/******************************************************************************
*Function: readline
*Description： read a line from a file descriptor
*Input: fd(file descriptor) / n(number)
*Output: vptr(output buffer)
*Return: read bytes
*Date: 2015/6/5
******************************************************************************/
ssize_t
readline(int fd, void *vptr, size_t maxlen)
{
ssize_t n, rc;
char c, *ptr;
ptr = vptr;
for(n=1; n<maxlen; n++) {
if( (rc = read_1byte(fd, &c)) == 1) {
*ptr++ = c;
if(c == '\n')
break; //new line is stored, like fgets()
} else if(rc == 0) {
*ptr = '\0';
return (n - 1); //EOF, n-1 bytes were read
} else {
return -1; //error, errno set by read()
}
}
*ptr = '\0'; //null terminate like fgets()
return n;
}
static void *
execute_cfa_insn (void *p, struct frame_state_internal *state,
struct cie_info *info, void **pc)
{
unsigned insn = *(unsigned char *)p++;
unsigned reg;
int offset;
if (insn & DW_CFA_advance_loc)
*pc += ((insn & 0x3f) * info->code_align);
else if (insn & DW_CFA_offset)
{
reg = (insn & 0x3f);
p = decode_uleb128 (p, &offset);
offset *= info->data_align;
state->s.saved[reg] = REG_SAVED_OFFSET;
state->s.reg_or_offset[reg] = offset;
}
else if (insn & DW_CFA_restore)
{
reg = (insn & 0x3f);
state->s.saved[reg] = REG_UNSAVED;
}
else switch (insn)
{
case DW_CFA_set_loc:
*pc = read_pointer (p);
p += sizeof (void *);
break;
case DW_CFA_advance_loc1:
*pc += read_1byte (p);
p += 1;
break;
case DW_CFA_advance_loc2:
*pc += read_2byte (p);
p += 2;
break;
case DW_CFA_advance_loc4:
*pc += read_4byte (p);
p += 4;
break;
case DW_CFA_offset_extended:
p = decode_uleb128 (p, ®);
p = decode_uleb128 (p, &offset);
offset *= info->data_align;
state->s.saved[reg] = REG_SAVED_OFFSET;
state->s.reg_or_offset[reg] = offset;
break;
case DW_CFA_restore_extended:
p = decode_uleb128 (p, ®);
state->s.saved[reg] = REG_UNSAVED;
break;
case DW_CFA_undefined:
case DW_CFA_same_value:
case DW_CFA_nop:
break;
case DW_CFA_register:
{
unsigned reg2;
p = decode_uleb128 (p, ®);
p = decode_uleb128 (p, ®2);
state->s.saved[reg] = REG_SAVED_REG;
state->s.reg_or_offset[reg] = reg2;
}
break;
case DW_CFA_def_cfa:
p = decode_uleb128 (p, ®);
p = decode_uleb128 (p, &offset);
state->s.cfa_reg = reg;
state->s.cfa_offset = offset;
break;
case DW_CFA_def_cfa_register:
p = decode_uleb128 (p, ®);
state->s.cfa_reg = reg;
break;
case DW_CFA_def_cfa_offset:
p = decode_uleb128 (p, &offset);
state->s.cfa_offset = offset;
break;
case DW_CFA_remember_state:
{
struct frame_state_internal *save =
(struct frame_state_internal *)
malloc (sizeof (struct frame_state_internal));
memcpy (save, state, sizeof (struct frame_state_internal));
state->saved_state = save;
}
break;
case DW_CFA_restore_state:
{
struct frame_state_internal *save = state->saved_state;
memcpy (state, save, sizeof (struct frame_state_internal));
free (save);
}
break;
/* FIXME: Hardcoded for SPARC register window configuration. */
case DW_CFA_GNU_window_save:
for (reg = 16; reg < 32; ++reg)
{
state->s.saved[reg] = REG_SAVED_OFFSET;
state->s.reg_or_offset[reg] = (reg - 16) * sizeof (void *);
}
break;
case DW_CFA_GNU_args_size:
p = decode_uleb128 (p, &offset);
state->s.args_size = offset;
break;
default:
abort ();
}
return p;
}
