Re: [PATCH] powerpc/math-emu: Fix building with clang

On Fri, Nov 02, 2018 at 10:38:36AM -0700, Nick Desaulniers wrote:

On Fri, Nov 2, 2018 at 10:34 AM Segher Boessenkool
[off-list ref] wrote:

quoted

On Fri, Nov 02, 2018 at 02:07:13PM +1030, Joel Stanley wrote:

quoted

  arch/powerpc/math-emu/fnmsub.c:46:2: error: invalid use of a cast in a
  inline asm context requiring an l-value: remove the cast or build with
  -fheinous-gnu-extensions

(It is spelled lvalue).

*All* of extended asm is a GNU extension, what is clang trying to say here?
Confused :-)

Isn't the result of a cast a temporary value?  Probably just need to
move the case out of the inline asm block to a separate statement.
Having the full backtrace should help.

The kernel's sfp-machine.h has casts in lvalues, inside macros.  All such
casts seem to be casts to compatible types (and if not, it probably won't
work with GCC either).


Segher