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Add struct to record dwarf line number state machine.

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gdb/ChangeLog:

	* dwarf2read.c (lnp_state_machine): New typedef.
	(lnp_reader_state): New typedef.
	(dwarf_record_line_1): Renamed from dwarf_record_line.
	All callers updated.
	(dwarf_record_line): New function.
	(init_lnp_state_machine): New function.
	(check_line_address): Replace p_record_line parameter with state.
	All callers updated.
	(dwarf_decode_lines_1): Call dwarf_record_line, init_lnp_state_machine.
	Update to record state in lnp_state_machine.
This commit is contained in:
Doug Evans 2015-05-27 14:44:29 -07:00
parent 8ded2ddc8b
commit d9b3de22f3
2 changed files with 260 additions and 150 deletions
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13
gdb/ChangeLog
View file

@ -1,3 +1,16 @@
2015-05-27 Doug Evans <dje@google.com>
* dwarf2read.c (lnp_state_machine): New typedef.
(lnp_reader_state): New typedef.
(dwarf_record_line_1): Renamed from dwarf_record_line.
All callers updated.
(dwarf_record_line): New function.
(init_lnp_state_machine): New function.
(check_line_address): Replace p_record_line parameter with state.
All callers updated.
(dwarf_decode_lines_1): Call dwarf_record_line, init_lnp_state_machine.
Update to record state in lnp_state_machine.
2015-05-27 Doug Evans <dje@google.com>
* dwarf2read.c (record_line_ftype): New typedef.

397
gdb/dwarf2read.c
View file

@ -17480,6 +17480,54 @@ psymtab_include_file_name (const struct line_header *lh, int file_index,
typedef void (record_line_ftype) (struct subfile *subfile, int line,
CORE_ADDR pc);
/* State machine to track the state of the line number program. */
typedef struct
{
/* These are part of the standard DWARF line number state machine. */
unsigned char op_index;
unsigned int file;
unsigned int line;
CORE_ADDR address;
int is_stmt;
unsigned int discriminator;
/* Additional bits of state we need to track. */
/* The last file that we called dwarf2_start_subfile for.
This is only used for TLLs. */
unsigned int last_file;
/* The last file a line number was recorded for. */
struct subfile *last_subfile;
/* The function to call to record a line. */
record_line_ftype *record_line;
/* The last line number that was recorded, used to coalesce
consecutive entries for the same line. This can happen, for
example, when discriminators are present. PR 17276. */
unsigned int last_line;
int line_has_non_zero_discriminator;
} lnp_state_machine;
/* There's a lot of static state to pass to dwarf_record_line.
This keeps it all together. */
typedef struct
{
/* The gdbarch. */
struct gdbarch *gdbarch;
/* The line number header. */
struct line_header *line_header;
/* Non-zero if we're recording lines.
Otherwise we're building partial symtabs and are just interested in
finding include files mentioned by the line number program. */
int record_lines_p;
} lnp_reader_state;
/* Ignore this record_line request. */
static void
@ -17539,9 +17587,9 @@ dwarf_record_line_p (unsigned int line, unsigned int last_line,
in the line table of subfile SUBFILE. */
static void
dwarf_record_line (struct gdbarch *gdbarch, struct subfile *subfile,
unsigned int line, CORE_ADDR address,
record_line_ftype p_record_line)
dwarf_record_line_1 (struct gdbarch *gdbarch, struct subfile *subfile,
unsigned int line, CORE_ADDR address,
record_line_ftype p_record_line)
{
CORE_ADDR addr = gdbarch_addr_bits_remove (gdbarch, address);
@ -17558,7 +17606,7 @@ dwarf_record_line (struct gdbarch *gdbarch, struct subfile *subfile,
/* Subroutine of dwarf_decode_lines_1 to simplify it.
Mark the end of a set of line number records.
The arguments are the same as for dwarf_record_line.
The arguments are the same as for dwarf_record_line_1.
If SUBFILE is NULL the request is ignored. */
static void
@ -17576,14 +17624,103 @@ dwarf_finish_line (struct gdbarch *gdbarch, struct subfile *subfile,
paddress (gdbarch, address));
}
dwarf_record_line (gdbarch, subfile, 0, address, p_record_line);
dwarf_record_line_1 (gdbarch, subfile, 0, address, p_record_line);
}
/* Record the line in STATE.
END_SEQUENCE is non-zero if we're processing the end of a sequence. */
static void
dwarf_record_line (lnp_reader_state *reader, lnp_state_machine *state,
int end_sequence)
{
const struct line_header *lh = reader->line_header;
unsigned int file, line, discriminator;
int is_stmt;
file = state->file;
line = state->line;
is_stmt = state->is_stmt;
discriminator = state->discriminator;
if (dwarf_line_debug)
{
fprintf_unfiltered (gdb_stdlog,
"Processing actual line %u: file %u,"
" address %s, is_stmt %u, discrim %u\n",
line, file,
paddress (reader->gdbarch, state->address),
is_stmt, discriminator);
}
if (file == 0 || file - 1 >= lh->num_file_names)
dwarf2_debug_line_missing_file_complaint ();
/* For now we ignore lines not starting on an instruction boundary.
But not when processing end_sequence for compatibility with the
previous version of the code. */
else if (state->op_index == 0 || end_sequence)
{
lh->file_names[file - 1].included_p = 1;
if (reader->record_lines_p && is_stmt)
{
if (state->last_subfile != current_subfile)
{
dwarf_finish_line (reader->gdbarch, state->last_subfile,
state->address, state->record_line);
}
if (!end_sequence)
{
if (dwarf_record_line_p (line, state->last_line,
state->line_has_non_zero_discriminator,
state->last_subfile))
{
dwarf_record_line_1 (reader->gdbarch, current_subfile,
line, state->address,
state->record_line);
}
state->last_subfile = current_subfile;
state->last_line = line;
}
}
}
}
/* Initialize STATE for the start of a line number program. */
static void
init_lnp_state_machine (lnp_state_machine *state,
const lnp_reader_state *reader)
{
memset (state, 0, sizeof (*state));
/* Just starting, there is no "last file". */
state->last_file = 0;
state->last_subfile = NULL;
state->record_line = record_line;
state->last_line = 0;
state->line_has_non_zero_discriminator = 0;
/* Initialize these according to the DWARF spec. */
state->op_index = 0;
state->file = 1;
state->line = 1;
/* Call `gdbarch_adjust_dwarf2_line' on the initial 0 address as if there
was a line entry for it so that the backend has a chance to adjust it
and also record it in case it needs it. This is currently used by MIPS
code, cf. `mips_adjust_dwarf2_line'. */
state->address = gdbarch_adjust_dwarf2_line (reader->gdbarch, 0, 0);
state->is_stmt = reader->line_header->default_is_stmt;
state->discriminator = 0;
}
/* Check address and if invalid nop-out the rest of the lines in this
sequence. */
static void
check_line_address (struct dwarf2_cu *cu, record_line_ftype **p_record_line,
check_line_address (struct dwarf2_cu *cu, lnp_state_machine *state,
const gdb_byte *line_ptr,
CORE_ADDR lowpc, CORE_ADDR address)
{
@ -17603,14 +17740,16 @@ check_line_address (struct dwarf2_cu *cu, record_line_ftype **p_record_line,
complaint (&symfile_complaints,
_(".debug_line address at offset 0x%lx is 0 [in module %s]"),
line_offset, objfile_name (objfile));
*p_record_line = noop_record_line;
/* Note: *p_record_line is left as noop_record_line
state->record_line = noop_record_line;
/* Note: sm.record_line is left as noop_record_line
until we see DW_LNE_end_sequence. */
}
}
/* Subroutine of dwarf_decode_lines to simplify it.
Process the line number information in LH. */
Process the line number information in LH.
If DECODE_FOR_PST_P is non-zero, all we do is process the line number
program in order to set included_p for every referenced header. */
static void
dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
@ -17624,43 +17763,38 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
struct objfile *objfile = cu->objfile;
bfd *abfd = objfile->obfd;
struct gdbarch *gdbarch = get_objfile_arch (objfile);
struct subfile *last_subfile = NULL;
void (*p_record_line) (struct subfile *subfile, int line, CORE_ADDR pc)
= record_line;
/* Non-zero if we're recording line info (as opposed to building partial
symtabs). */
int record_lines_p = !decode_for_pst_p;
/* A collection of things we need to pass to dwarf_record_line. */
lnp_reader_state reader_state;
baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
line_ptr = lh->statement_program_start;
line_end = lh->statement_program_end;
reader_state.gdbarch = gdbarch;
reader_state.line_header = lh;
reader_state.record_lines_p = record_lines_p;
/* Read the statement sequences until there's nothing left. */
while (line_ptr < line_end)
{
/* State machine registers. Call `gdbarch_adjust_dwarf2_line'
on the initial 0 address as if there was a line entry for it
so that the backend has a chance to adjust it and also record
it in case it needs it. This is currently used by MIPS code,
cf. `mips_adjust_dwarf2_line'. */
CORE_ADDR address = gdbarch_adjust_dwarf2_line (gdbarch, 0, 0);
unsigned int file = 1;
unsigned int line = 1;
int is_stmt = lh->default_is_stmt;
/* The DWARF line number program state machine. */
lnp_state_machine state_machine;
int end_sequence = 0;
unsigned char op_index = 0;
unsigned int discriminator = 0;
/* The last line number that was recorded, used to coalesce
consecutive entries for the same line. This can happen, for
example, when discriminators are present. PR 17276. */
unsigned int last_line = 0;
int line_has_non_zero_discriminator = 0;
if (!decode_for_pst_p && lh->num_file_names >= file)
/* Reset the state machine at the start of each sequence. */
init_lnp_state_machine (&state_machine, &reader_state);
if (record_lines_p && lh->num_file_names >= state_machine.file)
{
/* Start a subfile for the current file of the state machine. */
/* lh->include_dirs and lh->file_names are 0-based, but the
directory and file name numbers in the statement program
are 1-based. */
struct file_entry *fe = &lh->file_names[file - 1];
struct file_entry *fe = &lh->file_names[state_machine.file - 1];
const char *dir = NULL;
if (fe->dir_index && lh->include_dirs != NULL)
@ -17670,15 +17804,10 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
}
/* Decode the table. */
while (!end_sequence)
while (line_ptr < line_end && !end_sequence)
{
op_code = read_1_byte (abfd, line_ptr);
line_ptr += 1;
if (line_ptr > line_end)
{
dwarf2_debug_line_missing_end_sequence_complaint ();
break;
}
if (op_code >= lh->opcode_base)
{
@ -17688,42 +17817,23 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
int line_delta;
adj_opcode = op_code - lh->opcode_base;
addr_adj = (((op_index + (adj_opcode / lh->line_range))
addr_adj = (((state_machine.op_index
+ (adj_opcode / lh->line_range))
/ lh->maximum_ops_per_instruction)
* lh->minimum_instruction_length);
address += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
op_index = ((op_index + (adj_opcode / lh->line_range))
% lh->maximum_ops_per_instruction);
state_machine.address
+= gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
state_machine.op_index = ((state_machine.op_index
+ (adj_opcode / lh->line_range))
% lh->maximum_ops_per_instruction);
line_delta = lh->line_base + (adj_opcode % lh->line_range);
line += line_delta;
state_machine.line += line_delta;
if (line_delta != 0)
line_has_non_zero_discriminator = discriminator != 0;
if (lh->num_file_names < file || file == 0)
dwarf2_debug_line_missing_file_complaint ();
/* For now we ignore lines not starting on an
instruction boundary. */
else if (op_index == 0)
{
lh->file_names[file - 1].included_p = 1;
if (!decode_for_pst_p && is_stmt)
{
if (last_subfile != current_subfile)
{
dwarf_finish_line (gdbarch, last_subfile,
address, p_record_line);
}
if (dwarf_record_line_p (line, last_line,
line_has_non_zero_discriminator,
last_subfile))
{
dwarf_record_line (gdbarch, current_subfile,
line, address, p_record_line);
}
last_subfile = current_subfile;
last_line = line;
}
}
discriminator = 0;
state_machine.line_has_non_zero_discriminator
= state_machine.discriminator != 0;
dwarf_record_line (&reader_state, &state_machine, 0);
state_machine.discriminator = 0;
}
else switch (op_code)
{
@ -17737,17 +17847,22 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
switch (extended_op)
{
case DW_LNE_end_sequence:
p_record_line = record_line;
state_machine.record_line = record_line;
end_sequence = 1;
break;
case DW_LNE_set_address:
address = read_address (abfd, line_ptr, cu, &bytes_read);
line_ptr += bytes_read;
check_line_address (cu, &p_record_line, line_ptr,
lowpc, address);
op_index = 0;
address += baseaddr;
address = gdbarch_adjust_dwarf2_line (gdbarch, address, 0);
{
CORE_ADDR address
= read_address (abfd, line_ptr, cu, &bytes_read);
line_ptr += bytes_read;
check_line_address (cu, &state_machine, line_ptr,
lowpc, address);
state_machine.op_index = 0;
address += baseaddr;
state_machine.address
= gdbarch_adjust_dwarf2_line (gdbarch, address, 0);
}
break;
case DW_LNE_define_file:
{
@ -17775,9 +17890,10 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
if there are consecutive entries for the same
(non-prologue) line we want to coalesce them.
PR 17276. */
discriminator = read_unsigned_leb128 (abfd, line_ptr,
&bytes_read);
line_has_non_zero_discriminator |= discriminator != 0;
state_machine.discriminator
= read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
state_machine.line_has_non_zero_discriminator
|= state_machine.discriminator != 0;
line_ptr += bytes_read;
break;
default:
@ -17796,30 +17912,8 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
}
break;
case DW_LNS_copy:
if (lh->num_file_names < file || file == 0)
dwarf2_debug_line_missing_file_complaint ();
else
{
lh->file_names[file - 1].included_p = 1;
if (!decode_for_pst_p && is_stmt)
{
if (last_subfile != current_subfile)
{
dwarf_finish_line (gdbarch, last_subfile,
address, p_record_line);
}
if (dwarf_record_line_p (line, last_line,
line_has_non_zero_discriminator,
last_subfile))
{
dwarf_record_line (gdbarch, current_subfile,
line, address, p_record_line);
}
last_subfile = current_subfile;
last_line = line;
}
}
discriminator = 0;
dwarf_record_line (&reader_state, &state_machine, 0);
state_machine.discriminator = 0;
break;
case DW_LNS_advance_pc:
{
@ -17827,12 +17921,13 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
= read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
CORE_ADDR addr_adj;
addr_adj = (((op_index + adjust)
addr_adj = (((state_machine.op_index + adjust)
/ lh->maximum_ops_per_instruction)
* lh->minimum_instruction_length);
address += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
op_index = ((op_index + adjust)
% lh->maximum_ops_per_instruction);
state_machine.address
+= gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
state_machine.op_index = ((state_machine.op_index + adjust)
% lh->maximum_ops_per_instruction);
line_ptr += bytes_read;
}
break;
@ -17841,44 +17936,48 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
int line_delta
= read_signed_leb128 (abfd, line_ptr, &bytes_read);
line += line_delta;
state_machine.line += line_delta;
if (line_delta != 0)
line_has_non_zero_discriminator = discriminator != 0;
state_machine.line_has_non_zero_discriminator
= state_machine.discriminator != 0;
line_ptr += bytes_read;
}
break;
case DW_LNS_set_file:
{
/* The arrays lh->include_dirs and lh->file_names are
0-based, but the directory and file name numbers in
the statement program are 1-based. */
struct file_entry *fe;
const char *dir = NULL;
{
/* The arrays lh->include_dirs and lh->file_names are
0-based, but the directory and file name numbers in
the statement program are 1-based. */
struct file_entry *fe;
const char *dir = NULL;
file = read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
line_ptr += bytes_read;
if (lh->num_file_names < file || file == 0)
dwarf2_debug_line_missing_file_complaint ();
else
{
fe = &lh->file_names[file - 1];
if (fe->dir_index && lh->include_dirs != NULL)
dir = lh->include_dirs[fe->dir_index - 1];
if (!decode_for_pst_p)
{
last_subfile = current_subfile;
line_has_non_zero_discriminator = discriminator != 0;
dwarf2_start_subfile (fe->name, dir);
}
}
}
state_machine.file = read_unsigned_leb128 (abfd, line_ptr,
&bytes_read);
line_ptr += bytes_read;
if (state_machine.file == 0
|| state_machine.file - 1 >= lh->num_file_names)
dwarf2_debug_line_missing_file_complaint ();
else
{
fe = &lh->file_names[state_machine.file - 1];
if (fe->dir_index && lh->include_dirs != NULL)
dir = lh->include_dirs[fe->dir_index - 1];
if (record_lines_p)
{
state_machine.last_subfile = current_subfile;
state_machine.line_has_non_zero_discriminator
= state_machine.discriminator != 0;
dwarf2_start_subfile (fe->name, dir);
}
}
}
break;
case DW_LNS_set_column:
(void) read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
line_ptr += bytes_read;
break;
case DW_LNS_negate_stmt:
is_stmt = (!is_stmt);
state_machine.is_stmt = (!state_machine.is_stmt);
break;
case DW_LNS_set_basic_block:
break;
@ -17892,12 +17991,13 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
CORE_ADDR adjust = (255 - lh->opcode_base) / lh->line_range;
CORE_ADDR addr_adj;
addr_adj = (((op_index + adjust)
addr_adj = (((state_machine.op_index + adjust)
/ lh->maximum_ops_per_instruction)
* lh->minimum_instruction_length);
address += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
op_index = ((op_index + adjust)
% lh->maximum_ops_per_instruction);
state_machine.address
+= gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
state_machine.op_index = ((state_machine.op_index + adjust)
% lh->maximum_ops_per_instruction);
}
break;
case DW_LNS_fixed_advance_pc:
@ -17905,8 +18005,9 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
CORE_ADDR addr_adj;
addr_adj = read_2_bytes (abfd, line_ptr);
address += gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
op_index = 0;
state_machine.address
+= gdbarch_adjust_dwarf2_line (gdbarch, addr_adj, 1);
state_machine.op_index = 0;
line_ptr += 2;
}
break;
@ -17923,17 +18024,13 @@ dwarf_decode_lines_1 (struct line_header *lh, struct dwarf2_cu *cu,
}
}
}
if (lh->num_file_names < file || file == 0)
dwarf2_debug_line_missing_file_complaint ();
else
{
lh->file_names[file - 1].included_p = 1;
if (!decode_for_pst_p)
{
dwarf_finish_line (gdbarch, current_subfile, address,
p_record_line);
}
}
if (!end_sequence)
dwarf2_debug_line_missing_end_sequence_complaint ();
/* We got a DW_LNE_end_sequence (or we ran off the end of the buffer,
in which case we still finish recording the last line). */
dwarf_record_line (&reader_state, &state_machine, 1);
}
}