In this PR, we find ourselves instrumenting a static initializer and
then crashing when expanding an unlowered UBSAN_NULL. Jakub suggests
to not instrument DECL_INITIAL of a static variable. The following
patch is an attempt to do that. Note that we're still able to sanitize
similar cases (they don't have DECL_INITIAL but something else).
Bootstrap/regtest/bootstrap-ubsan passed on x86_64-linux, ok for trunk?
2015-05-21 Marek Polacek <pola...@redhat.com>
PR sanitizer/66190
* cp-gimplify.c (struct cp_genericize_data): Add no_sanitize_p.
(cp_genericize_r): Don't instrument static initializers.
(cp_genericize_tree): Initialize wtd.no_sanitize_p.
* g++.dg/ubsan/static-init-1.C: New test.
* g++.dg/ubsan/static-init-2.C: New test.
* g++.dg/ubsan/static-init-3.C: New test.
diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
index d5a64fc..778d8f3 100644
--- gcc/cp/cp-gimplify.c
+++ gcc/cp/cp-gimplify.c
@@ -906,6 +906,7 @@ struct cp_genericize_data
vec<tree> bind_expr_stack;
struct cp_genericize_omp_taskreg *omp_ctx;
tree try_block;
+ bool no_sanitize_p;
};
/* Perform any pre-gimplification lowering of C++ front end trees to
@@ -1150,6 +1151,21 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void
*data)
*stmt_p = build1 (NOP_EXPR, void_type_node, integer_zero_node);
*walk_subtrees = 0;
}
+ else if ((flag_sanitize
+ & (SANITIZE_NULL | SANITIZE_ALIGNMENT | SANITIZE_VPTR))
+ && TREE_CODE (stmt) == DECL_EXPR
+ && VAR_P (DECL_EXPR_DECL (stmt))
+ && TREE_STATIC (DECL_EXPR_DECL (stmt))
+ && DECL_INITIAL (DECL_EXPR_DECL (stmt)))
+ {
+ *walk_subtrees = 0;
+ /* The point here is to not sanitize static initializers. */
+ bool no_sanitize_p = wtd->no_sanitize_p;
+ wtd->no_sanitize_p = true;
+ cp_walk_tree (&DECL_INITIAL (DECL_EXPR_DECL (stmt)), cp_genericize_r,
+ data, NULL);
+ wtd->no_sanitize_p = no_sanitize_p;
+ }
else if (TREE_CODE (stmt) == OMP_PARALLEL || TREE_CODE (stmt) == OMP_TASK)
{
struct cp_genericize_omp_taskreg omp_ctx;
@@ -1275,9 +1291,10 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void
*data)
if (*stmt_p == error_mark_node)
*stmt_p = size_one_node;
return NULL;
- }
- else if (flag_sanitize
- & (SANITIZE_NULL | SANITIZE_ALIGNMENT | SANITIZE_VPTR))
+ }
+ else if ((flag_sanitize
+ & (SANITIZE_NULL | SANITIZE_ALIGNMENT | SANITIZE_VPTR))
+ && !wtd->no_sanitize_p)
{
if ((flag_sanitize & (SANITIZE_NULL | SANITIZE_ALIGNMENT))
&& TREE_CODE (stmt) == NOP_EXPR
@@ -1319,6 +1336,7 @@ cp_genericize_tree (tree* t_p)
wtd.bind_expr_stack.create (0);
wtd.omp_ctx = NULL;
wtd.try_block = NULL_TREE;
+ wtd.no_sanitize_p = false;
cp_walk_tree (t_p, cp_genericize_r, &wtd, NULL);
delete wtd.p_set;
wtd.bind_expr_stack.release ();
diff --git gcc/testsuite/g++.dg/ubsan/static-init-1.C
gcc/testsuite/g++.dg/ubsan/static-init-1.C
index e69de29..0b424c0 100644
--- gcc/testsuite/g++.dg/ubsan/static-init-1.C
+++ gcc/testsuite/g++.dg/ubsan/static-init-1.C
@@ -0,0 +1,21 @@
+// PR sanitizer/66190
+// { dg-do compile }
+// { dg-options "-fsanitize=null -std=c++11" }
+
+class A {
+public:
+ void fn1 (int);
+};
+
+class G {
+ ~G ();
+ A t;
+ virtual void fn2 () {
+ static int a;
+ static int &b = a;
+ static int &c (a);
+ static int &d {a};
+ t.fn1 (b);
+ }
+};
+G ::~G () {}
diff --git gcc/testsuite/g++.dg/ubsan/static-init-2.C
gcc/testsuite/g++.dg/ubsan/static-init-2.C
index e69de29..d046b33 100644
--- gcc/testsuite/g++.dg/ubsan/static-init-2.C
+++ gcc/testsuite/g++.dg/ubsan/static-init-2.C
@@ -0,0 +1,17 @@
+// PR sanitizer/66190
+// { dg-do run }
+// { dg-options "-fsanitize=null -std=c++11" }
+
+int
+main ()
+{
+ static int *a;
+ static int &b = *a;
+ static int &c (*a);
+ static int &d {*a};
+ return 0;
+}
+
+// { dg-output "reference binding to null pointer of type 'int'(\n|\r\n|\r)" }
+// { dg-output "\[^\n\r]*reference binding to null pointer of type
'int'(\n|\r\n|\r)" }
+// { dg-output "\[^\n\r]*reference binding to null pointer of type 'int'" }
diff --git gcc/testsuite/g++.dg/ubsan/static-init-3.C
gcc/testsuite/g++.dg/ubsan/static-init-3.C
index e69de29..7fd6cbd 100644
--- gcc/testsuite/g++.dg/ubsan/static-init-3.C
+++ gcc/testsuite/g++.dg/ubsan/static-init-3.C
@@ -0,0 +1,19 @@
+// PR sanitizer/66190
+// { dg-do run }
+// { dg-options "-fsanitize=null -std=c++11" }
+
+int *fn (void) { return 0; }
+
+int
+main ()
+{
+ static int a;
+ static int &b = *fn ();
+ static int &c (*fn ());
+ static int &d {*fn ()};
+ return 0;
+}
+
+// { dg-output "reference binding to null pointer of type 'int'(\n|\r\n|\r)" }
+// { dg-output "\[^\n\r]*reference binding to null pointer of type
'int'(\n|\r\n|\r)" }
+// { dg-output "\[^\n\r]*reference binding to null pointer of type 'int'" }
Marek
