diff options
Diffstat (limited to 'gcc/gimple-ssa-nonnull-compare.c')
| -rw-r--r-- | gcc/gimple-ssa-nonnull-compare.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/gcc/gimple-ssa-nonnull-compare.c b/gcc/gimple-ssa-nonnull-compare.c new file mode 100644 index 0000000..910188b --- /dev/null +++ b/gcc/gimple-ssa-nonnull-compare.c @@ -0,0 +1,151 @@ +/* -Wnonnull-compare warning support. + Copyright (C) 2016 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))) + 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); +} |