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binutils-gdb/gas/dw2gencfi.c
Nick Clifton 9497f5ac6b This adjusts equate handling by 
- allowing true forward references (which will always assume the referenced
  symbols have at the point of use) through the new .eqv pseudo-op and the
  new == operator
- disallowing changing .equiv-generated equates (so that the protection this
  provides is both forward and backward)
- snapshotting equates when their value gets changed so that previous uses
  don't get affected by the new value.
- allowing expressions in places where absolute expressions (or register
  names) are needed which were not completely resolvable at the point of
  their definition but which are fully resolvable at the point of use

In addition it fixes PR/288.
2005-10-11 11:16:17 +00:00

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/* dw2gencfi.c - Support for generating Dwarf2 CFI information.
Copyright 2003, 2004, 2005 Free Software Foundation, Inc.
Contributed by Michal Ludvig <mludvig@suse.cz>
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
#include "as.h"
#include "dw2gencfi.h"
/* We re-use DWARF2_LINE_MIN_INSN_LENGTH for the code alignment field
of the CIE. Default to 1 if not otherwise specified. */
#ifndef DWARF2_LINE_MIN_INSN_LENGTH
# define DWARF2_LINE_MIN_INSN_LENGTH 1
#endif
/* If TARGET_USE_CFIPOP is defined, it is required that the target
provide the following definitions. Otherwise provide them to
allow compilation to continue. */
#ifndef TARGET_USE_CFIPOP
# ifndef DWARF2_DEFAULT_RETURN_COLUMN
# define DWARF2_DEFAULT_RETURN_COLUMN 0
# endif
# ifndef DWARF2_CIE_DATA_ALIGNMENT
# define DWARF2_CIE_DATA_ALIGNMENT 1
# endif
#endif
#ifndef EH_FRAME_ALIGNMENT
# define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2)
#endif
#ifndef tc_cfi_frame_initial_instructions
# define tc_cfi_frame_initial_instructions() ((void)0)
#endif
struct cfi_insn_data
{
struct cfi_insn_data *next;
int insn;
union {
struct {
unsigned reg;
offsetT offset;
} ri;
struct {
unsigned reg1;
unsigned reg2;
} rr;
unsigned r;
offsetT i;
struct {
symbolS *lab1;
symbolS *lab2;
} ll;
struct cfi_escape_data {
struct cfi_escape_data *next;
expressionS exp;
} *esc;
} u;
};
struct fde_entry
{
struct fde_entry *next;
symbolS *start_address;
symbolS *end_address;
struct cfi_insn_data *data;
struct cfi_insn_data **last;
unsigned int return_column;
};
struct cie_entry
{
struct cie_entry *next;
symbolS *start_address;
unsigned int return_column;
struct cfi_insn_data *first, *last;
};
/* Current open FDE entry. */
static struct fde_entry *cur_fde_data;
static symbolS *last_address;
static offsetT cur_cfa_offset;
/* List of FDE entries. */
static struct fde_entry *all_fde_data;
static struct fde_entry **last_fde_data = &all_fde_data;
/* List of CIEs so that they could be reused. */
static struct cie_entry *cie_root;
/* Stack of old CFI data, for save/restore. */
struct cfa_save_data
{
struct cfa_save_data *next;
offsetT cfa_offset;
};
static struct cfa_save_data *cfa_save_stack;
/* Construct a new FDE structure and add it to the end of the fde list. */
static struct fde_entry *
alloc_fde_entry (void)
{
struct fde_entry *fde = xcalloc (1, sizeof (struct fde_entry));
cur_fde_data = fde;
*last_fde_data = fde;
last_fde_data = &fde->next;
fde->last = &fde->data;
fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN;
return fde;
}
/* The following functions are available for a backend to construct its
own unwind information, usually from legacy unwind directives. */
/* Construct a new INSN structure and add it to the end of the insn list
for the currently active FDE. */
static struct cfi_insn_data *
alloc_cfi_insn_data (void)
{
struct cfi_insn_data *insn = xcalloc (1, sizeof (struct cfi_insn_data));
*cur_fde_data->last = insn;
cur_fde_data->last = &insn->next;
return insn;
}
/* Construct a new FDE structure that begins at LABEL. */
void
cfi_new_fde (symbolS *label)
{
struct fde_entry *fde = alloc_fde_entry ();
fde->start_address = label;
last_address = label;
}
/* End the currently open FDE. */
void
cfi_end_fde (symbolS *label)
{
cur_fde_data->end_address = label;
cur_fde_data = NULL;
}
/* Set the return column for the current FDE. */
void
cfi_set_return_column (unsigned regno)
{
cur_fde_data->return_column = regno;
}
/* Universal functions to store new instructions. */
static void
cfi_add_CFA_insn(int insn)
{
struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
insn_ptr->insn = insn;
}
static void
cfi_add_CFA_insn_reg (int insn, unsigned regno)
{
struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
insn_ptr->insn = insn;
insn_ptr->u.r = regno;
}
static void
cfi_add_CFA_insn_offset (int insn, offsetT offset)
{
struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
insn_ptr->insn = insn;
insn_ptr->u.i = offset;
}
static void
cfi_add_CFA_insn_reg_reg (int insn, unsigned reg1, unsigned reg2)
{
struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
insn_ptr->insn = insn;
insn_ptr->u.rr.reg1 = reg1;
insn_ptr->u.rr.reg2 = reg2;
}
static void
cfi_add_CFA_insn_reg_offset (int insn, unsigned regno, offsetT offset)
{
struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
insn_ptr->insn = insn;
insn_ptr->u.ri.reg = regno;
insn_ptr->u.ri.offset = offset;
}
/* Add a CFI insn to advance the PC from the last address to LABEL. */
void
cfi_add_advance_loc (symbolS *label)
{
struct cfi_insn_data *insn = alloc_cfi_insn_data ();
insn->insn = DW_CFA_advance_loc;
insn->u.ll.lab1 = last_address;
insn->u.ll.lab2 = label;
last_address = label;
}
/* Add a DW_CFA_offset record to the CFI data. */
void
cfi_add_CFA_offset (unsigned regno, offsetT offset)
{
unsigned int abs_data_align;
cfi_add_CFA_insn_reg_offset (DW_CFA_offset, regno, offset);
abs_data_align = (DWARF2_CIE_DATA_ALIGNMENT < 0
? -DWARF2_CIE_DATA_ALIGNMENT : DWARF2_CIE_DATA_ALIGNMENT);
if (offset % abs_data_align)
as_bad (_("register save offset not a multiple of %u"), abs_data_align);
}
/* Add a DW_CFA_def_cfa record to the CFI data. */
void
cfi_add_CFA_def_cfa (unsigned regno, offsetT offset)
{
cfi_add_CFA_insn_reg_offset (DW_CFA_def_cfa, regno, offset);
cur_cfa_offset = offset;
}
/* Add a DW_CFA_register record to the CFI data. */
void
cfi_add_CFA_register (unsigned reg1, unsigned reg2)
{
cfi_add_CFA_insn_reg_reg (DW_CFA_register, reg1, reg2);
}
/* Add a DW_CFA_def_cfa_register record to the CFI data. */
void
cfi_add_CFA_def_cfa_register (unsigned regno)
{
cfi_add_CFA_insn_reg (DW_CFA_def_cfa_register, regno);
}
/* Add a DW_CFA_def_cfa_offset record to the CFI data. */
void
cfi_add_CFA_def_cfa_offset (offsetT offset)
{
cfi_add_CFA_insn_offset (DW_CFA_def_cfa_offset, offset);
cur_cfa_offset = offset;
}
void
cfi_add_CFA_restore (unsigned regno)
{
cfi_add_CFA_insn_reg (DW_CFA_restore, regno);
}
void
cfi_add_CFA_undefined (unsigned regno)
{
cfi_add_CFA_insn_reg (DW_CFA_undefined, regno);
}
void
cfi_add_CFA_same_value (unsigned regno)
{
cfi_add_CFA_insn_reg (DW_CFA_same_value, regno);
}
void
cfi_add_CFA_remember_state (void)
{
struct cfa_save_data *p;
cfi_add_CFA_insn (DW_CFA_remember_state);
p = xmalloc (sizeof (*p));
p->cfa_offset = cur_cfa_offset;
p->next = cfa_save_stack;
cfa_save_stack = p;
}
void
cfi_add_CFA_restore_state (void)
{
struct cfa_save_data *p;
cfi_add_CFA_insn (DW_CFA_restore_state);
p = cfa_save_stack;
if (p)
{
cur_cfa_offset = p->cfa_offset;
cfa_save_stack = p->next;
free (p);
}
else
as_bad (_("CFI state restore without previous remember"));
}
/* Parse CFI assembler directives. */
static void dot_cfi (int);
static void dot_cfi_escape (int);
static void dot_cfi_startproc (int);
static void dot_cfi_endproc (int);
/* Fake CFI type; outside the byte range of any real CFI insn. */
#define CFI_adjust_cfa_offset 0x100
#define CFI_return_column 0x101
#define CFI_rel_offset 0x102
#define CFI_escape 0x103
const pseudo_typeS cfi_pseudo_table[] =
{
{ "cfi_startproc", dot_cfi_startproc, 0 },
{ "cfi_endproc", dot_cfi_endproc, 0 },
{ "cfi_def_cfa", dot_cfi, DW_CFA_def_cfa },
{ "cfi_def_cfa_register", dot_cfi, DW_CFA_def_cfa_register },
{ "cfi_def_cfa_offset", dot_cfi, DW_CFA_def_cfa_offset },
{ "cfi_adjust_cfa_offset", dot_cfi, CFI_adjust_cfa_offset },
{ "cfi_offset", dot_cfi, DW_CFA_offset },
{ "cfi_rel_offset", dot_cfi, CFI_rel_offset },
{ "cfi_register", dot_cfi, DW_CFA_register },
{ "cfi_return_column", dot_cfi, CFI_return_column },
{ "cfi_restore", dot_cfi, DW_CFA_restore },
{ "cfi_undefined", dot_cfi, DW_CFA_undefined },
{ "cfi_same_value", dot_cfi, DW_CFA_same_value },
{ "cfi_remember_state", dot_cfi, DW_CFA_remember_state },
{ "cfi_restore_state", dot_cfi, DW_CFA_restore_state },
{ "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save },
{ "cfi_escape", dot_cfi_escape, 0 },
{ NULL, NULL, 0 }
};
static void
cfi_parse_separator (void)
{
SKIP_WHITESPACE ();
if (*input_line_pointer == ',')
input_line_pointer++;
else
as_bad (_("missing separator"));
}
static unsigned
cfi_parse_reg (void)
{
int regno;
expressionS exp;
#ifdef tc_regname_to_dw2regnum
SKIP_WHITESPACE ();
if (is_name_beginner (*input_line_pointer)
|| (*input_line_pointer == '%'
&& is_name_beginner (*++input_line_pointer)))
{
char *name, c;
name = input_line_pointer;
c = get_symbol_end ();
if ((regno = tc_regname_to_dw2regnum (name)) < 0)
{
as_bad (_("bad register expression"));
regno = 0;
}
*input_line_pointer = c;
return regno;
}
#endif
expression_and_evaluate (&exp);
switch (exp.X_op)
{
case O_register:
case O_constant:
regno = exp.X_add_number;
break;
default:
as_bad (_("bad register expression"));
regno = 0;
break;
}
return regno;
}
static offsetT
cfi_parse_const (void)
{
return get_absolute_expression ();
}
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:
reg1 = cfi_parse_reg ();
cfi_add_CFA_restore (reg1);
break;
case DW_CFA_undefined:
reg1 = cfi_parse_reg ();
cfi_add_CFA_undefined (reg1);
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;
default:
abort ();
}
demand_empty_rest_of_line ();
}
static void
dot_cfi_escape (int ignored ATTRIBUTE_UNUSED)
{
struct cfi_escape_data *head, **tail, *e;
struct cfi_insn_data *insn;
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 ());
tail = &head;
do
{
e = xmalloc (sizeof (*e));
do_parse_cons_expression (&e->exp, 1);
*tail = e;
tail = &e->next;
}
while (*input_line_pointer++ == ',');
*tail = NULL;
insn = alloc_cfi_insn_data ();
insn->insn = CFI_escape;
insn->u.esc = head;
--input_line_pointer;
demand_empty_rest_of_line ();
}
static void
dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED)
{
int simple = 0;
if (cur_fde_data)
{
as_bad (_("previous CFI entry not closed (missing .cfi_endproc)"));
ignore_rest_of_line ();
return;
}
cfi_new_fde (symbol_temp_new_now ());
SKIP_WHITESPACE ();
if (is_name_beginner (*input_line_pointer))
{
char *name, c;
name = input_line_pointer;
c = get_symbol_end ();
if (strcmp (name, "simple") == 0)
{
simple = 1;
*input_line_pointer = c;
}
else
input_line_pointer = name;
}
demand_empty_rest_of_line ();
cur_cfa_offset = 0;
if (!simple)
tc_cfi_frame_initial_instructions ();
}
static void
dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED)
{
if (! cur_fde_data)
{
as_bad (_(".cfi_endproc without corresponding .cfi_startproc"));
ignore_rest_of_line ();
return;
}
cfi_end_fde (symbol_temp_new_now ());
demand_empty_rest_of_line ();
}
/* Emit a single byte into the current segment. */
static inline void
out_one (int byte)
{
FRAG_APPEND_1_CHAR (byte);
}
/* Emit a two-byte word into the current segment. */
static inline void
out_two (int data)
{
md_number_to_chars (frag_more (2), data, 2);
}
/* Emit a four byte word into the current segment. */
static inline void
out_four (int data)
{
md_number_to_chars (frag_more (4), data, 4);
}
/* Emit an unsigned "little-endian base 128" number. */
static void
out_uleb128 (addressT value)
{
output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
}
/* Emit an unsigned "little-endian base 128" number. */
static void
out_sleb128 (offsetT value)
{
output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1);
}
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
output_cie (struct cie_entry *cie)
{
symbolS *after_size_address, *end_address;
expressionS exp;
struct cfi_insn_data *i;
cie->start_address = symbol_temp_new_now ();
after_size_address = symbol_temp_make ();
end_address = symbol_temp_make ();
exp.X_op = O_subtract;
exp.X_add_symbol = end_address;
exp.X_op_symbol = after_size_address;
exp.X_add_number = 0;
emit_expr (&exp, 4); /* Length. */
symbol_set_value_now (after_size_address);
out_four (0); /* CIE id. */
out_one (DW_CIE_VERSION); /* Version. */
out_one ('z'); /* Augmentation. */
out_one ('R');
out_one (0);
out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment. */
out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment. */
if (DW_CIE_VERSION == 1) /* Return column. */
out_one (cie->return_column);
else
out_uleb128 (cie->return_column);
out_uleb128 (1); /* Augmentation size. */
#if defined DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
out_one (DW_EH_PE_pcrel | DW_EH_PE_sdata4);
#else
out_one (DW_EH_PE_sdata4);
#endif
if (cie->first)
for (i = cie->first; i != cie->last; i = i->next)
output_cfi_insn (i);
frag_align (2, DW_CFA_nop, 0);
symbol_set_value_now (end_address);
}
static void
output_fde (struct fde_entry *fde, struct cie_entry *cie,
struct cfi_insn_data *first, int align)
{
symbolS *after_size_address, *end_address;
expressionS exp;
after_size_address = symbol_temp_make ();
end_address = symbol_temp_make ();
exp.X_op = O_subtract;
exp.X_add_symbol = end_address;
exp.X_op_symbol = after_size_address;
exp.X_add_number = 0;
emit_expr (&exp, 4); /* Length. */
symbol_set_value_now (after_size_address);
exp.X_add_symbol = after_size_address;
exp.X_op_symbol = cie->start_address;
emit_expr (&exp, 4); /* CIE offset. */
#ifdef DIFF_EXPR_OK
exp.X_add_symbol = fde->start_address;
exp.X_op_symbol = symbol_temp_new_now ();
emit_expr (&exp, 4); /* Code offset. */
#else
exp.X_op = O_symbol;
exp.X_add_symbol = fde->start_address;
exp.X_op_symbol = NULL;
#ifdef tc_cfi_emit_pcrel_expr
tc_cfi_emit_pcrel_expr (&exp, 4); /* Code offset. */
#else
emit_expr (&exp, 4); /* Code offset. */
#endif
exp.X_op = O_subtract;
#endif
exp.X_add_symbol = fde->end_address;
exp.X_op_symbol = fde->start_address; /* Code length. */
emit_expr (&exp, 4);
out_uleb128 (0); /* Augmentation size. */
for (; first; first = first->next)
output_cfi_insn (first);
frag_align (align, DW_CFA_nop, 0);
symbol_set_value_now (end_address);
}
static struct cie_entry *
select_cie_for_fde (struct fde_entry *fde, struct cfi_insn_data **pfirst)
{
struct cfi_insn_data *i, *j;
struct cie_entry *cie;
for (cie = cie_root; cie; cie = cie->next)
{
if (cie->return_column != fde->return_column)
continue;
for (i = cie->first, j = fde->data;
i != cie->last && j != NULL;
i = i->next, j = j->next)
{
if (i->insn != j->insn)
goto fail;
switch (i->insn)
{
case DW_CFA_advance_loc:
case DW_CFA_remember_state:
/* We reached the first advance/remember in the FDE,
but did not reach the end of the CIE list. */
goto fail;
case DW_CFA_offset:
case DW_CFA_def_cfa:
if (i->u.ri.reg != j->u.ri.reg)
goto fail;
if (i->u.ri.offset != j->u.ri.offset)
goto fail;
break;
case DW_CFA_register:
if (i->u.rr.reg1 != j->u.rr.reg1)
goto fail;
if (i->u.rr.reg2 != j->u.rr.reg2)
goto fail;
break;
case DW_CFA_def_cfa_register:
case DW_CFA_restore:
case DW_CFA_undefined:
case DW_CFA_same_value:
if (i->u.r != j->u.r)
goto fail;
break;
case DW_CFA_def_cfa_offset:
if (i->u.i != j->u.i)
goto fail;
break;
case CFI_escape:
/* Don't bother matching these for now. */
goto fail;
default:
abort ();
}
}
/* Success if we reached the end of the CIE list, and we've either
run out of FDE entries or we've encountered an advance,
remember, or escape. */
if (i == cie->last
&& (!j
|| j->insn == DW_CFA_advance_loc
|| j->insn == DW_CFA_remember_state
|| j->insn == CFI_escape))
{
*pfirst = j;
return cie;
}
fail:;
}
cie = xmalloc (sizeof (struct cie_entry));
cie->next = cie_root;
cie_root = cie;
cie->return_column = fde->return_column;
cie->first = fde->data;
for (i = cie->first; i ; i = i->next)
if (i->insn == DW_CFA_advance_loc
|| i->insn == DW_CFA_remember_state
|| i->insn == CFI_escape)
break;
cie->last = i;
*pfirst = i;
output_cie (cie);
return cie;
}
void
cfi_finish (void)
{
segT cfi_seg;
struct fde_entry *fde;
int save_flag_traditional_format;
if (cur_fde_data)
{
as_bad (_("open CFI at the end of file; missing .cfi_endproc directive"));
cur_fde_data->end_address = cur_fde_data->start_address;
}
if (all_fde_data == 0)
return;
/* Open .eh_frame section. */
cfi_seg = subseg_new (".eh_frame", 0);
bfd_set_section_flags (stdoutput, cfi_seg,
SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_READONLY);
subseg_set (cfi_seg, 0);
record_alignment (cfi_seg, EH_FRAME_ALIGNMENT);
/* Make sure check_eh_frame doesn't do anything with our output. */
save_flag_traditional_format = flag_traditional_format;
flag_traditional_format = 1;
for (fde = all_fde_data; fde ; fde = fde->next)
{
struct cfi_insn_data *first;
struct cie_entry *cie;
cie = select_cie_for_fde (fde, &first);
output_fde (fde, cie, first, fde->next == NULL ? EH_FRAME_ALIGNMENT : 2);
}
flag_traditional_format = save_flag_traditional_format;
}
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