On Mon, 23 Aug 2021, Jakub Jelinek wrote:
> Hi!
>
> The following patch emits DW_AT_location for global register variables
> already during early dwarf, since usually late_global_decl hook isn't even
> called for those, as nothing needs to be emitted for them.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2021-08-23 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/101905
> * dwarf2out.c (gen_variable_die): Add DW_AT_location for global
> register variables already during early_dwarf if possible.
>
> * gcc.dg/guality/pr101905.c: New test.
>
> --- gcc/dwarf2out.c.jj 2021-08-19 10:28:38.009074528 +0200
> +++ gcc/dwarf2out.c 2021-08-20 12:41:00.719743186 +0200
> @@ -24476,7 +24476,26 @@ gen_variable_die (tree decl, tree origin
> && DECL_RTL_SET_P (decl_or_origin))))
> {
> if (early_dwarf)
> - add_pubname (decl_or_origin, var_die);
> + {
> + add_pubname (decl_or_origin, var_die);
> + /* For global register variables, emit DW_AT_location if possible
> + already during early_dwarf, as late_global_decl won't be usually
> + called. */
> + if (DECL_HARD_REGISTER (decl_or_origin)
> + && TREE_STATIC (decl_or_origin)
> + && !decl_by_reference_p (decl_or_origin)
> + && !get_AT (var_die, DW_AT_location)
> + && !get_AT (var_die, DW_AT_const_value)
> + && DECL_RTL_SET_P (decl_or_origin)
> + && REG_P (DECL_RTL (decl_or_origin)))
> + {
> + dw_loc_descr_ref descr
> + = reg_loc_descriptor (DECL_RTL (decl_or_origin),
> + VAR_INIT_STATUS_INITIALIZED);
> + if (descr)
> + add_AT_loc (var_die, DW_AT_location, descr);
> + }
> + }
> else
> add_location_or_const_value_attribute (var_die, decl_or_origin,
> decl == NULL);
> --- gcc/testsuite/gcc.dg/guality/pr101905.c.jj 2021-08-20
> 12:56:18.287061723 +0200
> +++ gcc/testsuite/gcc.dg/guality/pr101905.c 2021-08-20 12:56:52.747585528
> +0200
> @@ -0,0 +1,15 @@
> +/* { dg-do run { target { { i?86-*-* x86_64-*-* } && lp64 } } } */
> +/* { dg-options "-g -ffixed-r15" } */
> +/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */
> +
> +register unsigned long long regVar asm ("r15");
> +
> +int
> +main()
> +{
> + regVar = 0xdeadbeefcafebabeULL;
> + asm ("nop" : "+r" (regVar));
> + asm volatile ("nop"); /* { dg-final { gdb-test . "regVar"
> "0xdeadbeefcafebabeULL" } } */
> + asm volatile ("nop" : : "r" (regVar));
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
