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

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

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?

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))" \