Re: [PATCH] sim: igen: do not reindent literal semantics output

[Andrew Burgess <aburgess@redhat.com>]

Mike Frysinger <vapier@gentoo.org> writes:

> When generating semantics.c from .igen source files, indenting the code
> makes it more readable, but confuses compiler diagnostics.  The latter
> is a bit more important than the former, so bias towards that.
>
> For example, with an introduced error, we can see w/gcc-13:

Makes sense.

Reviewed-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew

>
> (before this change)
>   CC       mn10300/semantics.o
> ../../../sim/mn10300/am33-2.igen: In function ‘semantic_dcpf_D1a’:
> ../../../sim/mn10300/am33-2.igen:11:5: error: ‘srcreg’ undeclared (first use in this function)
>    11 |   srcreg = translate_rreg (SD_, RN2);
>       |     ^~~~~~
>
> (with this change)
>   CC       mn10300/semantics.o
> ../../../sim/mn10300/am33-2.igen: In function ‘semantic_dcpf_D1a’:
> ../../../sim/mn10300/am33-2.igen:11:3: error: ‘srcreg’ undeclared (first use in this function)
>    11 |   srcreg = translate_rreg (SD_, RN2);
>       |   ^~~~~~
> ---
>  sim/igen/gen-semantics.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/sim/igen/gen-semantics.c b/sim/igen/gen-semantics.c
> index 54d83d61eccd..455702973e4b 100644
> --- a/sim/igen/gen-semantics.c
> +++ b/sim/igen/gen-semantics.c
> @@ -262,10 +262,17 @@ print_semantic_body (lf *file,
>      {
>        /* true code */
>        lf_printf (file, "{\n");
> -      lf_indent (file, +2);
> +      /* NB: Do not indent the code.  If the .igen source files cause a compiler
> +	 warning, the diagnostics can read the line from the original source,
> +	 but use column offsets from the generated files, causing columns to be
> +	 misaligned.  It makes the generated code slightly more difficult to
> +	 read, but accurate compiler diagnostics relative to the original source
> +	 are more important here.
> +      lf_indent (file, +2); */
>        lf_print__line_ref (file, instruction->code->line);
>        table_print_code (file, instruction->code);
> -      lf_indent (file, -2);
> +      /* NB: Disabled -- see above.
> +      lf_indent (file, -2); */
>        lf_printf (file, "}\n");
>        lf_print__internal_ref (file);
>      }
> -- 
> 2.43.0