re PR c++/77722 (-fsanitize=undefined doesn't give runtime error in function without return value, unless at least 2 instructions)

	PR c++/77722
	* cp-gimplify.c (cp_ubsan_maybe_instrument_return): Instrument also
	functions that have just a STATEMENT_LIST instead of BIND_EXPR, or
	BIND_EXPR with some statement rather than STATEMENT_LIST as body.

	* g++.dg/ubsan/return-4.C: New test.
	* g++.dg/ubsan/return-5.C: New test.
	* g++.dg/ubsan/return-6.C: New test.

From-SVN: r240555

6 files changed, 76 insertions, 8 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index f250a82..75c9d36 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+2016-09-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/77722
+	* cp-gimplify.c (cp_ubsan_maybe_instrument_return): Instrument also
+	functions that have just a STATEMENT_LIST instead of BIND_EXPR, or
+	BIND_EXPR with some statement rather than STATEMENT_LIST as body.
+
 2016-09-26  Nathan Sidwell  <nathan@acm.org>
 
 	* init.c (expand_default_init): Fix } indentation.
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 6d514d0..5aca8f2 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -1570,14 +1570,11 @@ cp_ubsan_maybe_instrument_return (tree fndecl)
     }
   if (t == NULL_TREE)
     return;
-  t = DECL_SAVED_TREE (fndecl);
-  if (TREE_CODE (t) == BIND_EXPR
-      && TREE_CODE (BIND_EXPR_BODY (t)) == STATEMENT_LIST)
-    {
-      tree_stmt_iterator i = tsi_last (BIND_EXPR_BODY (t));
-      t = ubsan_instrument_return (DECL_SOURCE_LOCATION (fndecl));
-      tsi_link_after (&i, t, TSI_NEW_STMT);
-    }
+  tree *p = &DECL_SAVED_TREE (fndecl);
+  if (TREE_CODE (*p) == BIND_EXPR)
+    p = &BIND_EXPR_BODY (*p);
+  t = ubsan_instrument_return (DECL_SOURCE_LOCATION (fndecl));
+  append_to_statement_list (t, p);
 }
 
 void
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ddbb525..443a917 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2016-09-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/77722
+	* g++.dg/ubsan/return-4.C: New test.
+	* g++.dg/ubsan/return-5.C: New test.
+	* g++.dg/ubsan/return-6.C: New test.
+
 2016-09-27  Jiong Wang  <jiong.wang@arm.com>
 
 	* lib/target-supports.exp
diff --git a/gcc/testsuite/g++.dg/ubsan/return-4.C b/gcc/testsuite/g++.dg/ubsan/return-4.C
new file mode 100644
index 0000000..d30eef8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ubsan/return-4.C
@@ -0,0 +1,18 @@
+// PR c++/77722
+// { dg-do run }
+// { dg-options "-fsanitize=return -w" }
+// { dg-shouldfail "ubsan" }
+
+int
+foo ()
+{
+}
+
+int
+main ()
+{
+  foo ();
+  return 0;
+}
+
+// { dg-output "execution reached the end of a value-returning function without returning a value" }
diff --git a/gcc/testsuite/g++.dg/ubsan/return-5.C b/gcc/testsuite/g++.dg/ubsan/return-5.C
new file mode 100644
index 0000000..2956c33
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ubsan/return-5.C
@@ -0,0 +1,19 @@
+// PR c++/77722
+// { dg-do run }
+// { dg-options "-fsanitize=return -w" }
+// { dg-shouldfail "ubsan" }
+
+int
+foo ()
+{
+  int a = 5;
+}
+
+int
+main ()
+{
+  foo ();
+  return 0;
+}
+
+// { dg-output "execution reached the end of a value-returning function without returning a value" }
diff --git a/gcc/testsuite/g++.dg/ubsan/return-6.C b/gcc/testsuite/g++.dg/ubsan/return-6.C
new file mode 100644
index 0000000..0c1e792
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ubsan/return-6.C
@@ -0,0 +1,20 @@
+// PR c++/77722
+// { dg-do run }
+// { dg-options "-fsanitize=return -w" }
+// { dg-shouldfail "ubsan" }
+
+int
+foo ()
+{
+  int a = 5;
+  int b = 5;
+}
+
+int
+main ()
+{
+  foo ();
+  return 0;
+}
+
+// { dg-output "execution reached the end of a value-returning function without returning a value" }