Nested struct type...

[joecar]

When I reference the type of a nested struct, SlickEdit highlights it as unknown (symbol not found)...

for example, from outside the outer struct, when I reference the type of struct fwdt (which is defined within struct qla_hw_data), see screenshot image below...

Code: [Select]

struct qla_hw_data {
        uint some;
uint other;
        struct fwdt {
void *template;
ulong length;
ulong dump_size;
} fwdt[2];
 };


[joecar]

Also, observation, if you look at the object fwdt of type struct fwdt, only some occurrences of it are highlighted as unknown, and the other occurrences are ok (not highlighted).

[Dennis]

I'll look into this.  It certainly makes the problem harder naming the variable the same name as the struct.

[joecar]

I'll look into this.  It certainly makes the problem harder naming the variable the same name as the struct.

It happens regardless of the variables' name... just rename it to xxxx.

[Clark]

Here's a simplified sample:

Code: [Select]

struct outer {
    int some;
    int other;
    struct inner {
        void *templat;
        long length;
        long dump_size;
    } fwdt[2];
};

void main(int argc, char *argv[]) {
    struct outer::inner a1; // This compiles
    struct inner a2; // This doesn't compile
}

I hope I'm following what's going on here. Am I?

Here's the error I get compiling this with the Microsoft 2015 compiler:

Code: [Select]

sample.cpp(13): error C2079: 'a2' uses undefined struct 'main::inner'


[joecar]

Yes, the nested structs (inner, outer) are correct.

I'm not using C++

I'm using GNU C, and it compiles ok.


Declaring the inner struct does not shield it from being visible outside the outer struct.

[Clark]

I never realized that C treats this totally differently.

[joecar]

lol, yes, there are some of us old C-only hacks still around 

[Dennis]

I wasn't aware of this C thing either.  I think I just threw up a little too...

The fix may to go into the point release since it is not hot-fixable.

[Dennis]

Update:  This will be fixed in the next release candidate.

[joecar]

Also, not related to nested structs, how do you handle objects declared with typeof()...?

For example, see variable xyz in this pic, vs is highlighting it as unknown symbol:

[Dennis]

From what I gather, that is a GNU C extension, but I can add support for it.

[joecar]

ok, thanks; yes, it is a gcc extension.

[joecar]

I have a more complex example, if you're interested...

Code: [Select]

static struct qla27xx_fwdt_entry *
qla27xx_fwdt_entry_other(struct scsi_qla_host *vha,
    struct qla27xx_fwdt_entry *ent, void *buf, ulong *len)
{
qla27xx_skip_entry(ent, buf);

return qla27xx_next_entry(ent);
}

static struct {
uint type;
typeof(qla27xx_fwdt_entry_other)(*call);
} qla27xx_fwdt_entry_call[] = {
{ ENTRY_TYPE_TMP_END , qla27xx_fwdt_entry_t255  } ,
{ ENTRY_TYPE_RD_IOB_T1 , qla27xx_fwdt_entry_t256  } ,
{ ENTRY_TYPE_WR_IOB_T1 , qla27xx_fwdt_entry_t257  } ,
{ ENTRY_TYPE_RD_IOB_T2 , qla27xx_fwdt_entry_t258  } ,
{ -1 , qla27xx_fwdt_entry_other }
};

static inline
typeof(*qla27xx_fwdt_entry_call->call)(*qla27xx_find_entry(uint type))
{
typeof(*qla27xx_fwdt_entry_call) *list = qla27xx_fwdt_entry_call;

while (list->type < type)
list++;

if (list->type == type)
return list->call;

return qla27xx_fwdt_entry_other;
}

static void
qla27xx_walk_template(struct scsi_qla_host *vha,
    struct qla27xx_fwdt_template *tmp, void *buf, ulong *len)
{
struct qla27xx_fwdt_entry *ent = (void *)tmp + le32_to_cpu(tmp->entry_offset);
ulong count = le32_to_cpu(tmp->entry_count);

while (count--) {
ulong type = le32_to_cpu(ent->hdr.type);
ent = qla27xx_find_entry(type)(vha, ent, buf, len);
if (!ent)
break;
}
}
I chopped out some of the code that was not relevant, but this still compiles ok (using gnu c).



edit: also see 2nd image for minor variation (typeof is already a pointer to function).

[Dennis]

Yeah, not a really simple case, so that would require more work.  I'll file a future feature request for this case.

You can make the code a bit more readable and we handle it better if you do something like this.

Code: [Select]

typedef typeof(*qla27xx_fwdt_entry_call->call) typeof_qla27_yadda_yadda;
static inline typeof_qla27_yadda_yadda qla27xx_find_entry(uint type)