[Bug target/37954] odd sized packed structures passed by value, under ARM, cause lockup of application

["maurice35 dot david at laposte dot net" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #7 from maurice35 dot david at laposte dot net  2009-10-21 09:37 -------
It seems that I have a similar issue with ccmips compilator :
typedef struct
{
char A;  
char B;
char C;
/*char padding;*/
} tStructABC;

typedef struct
{
tStructABC ABC1;  
tStructABC ABC2;  
} tStruct2ABC;

tStruct2ABC Struct2ABC;

int Compute(tStructABC ArgA,tStructABC ArgB)
{
                return(ArgA.A+ArgA.B);
}
int main(int argc, char *argv[])
{
tStructABC * pABC1;
tStructABC * pABC2;
                pABC1 = &(Struct2ABC.ABC1);
                pABC2 = &(Struct2ABC.ABC2);
                printf("Compute=%d\n",Compute(*pABC1,*pABC2));
}

This code crash with the printout:
Address load Exception
Exception Program Counter: 0x803f56f8
Status Register: 0x3000ff01
Cause Register: 0x00000010
Access Address : 0x80b8da83
Task: 0x80ffa440 "PGL_Main"
0x80ffa440 (PGL_Main): task 0x80ffa440 has had a failure and has been stopped.
0x80ffa440 (PGL_Main): fatal kernel task-level exception!

So The crash is due to an alignment issue on the address &(Struct2ABC.ABC2);.
To avoid this issue we need to add a padding byte in tStructABC because it
seems that there is no way to force a padding through a compilation option or
through a #pragma (as example  #pragma pack(4)).

Please could you confirm this issue in compilation sw (ccmips) or not.

see: Created an attachment (id=18854)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18854&action=view) [edit]
Screen shoot form lauterbach


Best regard,


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37954