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/* RTL manipulation functions exported by Pointer Bounds Checker.
Copyright (C) 2014-2015 Free Software Foundation, Inc.
Contributed by Ilya Enkovich (ilya.enkovich@intel.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 "symtab.h"
#include "hashtab.h"
#include "hash-set.h"
#include "vec.h"
#include "machmode.h"
#include "tm.h"
#include "hard-reg-set.h"
#include "input.h"
#include "function.h"
#include "rtl.h"
#include "flags.h"
#include "statistics.h"
#include "double-int.h"
#include "real.h"
#include "fixed-value.h"
#include "alias.h"
#include "wide-int.h"
#include "inchash.h"
#include "tree.h"
#include "insn-config.h"
#include "expmed.h"
#include "dojump.h"
#include "explow.h"
#include "calls.h"
#include "emit-rtl.h"
#include "varasm.h"
#include "stmt.h"
#include "expr.h"
#include "target.h"
#include "tree-ssa-alias.h"
#include "internal-fn.h"
#include "is-a.h"
#include "predict.h"
#include "basic-block.h"
#include "fold-const.h"
#include "gimple-expr.h"
#include "gimple.h"
#include "bitmap.h"
#include "rtl-chkp.h"
#include "tree-chkp.h"
#include "hash-map.h"
static hash_map<tree, rtx> *chkp_rtx_bounds_map;
/* Get bounds rtx associated with NODE via
chkp_set_rtl_bounds call. */
rtx
chkp_get_rtl_bounds (tree node)
{
rtx *slot;
if (!chkp_rtx_bounds_map)
return NULL_RTX;
slot = chkp_rtx_bounds_map->get (node);
return slot ? *slot : NULL_RTX;
}
/* Associate bounds rtx VAL with NODE. */
void
chkp_set_rtl_bounds (tree node, rtx val)
{
if (!chkp_rtx_bounds_map)
chkp_rtx_bounds_map = new hash_map<tree, rtx>;
chkp_rtx_bounds_map->put (node, val);
}
/* Reset all bounds stored via chkp_set_rtl_bounds. */
void
chkp_reset_rtl_bounds ()
{
if (!chkp_rtx_bounds_map)
return;
delete chkp_rtx_bounds_map;
chkp_rtx_bounds_map = NULL;
}
/* Split SLOT identifying slot for function value or
argument into two parts SLOT_VAL and SLOT_BND.
First is the slot for regular value and the other one is
for bounds. */
void
chkp_split_slot (rtx slot, rtx *slot_val, rtx *slot_bnd)
{
int i;
int val_num = 0;
int bnd_num = 0;
rtx *val_tmps;
rtx *bnd_tmps;
*slot_bnd = 0;
if (!slot
|| GET_CODE (slot) != PARALLEL)
{
*slot_val = slot;
return;
}
val_tmps = XALLOCAVEC (rtx, XVECLEN (slot, 0));
bnd_tmps = XALLOCAVEC (rtx, XVECLEN (slot, 0));
for (i = 0; i < XVECLEN (slot, 0); i++)
{
rtx elem = XVECEXP (slot, 0, i);
rtx reg = GET_CODE (elem) == EXPR_LIST ? XEXP (elem, 0) : elem;
if (!reg)
continue;
if (POINTER_BOUNDS_MODE_P (GET_MODE (reg)) || CONST_INT_P (reg))
bnd_tmps[bnd_num++] = elem;
else
val_tmps[val_num++] = elem;
}
gcc_assert (val_num);
if (!bnd_num)
{
*slot_val = slot;
return;
}
if ((GET_CODE (val_tmps[0]) == EXPR_LIST) || (val_num > 1))
*slot_val = gen_rtx_PARALLEL (GET_MODE (slot),
gen_rtvec_v (val_num, val_tmps));
else
*slot_val = val_tmps[0];
if ((GET_CODE (bnd_tmps[0]) == EXPR_LIST) || (bnd_num > 1))
*slot_bnd = gen_rtx_PARALLEL (VOIDmode,
gen_rtvec_v (bnd_num, bnd_tmps));
else
*slot_bnd = bnd_tmps[0];
}
/* Join previously splitted to VAL and BND rtx for function
value or argument and return it. */
rtx
chkp_join_splitted_slot (rtx val, rtx bnd)
{
rtx res;
int i, n = 0;
if (!bnd)
return val;
if (GET_CODE (val) == PARALLEL)
n += XVECLEN (val, 0);
else
n++;
if (GET_CODE (bnd) == PARALLEL)
n += XVECLEN (bnd, 0);
else
n++;
res = gen_rtx_PARALLEL (GET_MODE (val), rtvec_alloc (n));
n = 0;
if (GET_CODE (val) == PARALLEL)
for (i = 0; i < XVECLEN (val, 0); i++)
XVECEXP (res, 0, n++) = XVECEXP (val, 0, i);
else
XVECEXP (res, 0, n++) = val;
if (GET_CODE (bnd) == PARALLEL)
for (i = 0; i < XVECLEN (bnd, 0); i++)
XVECEXP (res, 0, n++) = XVECEXP (bnd, 0, i);
else
XVECEXP (res, 0, n++) = bnd;
return res;
}
/* If PAR is PARALLEL holding registers then transform
it into PARALLEL holding EXPR_LISTs of those regs
and zero constant (similar to how function value
on multiple registers looks like). */
void
chkp_put_regs_to_expr_list (rtx par)
{
int n;
if (GET_CODE (par) != PARALLEL
|| GET_CODE (XVECEXP (par, 0, 0)) == EXPR_LIST)
return;
for (n = 0; n < XVECLEN (par, 0); n++)
XVECEXP (par, 0, n) = gen_rtx_EXPR_LIST (VOIDmode,
XVECEXP (par, 0, n),
const0_rtx);
}
/* Search rtx PAR describing function return value for an
item related to value at offset OFFS and return it.
Return NULL if item was not found. */
rtx
chkp_get_value_with_offs (rtx par, rtx offs)
{
int n;
gcc_assert (GET_CODE (par) == PARALLEL);
for (n = 0; n < XVECLEN (par, 0); n++)
{
rtx par_offs = XEXP (XVECEXP (par, 0, n), 1);
if (INTVAL (offs) == INTVAL (par_offs))
return XEXP (XVECEXP (par, 0, n), 0);
}
return NULL;
}
/* Emit instructions to store BOUNDS for pointer VALUE
stored in MEM.
Function is used by expand to pass bounds for args
passed on stack. */
void
chkp_emit_bounds_store (rtx bounds, rtx value, rtx mem)
{
gcc_assert (MEM_P (mem));
if (REG_P (bounds) || CONST_INT_P (bounds))
{
rtx ptr;
if (REG_P (value))
ptr = value;
else
{
rtx slot = adjust_address (value, Pmode, 0);
ptr = gen_reg_rtx (Pmode);
emit_move_insn (ptr, slot);
}
if (CONST_INT_P (bounds))
bounds = targetm.calls.load_bounds_for_arg (value, ptr, bounds);
targetm.calls.store_bounds_for_arg (ptr, mem,
bounds, NULL);
}
else
{
int i;
gcc_assert (GET_CODE (bounds) == PARALLEL);
gcc_assert (GET_CODE (value) == PARALLEL || MEM_P (value) || REG_P (value));
for (i = 0; i < XVECLEN (bounds, 0); i++)
{
rtx reg = XEXP (XVECEXP (bounds, 0, i), 0);
rtx offs = XEXP (XVECEXP (bounds, 0, i), 1);
rtx slot = adjust_address (mem, Pmode, INTVAL (offs));
rtx ptr;
if (GET_CODE (value) == PARALLEL)
ptr = chkp_get_value_with_offs (value, offs);
else if (MEM_P (value))
{
rtx tmp = adjust_address (value, Pmode, INTVAL (offs));
ptr = gen_reg_rtx (Pmode);
emit_move_insn (ptr, tmp);
}
else
ptr = gen_rtx_SUBREG (Pmode, value, INTVAL (offs));
targetm.calls.store_bounds_for_arg (ptr, slot, reg, NULL);
}
}
}
/* Emit code to copy bounds for structure VALUE of type TYPE
copied to SLOT. */
void
chkp_copy_bounds_for_stack_parm (rtx slot, rtx value, tree type)
{
bitmap have_bound;
bitmap_iterator bi;
unsigned i;
rtx tmp = NULL, bnd;
gcc_assert (TYPE_SIZE (type));
gcc_assert (MEM_P (value));
gcc_assert (MEM_P (slot));
gcc_assert (RECORD_OR_UNION_TYPE_P (type));
bitmap_obstack_initialize (NULL);
have_bound = BITMAP_ALLOC (NULL);
chkp_find_bound_slots (type, have_bound);
EXECUTE_IF_SET_IN_BITMAP (have_bound, 0, i, bi)
{
rtx ptr = adjust_address (value, Pmode, i * POINTER_SIZE / 8);
rtx to = adjust_address (slot, Pmode, i * POINTER_SIZE / 8);
if (!tmp)
tmp = gen_reg_rtx (Pmode);
emit_move_insn (tmp, ptr);
bnd = targetm.calls.load_bounds_for_arg (ptr, tmp, NULL);
targetm.calls.store_bounds_for_arg (tmp, to, bnd, NULL);
}
BITMAP_FREE (have_bound);
bitmap_obstack_release (NULL);
}