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Diffstat (limited to 'gcc/tree-chkp-opt.c')
| -rw-r--r-- | gcc/tree-chkp-opt.c | 1355 |
1 files changed, 0 insertions, 1355 deletions
diff --git a/gcc/tree-chkp-opt.c b/gcc/tree-chkp-opt.c deleted file mode 100644 index 5a005a6..0000000 --- a/gcc/tree-chkp-opt.c +++ /dev/null @@ -1,1355 +0,0 @@ -/* Pointer Bounds Checker optimization pass. - Copyright (C) 2014-2018 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 "backend.h" -#include "target.h" -#include "rtl.h" -#include "tree.h" -#include "gimple.h" -#include "tree-pass.h" -#include "ssa.h" -#include "gimple-pretty-print.h" -#include "diagnostic.h" -#include "fold-const.h" -#include "tree-cfg.h" -#include "tree-ssa-loop-niter.h" -#include "gimple-iterator.h" -#include "tree-chkp.h" -#include "ipa-chkp.h" - -enum check_type -{ - CHECK_LOWER_BOUND, - CHECK_UPPER_BOUND -}; - -struct pol_item -{ - tree cst; - tree var; -}; - -struct address_t -{ - vec<struct pol_item> pol; -}; - -/* Structure to hold check informtation. */ -struct check_info -{ - /* Type of the check. */ - check_type type; - /* Address used for the check. */ - address_t addr; - /* Bounds used for the check. */ - tree bounds; - /* Check statement. Can be NULL for removed checks. */ - gimple *stmt; -}; - -/* Structure to hold checks information for BB. */ -struct bb_checks -{ - vec<struct check_info, va_heap, vl_ptr> checks; -}; - -static void chkp_collect_value (tree ssa_name, address_t &res); - -#define chkp_bndmk_fndecl \ - (targetm.builtin_chkp_function (BUILT_IN_CHKP_BNDMK)) -#define chkp_intersect_fndecl \ - (targetm.builtin_chkp_function (BUILT_IN_CHKP_INTERSECT)) -#define chkp_checkl_fndecl \ - (targetm.builtin_chkp_function (BUILT_IN_CHKP_BNDCL)) -#define chkp_checku_fndecl \ - (targetm.builtin_chkp_function (BUILT_IN_CHKP_BNDCU)) - -static vec<struct bb_checks, va_heap, vl_ptr> check_infos; - -/* Comparator for pol_item structures I1 and I2 to be used - to find items with equal var. Also used for polynomial - sorting. */ -static int -chkp_pol_item_compare (const void *i1, const void *i2) -{ - const struct pol_item *p1 = (const struct pol_item *)i1; - const struct pol_item *p2 = (const struct pol_item *)i2; - - if (p1->var == p2->var) - return 0; - else if (p1->var > p2->var) - return 1; - else - return -1; -} - -/* Find polynomial item in ADDR with var equal to VAR - and return its index. Return -1 if item was not - found. */ -static int -chkp_pol_find (address_t &addr, tree var) -{ - int left = 0; - int right = addr.pol.length () - 1; - int n; - - while (right >= left) - { - n = (left + right) / 2; - - if (addr.pol[n].var == var - || (var && addr.pol[n].var - && TREE_CODE (var) == ADDR_EXPR - && TREE_CODE (addr.pol[n].var) == ADDR_EXPR - && TREE_OPERAND (var, 0) == TREE_OPERAND (addr.pol[n].var, 0))) - return n; - else if (addr.pol[n].var > var) - right = n - 1; - else - left = n + 1; - } - - return -1; -} - -/* Return constant CST extended to size type. */ -static tree -chkp_extend_const (tree cst) -{ - if (TYPE_PRECISION (TREE_TYPE (cst)) < TYPE_PRECISION (size_type_node)) - return build_int_cst_type (size_type_node, tree_to_shwi (cst)); - - return cst; -} - -/* Add polynomial item CST * VAR to ADDR. */ -static void -chkp_add_addr_item (address_t &addr, tree cst, tree var) -{ - int n = chkp_pol_find (addr, var); - - cst = chkp_extend_const (cst); - - if (n < 0) - { - struct pol_item item; - item.cst = cst; - item.var = var; - - addr.pol.safe_push (item); - addr.pol.qsort (&chkp_pol_item_compare); - } - else - { - addr.pol[n].cst = fold_build2 (PLUS_EXPR, TREE_TYPE (addr.pol[n].cst), - addr.pol[n].cst, cst); - if (TREE_CODE (addr.pol[n].cst) == INTEGER_CST - && integer_zerop (addr.pol[n].cst)) - addr.pol.ordered_remove (n); - } -} - -/* Subtract polynomial item CST * VAR from ADDR. */ -static void -chkp_sub_addr_item (address_t &addr, tree cst, tree var) -{ - int n = chkp_pol_find (addr, var); - - cst = chkp_extend_const (cst); - - if (n < 0) - { - struct pol_item item; - item.cst = fold_build2 (MINUS_EXPR, TREE_TYPE (cst), - integer_zero_node, cst); - item.var = var; - - addr.pol.safe_push (item); - addr.pol.qsort (&chkp_pol_item_compare); - } - else - { - addr.pol[n].cst = fold_build2 (MINUS_EXPR, TREE_TYPE (addr.pol[n].cst), - addr.pol[n].cst, cst); - if (TREE_CODE (addr.pol[n].cst) == INTEGER_CST - && integer_zerop (addr.pol[n].cst)) - addr.pol.ordered_remove (n); - } -} - -/* Add address DELTA to ADDR. */ -static void -chkp_add_addr_addr (address_t &addr, address_t &delta) -{ - unsigned int i; - for (i = 0; i < delta.pol.length (); i++) - chkp_add_addr_item (addr, delta.pol[i].cst, delta.pol[i].var); -} - -/* Subtract address DELTA from ADDR. */ -static void -chkp_sub_addr_addr (address_t &addr, address_t &delta) -{ - unsigned int i; - for (i = 0; i < delta.pol.length (); i++) - chkp_sub_addr_item (addr, delta.pol[i].cst, delta.pol[i].var); -} - -/* Mutiply address ADDR by integer constant MULT. */ -static void -chkp_mult_addr (address_t &addr, tree mult) -{ - unsigned int i; - for (i = 0; i < addr.pol.length (); i++) - addr.pol[i].cst = fold_build2 (MULT_EXPR, TREE_TYPE (addr.pol[i].cst), - addr.pol[i].cst, mult); -} - -/* Return 1 if we may prove ADDR has a constant value with - determined sign, which is put into *SIGN. Otherwise - return 0. */ -static bool -chkp_is_constant_addr (const address_t &addr, int *sign) -{ - *sign = 0; - - if (addr.pol.length () == 0) - return true; - else if (addr.pol.length () > 1) - return false; - else if (addr.pol[0].var) - return false; - else if (TREE_CODE (addr.pol[0].cst) != INTEGER_CST) - return false; - else if (integer_zerop (addr.pol[0].cst)) - *sign = 0; - else if (tree_int_cst_sign_bit (addr.pol[0].cst)) - *sign = -1; - else - *sign = 1; - - return true; -} - -/* Dump ADDR into dump_file. */ -static void -chkp_print_addr (const address_t &addr) -{ - unsigned int n = 0; - for (n = 0; n < addr.pol.length (); n++) - { - if (n > 0) - fprintf (dump_file, " + "); - - if (addr.pol[n].var == NULL_TREE) - print_generic_expr (dump_file, addr.pol[n].cst); - else - { - if (TREE_CODE (addr.pol[n].cst) != INTEGER_CST - || !integer_onep (addr.pol[n].cst)) - { - print_generic_expr (dump_file, addr.pol[n].cst); - fprintf (dump_file, " * "); - } - print_generic_expr (dump_file, addr.pol[n].var); - } - } -} - -/* Compute value of PTR and put it into address RES. - PTR has to be ADDR_EXPR. */ -static void -chkp_collect_addr_value (tree ptr, address_t &res) -{ - tree obj = TREE_OPERAND (ptr, 0); - address_t addr; - - switch (TREE_CODE (obj)) - { - case INDIRECT_REF: - chkp_collect_value (TREE_OPERAND (obj, 0), res); - break; - - case MEM_REF: - chkp_collect_value (TREE_OPERAND (obj, 0), res); - addr.pol.create (0); - chkp_collect_value (TREE_OPERAND (obj, 1), addr); - chkp_add_addr_addr (res, addr); - addr.pol.release (); - break; - - case ARRAY_REF: - chkp_collect_value (build_fold_addr_expr (TREE_OPERAND (obj, 0)), res); - addr.pol.create (0); - chkp_collect_value (TREE_OPERAND (obj, 1), addr); - chkp_mult_addr (addr, array_ref_element_size (obj)); - chkp_add_addr_addr (res, addr); - addr.pol.release (); - break; - - case COMPONENT_REF: - { - tree str = TREE_OPERAND (obj, 0); - tree field = TREE_OPERAND (obj, 1); - chkp_collect_value (build_fold_addr_expr (str), res); - addr.pol.create (0); - chkp_collect_value (component_ref_field_offset (obj), addr); - chkp_add_addr_addr (res, addr); - addr.pol.release (); - if (DECL_FIELD_BIT_OFFSET (field)) - { - addr.pol.create (0); - chkp_collect_value (fold_build2 (TRUNC_DIV_EXPR, size_type_node, - DECL_FIELD_BIT_OFFSET (field), - size_int (BITS_PER_UNIT)), - addr); - chkp_add_addr_addr (res, addr); - addr.pol.release (); - } - } - break; - - default: - chkp_add_addr_item (res, integer_one_node, ptr); - break; - } -} - -/* Compute value of PTR and put it into address RES. */ -static void -chkp_collect_value (tree ptr, address_t &res) -{ - gimple *def_stmt; - enum gimple_code code; - enum tree_code rhs_code; - address_t addr; - tree rhs1; - - if (TREE_CODE (ptr) == INTEGER_CST) - { - chkp_add_addr_item (res, ptr, NULL); - return; - } - else if (TREE_CODE (ptr) == ADDR_EXPR) - { - chkp_collect_addr_value (ptr, res); - return; - } - else if (TREE_CODE (ptr) != SSA_NAME) - { - chkp_add_addr_item (res, integer_one_node, ptr); - return; - } - - /* Now we handle the case when polynomial is computed - for SSA NAME. */ - def_stmt = SSA_NAME_DEF_STMT (ptr); - code = gimple_code (def_stmt); - - /* Currently we do not walk through statements other - than assignment. */ - if (code != GIMPLE_ASSIGN) - { - chkp_add_addr_item (res, integer_one_node, ptr); - return; - } - - rhs_code = gimple_assign_rhs_code (def_stmt); - rhs1 = gimple_assign_rhs1 (def_stmt); - - switch (rhs_code) - { - case SSA_NAME: - case INTEGER_CST: - case ADDR_EXPR: - chkp_collect_value (rhs1, res); - break; - - case PLUS_EXPR: - case POINTER_PLUS_EXPR: - chkp_collect_value (rhs1, res); - addr.pol.create (0); - chkp_collect_value (gimple_assign_rhs2 (def_stmt), addr); - chkp_add_addr_addr (res, addr); - addr.pol.release (); - break; - - case MINUS_EXPR: - chkp_collect_value (rhs1, res); - addr.pol.create (0); - chkp_collect_value (gimple_assign_rhs2 (def_stmt), addr); - chkp_sub_addr_addr (res, addr); - addr.pol.release (); - break; - - case MULT_EXPR: - if (TREE_CODE (rhs1) == SSA_NAME - && TREE_CODE (gimple_assign_rhs2 (def_stmt)) == INTEGER_CST) - { - chkp_collect_value (rhs1, res); - chkp_mult_addr (res, gimple_assign_rhs2 (def_stmt)); - } - else if (TREE_CODE (gimple_assign_rhs2 (def_stmt)) == SSA_NAME - && TREE_CODE (rhs1) == INTEGER_CST) - { - chkp_collect_value (gimple_assign_rhs2 (def_stmt), res); - chkp_mult_addr (res, rhs1); - } - else - chkp_add_addr_item (res, integer_one_node, ptr); - break; - - default: - chkp_add_addr_item (res, integer_one_node, ptr); - break; - } -} - -/* Fill check_info structure *CI with information about - check STMT. */ -static void -chkp_fill_check_info (gimple *stmt, struct check_info *ci) -{ - ci->addr.pol.create (0); - ci->bounds = gimple_call_arg (stmt, 1); - chkp_collect_value (gimple_call_arg (stmt, 0), ci->addr); - ci->type = (gimple_call_fndecl (stmt) == chkp_checkl_fndecl - ? CHECK_LOWER_BOUND - : CHECK_UPPER_BOUND); - ci->stmt = stmt; -} - -/* Release structures holding check information - for current function. */ -static void -chkp_release_check_info (void) -{ - unsigned int n, m; - - if (check_infos.exists ()) - { - for (n = 0; n < check_infos.length (); n++) - { - for (m = 0; m < check_infos[n].checks.length (); m++) - if (check_infos[n].checks[m].addr.pol.exists ()) - check_infos[n].checks[m].addr.pol.release (); - check_infos[n].checks.release (); - } - check_infos.release (); - } -} - -/* Create structures to hold check information - for current function. */ -static void -chkp_init_check_info (void) -{ - struct bb_checks empty_bbc; - int n; - - empty_bbc.checks = vNULL; - - chkp_release_check_info (); - - check_infos.create (last_basic_block_for_fn (cfun)); - for (n = 0; n < last_basic_block_for_fn (cfun); n++) - { - check_infos.safe_push (empty_bbc); - check_infos.last ().checks.create (0); - } -} - -/* Find all checks in current function and store info about them - in check_infos. */ -static void -chkp_gather_checks_info (void) -{ - basic_block bb; - gimple_stmt_iterator i; - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "Gathering information about checks...\n"); - - chkp_init_check_info (); - - FOR_EACH_BB_FN (bb, cfun) - { - struct bb_checks *bbc = &check_infos[bb->index]; - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "Searching checks in BB%d...\n", bb->index); - - for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) - { - gimple *stmt = gsi_stmt (i); - - if (gimple_code (stmt) != GIMPLE_CALL) - continue; - - if (gimple_call_fndecl (stmt) == chkp_checkl_fndecl - || gimple_call_fndecl (stmt) == chkp_checku_fndecl) - { - struct check_info ci; - - chkp_fill_check_info (stmt, &ci); - bbc->checks.safe_push (ci); - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Adding check information:\n"); - fprintf (dump_file, " bounds: "); - print_generic_expr (dump_file, ci.bounds); - fprintf (dump_file, "\n address: "); - chkp_print_addr (ci.addr); - fprintf (dump_file, "\n check: "); - print_gimple_stmt (dump_file, stmt, 0); - } - } - } - } -} - -/* Return 1 if check CI against BOUNDS always pass, - -1 if check CI against BOUNDS always fails and - 0 if we cannot compute check result. */ -static int -chkp_get_check_result (struct check_info *ci, tree bounds) -{ - gimple *bnd_def; - address_t bound_val; - int sign, res = 0; - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Trying to compute result of the check\n"); - fprintf (dump_file, " check: "); - print_gimple_stmt (dump_file, ci->stmt, 0); - fprintf (dump_file, " address: "); - chkp_print_addr (ci->addr); - fprintf (dump_file, "\n bounds: "); - print_generic_expr (dump_file, bounds); - fprintf (dump_file, "\n"); - } - - if (TREE_CODE (bounds) != SSA_NAME) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: bounds tree code is not ssa_name\n"); - return 0; - } - - bnd_def = SSA_NAME_DEF_STMT (bounds); - /* Currently we handle cases when bounds are result of bndmk - or loaded static bounds var. */ - if (gimple_code (bnd_def) == GIMPLE_CALL - && gimple_call_fndecl (bnd_def) == chkp_bndmk_fndecl) - { - bound_val.pol.create (0); - chkp_collect_value (gimple_call_arg (bnd_def, 0), bound_val); - if (ci->type == CHECK_UPPER_BOUND) - { - address_t size_val; - size_val.pol.create (0); - chkp_collect_value (gimple_call_arg (bnd_def, 1), size_val); - chkp_add_addr_addr (bound_val, size_val); - size_val.pol.release (); - chkp_add_addr_item (bound_val, integer_minus_one_node, NULL); - } - } - else if (gimple_code (bnd_def) == GIMPLE_ASSIGN - && gimple_assign_rhs1 (bnd_def) == chkp_get_zero_bounds_var ()) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: always pass with zero bounds\n"); - return 1; - } - else if (gimple_code (bnd_def) == GIMPLE_ASSIGN - && gimple_assign_rhs1 (bnd_def) == chkp_get_none_bounds_var ()) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: always fails with none bounds\n"); - return -1; - } - else if (gimple_code (bnd_def) == GIMPLE_ASSIGN - && TREE_CODE (gimple_assign_rhs1 (bnd_def)) == VAR_DECL) - { - tree bnd_var = gimple_assign_rhs1 (bnd_def); - tree var; - tree size; - - if (!DECL_INITIAL (bnd_var) - || DECL_INITIAL (bnd_var) == error_mark_node) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: cannot compute bounds\n"); - return 0; - } - - gcc_assert (TREE_CODE (DECL_INITIAL (bnd_var)) == ADDR_EXPR); - var = TREE_OPERAND (DECL_INITIAL (bnd_var), 0); - - bound_val.pol.create (0); - chkp_collect_value (DECL_INITIAL (bnd_var), bound_val); - if (ci->type == CHECK_UPPER_BOUND) - { - if (VAR_P (var)) - { - if (DECL_SIZE (var) - && !chkp_variable_size_type (TREE_TYPE (var))) - size = DECL_SIZE_UNIT (var); - else - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: cannot compute bounds\n"); - return 0; - } - } - else - { - gcc_assert (TREE_CODE (var) == STRING_CST); - size = build_int_cst (size_type_node, - TREE_STRING_LENGTH (var)); - } - - address_t size_val; - size_val.pol.create (0); - chkp_collect_value (size, size_val); - chkp_add_addr_addr (bound_val, size_val); - size_val.pol.release (); - chkp_add_addr_item (bound_val, integer_minus_one_node, NULL); - } - } - else - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: cannot compute bounds\n"); - return 0; - } - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, " bound value: "); - chkp_print_addr (bound_val); - fprintf (dump_file, "\n"); - } - - chkp_sub_addr_addr (bound_val, ci->addr); - - if (!chkp_is_constant_addr (bound_val, &sign)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: cannot compute result\n"); - - res = 0; - } - else if (sign == 0 - || (ci->type == CHECK_UPPER_BOUND && sign > 0) - || (ci->type == CHECK_LOWER_BOUND && sign < 0)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: always pass\n"); - - res = 1; - } - else - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " result: always fail\n"); - - res = -1; - } - - bound_val.pol.release (); - - return res; -} - -/* Try to compare bounds value and address value - used in the check CI. If we can prove that check - always pass then remove it. */ -static void -chkp_remove_check_if_pass (struct check_info *ci) -{ - int result = 0; - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Trying to remove check: "); - print_gimple_stmt (dump_file, ci->stmt, 0); - } - - result = chkp_get_check_result (ci, ci->bounds); - - if (result == 1) - { - gimple_stmt_iterator i = gsi_for_stmt (ci->stmt); - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " action: delete check (always pass)\n"); - - gsi_remove (&i, true); - unlink_stmt_vdef (ci->stmt); - release_defs (ci->stmt); - ci->stmt = NULL; - } - else if (result == -1) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " action: keep check (always fail)\n"); - warning_at (gimple_location (ci->stmt), OPT_Wchkp, - "memory access check always fail"); - } - else if (result == 0) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, " action: keep check (cannot compute result)\n"); - } -} - -/* For bounds used in CI check if bounds are produced by - intersection and we may use outer bounds instead. If - transformation is possible then fix check statement and - recompute its info. */ -static void -chkp_use_outer_bounds_if_possible (struct check_info *ci) -{ - gimple *bnd_def; - tree bnd1, bnd2, bnd_res = NULL; - int check_res1, check_res2; - - if (TREE_CODE (ci->bounds) != SSA_NAME) - return; - - bnd_def = SSA_NAME_DEF_STMT (ci->bounds); - if (gimple_code (bnd_def) != GIMPLE_CALL - || gimple_call_fndecl (bnd_def) != chkp_intersect_fndecl) - return; - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Check if bounds intersection is redundant: \n"); - fprintf (dump_file, " check: "); - print_gimple_stmt (dump_file, ci->stmt, 0); - fprintf (dump_file, " intersection: "); - print_gimple_stmt (dump_file, bnd_def, 0); - fprintf (dump_file, "\n"); - } - - bnd1 = gimple_call_arg (bnd_def, 0); - bnd2 = gimple_call_arg (bnd_def, 1); - - check_res1 = chkp_get_check_result (ci, bnd1); - check_res2 = chkp_get_check_result (ci, bnd2); - if (check_res1 == 1) - bnd_res = bnd2; - else if (check_res1 == -1) - bnd_res = bnd1; - else if (check_res2 == 1) - bnd_res = bnd1; - else if (check_res2 == -1) - bnd_res = bnd2; - - if (bnd_res) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, " action: use "); - print_generic_expr (dump_file, bnd2); - fprintf (dump_file, " instead of "); - print_generic_expr (dump_file, ci->bounds); - fprintf (dump_file, "\n"); - } - - ci->bounds = bnd_res; - gimple_call_set_arg (ci->stmt, 1, bnd_res); - update_stmt (ci->stmt); - chkp_fill_check_info (ci->stmt, ci); - } -} - -/* Try to find checks whose bounds were produced by intersection - which does not affect check result. In such check outer bounds - are used instead. It allows to remove excess intersections - and helps to compare checks. */ -static void -chkp_remove_excess_intersections (void) -{ - basic_block bb; - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "Searching for redundant bounds intersections...\n"); - - FOR_EACH_BB_FN (bb, cfun) - { - struct bb_checks *bbc = &check_infos[bb->index]; - unsigned int no; - - /* Iterate through all found checks in BB. */ - for (no = 0; no < bbc->checks.length (); no++) - if (bbc->checks[no].stmt) - chkp_use_outer_bounds_if_possible (&bbc->checks[no]); - } -} - -/* Try to remove all checks which are known to alwyas pass. */ -static void -chkp_remove_constant_checks (void) -{ - basic_block bb; - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "Searching for redundant checks...\n"); - - FOR_EACH_BB_FN (bb, cfun) - { - struct bb_checks *bbc = &check_infos[bb->index]; - unsigned int no; - - /* Iterate through all found checks in BB. */ - for (no = 0; no < bbc->checks.length (); no++) - if (bbc->checks[no].stmt) - chkp_remove_check_if_pass (&bbc->checks[no]); - } -} - -/* Return fast version of string function FNCODE. */ -static tree -chkp_get_nobnd_fndecl (enum built_in_function fncode) -{ - /* Check if we are allowed to use fast string functions. */ - if (!flag_chkp_use_fast_string_functions) - return NULL_TREE; - - tree fndecl = NULL_TREE; - - switch (fncode) - { - case BUILT_IN_MEMCPY_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMCPY_NOBND); - break; - - case BUILT_IN_MEMPCPY_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMPCPY_NOBND); - break; - - case BUILT_IN_MEMMOVE_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMMOVE_NOBND); - break; - - case BUILT_IN_MEMSET_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMSET_NOBND); - break; - - case BUILT_IN_CHKP_MEMCPY_NOCHK_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMCPY_NOBND_NOCHK); - break; - - case BUILT_IN_CHKP_MEMPCPY_NOCHK_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMPCPY_NOBND_NOCHK); - break; - - case BUILT_IN_CHKP_MEMMOVE_NOCHK_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMMOVE_NOBND_NOCHK); - break; - - case BUILT_IN_CHKP_MEMSET_NOCHK_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMSET_NOBND_NOCHK); - break; - - default: - break; - } - - if (fndecl) - fndecl = chkp_maybe_clone_builtin_fndecl (fndecl); - - return fndecl; -} - - -/* Return no-check version of string function FNCODE. */ -static tree -chkp_get_nochk_fndecl (enum built_in_function fncode) -{ - /* Check if we are allowed to use fast string functions. */ - if (!flag_chkp_use_nochk_string_functions) - return NULL_TREE; - - tree fndecl = NULL_TREE; - - switch (fncode) - { - case BUILT_IN_MEMCPY_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMCPY_NOCHK); - break; - - case BUILT_IN_MEMPCPY_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMPCPY_NOCHK); - break; - - case BUILT_IN_MEMMOVE_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMMOVE_NOCHK); - break; - - case BUILT_IN_MEMSET_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMSET_NOCHK); - break; - - case BUILT_IN_CHKP_MEMCPY_NOBND_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMCPY_NOBND_NOCHK); - break; - - case BUILT_IN_CHKP_MEMPCPY_NOBND_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMPCPY_NOBND_NOCHK); - break; - - case BUILT_IN_CHKP_MEMMOVE_NOBND_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMMOVE_NOBND_NOCHK); - break; - - case BUILT_IN_CHKP_MEMSET_NOBND_CHKP: - fndecl = builtin_decl_implicit (BUILT_IN_CHKP_MEMSET_NOBND_NOCHK); - break; - - default: - break; - } - - if (fndecl) - fndecl = chkp_maybe_clone_builtin_fndecl (fndecl); - - return fndecl; -} - -/* Find memcpy, mempcpy, memmove and memset calls, perform - checks before call and then call no_chk version of - functions. We do it on O2 to enable inlining of these - functions during expand. - - Also try to find memcpy, mempcpy, memmove and memset calls - which are known to not write pointers to memory and use - faster function versions for them. */ -static void -chkp_optimize_string_function_calls (void) -{ - basic_block bb; - - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "Searching for replaceable string function calls...\n"); - - FOR_EACH_BB_FN (bb, cfun) - { - gimple_stmt_iterator i; - - for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) - { - gimple *stmt = gsi_stmt (i); - tree fndecl; - - if (!is_gimple_call (stmt) - || !gimple_call_with_bounds_p (stmt) - || !gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) - continue; - - fndecl = gimple_call_fndecl (stmt); - if (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMCPY_CHKP - || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMPCPY_CHKP - || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMMOVE_CHKP - || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMSET_CHKP) - { - tree dst = gimple_call_arg (stmt, 0); - tree dst_bnd = gimple_call_arg (stmt, 1); - bool is_memset = DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMSET_CHKP; - tree size = gimple_call_arg (stmt, is_memset ? 3 : 4); - tree fndecl_nochk; - gimple_stmt_iterator j; - basic_block check_bb; - address_t size_val; - int sign; - bool known; - - /* We may replace call with corresponding __chkp_*_nobnd - call in case destination pointer base type is not - void or pointer. */ - if (POINTER_TYPE_P (TREE_TYPE (dst)) - && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (dst))) - && !chkp_type_has_pointer (TREE_TYPE (TREE_TYPE (dst)))) - { - tree fndecl_nobnd - = chkp_get_nobnd_fndecl (DECL_FUNCTION_CODE (fndecl)); - - if (fndecl_nobnd) - fndecl = fndecl_nobnd; - } - - fndecl_nochk = chkp_get_nochk_fndecl (DECL_FUNCTION_CODE (fndecl)); - - if (fndecl_nochk) - fndecl = fndecl_nochk; - - if (fndecl != gimple_call_fndecl (stmt)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Replacing call: "); - print_gimple_stmt (dump_file, stmt, 0, - TDF_VOPS|TDF_MEMSYMS); - } - - gimple_call_set_fndecl (stmt, fndecl); - - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "With a new call: "); - print_gimple_stmt (dump_file, stmt, 0, - TDF_VOPS|TDF_MEMSYMS); - } - } - - /* If there is no nochk version of function then - do nothing. Otherwise insert checks before - the call. */ - if (!fndecl_nochk) - continue; - - /* If size passed to call is known and > 0 - then we may insert checks unconditionally. */ - size_val.pol.create (0); - chkp_collect_value (size, size_val); - known = chkp_is_constant_addr (size_val, &sign); - size_val.pol.release (); - - /* If we are not sure size is not zero then we have - to perform runtime check for size and perform - checks only when size is not zero. */ - if (!known) - { - gimple *check = gimple_build_cond (NE_EXPR, - size, - size_zero_node, - NULL_TREE, - NULL_TREE); - - /* Split block before string function call. */ - gsi_prev (&i); - check_bb = insert_cond_bb (bb, gsi_stmt (i), check, - profile_probability::likely ()); - - /* Set position for checks. */ - j = gsi_last_bb (check_bb); - - /* The block was splitted and therefore we - need to set iterator to its end. */ - i = gsi_last_bb (bb); - } - /* If size is known to be zero then no checks - should be performed. */ - else if (!sign) - continue; - else - j = i; - - size = size_binop (MINUS_EXPR, size, size_one_node); - if (!is_memset) - { - tree src = gimple_call_arg (stmt, 2); - tree src_bnd = gimple_call_arg (stmt, 3); - - chkp_check_mem_access (src, fold_build_pointer_plus (src, size), - src_bnd, j, gimple_location (stmt), - integer_zero_node); - } - - chkp_check_mem_access (dst, fold_build_pointer_plus (dst, size), - dst_bnd, j, gimple_location (stmt), - integer_one_node); - - } - } - } -} - -/* Intrumentation pass inserts most of bounds creation code - in the header of the function. We want to move bounds - creation closer to bounds usage to reduce bounds lifetime. - We also try to avoid bounds creation code on paths where - bounds are not used. */ -static void -chkp_reduce_bounds_lifetime (void) -{ - basic_block bb = FALLTHRU_EDGE (ENTRY_BLOCK_PTR_FOR_FN (cfun))->dest; - gimple_stmt_iterator i; - - for (i = gsi_start_bb (bb); !gsi_end_p (i); ) - { - gimple *dom_use, *use_stmt, *stmt = gsi_stmt (i); - basic_block dom_bb; - ssa_op_iter iter; - imm_use_iterator use_iter; - use_operand_p use_p; - tree op; - bool want_move = false; - bool deps = false; - - if (gimple_code (stmt) == GIMPLE_CALL - && gimple_call_fndecl (stmt) == chkp_bndmk_fndecl) - want_move = true; - - if (gimple_code (stmt) == GIMPLE_ASSIGN - && POINTER_BOUNDS_P (gimple_assign_lhs (stmt)) - && gimple_assign_rhs_code (stmt) == VAR_DECL) - want_move = true; - - if (!want_move) - { - gsi_next (&i); - continue; - } - - /* Check we do not increase other values lifetime. */ - FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE) - { - op = USE_FROM_PTR (use_p); - - if (TREE_CODE (op) == SSA_NAME - && gimple_code (SSA_NAME_DEF_STMT (op)) != GIMPLE_NOP) - { - deps = true; - break; - } - } - - if (deps) - { - gsi_next (&i); - continue; - } - - /* Check all usages of bounds. */ - if (gimple_code (stmt) == GIMPLE_CALL) - op = gimple_call_lhs (stmt); - else - { - gcc_assert (gimple_code (stmt) == GIMPLE_ASSIGN); - op = gimple_assign_lhs (stmt); - } - - dom_use = NULL; - dom_bb = NULL; - - FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, op) - { - if (is_gimple_debug (use_stmt)) - continue; - - if (dom_bb && - dominated_by_p (CDI_DOMINATORS, - dom_bb, gimple_bb (use_stmt))) - { - dom_use = use_stmt; - dom_bb = NULL; - } - else if (dom_bb) - dom_bb = nearest_common_dominator (CDI_DOMINATORS, dom_bb, - gimple_bb (use_stmt)); - else if (!dom_use) - dom_use = use_stmt; - else if (stmt_dominates_stmt_p (use_stmt, dom_use)) - dom_use = use_stmt; - else if (!stmt_dominates_stmt_p (dom_use, use_stmt) - /* If dom_use and use_stmt are PHI nodes in one BB - then it is OK to keep any of them as dom_use. - stmt_dominates_stmt_p returns 0 for such - combination, so check it here manually. */ - && (gimple_code (dom_use) != GIMPLE_PHI - || gimple_code (use_stmt) != GIMPLE_PHI - || gimple_bb (use_stmt) != gimple_bb (dom_use)) - ) - { - dom_bb = nearest_common_dominator (CDI_DOMINATORS, - gimple_bb (use_stmt), - gimple_bb (dom_use)); - dom_use = NULL; - } - } - - /* In case there is a single use, just move bounds - creation to the use. */ - if (dom_use || dom_bb) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Moving creation of "); - print_generic_expr (dump_file, op); - fprintf (dump_file, " down to its use.\n"); - } - - if (dom_use && gimple_code (dom_use) == GIMPLE_PHI) - { - dom_bb = get_immediate_dominator (CDI_DOMINATORS, - gimple_bb (dom_use)); - dom_use = NULL; - } - - if (dom_bb == bb - || (dom_use && gimple_bb (dom_use) == bb)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - fprintf (dump_file, "Cannot move statement bacause there is no " - "suitable dominator block other than entry block.\n"); - - gsi_next (&i); - } - else - { - if (dom_bb) - { - gimple_stmt_iterator last = gsi_last_bb (dom_bb); - if (!gsi_end_p (last) && stmt_ends_bb_p (gsi_stmt (last))) - gsi_move_before (&i, &last); - else - gsi_move_after (&i, &last); - } - else - { - gimple_stmt_iterator gsi = gsi_for_stmt (dom_use); - gsi_move_before (&i, &gsi); - } - - gimple_set_vdef (stmt, NULL_TREE); - gimple_set_vuse (stmt, NULL_TREE); - update_stmt (stmt); - } - } - else - gsi_next (&i); - } -} - -/* Initilize checker optimization pass. */ -static void -chkp_opt_init (void) -{ - check_infos.create (0); - - calculate_dominance_info (CDI_DOMINATORS); - calculate_dominance_info (CDI_POST_DOMINATORS); - - /* With LTO constant bounds vars may be not initialized by now. - Get constant bounds vars to handle their assignments during - optimizations. */ - chkp_get_zero_bounds_var (); - chkp_get_none_bounds_var (); -} - -/* Finalise checker optimization pass. */ -static void -chkp_opt_fini (void) -{ - chkp_fix_cfg (); - - free_dominance_info (CDI_POST_DOMINATORS); -} - -/* Checker optimization pass function. */ -static unsigned int -chkp_opt_execute (void) -{ - chkp_opt_init(); - - /* This optimization may introduce new checks - and thus we put it before checks search. */ - chkp_optimize_string_function_calls (); - - chkp_gather_checks_info (); - - chkp_remove_excess_intersections (); - - chkp_remove_constant_checks (); - - chkp_reduce_bounds_lifetime (); - - chkp_release_check_info (); - - chkp_opt_fini (); - - return 0; -} - -/* Pass gate. */ -static bool -chkp_opt_gate (void) -{ - return chkp_function_instrumented_p (cfun->decl) - && (flag_chkp_optimize > 0 - || (flag_chkp_optimize == -1 && optimize > 0)); -} - -namespace { - -const pass_data pass_data_chkp_opt = -{ - GIMPLE_PASS, /* type */ - "chkpopt", /* name */ - OPTGROUP_NONE, /* optinfo_flags */ - TV_NONE, /* tv_id */ - PROP_ssa | PROP_cfg, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_verify_il - | TODO_update_ssa /* todo_flags_finish */ -}; - -class pass_chkp_opt : public gimple_opt_pass -{ -public: - pass_chkp_opt (gcc::context *ctxt) - : gimple_opt_pass (pass_data_chkp_opt, ctxt) - {} - - /* opt_pass methods: */ - virtual opt_pass * clone () - { - return new pass_chkp_opt (m_ctxt); - } - - virtual bool gate (function *) - { - return chkp_opt_gate (); - } - - virtual unsigned int execute (function *) - { - return chkp_opt_execute (); - } - -}; // class pass_chkp_opt - -} // anon namespace - -gimple_opt_pass * -make_pass_chkp_opt (gcc::context *ctxt) -{ - return new pass_chkp_opt (ctxt); -} |