Re: [PATCHv3] libopcodes: extend the styling within the i386 disassembler

[Jan Beulich <jbeulich@suse.com>]

On 27.05.2022 19:44, Andrew Burgess via Binutils wrote:
> @@ -9299,11 +9304,117 @@ get_sib (instr_info *ins, int sizeflag)
>  }
>  
>  /* Like oappend (below), but S is a string starting with '%'.
> -   In Intel syntax, the '%' is elided.  */
> +   In Intel syntax, the '%' is elided.  STYLE is used when displaying this
> +   part of the output in the disassembler.

As you're touching this comment anyway, can you add reference to
'$'? Or alternatively (that's what I was envisioning with the
comment on v2) drop this function altogether, doing what it does
separately in oappend_register() and oappend_immediate()?

> +   This function should not be used directly from the general disassembler
> +   code, instead the helpers oappend_register and oappend_immediate should
> +   be called as appropriate.  */
> +
> +static void
> +oappend_maybe_intel_with_style (instr_info *ins, const char *s,
> +				enum disassembler_style style)
> +{
> +  oappend_with_style (ins, s + ins->intel_syntax, style);
> +}
> +
> +/* Like oappend_maybe_intel_with_style above, but called when S is the
> +   name of a register.  */
> +
>  static void
> -oappend_maybe_intel (instr_info *ins, const char *s)
> +oappend_register (instr_info *ins, const char *s)
> +{
> +  oappend_maybe_intel_with_style (ins, s, dis_style_register);
> +}
> +
> +/* Like oappend_maybe_intel_with_style above, but called when S represents
> +   an immediate.  */
> +
> +static void
> +oappend_immediate (instr_info *ins, const char *s)
> +{
> +  oappend_maybe_intel_with_style (ins, s, dis_style_immediate);
> +}
> +
> +/* Wrap around a call to INS->info->fprintf_styled_func, printing FMT.
> +   STYLE is the default style to use in the fprintf_styled_func calls,
> +   however, FMT might include embedded style markers (see oappend_style),
> +   these embedded markers are not printed, but instead change the style
> +   used in the next fprintf_styled_func call.
> +
> +   Return non-zero to indicate the print call was a success.  */
> +
> +static int ATTRIBUTE_PRINTF_3
> +i386_dis_printf (instr_info *ins, enum disassembler_style style,
> +		 const char *fmt, ...)
>  {
> -  oappend (ins, s + ins->intel_syntax);
> +  va_list ap;
> +  enum disassembler_style curr_style = style;
> +  char *start, *curr;
> +  char staging_area[100];
> +  int res;
> +
> +  va_start (ap, fmt);
> +  res = vsnprintf (staging_area, sizeof (staging_area), fmt, ap);
> +  va_end (ap);
> +
> +  if (res < 0)
> +    return res;

Perhaps additionally assert no truncation?

Everything else looks good to me, thanks. One more question though
below.

> @@ -9404,8 +9515,7 @@ print_insn (bfd_vma pc, instr_info *ins)
>  
>    if (ins->address_mode == mode_64bit && sizeof (bfd_vma) < 8)
>      {
> -      (*ins->info->fprintf_styled_func) (ins->info->stream, dis_style_text,
> -					 _("64-bit address is disabled"));
> +      i386_dis_printf (ins, dis_style_text, _("64-bit address is disabled"));

Just wondering: Couldn't there be an "error" style?

Jan