[PING][PATCH][gdb/testsuite] Fix gdb.guile/scm-type.exp with gcc 4.8

[Tom de Vries via Gdb-patches <gdb-patches@sourceware.org>]

On 9/15/21 3:25 PM, Tom de Vries wrote:
> Hi,
> 
> With gcc 7.5.0, I get:
> ...
> (gdb) guile (print (type-range (field-type (type-field (value-type \
>   (value-dereference f)) "items"))))^M
> = (0 0)^M
> (gdb) PASS: gdb.guile/scm-type.exp: lang_cpp: test_range: \
>   on flexible array member: $cmd
> ...
> but with gcc 4.8.5, I get instead:
> ...
> (gdb) guile (print (type-range (field-type (type-field (value-type \
>   (value-dereference f)) "items"))))^M
> = (0 -1)^M
> (gdb) FAIL: gdb.guile/scm-type.exp: lang_cpp: test_range: \
>   on flexible array member: $cmd
> ...
> 
> There's a difference in debug info.  With gcc 4.8.5, we have:
> ...
>  <2><224>: Abbrev Number: 15 (DW_TAG_member)
>     <225>   DW_AT_name        : items
>     <22b>   DW_AT_type        : <0x231>
>  <1><231>: Abbrev Number: 4 (DW_TAG_array_type)
>     <232>   DW_AT_type        : <0x105>
>  <2><23a>: Abbrev Number: 16 (DW_TAG_subrange_type)
>     <23b>   DW_AT_type        : <0x11a>
>     <23f>   DW_AT_upper_bound : 0xffffffffffffffff
> ...
> and with gcc 7.5.0, we have instead:
> ...
>  <2><89f>: Abbrev Number: 12 (DW_TAG_member)
>     <8a0>   DW_AT_name        : items
>     <8a6>   DW_AT_type        : <0x8ac>
>  <1><8ac>: Abbrev Number: 17 (DW_TAG_array_type)
>     <8ad>   DW_AT_type        : <0x29d>
>  <2><8b5>: Abbrev Number: 41 (DW_TAG_subrange_type)
>  <2><8b6>: Abbrev Number: 0
> ...
> 
> As mentioned in commit 858c8f2c1b9 "gdb/testsuite: adjust
> gdb.python/flexible-array-member.exp expected pattern":
> ...
> Ideally, GDB would present a consistent and documented value for an
> array member declared with size 0, regardless of how the debug info
> looks like.
> ...
> 
> As in gdb.python/flexible-array-member.exp, change the test to accept the two
> values.
> 
> Tested on x86_64-linux.
> 
> 
> Any comments?
> 

Ping.

Thanks,
- Tom

> [gdb/testsuite] Fix gdb.guile/scm-type.exp with gcc 4.8
> 
> ---
>  gdb/testsuite/gdb.guile/scm-type.exp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.guile/scm-type.exp b/gdb/testsuite/gdb.guile/scm-type.exp
> index ccde98ca224..e5eaab365cc 100644
> --- a/gdb/testsuite/gdb.guile/scm-type.exp
> +++ b/gdb/testsuite/gdb.guile/scm-type.exp
> @@ -267,7 +267,7 @@ proc test_range {} {
>  	    gdb_scm_test_silent_cmd "guile (define f (history-ref 0))" \
>  		"get value (f) from history"
>  	    gdb_test "guile (print (type-range (field-type (type-field (value-type (value-dereference f)) \"items\"))))" \
> -		"= \\(0 0\\)"
> +		"= \\(0 (0|-1)\\)"
>  	    gdb_test "guile (print (value-subscript (value-field (value-dereference f) \"items\") 0))" \
>  		"= 111"
>  	    gdb_test "guile (print (value-subscript (value-field (value-dereference f) \"items\") 1))" \
>