From 83e06f5e5c034378e7f2fef8792ceb38f01925c1 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 15 May 2012 15:00:32 +0300
Subject: [PATCH] *new* returns: merge all slists from all returns

This provides a call back:
void all_return_states_hook(void (*callback)(struct state_list *slist));

The way I'm going to use this is to tell if a parameter is derefenced on
every path through a function.  This combines all the end states together
and I'll just do a get_state_slist() to find out which parameters are
always dereferenced.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 Makefile         |  2 +-
 check_list.h     |  1 +
 smatch_returns.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 smatch_slist.h   |  5 +++++
 4 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 smatch_returns.c

diff --git a/Makefile b/Makefile
index 0e63a784..0879454d 100644
--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,7 @@ SMATCH_FILES=smatch_flow.o smatch_conditions.o smatch_slist.o smatch_states.o \
 	smatch_ranges.o smatch_implied.o smatch_ignore.o smatch_project.o \
 	smatch_tracker.o smatch_files.o smatch_expression_stacks.o \
 	smatch_constraints.o smatch_buf_size.o smatch_capped.o smatch_db.o \
-	smatch_expressions.o
+	smatch_expressions.o smatch_returns.o
 
 SMATCH_CHECKS=$(shell ls check_*.c | sed -e 's/\.c/.o/')
 SMATCH_DATA=smatch_data/kernel.allocation_funcs smatch_data/kernel.balanced_funcs \
diff --git a/check_list.h b/check_list.h
index 7a3d59db..cf6bd530 100644
--- a/check_list.h
+++ b/check_list.h
@@ -100,6 +100,7 @@ CK(check_wine_WtoA)
 
 CK(register_modification_hooks_late)
 CK(register_smatch_extra_late)
+CK(register_returns)
 CK(register_implications) /* implications always has to be last */
 
 #ifdef __undo_CK_def
diff --git a/smatch_returns.c b/smatch_returns.c
new file mode 100644
index 00000000..c2f6c30a
--- /dev/null
+++ b/smatch_returns.c
@@ -0,0 +1,59 @@
+/*
+ * smatch/smatch_returns.c
+ *
+ * Copyright (C) 2011 Oracle.
+ *
+ * Licensed under the Open Software License version 1.1
+ *
+ */
+
+#include "smatch.h"
+#include "smatch_slist.h"
+
+static int my_id;
+
+struct return_states_callback {
+	void (*callback)(struct state_list *slist);
+};
+ALLOCATOR(return_states_callback, "return states callbacks");
+DECLARE_PTR_LIST(callback_list, struct return_states_callback);
+static struct callback_list *callback_list;
+
+static struct state_list *all_return_states;
+
+void all_return_states_hook(void (*callback)(struct state_list *slist))
+{
+	struct return_states_callback *rs_cb = __alloc_return_states_callback(0);
+
+	rs_cb->callback = callback;
+	add_ptr_list(&callback_list, rs_cb);
+}
+
+static void call_hooks()
+{
+	struct return_states_callback *rs_cb;
+
+	FOR_EACH_PTR(callback_list, rs_cb) {
+		rs_cb->callback(all_return_states);
+	} END_FOR_EACH_PTR(rs_cb);
+}
+
+static void match_return(struct expression *ret_value)
+{
+	merge_slist(&all_return_states, __get_cur_slist());
+}
+
+static void match_end_func(struct symbol *sym)
+{
+	merge_slist(&all_return_states, __get_cur_slist());
+	call_hooks();
+	free_slist(&all_return_states);
+}
+
+void register_returns(int id)
+{
+	my_id = id;
+
+	add_hook(&match_return, RETURN_HOOK);
+	add_hook(&match_end_func, END_FUNC_HOOK);
+}
diff --git a/smatch_slist.h b/smatch_slist.h
index 75bb09fd..3dc84e68 100644
--- a/smatch_slist.h
+++ b/smatch_slist.h
@@ -72,3 +72,8 @@ struct state_list **get_slist_from_named_stack(struct named_stack *stack,
 					      const char *name);
 
 void overwrite_slist(struct state_list *from, struct state_list **to);
+
+/* add stuff smatch_returns.c here */
+
+void all_return_states_hook(void (*callback)(struct state_list *slist));
+
-- 
2.11.4.GIT