* [PATCH] bitfield-parent-optimized-out: Fix struct definition
@ 2016-11-11 19:37 Andreas Arnez
2016-11-11 23:27 ` Luis Machado
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Arnez @ 2016-11-11 19:37 UTC (permalink / raw)
To: gdb-patches
The "struct S" type in bitfield-parent-optimized-out.exp is declared to
have a size of 4 bytes but to hold two 4-byte members: an int-based
bitfield and a 4-byte int. Also, both members have the same
data_member_location 2, causing them to overlap and to reach 2 bytes
beyond the structure's boundary.
This is fixed by increasing the structure size to 8 and setting the
first and second member's data_member_location to 0 and 4, respectively.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/bitfield-parent-optimized-out.exp: Fix DWARF code for
the definition of struct S.
---
gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
index 27d8044..b789970 100644
--- a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
+++ b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
@@ -43,19 +43,18 @@ Dwarf::assemble $asm_file {
struct_label: structure_type {
{name S}
- {byte_size 4 DW_FORM_sdata}
+ {byte_size 8 DW_FORM_sdata}
} {
member {
{name bitfield}
{type :$int_label}
{bit_size 12 DW_FORM_sdata}
{bit_offset 20 DW_FORM_sdata}
- {data_member_location 2 DW_FORM_sdata}
}
member {
{name intfield}
{type :$int_label}
- {data_member_location 2 DW_FORM_sdata}
+ {data_member_location 4 DW_FORM_sdata}
}
}
--
2.3.0
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] bitfield-parent-optimized-out: Fix struct definition
2016-11-11 19:37 [PATCH] bitfield-parent-optimized-out: Fix struct definition Andreas Arnez
@ 2016-11-11 23:27 ` Luis Machado
2016-11-15 18:12 ` Pedro Alves
0 siblings, 1 reply; 4+ messages in thread
From: Luis Machado @ 2016-11-11 23:27 UTC (permalink / raw)
To: Andreas Arnez, gdb-patches, Pedro Alves
On 11/11/2016 01:37 PM, Andreas Arnez wrote:
> The "struct S" type in bitfield-parent-optimized-out.exp is declared to
> have a size of 4 bytes but to hold two 4-byte members: an int-based
> bitfield and a 4-byte int. Also, both members have the same
> data_member_location 2, causing them to overlap and to reach 2 bytes
> beyond the structure's boundary.
>
> This is fixed by increasing the structure size to 8 and setting the
> first and second member's data_member_location to 0 and 4, respectively.
>
> gdb/testsuite/ChangeLog:
>
> * gdb.dwarf2/bitfield-parent-optimized-out.exp: Fix DWARF code for
> the definition of struct S.
> ---
> gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
> index 27d8044..b789970 100644
> --- a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
> +++ b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
> @@ -43,19 +43,18 @@ Dwarf::assemble $asm_file {
>
> struct_label: structure_type {
> {name S}
> - {byte_size 4 DW_FORM_sdata}
> + {byte_size 8 DW_FORM_sdata}
> } {
> member {
> {name bitfield}
> {type :$int_label}
> {bit_size 12 DW_FORM_sdata}
> {bit_offset 20 DW_FORM_sdata}
> - {data_member_location 2 DW_FORM_sdata}
> }
> member {
> {name intfield}
> {type :$int_label}
> - {data_member_location 2 DW_FORM_sdata}
> + {data_member_location 4 DW_FORM_sdata}
> }
> }
>
>
The patch looks good to me, but i'm wondering if Pedro meant for both
members to overlap (a union) instead of being two separate members?
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] bitfield-parent-optimized-out: Fix struct definition
2016-11-11 23:27 ` Luis Machado
@ 2016-11-15 18:12 ` Pedro Alves
2016-11-15 19:53 ` Andreas Arnez
0 siblings, 1 reply; 4+ messages in thread
From: Pedro Alves @ 2016-11-15 18:12 UTC (permalink / raw)
To: Luis Machado, Andreas Arnez, gdb-patches
On 11/11/2016 11:26 PM, Luis Machado wrote:
> On 11/11/2016 01:37 PM, Andreas Arnez wrote:
>> The "struct S" type in bitfield-parent-optimized-out.exp is declared to
>> have a size of 4 bytes but to hold two 4-byte members: an int-based
>> bitfield and a 4-byte int. Also, both members have the same
>> data_member_location 2, causing them to overlap and to reach 2 bytes
>> beyond the structure's boundary.
>>
>> This is fixed by increasing the structure size to 8 and setting the
>> first and second member's data_member_location to 0 and 4, respectively.
>>
>> gdb/testsuite/ChangeLog:
>>
>> * gdb.dwarf2/bitfield-parent-optimized-out.exp: Fix DWARF code for
>> the definition of struct S.
>> ---
>> gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp | 5 ++---
>> 1 file changed, 2 insertions(+), 3 deletions(-)
>>
>> diff --git
>> a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
>> b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
>> index 27d8044..b789970 100644
>> --- a/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
>> +++ b/gdb/testsuite/gdb.dwarf2/bitfield-parent-optimized-out.exp
>> @@ -43,19 +43,18 @@ Dwarf::assemble $asm_file {
>>
>> struct_label: structure_type {
>> {name S}
>> - {byte_size 4 DW_FORM_sdata}
>> + {byte_size 8 DW_FORM_sdata}
>> } {
>> member {
>> {name bitfield}
>> {type :$int_label}
>> {bit_size 12 DW_FORM_sdata}
>> {bit_offset 20 DW_FORM_sdata}
>> - {data_member_location 2 DW_FORM_sdata}
>> }
>> member {
>> {name intfield}
>> {type :$int_label}
>> - {data_member_location 2 DW_FORM_sdata}
>> + {data_member_location 4 DW_FORM_sdata}
>> }
>> }
>>
>>
>
> The patch looks good to me, but i'm wondering if Pedro meant for both
> members to overlap (a union) instead of being two separate members?
Possibly; I don't remember. If the changed test would still trigger
the old GDB bug, then I'm fine with the change.
Thanks,
Pedro Alves
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] bitfield-parent-optimized-out: Fix struct definition
2016-11-15 18:12 ` Pedro Alves
@ 2016-11-15 19:53 ` Andreas Arnez
0 siblings, 0 replies; 4+ messages in thread
From: Andreas Arnez @ 2016-11-15 19:53 UTC (permalink / raw)
To: Pedro Alves; +Cc: Luis Machado, gdb-patches
On Tue, Nov 15 2016, Pedro Alves wrote:
> On 11/11/2016 11:26 PM, Luis Machado wrote:
>> The patch looks good to me, but i'm wondering if Pedro meant for both
>> members to overlap (a union) instead of being two separate members?
>
> Possibly; I don't remember. If the changed test would still trigger
> the old GDB bug, then I'm fine with the change.
Yes, the bug is triggered both with the old and new version of
bitfield-parent-optimized-out.exp:
p var.bitfield
ERROR: Process no longer exists
UNRESOLVED: gdb.dwarf2/bitfield-parent-optimized-out.exp: p var.bitfield
ERROR: Couldn't send p var.intfield to GDB.
UNRESOLVED: gdb.dwarf2/bitfield-parent-optimized-out.exp: p var.intfield
Thanks, pushed.
--
Andreas
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-11-11 19:37 [PATCH] bitfield-parent-optimized-out: Fix struct definition Andreas Arnez
2016-11-11 23:27 ` Luis Machado
2016-11-15 18:12 ` Pedro Alves
2016-11-15 19:53 ` Andreas Arnez
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