Do not instrument void variables with MPX (PR tree-opt/79987).

2017-08-11  Martin Liska  <mliska@suse.cz>

	PR tree-opt/79987
	* tree-chkp.c (chkp_get_bounds_for_decl_addr): Do not instrument
	variables of void type.
2017-08-11  Martin Liska  <mliska@suse.cz>

	PR tree-opt/79987
	* gcc.target/i386/mpx/pr79987.c: New test.

From-SVN: r251049

gcc/ChangeLog

 2017-08-11  Martin Liska  <mliska@suse.cz>
 
+	PR tree-opt/79987
+	* tree-chkp.c (chkp_get_bounds_for_decl_addr): Do not instrument
+	variables of void type.
+
+2017-08-11  Martin Liska  <mliska@suse.cz>
+
 	* asan.c (asan_protect_global): Replace ASM_OUTPUT_DEF with
 	TARGET_SUPPORTS_ALIASES.
 	* cgraph.c (cgraph_node::create_same_body_alias): Likewise.

gcc/testsuite/ChangeLog

 2017-08-11  Martin Liska  <mliska@suse.cz>
 
+	PR tree-opt/79987
+	* gcc.target/i386/mpx/pr79987.c: New test.
+
+2017-08-11  Martin Liska  <mliska@suse.cz>
+
 	PR ipa/81213
 	* gcc.target/i386/pr81213.c: New test.
 

gcc/testsuite/gcc.target/i386/mpx/pr79987.c

+/* { dg-do compile } */
+/* { dg-options "-fcheck-pointer-bounds -mmpx" } */
+
+extern void foo;
+void *bar = &foo; /* { dg-warning "taking address of expression of type .void." } */

gcc/tree-chkp.c

@@ -3197,6 +3197,9 @@ chkp_get_bounds_for_decl_addr (tree decl)
       && !flag_chkp_incomplete_type)
       return chkp_get_zero_bounds ();
 
+  if (VOID_TYPE_P (TREE_TYPE (decl)))
+    return chkp_get_zero_bounds ();
+
   if (flag_chkp_use_static_bounds
       && VAR_P (decl)
       && (TREE_STATIC (decl)