PowerPC64 ELFv1 -fpatchable-function-entry

[Segher Boessenkool]

On Fri, May 07, 2021 at 08:47:02AM -0500, will schmidt wrote:
> On Fri, 2021-05-07 at 12:19 +0930, Alan Modra via Gcc-patches wrote:
> > --- a/gcc/varasm.c
> > +++ b/gcc/varasm.c
> > @@ -6866,6 +6866,26 @@ default_elf_asm_named_section (const char
> > *name, unsigned int flags,
> >        *f = '\0';
> >      }
> > 
> > +  char func_label[256];
> > +  if (flags & SECTION_LINK_ORDER)
> > +    {
> > +      static int recur;
> > +      if (recur)
> > +	gcc_unreachable ();
> 
> Interesting..   Is there any anticipation of re-entry or parallel runs
> through this function that requires the recur lock/protection?

Not parallel runs :-)  But:

> > +      else
> > +	{
> > +	  ++recur;
> > +	  section *save_section = in_section;
> > +	  static int func_code_labelno;
> > +	  switch_to_section (function_section (decl));

This could in theory call us again.  That should not be a problem, if

> > +	  ++func_code_labelno;

(Please use postfix increments btw)

...this is done *before* the call, so that we get two different labels.


Segher