE1 is enabled).

llvm-svn: 73289

I'm not completely sure this is the right way to fix this issue, but it seems 
reasonable, and it's consistent with the non-template code for this 
construct.

llvm-svn: 73285

If a CXXRecordDecl is a class template, the 'this' type should be the injected class name type. Fixes pr4383.

llvm-svn: 73284

llvm-svn: 73281

logic.

llvm-svn: 73279

obviously written by someone who didn't read C++ [temp.class.spec].

llvm-svn: 73276

llvm-svn: 73275

specialization cannot be deduced, produce a warning noting that the
affected class template partial specialization will never be used.

llvm-svn: 73274

always_inline from working.

llvm-svn: 73273

llvm-svn: 73272

llvm-svn: 73269

llvm-svn: 73268

llvm-svn: 73267

This fixes a source range problem reported by Olaf Krzikalla.

llvm-svn: 73266

llvm-svn: 73264

It looks like we've finished off matching of class template partial specializations; add comments and update the C++ status page

llvm-svn: 73263

llvm-svn: 73262

llvm-svn: 73261

llvm-svn: 73260

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

template partial specializations.

llvm-svn: 73254

llvm-svn: 73247

specialization do not have default arguments 
(C++ [temp.class.spec]p10). 

llvm-svn: 73245

llvm-svn: 73240

argument deduction failed. For example, given

  template<typename T> struct is_same<T, T> { ... };

template argument deduction will fail for is_same<int, float>, and now
reports enough information

Right now, we don't do anything with this extra information, but it
can be used for informative diagnostics that say, e.g., "template
argument deduction failed because T was deduced to 'int' in one
context and 'float' in another".

llvm-svn: 73237

It's an error to use a function declared in a class definition as a default argument before the function has been declared.

llvm-svn: 73234

llvm-svn: 73232

llvm-svn: 73218