static void
output_cfi_insn (struct cfi_insn_data *insn)
{
offsetT offset;
unsigned int regno;
switch (insn->insn)
{
case DW_CFA_advance_loc:
{
symbolS *from = insn->u.ll.lab1;
symbolS *to = insn->u.ll.lab2;
if (symbol_get_frag (to) == symbol_get_frag (from))
{
addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from);
addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH;
if (scaled <= 0x3F)
out_one (DW_CFA_advance_loc + scaled);
else if (delta <= 0xFF)
{
out_one (DW_CFA_advance_loc1);
out_one (delta);
}
else if (delta <= 0xFFFF)
{
out_one (DW_CFA_advance_loc2);
out_two (delta);
}
else
{
out_one (DW_CFA_advance_loc4);
out_four (delta);
}
}
else
{
expressionS exp;
exp.X_op = O_subtract;
exp.X_add_symbol = to;
exp.X_op_symbol = from;
exp.X_add_number = 0;
/* The code in ehopt.c expects that one byte of the encoding
is already allocated to the frag. This comes from the way
that it scans the .eh_frame section looking first for the
.byte DW_CFA_advance_loc4. */
frag_more (1);
frag_var (rs_cfa, 4, 0, DWARF2_LINE_MIN_INSN_LENGTH << 3,
make_expr_symbol (&exp), frag_now_fix () - 1,
(char *) frag_now);
}
}
break;
case DW_CFA_def_cfa:
offset = insn->u.ri.offset;
if (offset < 0)
{
out_one (DW_CFA_def_cfa_sf);
out_uleb128 (insn->u.ri.reg);
out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT);
}
else
{
out_one (DW_CFA_def_cfa);
out_uleb128 (insn->u.ri.reg);
out_uleb128 (offset);
}
break;
case DW_CFA_def_cfa_register:
case DW_CFA_undefined:
case DW_CFA_same_value:
out_one (insn->insn);
out_uleb128 (insn->u.r);
break;
case DW_CFA_def_cfa_offset:
offset = insn->u.i;
if (offset < 0)
{
out_one (DW_CFA_def_cfa_offset_sf);
out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT);
}
else
{
out_one (DW_CFA_def_cfa_offset);
out_uleb128 (offset);
}
break;
case DW_CFA_restore:
regno = insn->u.r;
if (regno <= 0x3F)
{
out_one (DW_CFA_restore + regno);
}
else
{
out_one (DW_CFA_restore_extended);
out_uleb128 (regno);
}
break;
case DW_CFA_offset:
regno = insn->u.ri.reg;
offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT;
if (offset < 0)
{
out_one (DW_CFA_offset_extended_sf);
out_uleb128 (regno);
out_sleb128 (offset);
}
else if (regno <= 0x3F)
{
out_one (DW_CFA_offset + regno);
out_uleb128 (offset);
}
else
{
out_one (DW_CFA_offset_extended);
out_uleb128 (regno);
out_uleb128 (offset);
}
break;
case DW_CFA_register:
out_one (DW_CFA_register);
out_uleb128 (insn->u.rr.reg1);
out_uleb128 (insn->u.rr.reg2);
break;
case DW_CFA_remember_state:
case DW_CFA_restore_state:
out_one (insn->insn);
break;
case DW_CFA_GNU_window_save:
out_one (DW_CFA_GNU_window_save);
break;
case CFI_escape:
{
struct cfi_escape_data *e;
for (e = insn->u.esc; e ; e = e->next)
emit_expr (&e->exp, 1);
break;
}
default:
abort ();
}
}
static void
dot_cfi (int arg)
{
offsetT offset;
unsigned reg1, reg2;
if (!cur_fde_data)
{
as_bad (_("CFI instruction used without previous .cfi_startproc"));
ignore_rest_of_line ();
return;
}
/* If the last address was not at the current PC, advance to current. */
if (symbol_get_frag (last_address) != frag_now
|| S_GET_VALUE (last_address) != frag_now_fix ())
cfi_add_advance_loc (symbol_temp_new_now ());
switch (arg)
{
case DW_CFA_offset:
reg1 = cfi_parse_reg ();
cfi_parse_separator ();
offset = cfi_parse_const ();
cfi_add_CFA_offset (reg1, offset);
break;
case CFI_rel_offset:
reg1 = cfi_parse_reg ();
cfi_parse_separator ();
offset = cfi_parse_const ();
cfi_add_CFA_offset (reg1, offset - cur_cfa_offset);
break;
case DW_CFA_def_cfa:
reg1 = cfi_parse_reg ();
cfi_parse_separator ();
offset = cfi_parse_const ();
cfi_add_CFA_def_cfa (reg1, offset);
break;
case DW_CFA_register:
reg1 = cfi_parse_reg ();
cfi_parse_separator ();
reg2 = cfi_parse_reg ();
cfi_add_CFA_register (reg1, reg2);
break;
case DW_CFA_def_cfa_register:
reg1 = cfi_parse_reg ();
cfi_add_CFA_def_cfa_register (reg1);
break;
case DW_CFA_def_cfa_offset:
offset = cfi_parse_const ();
cfi_add_CFA_def_cfa_offset (offset);
break;
case CFI_adjust_cfa_offset:
offset = cfi_parse_const ();
cfi_add_CFA_def_cfa_offset (cur_cfa_offset + offset);
break;
case DW_CFA_restore:
for (;;)
{
reg1 = cfi_parse_reg ();
cfi_add_CFA_restore (reg1);
SKIP_WHITESPACE ();
if (*input_line_pointer != ',')
break;
++input_line_pointer;
}
break;
case DW_CFA_undefined:
for (;;)
{
reg1 = cfi_parse_reg ();
cfi_add_CFA_undefined (reg1);
SKIP_WHITESPACE ();
if (*input_line_pointer != ',')
break;
++input_line_pointer;
}
break;
case DW_CFA_same_value:
reg1 = cfi_parse_reg ();
cfi_add_CFA_same_value (reg1);
break;
case CFI_return_column:
reg1 = cfi_parse_reg ();
cfi_set_return_column (reg1);
break;
case DW_CFA_remember_state:
cfi_add_CFA_remember_state ();
break;
case DW_CFA_restore_state:
cfi_add_CFA_restore_state ();
break;
case DW_CFA_GNU_window_save:
cfi_add_CFA_insn (DW_CFA_GNU_window_save);
break;
case CFI_signal_frame:
cur_fde_data->signal_frame = 1;
break;
default:
abort ();
}
demand_empty_rest_of_line ();
}
static void
output_cfi_insn (struct cfi_insn_data *insn)
{
offsetT offset;
unsigned int regno;
switch (insn->insn)
{
case DW_CFA_advance_loc:
{
symbolS *from = insn->u.ll.lab1;
symbolS *to = insn->u.ll.lab2;
if (symbol_get_frag (to) == symbol_get_frag (from))
{
addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from);
addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH;
if (scaled <= 0x3F)
out_one (DW_CFA_advance_loc + scaled);
else if (scaled <= 0xFF)
{
out_one (DW_CFA_advance_loc1);
out_one (scaled);
}
else if (scaled <= 0xFFFF)
{
out_one (DW_CFA_advance_loc2);
out_two (scaled);
}
else
{
out_one (DW_CFA_advance_loc4);
out_four (scaled);
}
}
else
{
expressionS exp;
exp.X_op = O_subtract;
exp.X_add_symbol = to;
exp.X_op_symbol = from;
exp.X_add_number = 0;
/* The code in ehopt.c expects that one byte of the encoding
is already allocated to the frag. This comes from the way
that it scans the .eh_frame section looking first for the
.byte DW_CFA_advance_loc4. */
frag_more (1);
frag_var (rs_cfa, 4, 0, DWARF2_LINE_MIN_INSN_LENGTH << 3,
make_expr_symbol (&exp), frag_now_fix () - 1,
(char *) frag_now);
}
}
break;
case DW_CFA_def_cfa:
offset = insn->u.ri.offset;
if (offset < 0)
{
out_one (DW_CFA_def_cfa_sf);
out_uleb128 (insn->u.ri.reg);
out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT);
}
else
{
out_one (DW_CFA_def_cfa);
out_uleb128 (insn->u.ri.reg);
out_uleb128 (offset);
}
break;
case DW_CFA_def_cfa_register:
case DW_CFA_undefined:
case DW_CFA_same_value:
out_one (insn->insn);
out_uleb128 (insn->u.r);
break;
case DW_CFA_def_cfa_offset:
offset = insn->u.i;
if (offset < 0)
{
out_one (DW_CFA_def_cfa_offset_sf);
out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT);
}
else
{
out_one (DW_CFA_def_cfa_offset);
out_uleb128 (offset);
}
break;
case DW_CFA_restore:
regno = insn->u.r;
if (regno <= 0x3F)
{
out_one (DW_CFA_restore + regno);
}
else
{
out_one (DW_CFA_restore_extended);
out_uleb128 (regno);
}
break;
case DW_CFA_offset:
regno = insn->u.ri.reg;
offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT;
if (offset < 0)
{
out_one (DW_CFA_offset_extended_sf);
out_uleb128 (regno);
out_sleb128 (offset);
}
else if (regno <= 0x3F)
{
out_one (DW_CFA_offset + regno);
out_uleb128 (offset);
}
else
{
out_one (DW_CFA_offset_extended);
out_uleb128 (regno);
out_uleb128 (offset);
}
break;
case DW_CFA_register:
out_one (DW_CFA_register);
out_uleb128 (insn->u.rr.reg1);
out_uleb128 (insn->u.rr.reg2);
break;
case DW_CFA_remember_state:
case DW_CFA_restore_state:
out_one (insn->insn);
break;
case DW_CFA_GNU_window_save:
out_one (DW_CFA_GNU_window_save);
break;
case CFI_escape:
{
struct cfi_escape_data *e;
for (e = insn->u.esc; e ; e = e->next)
emit_expr (&e->exp, 1);
break;
}
case CFI_val_encoded_addr:
{
unsigned encoding = insn->u.ea.encoding;
offsetT encoding_size;
if (encoding == DW_EH_PE_omit)
break;
out_one (DW_CFA_val_expression);
out_uleb128 (insn->u.ea.reg);
switch (encoding & 0x7)
{
case DW_EH_PE_absptr:
encoding_size = DWARF2_ADDR_SIZE (stdoutput);
break;
case DW_EH_PE_udata2:
encoding_size = 2;
break;
case DW_EH_PE_udata4:
encoding_size = 4;
break;
case DW_EH_PE_udata8:
encoding_size = 8;
break;
default:
abort ();
}
/* If the user has requested absolute encoding,
then use the smaller DW_OP_addr encoding. */
if (insn->u.ea.encoding == DW_EH_PE_absptr)
{
out_uleb128 (1 + encoding_size);
out_one (DW_OP_addr);
}
else
{
out_uleb128 (1 + 1 + encoding_size);
out_one (DW_OP_GNU_encoded_addr);
out_one (encoding);
if ((encoding & 0x70) == DW_EH_PE_pcrel)
{
#if CFI_DIFF_EXPR_OK
insn->u.ea.exp.X_op = O_subtract;
insn->u.ea.exp.X_op_symbol = symbol_temp_new_now ();
#elif defined (tc_cfi_emit_pcrel_expr)
tc_cfi_emit_pcrel_expr (&insn->u.ea.exp, encoding_size);
break;
#else
abort ();
#endif
}
}
emit_expr (&insn->u.ea.exp, encoding_size);
}
break;
default:
abort ();
}
}
int
check_eh_frame (expressionS *exp, unsigned int *pnbytes)
{
struct frame_data
{
enum frame_state
{
state_idle,
state_saw_size,
state_saw_cie_offset,
state_saw_pc_begin,
state_seeing_aug_size,
state_skipping_aug,
state_wait_loc4,
state_saw_loc4,
state_error,
} state;
int cie_info_ok;
struct cie_info cie_info;
symbolS *size_end_sym;
fragS *loc4_frag;
int loc4_fix;
int aug_size;
int aug_shift;
};
static struct frame_data eh_frame_data;
static struct frame_data debug_frame_data;
struct frame_data *d;
/* Don't optimize. */
if (flag_traditional_format)
return 0;
/* Select the proper section data. */
if (strcmp (segment_name (now_seg), ".eh_frame") == 0)
d = &eh_frame_data;
else if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
d = &debug_frame_data;
else
return 0;
if (d->state >= state_saw_size && S_IS_DEFINED (d->size_end_sym))
{
/* We have come to the end of the CIE or FDE. See below where
we set saw_size. We must check this first because we may now
be looking at the next size. */
d->state = state_idle;
}
switch (d->state)
{
case state_idle:
if (*pnbytes == 4)
{
/* This might be the size of the CIE or FDE. We want to know
the size so that we don't accidentally optimize across an FDE
boundary. We recognize the size in one of two forms: a
symbol which will later be defined as a difference, or a
subtraction of two symbols. Either way, we can tell when we
are at the end of the FDE because the symbol becomes defined
(in the case of a subtraction, the end symbol, from which the
start symbol is being subtracted). Other ways of describing
the size will not be optimized. */
if ((exp->X_op == O_symbol || exp->X_op == O_subtract)
&& ! S_IS_DEFINED (exp->X_add_symbol))
{
d->state = state_saw_size;
d->size_end_sym = exp->X_add_symbol;
}
}
break;
case state_saw_size:
case state_saw_cie_offset:
/* Assume whatever form it appears in, it appears atomically. */
d->state += 1;
break;
case state_saw_pc_begin:
/* Decide whether we should see an augmentation. */
if (! d->cie_info_ok
&& ! (d->cie_info_ok = get_cie_info (&d->cie_info)))
d->state = state_error;
else if (d->cie_info.z_augmentation)
{
d->state = state_seeing_aug_size;
d->aug_size = 0;
d->aug_shift = 0;
}
else
d->state = state_wait_loc4;
break;
case state_seeing_aug_size:
/* Bytes == -1 means this comes from an leb128 directive. */
if ((int)*pnbytes == -1 && exp->X_op == O_constant)
{
d->aug_size = exp->X_add_number;
d->state = state_skipping_aug;
}
else if (*pnbytes == 1 && exp->X_op == O_constant)
{
unsigned char byte = exp->X_add_number;
d->aug_size |= (byte & 0x7f) << d->aug_shift;
d->aug_shift += 7;
if ((byte & 0x80) == 0)
d->state = state_skipping_aug;
}
else
d->state = state_error;
if (d->state == state_skipping_aug && d->aug_size == 0)
d->state = state_wait_loc4;
break;
case state_skipping_aug:
if ((int)*pnbytes < 0)
d->state = state_error;
else
{
int left = (d->aug_size -= *pnbytes);
if (left == 0)
d->state = state_wait_loc4;
else if (left < 0)
d->state = state_error;
}
break;
case state_wait_loc4:
if (*pnbytes == 1
&& exp->X_op == O_constant
&& exp->X_add_number == DW_CFA_advance_loc4)
{
/* This might be a DW_CFA_advance_loc4. Record the frag and the
position within the frag, so that we can change it later. */
frag_grow (1);
d->state = state_saw_loc4;
d->loc4_frag = frag_now;
d->loc4_fix = frag_now_fix ();
}
break;
case state_saw_loc4:
d->state = state_wait_loc4;
if (*pnbytes != 4)
break;
if (exp->X_op == O_constant)
{
/* This is a case which we can optimize. The two symbols being
subtracted were in the same frag and the expression was
reduced to a constant. We can do the optimization entirely
in this function. */
if (d->cie_info.code_alignment > 0
&& exp->X_add_number % d->cie_info.code_alignment == 0
&& exp->X_add_number / d->cie_info.code_alignment < 0x40)
{
d->loc4_frag->fr_literal[d->loc4_fix]
= DW_CFA_advance_loc
| (exp->X_add_number / d->cie_info.code_alignment);
/* No more bytes needed. */
return 1;
}
else if (exp->X_add_number < 0x100)
{
d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc1;
*pnbytes = 1;
}
else if (exp->X_add_number < 0x10000)
{
d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc2;
*pnbytes = 2;
}
}
else if (exp->X_op == O_subtract)
{
/* This is a case we can optimize. The expression was not
reduced, so we can not finish the optimization until the end
of the assembly. We set up a variant frag which we handle
later. */
int fr_subtype;
if (d->cie_info.code_alignment > 0)
fr_subtype = d->cie_info.code_alignment << 3;
else
fr_subtype = 0;
frag_var (rs_cfa, 4, 0, fr_subtype, make_expr_symbol (exp),
d->loc4_fix, (char *) d->loc4_frag);
return 1;
}
break;
case state_error:
/* Just skipping everything. */
break;
}
return 0;
}
static void
dot_cfi_val_encoded_addr (int ignored ATTRIBUTE_UNUSED)
{
struct cfi_insn_data *insn_ptr;
offsetT encoding;
if (frchain_now->frch_cfi_data == NULL)
{
as_bad (_("CFI instruction used without previous .cfi_startproc"));
ignore_rest_of_line ();
return;
}
/* If the last address was not at the current PC, advance to current. */
if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now
|| S_GET_VALUE (frchain_now->frch_cfi_data->last_address)
!= frag_now_fix ())
cfi_add_advance_loc (symbol_temp_new_now ());
insn_ptr = alloc_cfi_insn_data ();
insn_ptr->insn = CFI_val_encoded_addr;
insn_ptr->u.ea.reg = cfi_parse_reg ();
cfi_parse_separator ();
encoding = cfi_parse_const ();
if ((encoding & 0xff) != encoding
|| ((encoding & 0x70) != 0
#if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
&& (encoding & 0x70) != DW_EH_PE_pcrel
#endif
)
/* leb128 can be handled, but does something actually need it? */
|| (encoding & 7) == DW_EH_PE_uleb128
|| (encoding & 7) > DW_EH_PE_udata8)
{
as_bad (_("invalid or unsupported encoding in .cfi_lsda"));
encoding = DW_EH_PE_omit;
}
cfi_parse_separator ();
expression_and_evaluate (&insn_ptr->u.ea.exp);
switch (insn_ptr->u.ea.exp.X_op)
{
case O_symbol:
break;
case O_constant:
if ((encoding & 0x70) != DW_EH_PE_pcrel)
break;
default:
encoding = DW_EH_PE_omit;
break;
}
insn_ptr->u.ea.encoding = encoding;
if (encoding == DW_EH_PE_omit)
{
as_bad (_("wrong third argument to .cfi_val_encoded_addr"));
ignore_rest_of_line ();
return;
}
demand_empty_rest_of_line ();
}
