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binutils-gdb/gas/dw2gencfi.c

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/* dw2gencfi.c - Support for generating Dwarf2 CFI information.
Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
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 3, 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"
#include "subsegs.h"
#include "dwarf2dbg.h"
#ifdef TARGET_USE_CFIPOP
/* By default, use difference expressions if DIFF_EXPR_OK is defined. */
#ifndef CFI_DIFF_EXPR_OK
# ifdef DIFF_EXPR_OK
# define CFI_DIFF_EXPR_OK 1
# else
# define CFI_DIFF_EXPR_OK 0
# endif
#endif
#ifndef CFI_DIFF_LSDA_OK
# define CFI_DIFF_LSDA_OK CFI_DIFF_EXPR_OK
#endif
#if CFI_DIFF_EXPR_OK == 1 && CFI_DIFF_LSDA_OK == 0
# error "CFI_DIFF_EXPR_OK should imply CFI_DIFF_LSDA_OK"
#endif
/* 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
/* By default, use 32-bit relocations from .eh_frame into .text. */
#ifndef DWARF2_FDE_RELOC_SIZE
# define DWARF2_FDE_RELOC_SIZE 4
#endif
/* By default, use a read-only .eh_frame section. */
#ifndef DWARF2_EH_FRAME_READ_ONLY
# define DWARF2_EH_FRAME_READ_ONLY SEC_READONLY
#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
#ifndef DWARF2_FORMAT
# define DWARF2_FORMAT(SEC) dwarf2_format_32bit
#endif
#ifndef DWARF2_ADDR_SIZE
# define DWARF2_ADDR_SIZE(bfd) (bfd_arch_bits_per_address (bfd) / 8)
#endif
/* ??? Share this with dwarf2cfg.c. */
#ifndef TC_DWARF2_EMIT_OFFSET
#define TC_DWARF2_EMIT_OFFSET generic_dwarf2_emit_offset
/* Create an offset to .dwarf2_*. */
static void
generic_dwarf2_emit_offset (symbolS *symbol, unsigned int size)
{
expressionS exp;
exp.X_op = O_symbol;
exp.X_add_symbol = symbol;
exp.X_add_number = 0;
emit_expr (&exp, size);
}
#endif
struct cfi_escape_data {
struct cfi_escape_data *next;
expressionS exp;
};
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 *esc;
struct {
unsigned reg, encoding;
expressionS exp;
} ea;
} 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 char per_encoding;
unsigned char lsda_encoding;
expressionS personality;
expressionS lsda;
unsigned int return_column;
unsigned int signal_frame;
};
struct cie_entry
{
struct cie_entry *next;
symbolS *start_address;
unsigned int return_column;
unsigned int signal_frame;
unsigned char per_encoding;
unsigned char lsda_encoding;
expressionS personality;
struct cfi_insn_data *first, *last;
};
/* 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;
};
/* Current open FDE entry. */
struct frch_cfi_data
{
struct fde_entry *cur_fde_data;
symbolS *last_address;
offsetT cur_cfa_offset;
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 = (struct fde_entry *)
xcalloc (1, sizeof (struct fde_entry));
frchain_now->frch_cfi_data = (struct frch_cfi_data *)
xcalloc (1, sizeof (struct frch_cfi_data));
frchain_now->frch_cfi_data->cur_fde_data = fde;
*last_fde_data = fde;
last_fde_data = &fde->next;
fde->last = &fde->data;
fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN;
fde->per_encoding = DW_EH_PE_omit;
fde->lsda_encoding = DW_EH_PE_omit;
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 = (struct cfi_insn_data *)
xcalloc (1, sizeof (struct cfi_insn_data));
struct fde_entry *cur_fde_data = frchain_now->frch_cfi_data->cur_fde_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;
frchain_now->frch_cfi_data->last_address = label;
}
/* End the currently open FDE. */
void
cfi_end_fde (symbolS *label)
{
frchain_now->frch_cfi_data->cur_fde_data->end_address = label;
free (frchain_now->frch_cfi_data);
frchain_now->frch_cfi_data = NULL;
}
/* Set the return column for the current FDE. */
void
cfi_set_return_column (unsigned regno)
{
frchain_now->frch_cfi_data->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 = frchain_now->frch_cfi_data->last_address;
insn->u.ll.lab2 = label;
frchain_now->frch_cfi_data->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;
gas_assert (DWARF2_CIE_DATA_ALIGNMENT != 0);
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);
frchain_now->frch_cfi_data->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);
frchain_now->frch_cfi_data->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 = (struct cfa_save_data *) xmalloc (sizeof (*p));
p->cfa_offset = frchain_now->frch_cfi_data->cur_cfa_offset;
p->next = frchain_now->frch_cfi_data->cfa_save_stack;
frchain_now->frch_cfi_data->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 = frchain_now->frch_cfi_data->cfa_save_stack;
if (p)
{
frchain_now->frch_cfi_data->cur_cfa_offset = p->cfa_offset;
frchain_now->frch_cfi_data->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_sections (int);
static void dot_cfi_startproc (int);
static void dot_cfi_endproc (int);
static void dot_cfi_personality (int);
static void dot_cfi_lsda (int);
static void dot_cfi_val_encoded_addr (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
#define CFI_signal_frame 0x104
#define CFI_val_encoded_addr 0x105
const pseudo_typeS cfi_pseudo_table[] =
{
{ "cfi_sections", dot_cfi_sections, 0 },
{ "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 },
{ "cfi_signal_frame", dot_cfi, CFI_signal_frame },
{ "cfi_personality", dot_cfi_personality, 0 },
{ "cfi_lsda", dot_cfi_lsda, 0 },
{ "cfi_val_encoded_addr", dot_cfi_val_encoded_addr, 0 },
{ NULL, NULL, 0 }
};
static void
cfi_parse_separator (void)
{
SKIP_WHITESPACE ();
if (*input_line_pointer == ',')
input_line_pointer++;
else
as_bad (_("missing separator"));
}
#ifndef tc_parse_to_dw2regnum
static void
tc_parse_to_dw2regnum(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 ();
exp->X_op = O_constant;
exp->X_add_number = tc_regname_to_dw2regnum (name);
*input_line_pointer = c;
}
else
# endif
expression_and_evaluate (exp);
}
#endif
static unsigned
cfi_parse_reg (void)
{
int regno;
expressionS exp;
tc_parse_to_dw2regnum (&exp);
switch (exp.X_op)
{
case O_register:
case O_constant:
regno = exp.X_add_number;
break;
default:
regno = -1;
break;
}
if (regno < 0)
{
as_bad (_("bad register expression"));
regno = 0;
}
return regno;
}
static offsetT
cfi_parse_const (void)
{
return get_absolute_expression ();
}
static void
dot_cfi (int arg)
{
offsetT offset;
unsigned reg1, reg2;
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 ());
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 - frchain_now->frch_cfi_data->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 (frchain_now->frch_cfi_data->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:
frchain_now->frch_cfi_data->cur_fde_data->signal_frame = 1;
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 (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 ());
tail = &head;
do
{
e = (struct cfi_escape_data *) 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_personality (int ignored ATTRIBUTE_UNUSED)
{
struct fde_entry *fde;
offsetT encoding;
if (frchain_now->frch_cfi_data == NULL)
{
as_bad (_("CFI instruction used without previous .cfi_startproc"));
ignore_rest_of_line ();
return;
}
fde = frchain_now->frch_cfi_data->cur_fde_data;
encoding = cfi_parse_const ();
if (encoding == DW_EH_PE_omit)
{
demand_empty_rest_of_line ();
fde->per_encoding = encoding;
return;
}
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_personality"));
ignore_rest_of_line ();
return;
}
if (*input_line_pointer++ != ',')
{
as_bad (_(".cfi_personality requires encoding and symbol arguments"));
ignore_rest_of_line ();
return;
}
expression_and_evaluate (&fde->personality);
switch (fde->personality.X_op)
{
case O_symbol:
break;
case O_constant:
if ((encoding & 0x70) == DW_EH_PE_pcrel)
encoding = DW_EH_PE_omit;
break;
default:
encoding = DW_EH_PE_omit;
break;
}
fde->per_encoding = encoding;
if (encoding == DW_EH_PE_omit)
{
as_bad (_("wrong second argument to .cfi_personality"));
ignore_rest_of_line ();
return;
}
demand_empty_rest_of_line ();
}
static void
dot_cfi_lsda (int ignored ATTRIBUTE_UNUSED)
{
struct fde_entry *fde;
offsetT encoding;
if (frchain_now->frch_cfi_data == NULL)
{
as_bad (_("CFI instruction used without previous .cfi_startproc"));
ignore_rest_of_line ();
return;
}
fde = frchain_now->frch_cfi_data->cur_fde_data;
encoding = cfi_parse_const ();
if (encoding == DW_EH_PE_omit)
{
demand_empty_rest_of_line ();
fde->lsda_encoding = encoding;
return;
}
if ((encoding & 0xff) != encoding
|| ((encoding & 0x70) != 0
#if CFI_DIFF_LSDA_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"));
ignore_rest_of_line ();
return;
}
if (*input_line_pointer++ != ',')
{
as_bad (_(".cfi_lsda requires encoding and symbol arguments"));
ignore_rest_of_line ();
return;
}
fde->lsda_encoding = encoding;
expression_and_evaluate (&fde->lsda);
switch (fde->lsda.X_op)
{
case O_symbol:
break;
case O_constant:
if ((encoding & 0x70) == DW_EH_PE_pcrel)
encoding = DW_EH_PE_omit;
break;
default:
encoding = DW_EH_PE_omit;
break;
}
fde->lsda_encoding = encoding;
if (encoding == DW_EH_PE_omit)
{
as_bad (_("wrong second argument to .cfi_lsda"));
ignore_rest_of_line ();
return;
}
demand_empty_rest_of_line ();
}
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 ();
}
/* By default emit .eh_frame only, not .debug_frame. */
#define CFI_EMIT_eh_frame (1 << 0)
#define CFI_EMIT_debug_frame (1 << 1)
static int cfi_sections = CFI_EMIT_eh_frame;
static void
dot_cfi_sections (int ignored ATTRIBUTE_UNUSED)
{
int sections = 0;
SKIP_WHITESPACE ();
if (is_name_beginner (*input_line_pointer))
while (1)
{
char *name, c;
name = input_line_pointer;
c = get_symbol_end ();
if (strcmp (name, ".eh_frame") == 0)
sections |= CFI_EMIT_eh_frame;
else if (strcmp (name, ".debug_frame") == 0)
sections |= CFI_EMIT_debug_frame;
else
{
*input_line_pointer = c;
input_line_pointer = name;
break;
}
*input_line_pointer = c;
SKIP_WHITESPACE ();
if (*input_line_pointer == ',')
{
name = input_line_pointer++;
SKIP_WHITESPACE ();
if (!is_name_beginner (*input_line_pointer))
{
input_line_pointer = name;
break;
}
}
else if (is_name_beginner (*input_line_pointer))
break;
}
demand_empty_rest_of_line ();
cfi_sections = sections;
}
static void
dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED)
{
int simple = 0;
if (frchain_now->frch_cfi_data != NULL)
{
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 ();
frchain_now->frch_cfi_data->cur_cfa_offset = 0;
if (!simple)
tc_cfi_frame_initial_instructions ();
}
static void
dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED)
{
if (frchain_now->frch_cfi_data == NULL)
{
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 (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) = DW_CFA_advance_loc4;
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 ();
}
}
static offsetT
encoding_size (unsigned char encoding)
{
if (encoding == DW_EH_PE_omit)
return 0;
switch (encoding & 0x7)
{
case 0:
return bfd_get_arch_size (stdoutput) == 64 ? 8 : 4;
case DW_EH_PE_udata2:
return 2;
case DW_EH_PE_udata4:
return 4;
case DW_EH_PE_udata8:
return 8;
default:
abort ();
}
}
static void
output_cie (struct cie_entry *cie, bfd_boolean eh_frame, int align)
{
symbolS *after_size_address, *end_address;
expressionS exp;
struct cfi_insn_data *i;
offsetT augmentation_size;
int enc;
enum dwarf2_format fmt = DWARF2_FORMAT (now_seg);
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;
if (eh_frame || fmt == dwarf2_format_32bit)
emit_expr (&exp, 4); /* Length. */
else
{
if (fmt == dwarf2_format_64bit)
out_four (-1);
emit_expr (&exp, 8); /* Length. */
}
symbol_set_value_now (after_size_address);
if (eh_frame)
out_four (0); /* CIE id. */
else
{
out_four (-1); /* CIE id. */
if (fmt != dwarf2_format_32bit)
out_four (-1);
}
out_one (DW_CIE_VERSION); /* Version. */
if (eh_frame)
{
out_one ('z'); /* Augmentation. */
if (cie->per_encoding != DW_EH_PE_omit)
out_one ('P');
if (cie->lsda_encoding != DW_EH_PE_omit)
out_one ('L');
out_one ('R');
}
if (cie->signal_frame)
out_one ('S');
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);
if (eh_frame)
{
augmentation_size = 1 + (cie->lsda_encoding != DW_EH_PE_omit);
if (cie->per_encoding != DW_EH_PE_omit)
augmentation_size += 1 + encoding_size (cie->per_encoding);
out_uleb128 (augmentation_size); /* Augmentation size. */
if (cie->per_encoding != DW_EH_PE_omit)
{
offsetT size = encoding_size (cie->per_encoding);
out_one (cie->per_encoding);
exp = cie->personality;
if ((cie->per_encoding & 0x70) == DW_EH_PE_pcrel)
{
#if CFI_DIFF_EXPR_OK
exp.X_op = O_subtract;
exp.X_op_symbol = symbol_temp_new_now ();
emit_expr (&exp, size);
#elif defined (tc_cfi_emit_pcrel_expr)
tc_cfi_emit_pcrel_expr (&exp, size);
#else
abort ();
#endif
}
else
emit_expr (&exp, size);
}
if (cie->lsda_encoding != DW_EH_PE_omit)
out_one (cie->lsda_encoding);
}
switch (DWARF2_FDE_RELOC_SIZE)
{
case 2:
enc = DW_EH_PE_sdata2;
break;
case 4:
enc = DW_EH_PE_sdata4;
break;
case 8:
enc = DW_EH_PE_sdata8;
break;
default:
abort ();
}
#if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
enc |= DW_EH_PE_pcrel;
#endif
if (eh_frame)
out_one (enc);
if (cie->first)
for (i = cie->first; i != cie->last; i = i->next)
output_cfi_insn (i);
frag_align (align, DW_CFA_nop, 0);
symbol_set_value_now (end_address);
}
static void
output_fde (struct fde_entry *fde, struct cie_entry *cie,
bfd_boolean eh_frame, struct cfi_insn_data *first,
int align)
{
symbolS *after_size_address, *end_address;
expressionS exp;
offsetT augmentation_size;
enum dwarf2_format fmt = DWARF2_FORMAT (now_seg);
int offset_size;
int addr_size;
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;
if (eh_frame || fmt == dwarf2_format_32bit)
offset_size = 4;
else
{
if (fmt == dwarf2_format_64bit)
out_four (-1);
offset_size = 8;
}
emit_expr (&exp, offset_size); /* Length. */
symbol_set_value_now (after_size_address);
if (eh_frame)
{
exp.X_op = O_subtract;
exp.X_add_symbol = after_size_address;
exp.X_op_symbol = cie->start_address;
exp.X_add_number = 0;
emit_expr (&exp, offset_size); /* CIE offset. */
}
else
{
TC_DWARF2_EMIT_OFFSET (cie->start_address, offset_size);
}
if (eh_frame)
{
exp.X_op = O_subtract;
exp.X_add_number = 0;
#if CFI_DIFF_EXPR_OK
exp.X_add_symbol = fde->start_address;
exp.X_op_symbol = symbol_temp_new_now ();
emit_expr (&exp, DWARF2_FDE_RELOC_SIZE); /* Code offset. */
#else
exp.X_op = O_symbol;
exp.X_add_symbol = fde->start_address;
#ifdef tc_cfi_emit_pcrel_expr
tc_cfi_emit_pcrel_expr (&exp, DWARF2_FDE_RELOC_SIZE); /* Code offset. */
#else
emit_expr (&exp, DWARF2_FDE_RELOC_SIZE); /* Code offset. */
#endif
#endif
addr_size = DWARF2_FDE_RELOC_SIZE;
}
else
{
exp.X_op = O_symbol;
exp.X_add_symbol = fde->start_address;
exp.X_add_number = 0;
addr_size = DWARF2_ADDR_SIZE (stdoutput);
emit_expr (&exp, addr_size);
}
exp.X_op = O_subtract;
exp.X_add_symbol = fde->end_address;
exp.X_op_symbol = fde->start_address; /* Code length. */
exp.X_add_number = 0;
emit_expr (&exp, addr_size);
augmentation_size = encoding_size (fde->lsda_encoding);
if (eh_frame)
out_uleb128 (augmentation_size); /* Augmentation size. */
if (fde->lsda_encoding != DW_EH_PE_omit)
{
exp = fde->lsda;
if ((fde->lsda_encoding & 0x70) == DW_EH_PE_pcrel)
{
#if CFI_DIFF_LSDA_OK
exp.X_op = O_subtract;
exp.X_op_symbol = symbol_temp_new_now ();
emit_expr (&exp, augmentation_size);
#elif defined (tc_cfi_emit_pcrel_expr)
tc_cfi_emit_pcrel_expr (&exp, augmentation_size);
#else
abort ();
#endif
}
else
emit_expr (&exp, 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, bfd_boolean eh_frame,
struct cfi_insn_data **pfirst, int align)
{
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
|| cie->signal_frame != fde->signal_frame
|| cie->per_encoding != fde->per_encoding
|| cie->lsda_encoding != fde->lsda_encoding)
continue;
if (cie->per_encoding != DW_EH_PE_omit)
{
if (cie->personality.X_op != fde->personality.X_op
|| cie->personality.X_add_number
!= fde->personality.X_add_number)
continue;
switch (cie->personality.X_op)
{
case O_constant:
if (cie->personality.X_unsigned != fde->personality.X_unsigned)
continue;
break;
case O_symbol:
if (cie->personality.X_add_symbol
!= fde->personality.X_add_symbol)
continue;
break;
default:
abort ();
}
}
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:
case CFI_val_encoded_addr:
/* 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
|| j->insn == CFI_val_encoded_addr))
{
*pfirst = j;
return cie;
}
fail:;
}
cie = (struct cie_entry *) xmalloc (sizeof (struct cie_entry));
cie->next = cie_root;
cie_root = cie;
cie->return_column = fde->return_column;
cie->signal_frame = fde->signal_frame;
cie->per_encoding = fde->per_encoding;
cie->lsda_encoding = fde->lsda_encoding;
cie->personality = fde->personality;
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
|| i->insn == CFI_val_encoded_addr)
break;
cie->last = i;
*pfirst = i;
output_cie (cie, eh_frame, align);
return cie;
}
#ifdef md_reg_eh_frame_to_debug_frame
static void
cfi_change_reg_numbers (struct cfi_insn_data *insn)
{
for (; insn; insn = insn->next)
switch (insn->insn)
{
case DW_CFA_advance_loc:
case DW_CFA_def_cfa_offset:
case DW_CFA_remember_state:
case DW_CFA_restore_state:
case DW_CFA_GNU_window_save:
case CFI_escape:
break;
case DW_CFA_def_cfa:
case DW_CFA_offset:
insn->u.ri.reg = md_reg_eh_frame_to_debug_frame (insn->u.ri.reg);
break;
case DW_CFA_def_cfa_register:
case DW_CFA_undefined:
case DW_CFA_same_value:
case DW_CFA_restore:
insn->u.r = md_reg_eh_frame_to_debug_frame (insn->u.r);
break;
case DW_CFA_register:
insn->u.rr.reg1 = md_reg_eh_frame_to_debug_frame (insn->u.rr.reg1);
insn->u.rr.reg2 = md_reg_eh_frame_to_debug_frame (insn->u.rr.reg2);
break;
case CFI_val_encoded_addr:
insn->u.ea.reg = md_reg_eh_frame_to_debug_frame (insn->u.ea.reg);
break;
default:
abort ();
}
}
#else
#define cfi_change_reg_numbers(insn) do { } while (0)
#endif
void
cfi_finish (void)
{
segT cfi_seg;
struct fde_entry *fde;
int save_flag_traditional_format;
if (all_fde_data == 0)
return;
if ((cfi_sections & CFI_EMIT_eh_frame) != 0)
{
/* Open .eh_frame section. */
cfi_seg = subseg_new (".eh_frame", 0);
bfd_set_section_flags (stdoutput, cfi_seg,
SEC_ALLOC | SEC_LOAD | SEC_DATA
| DWARF2_EH_FRAME_READ_ONLY);
subseg_set (cfi_seg, 0);
record_alignment (cfi_seg, EH_FRAME_ALIGNMENT);
#ifdef md_fix_up_eh_frame
md_fix_up_eh_frame (cfi_seg);
#endif
/* 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;
if (fde->end_address == NULL)
{
as_bad (_("open CFI at the end of file; missing .cfi_endproc directive"));
fde->end_address = fde->start_address;
}
cie = select_cie_for_fde (fde, TRUE, &first, 2);
output_fde (fde, cie, TRUE, first,
fde->next == NULL ? EH_FRAME_ALIGNMENT : 2);
}
flag_traditional_format = save_flag_traditional_format;
}
if ((cfi_sections & CFI_EMIT_debug_frame) != 0)
{
struct cie_entry *cie, *cie_next;
int alignment = ffs (DWARF2_ADDR_SIZE (stdoutput)) - 1;
for (cie = cie_root; cie; cie = cie_next)
{
cie_next = cie->next;
free ((void *) cie);
}
cie_root = NULL;
/* Open .debug_frame section. */
cfi_seg = subseg_new (".debug_frame", 0);
bfd_set_section_flags (stdoutput, cfi_seg,
SEC_READONLY | SEC_DEBUGGING);
subseg_set (cfi_seg, 0);
record_alignment (cfi_seg, alignment);
for (fde = all_fde_data; fde ; fde = fde->next)
{
struct cfi_insn_data *first;
if (fde->end_address == NULL)
{
as_bad (_("open CFI at the end of file; missing .cfi_endproc directive"));
fde->end_address = fde->start_address;
}
fde->per_encoding = DW_EH_PE_omit;
fde->lsda_encoding = DW_EH_PE_omit;
cfi_change_reg_numbers (fde->data);
cie = select_cie_for_fde (fde, FALSE, &first, alignment);
output_fde (fde, cie, FALSE, first, alignment);
}
}
}
#else /* TARGET_USE_CFIPOP */
void
cfi_finish (void)
{
}
#endif /* TARGET_USE_CFIPOP */
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