[PATCH] Fix PR sanitizer/78270 (part 2)

[Martin Liška]

Hello.

Due to a stupid mistake I did, following patch is needed for the test-case
to properly save previous gimplify_ctxp->live_switch_vars.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
I was able to run asan bootstrap on x86_64-linux-gnu and kernel build with
allyesconfig works fine.

Ready to be installed?
Martin

>From 53dd3c035283863a25a24feb90bf359295999bca Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Fri, 11 Nov 2016 11:21:29 +0100
Subject: [PATCH] Fix PR sanitizer/78270 (part 2)

gcc/ChangeLog:

2016-11-11  Martin Liska  <mli...@suse.cz>

	PR sanitizer/78270
	* gimplify.c (gimplify_switch_expr): Always save previous
	gimplify_ctxp->live_switch_vars.

gcc/testsuite/ChangeLog:

2016-11-11  Martin Liska  <mli...@suse.cz>

	PR sanitizer/78270
	* gcc.dg/asan/pr78270-2.c: New test.
---
 gcc/gimplify.c                        |  8 ++++----
 gcc/testsuite/gcc.dg/asan/pr78270-2.c | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/asan/pr78270-2.c

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 16573dd..c23888b 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -2255,11 +2255,11 @@ gimplify_switch_expr (tree *expr_p, gimple_seq *pre_p)
       gimplify_ctxp->case_labels.create (8);
 
       /* Do not create live_switch_vars if SWITCH_BODY is not a BIND_EXPR.  */
+      saved_live_switch_vars = gimplify_ctxp->live_switch_vars;
       if (TREE_CODE (SWITCH_BODY (switch_expr)) == BIND_EXPR)
-	{
-	  saved_live_switch_vars = gimplify_ctxp->live_switch_vars;
-	  gimplify_ctxp->live_switch_vars = new hash_set<tree> (4);
-	}
+	gimplify_ctxp->live_switch_vars = new hash_set<tree> (4);
+      else
+	gimplify_ctxp->live_switch_vars = NULL;
 
       bool old_in_switch_expr = gimplify_ctxp->in_switch_expr;
       gimplify_ctxp->in_switch_expr = true;
diff --git a/gcc/testsuite/gcc.dg/asan/pr78270-2.c b/gcc/testsuite/gcc.dg/asan/pr78270-2.c
new file mode 100644
index 0000000..d1f5d26
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/asan/pr78270-2.c
@@ -0,0 +1,17 @@
+// { dg-do compile }
+// { dg-additional-options "-Wno-switch-unreachable" }
+
+int a;
+void
+fn1 ()
+{
+  switch (a)
+    {
+      char b;
+    case 8:
+      &b;
+      switch (0)
+	;
+    }
+}
+
-- 
2.10.1