[Crash-utility] fix gdb_get_datatype cannot handle integer type

[Lei Wen]

Dave,

On Wed, Mar 6, 2013 at 10:04 PM, Dave Anderson <anderson at redhat.com> wrote:
>
>
> ----- Original Message -----
>> Hi Dave,
>>
>> Current when pass integer type to gdb_get_datatype in crash, it would return
>> req->typecode=0 and req->length=0.
>>
>> As it only allow TYPE_CODE_ENUM to be passed. here is a patch for fixing it.
>> Do you think it could be merged?
>
> That's the OP_VAR_VALUE section -- what is the command that you're using that
> ends up passing an integer type to the function?  And what problem does it
> cause?

I enhance whatis command in my local code base to show the function's
original variant
name.
If not with my change, the original result is:
int schedule_delayed_work_on(int , struct delayed_work * , long unsigned int );
With my change, the result becomes:
int schedule_delayed_work_on(int cpu, struct delayed_work * dwork,
long unsigned int delay);

So it look nicer, right? :)

But I meet an issue that whatis is not intent for showing function
prototype only, but for
structure/union/integer type.

So I need to add arg_to_datatype in whatis_variable to tell the passed
data's type to whether
call gdb's function for exacting out the function parameter's name.

Then I face the bug as I reported...


>
> Dave
>

Thanks,
Lei

>
>>
>> +--- gdb-7.3.1/gdb/symtab.c
>> ++++ gdb-7.3.1/gdb/symtab.c
>> +@@ -5064,14 +5064,13 @@ gdb_get_datatype(struct gnu_request *req)
>> +               if (gdb_CRASHDEBUG(2))
>> +                       console("expr->elts[0].opcode:
>> OP_VAR_VALUE\n");
>> +               type = expr->elts[2].symbol->type;
>> +-              if (TYPE_CODE(type) == TYPE_CODE_ENUM) {
>> +-                      req->typecode = TYPE_CODE(type);
>> +-                      req->value =
>> SYMBOL_VALUE(expr->elts[2].symbol);
>> +-                      req->tagname = TYPE_TAG_NAME(type);
>> +-                      if (!req->tagname) {
>> +-                              val = evaluate_type(expr);
>> +-                              eval_enum(value_type(val), req);
>> +-                      }
>> ++              req->typecode = TYPE_CODE(type);
>> ++              req->length = TYPE_LENGTH(type);
>> ++              req->value = SYMBOL_VALUE(expr->elts[2].symbol);
>> ++              req->tagname = TYPE_TAG_NAME(type);
>> ++              if (!req->tagname) {
>> ++                      val = evaluate_type(expr);
>> ++                      eval_enum(value_type(val), req);
>> +               }
>> +               break;
>> +
>>
>> Thanks,
>> Lei
>>