From ccc51db76c5925f68f107456a4d6ef491ee5144a Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 15 May 2012 15:06:11 +0300
Subject: [PATCH] *new* check_dereferences_param: list functions that
 dereference parameters

Make a list of functions that dereference parameters.  It goes into the
DB.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 check_dereferences_param.c | 113 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 check_dereferences_param.c

diff --git a/check_dereferences_param.c b/check_dereferences_param.c
new file mode 100644
index 00000000..27a855e6
--- /dev/null
+++ b/check_dereferences_param.c
@@ -0,0 +1,113 @@
+/*
+ * sparse/check_dereferences_param.c
+ *
+ * Copyright (C) 2012 Oracle.
+ *
+ * Licensed under the Open Software License version 1.1
+ *
+ */
+
+#include "smatch.h"
+#include "smatch_extra.h"
+#include "smatch_slist.h"
+
+static int my_id;
+
+STATE(derefed);
+STATE(ignore);
+
+static int is_arg(struct expression *expr)
+{
+	struct symbol *arg;
+
+	if (expr->type != EXPR_SYMBOL)
+		return 0;
+
+	FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
+		if (arg == expr->symbol)
+			return 1;
+	} END_FOR_EACH_PTR(arg);
+	return 0;
+}
+
+static void set_ignore(const char *name, struct symbol *sym, struct expression *expr, void *unused)
+{
+	if (get_state(my_id, name, sym) == &derefed)
+		return;
+	set_state(my_id, name, sym, &ignore);
+}
+
+static void match_function_def(struct symbol *sym)
+{
+	struct symbol *arg;
+	int i;
+
+	i = -1;
+	FOR_EACH_PTR(sym->ctype.base_type->arguments, arg) {
+		i++;
+		if (!arg->ident)
+			continue;
+		add_modification_hook(my_id, arg->ident->name, &set_ignore, NULL);
+	} END_FOR_EACH_PTR(arg);
+}
+
+static void check_deref(struct expression *expr)
+{
+	struct sm_state *sm;
+
+	expr = strip_expr(expr);
+
+	if (!is_arg(expr))
+		return;
+	if (implied_not_equal(expr, 0))
+		return;
+
+	sm = get_sm_state_expr(my_id, expr);
+	if (sm && slist_has_state(sm->possible, &ignore))
+		return;
+	set_state_expr(my_id, expr, &derefed);
+}
+
+static void match_dereference(struct expression *expr)
+{
+	if (expr->type != EXPR_PREOP)
+		return;
+	if (getting_address())
+		return;
+	check_deref(expr->unop);
+}
+
+static void set_param_dereferenced(struct expression *arg, char *unused)
+{
+	check_deref(arg);
+}
+
+static void process_states(struct state_list *slist)
+{
+	struct symbol *arg;
+	int i;
+
+	i = -1;
+	FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
+		i++;
+		if (!arg->ident)
+			continue;
+		if (get_state_slist(slist, my_id, arg->ident->name, arg) == &derefed)
+			sm_msg("info: dereferences_param %d", i);
+	} END_FOR_EACH_PTR(arg);
+}
+
+void check_dereferences_param(int id)
+{
+	if (!option_info)
+		return;
+
+	my_id = id;
+
+	add_hook(&match_function_def, FUNC_DEF_HOOK);
+
+	add_hook(&match_dereference, DEREF_HOOK);
+	add_db_fn_call_callback(DEREFERENCE, &set_param_dereferenced);
+
+	all_return_states_hook(&process_states);
+}
-- 
2.11.4.GIT