| /* -Wnonnull-compare warning support. |
| Copyright (C) 2016-2021 Free Software Foundation, Inc. |
| Contributed by Jakub Jelinek <jakub@redhat.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 "tree-pass.h" |
| #include "ssa.h" |
| #include "diagnostic-core.h" |
| #include "tree-dfa.h" |
| |
| /* Warn about comparison of nonnull_arg_p argument initial values |
| with NULL. */ |
| |
| static void |
| do_warn_nonnull_compare (function *fun, tree arg) |
| { |
| if (!POINTER_TYPE_P (TREE_TYPE (arg)) |
| && TREE_CODE (TREE_TYPE (arg)) != OFFSET_TYPE) |
| return; |
| |
| if (!nonnull_arg_p (arg)) |
| return; |
| |
| tree d = ssa_default_def (fun, arg); |
| if (d == NULL_TREE) |
| return; |
| |
| use_operand_p use_p; |
| imm_use_iterator iter; |
| |
| FOR_EACH_IMM_USE_FAST (use_p, iter, d) |
| { |
| gimple *stmt = USE_STMT (use_p); |
| tree op = NULL_TREE; |
| location_t loc = gimple_location (stmt); |
| if (gimple_code (stmt) == GIMPLE_COND) |
| switch (gimple_cond_code (stmt)) |
| { |
| case EQ_EXPR: |
| case NE_EXPR: |
| if (gimple_cond_lhs (stmt) == d) |
| op = gimple_cond_rhs (stmt); |
| break; |
| default: |
| break; |
| } |
| else if (is_gimple_assign (stmt)) |
| switch (gimple_assign_rhs_code (stmt)) |
| { |
| case EQ_EXPR: |
| case NE_EXPR: |
| if (gimple_assign_rhs1 (stmt) == d) |
| op = gimple_assign_rhs2 (stmt); |
| break; |
| case COND_EXPR: |
| switch (TREE_CODE (gimple_assign_rhs1 (stmt))) |
| { |
| case EQ_EXPR: |
| case NE_EXPR: |
| op = gimple_assign_rhs1 (stmt); |
| if (TREE_OPERAND (op, 0) != d) |
| { |
| op = NULL_TREE; |
| break; |
| } |
| loc = EXPR_LOC_OR_LOC (op, loc); |
| op = TREE_OPERAND (op, 1); |
| break; |
| default: |
| break; |
| } |
| break; |
| default: |
| break; |
| } |
| if (op |
| && (POINTER_TYPE_P (TREE_TYPE (arg)) |
| ? integer_zerop (op) : integer_minus_onep (op)) |
| && !gimple_no_warning_p (stmt)) |
| warning_at (loc, OPT_Wnonnull_compare, |
| "%<nonnull%> argument %qD compared to NULL", arg); |
| } |
| } |
| |
| namespace { |
| |
| const pass_data pass_data_warn_nonnull_compare = |
| { |
| GIMPLE_PASS, /* type */ |
| "*nonnullcmp", /* name */ |
| OPTGROUP_NONE, /* optinfo_flags */ |
| TV_NONE, /* tv_id */ |
| PROP_ssa, /* properties_required */ |
| 0, /* properties_provided */ |
| 0, /* properties_destroyed */ |
| 0, /* todo_flags_start */ |
| 0, /* todo_flags_finish */ |
| }; |
| |
| class pass_warn_nonnull_compare : public gimple_opt_pass |
| { |
| public: |
| pass_warn_nonnull_compare (gcc::context *ctxt) |
| : gimple_opt_pass (pass_data_warn_nonnull_compare, ctxt) |
| {} |
| |
| /* opt_pass methods: */ |
| virtual bool gate (function *) { return warn_nonnull_compare; } |
| |
| virtual unsigned int execute (function *); |
| |
| }; // class pass_warn_nonnull_compare |
| |
| unsigned int |
| pass_warn_nonnull_compare::execute (function *fun) |
| { |
| if (fun->static_chain_decl) |
| do_warn_nonnull_compare (fun, fun->static_chain_decl); |
| |
| for (tree arg = DECL_ARGUMENTS (cfun->decl); arg; arg = DECL_CHAIN (arg)) |
| do_warn_nonnull_compare (fun, arg); |
| return 0; |
| } |
| |
| } // anon namespace |
| |
| gimple_opt_pass * |
| make_pass_warn_nonnull_compare (gcc::context *ctxt) |
| { |
| return new pass_warn_nonnull_compare (ctxt); |
| } |