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NetBSD/gnu/dist/toolchain/gas/dwarf2dbg.c

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/* dwarf2dbg.c - DWARF2 debug support
Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
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, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
/* Logical line numbers can be controlled by the compiler via the
following two directives:
.file FILENO "file.c"
.loc FILENO LINENO [COLUMN]
FILENO is the filenumber. */
#include "ansidecl.h"
#include "as.h"
#ifdef HAVE_LIMITS_H
#include <limits.h>
#else
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifndef INT_MAX
#define INT_MAX (int) (((unsigned) (-1)) >> 1)
#endif
#endif
#ifdef BFD_ASSEMBLER
#include "dwarf2dbg.h"
#include "subsegs.h"
#include "elf/dwarf2.h"
/* Since we can't generate the prolog until the body is complete, we
use three different subsegments for .debug_line: one holding the
prolog, one for the directory and filename info, and one for the
body ("statement program"). */
#define DL_PROLOG 0
#define DL_FILES 1
#define DL_BODY 2
/* First special line opcde - leave room for the standard opcodes.
Note: If you want to change this, you'll have to update the
"standard_opcode_lengths" table that is emitted below in
dwarf2_finish(). */
#define DWARF2_LINE_OPCODE_BASE 10
#ifndef DWARF2_LINE_BASE
/* Minimum line offset in a special line info. opcode. This value
was chosen to give a reasonable range of values. */
# define DWARF2_LINE_BASE -5
#endif
/* Range of line offsets in a special line info. opcode. */
#ifndef DWARF2_LINE_RANGE
# define DWARF2_LINE_RANGE 14
#endif
#ifndef DWARF2_LINE_MIN_INSN_LENGTH
/* Define the architecture-dependent minimum instruction length (in
bytes). This value should be rather too small than too big. */
# define DWARF2_LINE_MIN_INSN_LENGTH 1
#endif
/* Flag that indicates the initial value of the is_stmt_start flag.
In the present implementation, we do not mark any lines as
the beginning of a source statement, because that information
is not made available by the GCC front-end. */
#define DWARF2_LINE_DEFAULT_IS_STMT 1
/* Given a special op, return the line skip amount. */
#define SPECIAL_LINE(op) \
(((op) - DWARF2_LINE_OPCODE_BASE)%DWARF2_LINE_RANGE + DWARF2_LINE_BASE)
/* Given a special op, return the address skip amount (in units of
DWARF2_LINE_MIN_INSN_LENGTH. */
#define SPECIAL_ADDR(op) (((op) - DWARF2_LINE_OPCODE_BASE)/DWARF2_LINE_RANGE)
/* The maximum address skip amount that can be encoded with a special op. */
#define MAX_SPECIAL_ADDR_DELTA SPECIAL_ADDR(255)
struct line_entry {
struct line_entry *next;
fragS *frag;
addressT frag_ofs;
struct dwarf2_line_info loc;
};
struct line_subseg {
struct line_subseg *next;
subsegT subseg;
struct line_entry *head;
struct line_entry **ptail;
};
struct line_seg {
struct line_seg *next;
segT seg;
struct line_subseg *head;
symbolS *text_start;
symbolS *text_end;
};
/* Collects data for all line table entries during assembly. */
static struct line_seg *all_segs;
struct file_entry {
const char *filename;
unsigned int dir;
};
/* Table of files used by .debug_line. */
static struct file_entry *files;
static unsigned int files_in_use;
static unsigned int files_allocated;
/* True when we've seen a .loc directive recently. Used to avoid
doing work when there's nothing to do. */
static boolean loc_directive_seen;
/* Current location as indicated by the most recent .loc directive. */
static struct dwarf2_line_info current;
/* Fake label name. */
static char const fake_label_name[] = ".L0\001";
/* The size of an address on the target. */
static unsigned int sizeof_address;
static struct line_subseg *get_line_subseg PARAMS ((segT, subsegT));
static unsigned int get_filenum PARAMS ((const char *));
static struct frag *first_frag_for_seg PARAMS ((segT));
static struct frag *last_frag_for_seg PARAMS ((segT));
static void out_byte PARAMS ((int));
static void out_opcode PARAMS ((int));
static void out_two PARAMS ((int));
static void out_four PARAMS ((int));
static void out_abbrev PARAMS ((int, int));
static void out_uleb128 PARAMS ((addressT));
static symbolS *symbol_new_now PARAMS ((void));
static void set_symbol_value_now PARAMS ((symbolS *));
static offsetT get_frag_fix PARAMS ((fragS *));
static void out_set_addr PARAMS ((segT, fragS *, addressT));
static int size_inc_line_addr PARAMS ((int, addressT));
static void emit_inc_line_addr PARAMS ((int, addressT, char *, int));
static void out_inc_line_addr PARAMS ((int, addressT));
static void relax_inc_line_addr PARAMS ((int, segT, fragS *, addressT,
fragS *, addressT));
static void process_entries PARAMS ((segT, struct line_entry *));
static void out_file_list PARAMS ((void));
static void out_debug_line PARAMS ((segT));
static void out_debug_aranges PARAMS ((segT, segT));
static void out_debug_abbrev PARAMS ((segT));
static void out_debug_info PARAMS ((segT, segT, segT));
/* Find or create an entry for SEG+SUBSEG in ALL_SEGS. */
static struct line_subseg *
get_line_subseg (seg, subseg)
segT seg;
subsegT subseg;
{
static segT last_seg;
static subsegT last_subseg;
static struct line_subseg *last_line_subseg;
struct line_seg *s;
struct line_subseg **pss, *ss;
if (seg == last_seg && subseg == last_subseg)
return last_line_subseg;
for (s = all_segs; s; s = s->next)
if (s->seg == seg)
goto found_seg;
s = (struct line_seg *) xmalloc (sizeof (*s));
s->next = all_segs;
s->seg = seg;
s->head = NULL;
all_segs = s;
found_seg:
for (pss = &s->head; (ss = *pss) != NULL ; pss = &ss->next)
{
if (ss->subseg == subseg)
goto found_subseg;
if (ss->subseg > subseg)
break;
}
ss = (struct line_subseg *) xmalloc (sizeof (*ss));
ss->next = *pss;
ss->subseg = subseg;
ss->head = NULL;
ss->ptail = &ss->head;
*pss = ss;
found_subseg:
last_seg = seg;
last_subseg = subseg;
last_line_subseg = ss;
return ss;
}
/* Record an entry for LOC ocurring at OFS within the current fragment. */
void
dwarf2_gen_line_info (ofs, loc)
addressT ofs;
struct dwarf2_line_info *loc;
{
struct line_subseg *ss;
struct line_entry *e;
/* Early out for as-yet incomplete location information. */
if (loc->filenum == 0 || loc->line == 0)
return;
e = (struct line_entry *) xmalloc (sizeof (*e));
e->next = NULL;
e->frag = frag_now;
e->frag_ofs = ofs;
e->loc = *loc;
ss = get_line_subseg (now_seg, now_subseg);
*ss->ptail = e;
ss->ptail = &e->next;
}
void
dwarf2_where (line)
struct dwarf2_line_info *line;
{
if (debug_type == DEBUG_DWARF2)
{
char *filename;
as_where (&filename, &line->line);
line->filenum = get_filenum (filename);
line->column = 0;
line->flags = DWARF2_FLAG_BEGIN_STMT;
}
else
*line = current;
}
/* Called for each machine instruction, or relatively atomic group of
machine instructions (ie built-in macro). The instruction or group
is SIZE bytes in length. If dwarf2 line number generation is called
for, emit a line statement appropriately. */
void
dwarf2_emit_insn (size)
int size;
{
struct dwarf2_line_info loc;
if (debug_type != DEBUG_DWARF2 && ! loc_directive_seen)
return;
loc_directive_seen = false;
dwarf2_where (&loc);
dwarf2_gen_line_info (frag_now_fix () - size, &loc);
}
/* Get a .debug_line file number for FILENAME. */
static unsigned int
get_filenum (filename)
const char *filename;
{
static unsigned int last_used;
unsigned int i;
if (last_used)
if (strcmp (filename, files[last_used].filename) == 0)
return last_used;
for (i = 1; i < files_in_use; ++i)
if (strcmp (filename, files[i].filename) == 0)
return i;
if (i >= files_allocated)
{
unsigned int old = files_allocated;
files_allocated = i + 32;
files = (struct file_entry *)
xrealloc (files, (i + 32) * sizeof (struct file_entry));
memset (files + old, 0, (i + 32 - old) * sizeof (struct file_entry));
}
files[i].filename = xstrdup (filename);
files[i].dir = 0;
files_in_use = i + 1;
last_used = i;
return i;
}
/* Handle the .file directive. */
void
dwarf2_directive_file (dummy)
int dummy ATTRIBUTE_UNUSED;
{
offsetT num;
char *filename;
int filename_len;
/* Continue to accept a bare string and pass it off. */
SKIP_WHITESPACE ();
if (*input_line_pointer == '"')
{
s_app_file (0);
return;
}
num = get_absolute_expression ();
filename = demand_copy_C_string (&filename_len);
demand_empty_rest_of_line ();
if (num < 1)
{
as_bad (_("File number less than one"));
return;
}
if (num < files_in_use && files[num].filename != 0)
{
as_bad (_("File number %ld already allocated"), (long) num);
return;
}
if (num >= (int) files_allocated)
{
unsigned int old = files_allocated;
files_allocated = num + 16;
files = (struct file_entry *)
xrealloc (files, (num + 16) * sizeof (struct file_entry));
/* Zero the new memory. */
memset (files + old, 0, (num + 16 - old) * sizeof (struct file_entry));
}
files[num].filename = filename;
files[num].dir = 0;
files_in_use = num + 1;
}
void
dwarf2_directive_loc (dummy)
int dummy ATTRIBUTE_UNUSED;
{
offsetT filenum, line, column;
filenum = get_absolute_expression ();
SKIP_WHITESPACE ();
line = get_absolute_expression ();
SKIP_WHITESPACE ();
column = get_absolute_expression ();
demand_empty_rest_of_line ();
if (filenum < 1)
{
as_bad (_("File number less than one"));
return;
}
if (filenum >= (int) files_in_use || files[filenum].filename == 0)
{
as_bad (_("Unassigned file number %ld"), (long) filenum);
return;
}
current.filenum = filenum;
current.line = line;
current.column = column;
current.flags = DWARF2_FLAG_BEGIN_STMT;
loc_directive_seen = true;
#ifndef NO_LISTING
if (listing)
listing_source_line (line);
#endif
}
static struct frag *
first_frag_for_seg (seg)
segT seg;
{
frchainS *f, *first = NULL;
for (f = frchain_root; f; f = f->frch_next)
if (f->frch_seg == seg
&& (! first || first->frch_subseg > f->frch_subseg))
first = f;
return first ? first->frch_root : NULL;
}
static struct frag *
last_frag_for_seg (seg)
segT seg;
{
frchainS *f, *last = NULL;
for (f = frchain_root; f; f = f->frch_next)
if (f->frch_seg == seg
&& (! last || last->frch_subseg < f->frch_subseg))
last= f;
return last ? last->frch_last : NULL;
}
/* Emit a single byte into the current segment. */
static inline void
out_byte (byte)
int byte;
{
FRAG_APPEND_1_CHAR (byte);
}
/* Emit a statement program opcode into the current segment. */
static inline void
out_opcode (opc)
int opc;
{
out_byte (opc);
}
/* Emit a two-byte word into the current segment. */
static inline void
out_two (data)
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 (data)
int data;
{
md_number_to_chars (frag_more (4), data, 4);
}
/* Emit an unsigned "little-endian base 128" number. */
static void
out_uleb128 (value)
addressT value;
{
output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
}
/* Emit a tuple for .debug_abbrev. */
static inline void
out_abbrev (name, form)
int name, form;
{
out_uleb128 (name);
out_uleb128 (form);
}
/* Create a new fake symbol whose value is the current position. */
static symbolS *
symbol_new_now ()
{
return symbol_new (fake_label_name, now_seg, frag_now_fix (), frag_now);
}
/* Set the value of SYM to the current position in the current segment. */
static void
set_symbol_value_now (sym)
symbolS *sym;
{
S_SET_SEGMENT (sym, now_seg);
S_SET_VALUE (sym, frag_now_fix ());
symbol_set_frag (sym, frag_now);
}
/* Get the size of a fragment. */
static offsetT
get_frag_fix (frag)
fragS *frag;
{
frchainS *fr;
if (frag->fr_next)
return frag->fr_fix;
/* If a fragment is the last in the chain, special measures must be
taken to find its size before relaxation, since it may be pending
on some subsegment chain. */
for (fr = frchain_root; fr; fr = fr->frch_next)
if (fr->frch_last == frag)
{
return ((char *) obstack_next_free (&fr->frch_obstack)
- frag->fr_literal);
}
abort ();
}
/* Set an absolute address (may result in a relocation entry). */
static void
out_set_addr (seg, frag, ofs)
segT seg;
fragS *frag;
addressT ofs;
{
expressionS expr;
symbolS *sym;
sym = symbol_new (fake_label_name, seg, ofs, frag);
out_opcode (DW_LNS_extended_op);
out_uleb128 (sizeof_address + 1);
out_opcode (DW_LNE_set_address);
expr.X_op = O_symbol;
expr.X_add_symbol = sym;
expr.X_add_number = 0;
emit_expr (&expr, sizeof_address);
}
/* Encode a pair of line and address skips as efficiently as possible.
Note that the line skip is signed, whereas the address skip is unsigned.
The following two routines *must* be kept in sync. This is
enforced by making emit_inc_line_addr abort if we do not emit
exactly the expected number of bytes. */
static int
size_inc_line_addr (line_delta, addr_delta)
int line_delta;
addressT addr_delta;
{
unsigned int tmp, opcode;
int len = 0;
/* Scale the address delta by the minimum instruction length. */
#if DWARF2_LINE_MIN_INSN_LENGTH > 1
assert (addr_delta % DWARF2_LINE_MIN_INSN_LENGTH == 0);
addr_delta /= DWARF2_LINE_MIN_INSN_LENGTH;
#endif
/* INT_MAX is a signal that this is actually a DW_LNE_end_sequence.
We cannot use special opcodes here, since we want the end_sequence
to emit the matrix entry. */
if (line_delta == INT_MAX)
{
if (addr_delta == MAX_SPECIAL_ADDR_DELTA)
len = 1;
else
len = 1 + sizeof_leb128 (addr_delta, 0);
return len + 3;
}
/* Bias the line delta by the base. */
tmp = line_delta - DWARF2_LINE_BASE;
/* If the line increment is out of range of a special opcode, we
must encode it with DW_LNS_advance_line. */
if (tmp >= DWARF2_LINE_RANGE)
{
len = 1 + sizeof_leb128 (line_delta, 1);
line_delta = 0;
tmp = 0 - DWARF2_LINE_BASE;
}
/* Bias the opcode by the special opcode base. */
tmp += DWARF2_LINE_OPCODE_BASE;
/* Avoid overflow when addr_delta is large. */
if (addr_delta < 256 + MAX_SPECIAL_ADDR_DELTA)
{
/* Try using a special opcode. */
opcode = tmp + addr_delta * DWARF2_LINE_RANGE;
if (opcode <= 255)
return len + 1;
/* Try using DW_LNS_const_add_pc followed by special op. */
opcode = tmp + (addr_delta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
if (opcode <= 255)
return len + 2;
}
/* Otherwise use DW_LNS_advance_pc. */
len += 1 + sizeof_leb128 (addr_delta, 0);
/* DW_LNS_copy or special opcode. */
len += 1;
return len;
}
static void
emit_inc_line_addr (line_delta, addr_delta, p, len)
int line_delta;
addressT addr_delta;
char *p;
int len;
{
unsigned int tmp, opcode;
int need_copy = 0;
char *end = p + len;
#if DWARF2_LINE_MIN_INSN_LENGTH > 1
/* Scale the address delta by the minimum instruction length. */
assert (addr_delta % DWARF2_LINE_MIN_INSN_LENGTH == 0);
addr_delta /= DWARF2_LINE_MIN_INSN_LENGTH;
#endif
/* INT_MAX is a signal that this is actually a DW_LNE_end_sequence.
We cannot use special opcodes here, since we want the end_sequence
to emit the matrix entry. */
if (line_delta == INT_MAX)
{
if (addr_delta == MAX_SPECIAL_ADDR_DELTA)
*p++ = DW_LNS_const_add_pc;
else
{
*p++ = DW_LNS_advance_pc;
p += output_leb128 (p, addr_delta, 0);
}
*p++ = DW_LNS_extended_op;
*p++ = 1;
*p++ = DW_LNE_end_sequence;
goto done;
}
/* Bias the line delta by the base. */
tmp = line_delta - DWARF2_LINE_BASE;
/* If the line increment is out of range of a special opcode, we
must encode it with DW_LNS_advance_line. */
if (tmp >= DWARF2_LINE_RANGE)
{
*p++ = DW_LNS_advance_line;
p += output_leb128 (p, line_delta, 1);
/* Prettier, I think, to use DW_LNS_copy instead of a
"line +0, addr +0" special opcode. */
if (addr_delta == 0)
{
*p++ = DW_LNS_copy;
goto done;
}
line_delta = 0;
tmp = 0 - DWARF2_LINE_BASE;
need_copy = 1;
}
/* Bias the opcode by the special opcode base. */
tmp += DWARF2_LINE_OPCODE_BASE;
/* Avoid overflow when addr_delta is large. */
if (addr_delta < 256 + MAX_SPECIAL_ADDR_DELTA)
{
/* Try using a special opcode. */
opcode = tmp + addr_delta * DWARF2_LINE_RANGE;
if (opcode <= 255)
{
*p++ = opcode;
goto done;
}
/* Try using DW_LNS_const_add_pc followed by special op. */
opcode = tmp + (addr_delta - MAX_SPECIAL_ADDR_DELTA) * DWARF2_LINE_RANGE;
if (opcode <= 255)
{
*p++ = DW_LNS_const_add_pc;
*p++ = opcode;
goto done;
}
}
/* Otherwise use DW_LNS_advance_pc. */
*p++ = DW_LNS_advance_pc;
p += output_leb128 (p, addr_delta, 0);
if (need_copy)
*p++ = DW_LNS_copy;
else
*p++ = tmp;
done:
assert (p == end);
}
/* Handy routine to combine calls to the above two routines. */
static void
out_inc_line_addr (line_delta, addr_delta)
int line_delta;
addressT addr_delta;
{
int len = size_inc_line_addr (line_delta, addr_delta);
emit_inc_line_addr (line_delta, addr_delta, frag_more (len), len);
}
/* Generate a variant frag that we can use to relax address/line
increments between fragments of the target segment. */
static void
relax_inc_line_addr (line_delta, seg, to_frag, to_ofs, from_frag, from_ofs)
int line_delta;
segT seg;
fragS *to_frag, *from_frag;
addressT to_ofs, from_ofs;
{
symbolS *to_sym, *from_sym;
expressionS expr;
int max_chars;
to_sym = symbol_new (fake_label_name, seg, to_ofs, to_frag);
from_sym = symbol_new (fake_label_name, seg, from_ofs, from_frag);
expr.X_op = O_subtract;
expr.X_add_symbol = to_sym;
expr.X_op_symbol = from_sym;
expr.X_add_number = 0;
/* The maximum size of the frag is the line delta with a maximum
sized address delta. */
max_chars = size_inc_line_addr (line_delta, -DWARF2_LINE_MIN_INSN_LENGTH);
frag_var (rs_dwarf2dbg, max_chars, max_chars, 1,
make_expr_symbol (&expr), line_delta, NULL);
}
/* The function estimates the size of a rs_dwarf2dbg variant frag
based on the current values of the symbols. It is called before
the relaxation loop. We set fr_subtype to the expected length. */
int
dwarf2dbg_estimate_size_before_relax (frag)
fragS *frag;
{
offsetT addr_delta;
int size;
addr_delta = resolve_symbol_value (frag->fr_symbol, 0);
size = size_inc_line_addr (frag->fr_offset, addr_delta);
frag->fr_subtype = size;
return size;
}
/* This function relaxes a rs_dwarf2dbg variant frag based on the
current values of the symbols. fr_subtype is the current length
of the frag. This returns the change in frag length. */
int
dwarf2dbg_relax_frag (frag)
fragS *frag;
{
int old_size, new_size;
old_size = frag->fr_subtype;
new_size = dwarf2dbg_estimate_size_before_relax (frag);
return new_size - old_size;
}
/* This function converts a rs_dwarf2dbg variant frag into a normal
fill frag. This is called after all relaxation has been done.
fr_subtype will be the desired length of the frag. */
void
dwarf2dbg_convert_frag (frag)
fragS *frag;
{
offsetT addr_diff;
addr_diff = resolve_symbol_value (frag->fr_symbol, 1);
/* fr_var carries the max_chars that we created the fragment with.
fr_subtype carries the current expected length. We must, of
course, have allocated enough memory earlier. */
assert (frag->fr_var >= (int) frag->fr_subtype);
emit_inc_line_addr (frag->fr_offset, addr_diff,
frag->fr_literal + frag->fr_fix, frag->fr_subtype);
frag->fr_fix += frag->fr_subtype;
frag->fr_type = rs_fill;
frag->fr_var = 0;
frag->fr_offset = 0;
}
/* Generate .debug_line content for the chain of line number entries
beginning at E, for segment SEG. */
static void
process_entries (seg, e)
segT seg;
struct line_entry *e;
{
unsigned filenum = 1;
unsigned line = 1;
unsigned column = 0;
unsigned flags = DWARF2_LINE_DEFAULT_IS_STMT ? DWARF2_FLAG_BEGIN_STMT : 0;
fragS *frag = NULL;
fragS *last_frag;
addressT frag_ofs = 0;
addressT last_frag_ofs;
struct line_entry *next;
while (e)
{
int changed = 0;
if (filenum != e->loc.filenum)
{
filenum = e->loc.filenum;
out_opcode (DW_LNS_set_file);
out_uleb128 (filenum);
changed = 1;
}
if (column != e->loc.column)
{
column = e->loc.column;
out_opcode (DW_LNS_set_column);
out_uleb128 (column);
changed = 1;
}
if ((e->loc.flags ^ flags) & DWARF2_FLAG_BEGIN_STMT)
{
flags = e->loc.flags;
out_opcode (DW_LNS_negate_stmt);
changed = 1;
}
if (e->loc.flags & DWARF2_FLAG_BEGIN_BLOCK)
{
out_opcode (DW_LNS_set_basic_block);
changed = 1;
}
/* Don't try to optimize away redundant entries; gdb wants two
entries for a function where the code starts on the same line as
the {, and there's no way to identify that case here. Trust gcc
to optimize appropriately. */
if (1 /* line != e->loc.line || changed */)
{
int line_delta = e->loc.line - line;
if (frag == NULL)
{
out_set_addr (seg, e->frag, e->frag_ofs);
out_inc_line_addr (line_delta, 0);
}
else if (frag == e->frag)
out_inc_line_addr (line_delta, e->frag_ofs - frag_ofs);
else
relax_inc_line_addr (line_delta, seg, e->frag, e->frag_ofs,
frag, frag_ofs);
frag = e->frag;
frag_ofs = e->frag_ofs;
line = e->loc.line;
}
else if (frag == NULL)
{
out_set_addr (seg, e->frag, e->frag_ofs);
frag = e->frag;
frag_ofs = e->frag_ofs;
}
next = e->next;
free (e);
e = next;
}
/* Emit a DW_LNE_end_sequence for the end of the section. */
last_frag = last_frag_for_seg (seg);
last_frag_ofs = get_frag_fix (last_frag);
if (frag == last_frag)
out_inc_line_addr (INT_MAX, last_frag_ofs - frag_ofs);
else
relax_inc_line_addr (INT_MAX, seg, last_frag, last_frag_ofs,
frag, frag_ofs);
}
/* Emit the directory and file tables for .debug_line. */
static void
out_file_list ()
{
size_t size;
char *cp;
unsigned int i;
/* Terminate directory list. */
out_byte ('\0');
for (i = 1; i < files_in_use; ++i)
{
if (files[i].filename == NULL)
{
as_bad (_("Unassigned file number %u"), i);
continue;
}
size = strlen (files[i].filename) + 1;
cp = frag_more (size);
memcpy (cp, files[i].filename, size);
out_uleb128 (files[i].dir); /* directory number */
out_uleb128 (0); /* last modification timestamp */
out_uleb128 (0); /* filesize */
}
/* Terminate filename list. */
out_byte (0);
}
/* Emit the collected .debug_line data. */
static void
out_debug_line (line_seg)
segT line_seg;
{
expressionS expr;
symbolS *line_start;
symbolS *prologue_end;
symbolS *line_end;
struct line_seg *s;
subseg_set (line_seg, 0);
line_start = symbol_new_now ();
prologue_end = symbol_make (fake_label_name);
line_end = symbol_make (fake_label_name);
/* Total length of the information for this compilation unit. */
expr.X_op = O_subtract;
expr.X_add_symbol = line_end;
expr.X_op_symbol = line_start;
expr.X_add_number = -4;
emit_expr (&expr, 4);
/* Version. */
out_two (2);
/* Length of the prologue following this length. */
expr.X_op = O_subtract;
expr.X_add_symbol = prologue_end;
expr.X_op_symbol = line_start;
expr.X_add_number = - (4 + 2 + 4);
emit_expr (&expr, 4);
/* Parameters of the state machine. */
out_byte (DWARF2_LINE_MIN_INSN_LENGTH);
out_byte (DWARF2_LINE_DEFAULT_IS_STMT);
out_byte (DWARF2_LINE_BASE);
out_byte (DWARF2_LINE_RANGE);
out_byte (DWARF2_LINE_OPCODE_BASE);
/* Standard opcode lengths. */
out_byte (0); /* DW_LNS_copy */
out_byte (1); /* DW_LNS_advance_pc */
out_byte (1); /* DW_LNS_advance_line */
out_byte (1); /* DW_LNS_set_file */
out_byte (1); /* DW_LNS_set_column */
out_byte (0); /* DW_LNS_negate_stmt */
out_byte (0); /* DW_LNS_set_basic_block */
out_byte (0); /* DW_LNS_const_add_pc */
out_byte (1); /* DW_LNS_fixed_advance_pc */
out_file_list ();
set_symbol_value_now (prologue_end);
/* For each section, emit a statement program. */
for (s = all_segs; s; s = s->next)
process_entries (s->seg, s->head->head);
set_symbol_value_now (line_end);
}
/* Emit data for .debug_aranges. */
static void
out_debug_aranges (aranges_seg, info_seg)
segT aranges_seg;
segT info_seg;
{
unsigned int addr_size = sizeof_address;
addressT size, skip;
struct line_seg *s;
expressionS expr;
char *p;
size = 4 + 2 + 4 + 1 + 1;
skip = 2 * addr_size - (size & (2 * addr_size - 1));
if (skip == 2 * addr_size)
skip = 0;
size += skip;
for (s = all_segs; s; s = s->next)
size += 2 * addr_size;
size += 2 * addr_size;
subseg_set (aranges_seg, 0);
/* Length of the compilation unit. */
out_four (size - 4);
/* Version. */
out_two (2);
/* Offset to .debug_info. */
expr.X_op = O_symbol;
expr.X_add_symbol = section_symbol (info_seg);
expr.X_add_number = 0;
emit_expr (&expr, 4);
/* Size of an address (offset portion). */
out_byte (addr_size);
/* Size of a segment descriptor. */
out_byte (0);
/* Align the header. */
if (skip)
frag_align (ffs (2 * addr_size) - 1, 0, 0);
for (s = all_segs; s; s = s->next)
{
fragS *frag;
symbolS *beg, *end;
frag = first_frag_for_seg (s->seg);
beg = symbol_new (fake_label_name, s->seg, 0, frag);
s->text_start = beg;
frag = last_frag_for_seg (s->seg);
end = symbol_new (fake_label_name, s->seg, get_frag_fix (frag), frag);
s->text_end = end;
expr.X_op = O_symbol;
expr.X_add_symbol = beg;
expr.X_add_number = 0;
emit_expr (&expr, addr_size);
expr.X_op = O_subtract;
expr.X_add_symbol = end;
expr.X_op_symbol = beg;
expr.X_add_number = 0;
emit_expr (&expr, addr_size);
}
p = frag_more (2 * addr_size);
md_number_to_chars (p, 0, addr_size);
md_number_to_chars (p + addr_size, 0, addr_size);
}
/* Emit data for .debug_abbrev. Note that this must be kept in
sync with out_debug_info below. */
static void
out_debug_abbrev (abbrev_seg)
segT abbrev_seg;
{
subseg_set (abbrev_seg, 0);
out_uleb128 (1);
out_uleb128 (DW_TAG_compile_unit);
out_byte (DW_CHILDREN_no);
out_abbrev (DW_AT_stmt_list, DW_FORM_data4);
if (all_segs->next == NULL)
{
out_abbrev (DW_AT_low_pc, DW_FORM_addr);
out_abbrev (DW_AT_high_pc, DW_FORM_addr);
}
out_abbrev (DW_AT_comp_dir, DW_FORM_string);
out_abbrev (DW_AT_producer, DW_FORM_string);
out_abbrev (DW_AT_language, DW_FORM_data2);
out_abbrev (0, 0);
/* Terminate the abbreviations for this compilation unit. */
out_byte (0);
}
/* Emit a description of this compilation unit for .debug_info. */
static void
out_debug_info (info_seg, abbrev_seg, line_seg)
segT info_seg;
segT abbrev_seg;
segT line_seg;
{
char producer[128];
char *comp_dir;
expressionS expr;
symbolS *info_start;
symbolS *info_end;
char *p;
int len;
subseg_set (info_seg, 0);
info_start = symbol_new_now ();
info_end = symbol_make (fake_label_name);
/* Compilation Unit length. */
expr.X_op = O_subtract;
expr.X_add_symbol = info_end;
expr.X_op_symbol = info_start;
expr.X_add_number = -4;
emit_expr (&expr, 4);
/* DWARF version. */
out_two (2);
/* .debug_abbrev offset */
expr.X_op = O_symbol;
expr.X_add_symbol = section_symbol (abbrev_seg);
expr.X_add_number = 0;
emit_expr (&expr, 4);
/* Target address size. */
out_byte (sizeof_address);
/* DW_TAG_compile_unit DIE abbrev */
out_uleb128 (1);
/* DW_AT_stmt_list */
expr.X_op = O_symbol;
expr.X_add_symbol = section_symbol (line_seg);
expr.X_add_number = 0;
emit_expr (&expr, 4);
/* These two attributes may only be emitted if all of the code is
contiguous. Multiple sections are not that. */
if (all_segs->next == NULL)
{
/* DW_AT_low_pc */
expr.X_op = O_symbol;
expr.X_add_symbol = all_segs->text_start;
expr.X_add_number = 0;
emit_expr (&expr, sizeof_address);
/* DW_AT_high_pc */
expr.X_op = O_symbol;
expr.X_add_symbol = all_segs->text_end;
expr.X_add_number = 0;
emit_expr (&expr, sizeof_address);
}
/* DW_AT_comp_dir */
comp_dir = getpwd ();
len = strlen (comp_dir) + 1;
p = frag_more (len);
memcpy (p, comp_dir, len);
/* DW_AT_producer */
sprintf (producer, "GNU AS %s", VERSION);
len = strlen (producer) + 1;
p = frag_more (len);
memcpy (p, producer, len);
/* DW_AT_language. Yes, this is probably not really MIPS, but the
dwarf2 draft has no standard code for assembler. */
out_two (DW_LANG_Mips_Assembler);
set_symbol_value_now (info_end);
}
void
dwarf2_finish ()
{
segT line_seg;
struct line_seg *s;
/* If no debug information was recorded, nothing to do. */
if (all_segs == NULL)
return;
/* Calculate the size of an address for the target machine. */
sizeof_address = bfd_arch_bits_per_address (stdoutput) / 8;
/* Create and switch to the line number section. */
line_seg = subseg_new (".debug_line", 0);
bfd_set_section_flags (stdoutput, line_seg, SEC_READONLY);
/* For each subsection, chain the debug entries together. */
for (s = all_segs; s; s = s->next)
{
struct line_subseg *ss = s->head;
struct line_entry **ptail = ss->ptail;
while ((ss = ss->next) != NULL)
{
*ptail = ss->head;
ptail = ss->ptail;
}
}
out_debug_line (line_seg);
/* If this is assembler generated line info, we need .debug_info
and .debug_abbrev sections as well. */
if (debug_type == DEBUG_DWARF2)
{
segT abbrev_seg;
segT info_seg;
segT aranges_seg;
info_seg = subseg_new (".debug_info", 0);
abbrev_seg = subseg_new (".debug_abbrev", 0);
aranges_seg = subseg_new (".debug_aranges", 0);
bfd_set_section_flags (stdoutput, info_seg, SEC_READONLY);
bfd_set_section_flags (stdoutput, abbrev_seg, SEC_READONLY);
bfd_set_section_flags (stdoutput, aranges_seg, SEC_READONLY);
record_alignment (aranges_seg, ffs (2 * sizeof_address) - 1);
out_debug_aranges (aranges_seg, info_seg);
out_debug_abbrev (abbrev_seg);
out_debug_info (info_seg, abbrev_seg, line_seg);
}
}
#else
void
dwarf2_finish ()
{
}
int
dwarf2dbg_estimate_size_before_relax (frag)
fragS *frag ATTRIBUTE_UNUSED;
{
as_fatal (_("dwarf2 is not supported for this object file format"));
return 0;
}
int
dwarf2dbg_relax_frag (frag)
fragS *frag ATTRIBUTE_UNUSED;
{
as_fatal (_("dwarf2 is not supported for this object file format"));
return 0;
}
void
dwarf2dbg_convert_frag (frag)
fragS *frag ATTRIBUTE_UNUSED;
{
as_fatal (_("dwarf2 is not supported for this object file format"));
}
void
dwarf2_emit_insn (size)
int size ATTRIBUTE_UNUSED;
{
}
void
dwarf2_directive_file (dummy)
int dummy ATTRIBUTE_UNUSED;
{
s_app_file (0);
}
void
dwarf2_directive_loc (dummy)
int dummy ATTRIBUTE_UNUSED;
{
as_fatal (_("dwarf2 is not supported for this object file format"));
}
#endif /* BFD_ASSEMBLER */
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