[PATCH] D20337: [MC] Support symbolic expressions in assembly directives

[Joerg Sonnenberger via llvm-commits]

On Wed, May 25, 2016 at 12:12:03PM -0400, Nirav Davé wrote:
> Both clang and GCC expect such directives to have a # prefix for input.
> 
> That said, GCC isn't not consistent for output. For instance, my version of
> arm-linux-gnueabi-gcc emits this directive with the line comment prefix '@'
> (but still emits #APP for inline assembly) which the correspodning gas
> interprets as a line comment and not a line directive.

That's kind of my point. We don't create preprocessor assembler (foo.S), but
preprocessed assembler (foo.s). As such, emitting # unconditionally is a
bug and incompatible with system assemblers on platforms using a
different comment marker.

Joerg