Re: [PATCH] debug/111080 - avoid outputting debug info for unused restrict qualified type

[Jason Merrill <jason@redhat.com>]

On 8/21/23 05:11, Richard Biener wrote:
> The following applies some maintainance with respect to type qualifiers
> and kinds added by later DWARF standards to prune_unused_types_walk.
> The particular case in the bug is not handling (thus marking required)
> all restrict qualified type DIEs.  I've found more DW_TAG_*_type that
> are unhandled, looked up the DWARF docs and added them as well based
> on common sense.
> 
> Bootstrapped and tested on x86_64-unknown-linux-gnu, OK?

OK.

> Thanks,
> Richard.
> 
> 	PR debug/111080
> 	* dwarf2out.cc (prune_unused_types_walk): Handle
> 	DW_TAG_restrict_type, DW_TAG_shared_type, DW_TAG_atomic_type,
> 	DW_TAG_immutable_type, DW_TAG_coarray_type, DW_TAG_unspecified_type
> 	and DW_TAG_dynamic_type as to only output them when referenced.
> 
> 	* gcc.dg/debug/dwarf2/pr111080.c: New testcase.
> ---
>   gcc/dwarf2out.cc                             |  7 +++++++
>   gcc/testsuite/gcc.dg/debug/dwarf2/pr111080.c | 18 ++++++++++++++++++
>   2 files changed, 25 insertions(+)
>   create mode 100644 gcc/testsuite/gcc.dg/debug/dwarf2/pr111080.c
> 
> diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc
> index fa0fe4c41bb..69018bde238 100644
> --- a/gcc/dwarf2out.cc
> +++ b/gcc/dwarf2out.cc
> @@ -30141,8 +30141,13 @@ prune_unused_types_walk (dw_die_ref die)
>       case DW_TAG_reference_type:
>       case DW_TAG_rvalue_reference_type:
>       case DW_TAG_volatile_type:
> +    case DW_TAG_restrict_type:
> +    case DW_TAG_shared_type:
> +    case DW_TAG_atomic_type:
> +    case DW_TAG_immutable_type:
>       case DW_TAG_typedef:
>       case DW_TAG_array_type:
> +    case DW_TAG_coarray_type:
>       case DW_TAG_friend:
>       case DW_TAG_enumeration_type:
>       case DW_TAG_subroutine_type:
> @@ -30151,6 +30156,8 @@ prune_unused_types_walk (dw_die_ref die)
>       case DW_TAG_subrange_type:
>       case DW_TAG_ptr_to_member_type:
>       case DW_TAG_file_type:
> +    case DW_TAG_unspecified_type:
> +    case DW_TAG_dynamic_type:
>         /* Type nodes are useful only when other DIEs reference them --- don't
>   	 mark them.  */
>         /* FALLTHROUGH */
> diff --git a/gcc/testsuite/gcc.dg/debug/dwarf2/pr111080.c b/gcc/testsuite/gcc.dg/debug/dwarf2/pr111080.c
> new file mode 100644
> index 00000000000..3949d7e7c64
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/debug/dwarf2/pr111080.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile } */
> +/* { dg-options "-save-temps -gdwarf-3 -dA" } */
> +
> +struct foo {
> +        int field_number_1;
> +        int field_number_2;
> +        int field_number_3;
> +        int field_number_4;
> +        int field_number_5;
> +};
> +
> +typedef int fun_t(struct foo *restrict);
> +
> +int main() {
> +        return 0;
> +}
> +
> +/* { dg-final { scan-assembler-not "DW_TAG_structure_type" } } */