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/* Routines for restoring various data types from a file stream. This deals
with various data types like strings, integers, enums, etc.
Copyright (C) 2011-2017 Free Software Foundation, Inc.
Contributed by Diego Novillo <dnovillo@google.com>
This file is part of GCC.
GCC 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.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "tree.h"
#include "gimple.h"
#include "cgraph.h"
#include "data-streamer.h"
/* Read a string from the string table in DATA_IN using input block
IB. Write the length to RLEN. */
static const char *
string_for_index (struct data_in *data_in, unsigned int loc, unsigned int *rlen)
{
unsigned int len;
const char *result;
if (!loc)
{
*rlen = 0;
return NULL;
}
/* Get the string stored at location LOC in DATA_IN->STRINGS. */
lto_input_block str_tab (data_in->strings, loc - 1, data_in->strings_len, NULL);
len = streamer_read_uhwi (&str_tab);
*rlen = len;
if (str_tab.p + len > data_in->strings_len)
internal_error ("bytecode stream: string too long for the string table");
result = (const char *)(data_in->strings + str_tab.p);
return result;
}
/* Read a string from the string table in DATA_IN using input block
IB. Write the length to RLEN. */
const char *
streamer_read_indexed_string (struct data_in *data_in,
struct lto_input_block *ib, unsigned int *rlen)
{
return string_for_index (data_in, streamer_read_uhwi (ib), rlen);
}
/* Read a NULL terminated string from the string table in DATA_IN. */
const char *
streamer_read_string (struct data_in *data_in, struct lto_input_block *ib)
{
unsigned int len;
const char *ptr;
ptr = streamer_read_indexed_string (data_in, ib, &len);
if (!ptr)
return NULL;
if (ptr[len - 1] != '\0')
internal_error ("bytecode stream: found non-null terminated string");
return ptr;
}
/* Read a string from the string table in DATA_IN using the bitpack BP.
Write the length to RLEN. */
const char *
bp_unpack_indexed_string (struct data_in *data_in,
struct bitpack_d *bp, unsigned int *rlen)
{
return string_for_index (data_in, bp_unpack_var_len_unsigned (bp), rlen);
}
/* Read a NULL terminated string from the string table in DATA_IN. */
const char *
bp_unpack_string (struct data_in *data_in, struct bitpack_d *bp)
{
unsigned int len;
const char *ptr;
ptr = bp_unpack_indexed_string (data_in, bp, &len);
if (!ptr)
return NULL;
if (ptr[len - 1] != '\0')
internal_error ("bytecode stream: found non-null terminated string");
return ptr;
}
/* Read an unsigned HOST_WIDE_INT number from IB. */
unsigned HOST_WIDE_INT
streamer_read_uhwi (struct lto_input_block *ib)
{
unsigned HOST_WIDE_INT result;
int shift;
unsigned HOST_WIDE_INT byte;
unsigned int p = ib->p;
unsigned int len = ib->len;
const char *data = ib->data;
result = data[p++];
if ((result & 0x80) != 0)
{
result &= 0x7f;
shift = 7;
do
{
byte = data[p++];
result |= (byte & 0x7f) << shift;
shift += 7;
}
while ((byte & 0x80) != 0);
}
/* We check for section overrun after the fact for performance reason. */
if (p > len)
lto_section_overrun (ib);
ib->p = p;
return result;
}
/* Read a HOST_WIDE_INT number from IB. */
HOST_WIDE_INT
streamer_read_hwi (struct lto_input_block *ib)
{
HOST_WIDE_INT result = 0;
int shift = 0;
unsigned HOST_WIDE_INT byte;
while (true)
{
byte = streamer_read_uchar (ib);
result |= (byte & 0x7f) << shift;
shift += 7;
if ((byte & 0x80) == 0)
{
if ((shift < HOST_BITS_PER_WIDE_INT) && (byte & 0x40))
result |= - (HOST_WIDE_INT_1U << shift);
return result;
}
}
}
/* Read gcov_type value from IB. */
gcov_type
streamer_read_gcov_count (struct lto_input_block *ib)
{
gcov_type ret = streamer_read_hwi (ib);
return ret;
}
/* Read the physical representation of a wide_int val from
input block IB. */
wide_int
streamer_read_wide_int (struct lto_input_block *ib)
{
HOST_WIDE_INT a[WIDE_INT_MAX_ELTS];
int i;
int prec = streamer_read_uhwi (ib);
int len = streamer_read_uhwi (ib);
for (i = 0; i < len; i++)
a[i] = streamer_read_hwi (ib);
return wide_int::from_array (a, len, prec);
}
/* Read the physical representation of a widest_int val from
input block IB. */
widest_int
streamer_read_widest_int (struct lto_input_block *ib)
{
HOST_WIDE_INT a[WIDE_INT_MAX_ELTS];
int i;
int prec ATTRIBUTE_UNUSED = streamer_read_uhwi (ib);
int len = streamer_read_uhwi (ib);
for (i = 0; i < len; i++)
a[i] = streamer_read_hwi (ib);
return widest_int::from_array (a, len);
}