Re: [patch] Do not leak location information during inlining

[Richard Biener <richard dot guenther at gmail dot com>]

On Wed, Jun 20, 2018 at 12:25 AM Eric Botcazou <ebotcazou@adacore.com> wrote:
>
> Hi,
>
> the Ada compiler uses small functions defined in its runtime to implement
> various intrinsic operations and it always inlines them, even at -O0.  But it
> doesn't want location information from the runtime files to appear in the
> debug info so it puts DECL_IGNORED_P on these functions.  final.c already
> knows not to generate location information for DECL_IGNORED_P functions when
> they are standalone but that's not the case for the inliner, i.e. it leaks
> location information from these functions where they are inlined.
>
> The attached patch is aimed at preventing this from happening by explicitly
> putting input_location on the inlined bodies, adjusting the locations on debug
> statements, as well as a few other adjustements.
>
> Tested (GCC and GDB) on x86-64/Linux, OK for the mainline?

There are fixes in this patch together with the new functionality -
can you split
those out?  I'm thinking of the copy_edges_for_bb hunks as well as
the expand_call_inline ones.

As for the real change I'd prefer to not repeat the DECL_INGORED_P checks
but instead have a id->remap_location flag and a id->call_location that
locations are remapped to (to not sprinkle more input_location uses
in the code).

Also in case the call location is UNKNOWN_LOCATION do we at least want
to use a location that has the encompaning BLOCK recorded?

Thanks,
Richard.

>
> 2018-06-19  Eric Botcazou  <ebotcazou@adacore.com>
>
>         * tree-inline.c (remap_location): New function extracted from...
>         (remap_gimple_stmt): Force input_location on the copy if DECL_IGNORED_P
>         is set on the source function.
>         (copy_edges_for_bb): Add ID parameter.  Copy locus and remap block of
>         edges if DECL_IGNORED_P isn't set on the source function.
>         (copy_phis_for_bb): ...here.  Do not copy locus of arguments if
>         DECL_IGNORED_P is set on the source function.
>         (maybe_move_debug_stmts_to_successors): Also reset the locus of the
>         debug statement when resetting its value.
>         (copy_cfg_body): Adjust call to copy_edges_for_bb.
>         (expand_call_inline): Copy the locus of the call onto the assignment of
>         the return value, if any.  Use local variable in more cases.
>
>
> 2018-06-19  Eric Botcazou  <ebotcazou@adacore.com>
>
>         * gnat.dg/debug15.adb: New test.
>
> --
> Eric Botcazou