Compiler/AM3359: Type #395 pointer to incomplete class type is not allowed/incomplete type is not allowed

Andy Lin94

Part Number: AM3359

Tool/software: TI C/C++ Compiler

Compiler: TI v5.2.5

Payload_Manager.c:

struct __attribute__((__packed__))ATEIS_Payload	//payload
{
	u32 Addr;
	u16 Cmd;
	u16 Len;
	u8 Data[];	// If the expression is a constant expression, it shall have a value greater than zero. 所以裡面不能填0
};

Payload_Manager.h:

typedef struct ATEIS_Payload ATEIS_Payload_s;

DNM_PktXcvr.c:

#include "Payload_Manager.h"
ATEIS_Payload_s* pl_p = Payload_Manager_New(PAYLOAD_SIZE+dataLen); //incomplete type is not allowed

DNM_CmdHndlr.c:

#include "Payload_Manager.h"

ATEIS_Payload_s* pl_p = NULL;    //no problem

pl_p = OSTaskQPend(0, OS_OPT_PEND_BLOCKING, &msgSize, &ts, &err);	//wait for a message


DNM_temp = DNMManager_Ctor(DNM_temp,
                           &pl_p->Data[NAME],            //pointer to incomplete class type is not allowed
			   pl_p->Addr,                   //ditto
			   *(u32*)&pl_p->Data[SN],       //ditto
  			   *(u32*)&pl_p->Data[SUBMASK]); //ditto

I deliberately hide struct member in source file and only give enough information via header file.

I don't know why this doesn't work.

Thanks

over 6 years ago

0 George Mock over 6 years ago

TI__Guru**** 249830 points

Source lines that only work with pointers to ATEIS_Payload_s (declare pointers, pass pointers, assign pointers, etc.) are legal C even if all that is visible is this line from Payload_Manager.h ...

Andy Lin94 said:
typedef struct ATEIS_Payload ATEIS_Payload_s;

All other source lines need to see the full definition of struct ATEIS_Payload that presently hidden away in Payload_Manager.c. Consider ...

Andy Lin94 said:
ATEIS_Payload_s* pl_p = Payload_Manager_New(PAYLOAD_SIZE+dataLen);

I presume PAYLOAD_SIZE is something like ...

#define PAYLOAD_SIZE sizeof(ATEIS_Payload_s)

That sizeof can only work if it knows all the members in the structure.

This line fails to compile ...

Andy Lin94 said:
&pl_p->Data[NAME]

... because the compiler does not know what members are in ATEIS_Payload_s.

I think you are trying to implement abstract data types (you might call them opaque) as described in this FAQ (not from TI).

Thanks and regards,

-George

0 Andy Lin94 over 6 years ago in reply to George Mock

Expert 1390 points

I presume PAYLOAD_SIZE is something like ...
#define PAYLOAD_SIZE sizeof(ATEIS_Payload_s)

No, it's:

#define PAYLOAD_SIZE 8

0 George Mock over 6 years ago

TI__Guru**** 249830 points

I am unable to reproduce this behavior ...

Andy Lin94 said:
#include "Payload_Manager.h"
ATEIS_Payload_s* pl_p = Payload_Manager_New(PAYLOAD_SIZE+dataLen); //incomplete type is not allowed

For the source file DNM_PktXcvr.c, please follow the directions in the article How to Submit a Compiler Test Case.

Thanks and regards,

-George

0 Andy Lin94 over 6 years ago in reply to George Mock

Expert 1390 points

I just did a little test to confirm that if without forward declaration, compiler knows identifier or not.
The answer is no.

I better read your FAQ and do more research about ADT. Thanks.

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Compiler/AM3359: Type #395 pointer to incomplete class type is not allowed/incomplete type is not allowed

I presume PAYLOAD_SIZE is something like ...

#define PAYLOAD_SIZE sizeof(ATEIS_Payload_s)