[PATCH] gdb: LoongArch: Added support for static data member in struct

[PATCH] gdb: LoongArch: Added support for static data member in struct

[Hui Li]

As described in C++ reference [1], static data members are not part
of objects of a given class type. Modified compute_struct_member ()
to ignore static data member so that we can get the expected result.

loongson@linux:~$ cat test.c
  #include<stdio.h>
  struct struct_01 { static unsigned a; float b;};
  unsigned struct_01::a = 66;
  struct struct_01 struct_01_val = { 99.00 };
  int check_arg_struct(struct struct_01 arg)
    {
      printf("arg.a = %d\n", arg.a);
      printf("arg.b = %f\n", arg.b);
      return 0;
    }
  int main()
    {
      check_arg_struct(struct_01_val);
      return 0;
    }
loongson@linux:~$ g++ -g test.c -o test++
loongson@linux:~$ gdb test++

Without this patch:
...
(gdb) start
...
(gdb) p check_arg_struct(struct_01_val)
arg.a = 66
arg.b = 0.000000
$1 = 0

With this patch:
...
(gdb) start
...
(gdb) p check_arg_struct(struct_01_val)
arg.a = 66
arg.b = 99.000000
$1 = 0

[1] https://learn.microsoft.com/en-us/cpp/cpp/static-members-cpp?view=msvc-170

Signed-off-by: Hui Li <lihui@loongson.cn>
---
 gdb/loongarch-tdep.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gdb/loongarch-tdep.c b/gdb/loongarch-tdep.c
index f5ddad0ba65..b380bd7e2d4 100644
--- a/gdb/loongarch-tdep.c
+++ b/gdb/loongarch-tdep.c
@@ -520,6 +520,10 @@ compute_struct_member (struct type *type,
 {
   for (int i = 0; i < type->num_fields (); i++)
     {
+      /* Ignore any static fields.  */
+      if (field_is_static (&type->field (i)))
+	continue;
+
       struct type *field_type = check_typedef (type->field (i).type ());
 
       if (field_type->code () == TYPE_CODE_INT
-- 
2.38.0

Re: [PATCH] gdb: LoongArch: Added support for static data member in struct

[Tom Tromey]

>>>>> Hui Li <lihui@loongson.cn> writes:

> As described in C++ reference [1], static data members are not part
> of objects of a given class type. Modified compute_struct_member ()
> to ignore static data member so that we can get the expected result.

Looks good to me.  I don't know this arch but it's normal for tdep code
to have to do this.

Reviewed-By: Tom Tromey <tom@tromey.com>

Tom

Re: [PATCH] gdb: LoongArch: Added support for static data member in struct

[Hui Li]

On 2023/2/25 上午3:14, Tom Tromey wrote:
>>>>>> Hui Li <lihui@loongson.cn> writes:
> 
>> As described in C++ reference [1], static data members are not part
>> of objects of a given class type. Modified compute_struct_member ()
>> to ignore static data member so that we can get the expected result.
> 
> Looks good to me.  I don't know this arch but it's normal for tdep code
> to have to do this.
> 
> Reviewed-By: Tom Tromey <tom@tromey.com>
> 
> Tom
> 

Thanks for your review.

Hui

Re: [PATCH] gdb: LoongArch: Added support for static data member in struct

[Tiezhu Yang]

On 2/24/23 08:54, Hui Li wrote:
> As described in C++ reference [1], static data members are not part
> of objects of a given class type. Modified compute_struct_member ()
> to ignore static data member so that we can get the expected result.

Looks good to me, tested on LoongArch, pushed.

Thanks,
Tiezhu