[ubsan PATCH] Clear up unnecessary code
Marek Polacek
polacek@redhat.com
Fri Sep 25 11:30:00 GMT 2015
As discussed earlier, this patch removes now useless code and adds
tests to ensure we don't regress in diagnostics.
Bootstrapped/regtested on x86_64-linux, applying to trunk.
2015-09-25 Marek Polacek <polacek@redhat.com>
* c-ubsan.c (ubsan_instrument_division): Remove unnecessary code.
(ubsan_instrument_shift): Likewise.
* c-c++-common/ubsan/bounds-11.c: New test.
* c-c++-common/ubsan/bounds-12.c: New test.
diff --git gcc/c-family/c-ubsan.c gcc/c-family/c-ubsan.c
index d2bc264..672762c 100644
--- gcc/c-family/c-ubsan.c
+++ gcc/c-family/c-ubsan.c
@@ -89,20 +89,7 @@ ubsan_instrument_division (location_t loc, tree op0, tree op1)
return NULL_TREE;
/* In case we have a SAVE_EXPR in a conditional context, we need to
- make sure it gets evaluated before the condition. If the OP0 is
- an instrumented array reference, mark it as having side effects so
- it's not folded away. */
- if (flag_sanitize & SANITIZE_BOUNDS)
- {
- tree xop0 = op0;
- while (CONVERT_EXPR_P (xop0))
- xop0 = TREE_OPERAND (xop0, 0);
- if (TREE_CODE (xop0) == ARRAY_REF)
- {
- TREE_SIDE_EFFECTS (xop0) = 1;
- TREE_SIDE_EFFECTS (op0) = 1;
- }
- }
+ make sure it gets evaluated before the condition. */
t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), unshare_expr (op0), t);
t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), unshare_expr (op1), t);
if (flag_sanitize_undefined_trap_on_error)
@@ -187,20 +174,7 @@ ubsan_instrument_shift (location_t loc, enum tree_code code,
return NULL_TREE;
/* In case we have a SAVE_EXPR in a conditional context, we need to
- make sure it gets evaluated before the condition. If the OP0 is
- an instrumented array reference, mark it as having side effects so
- it's not folded away. */
- if (flag_sanitize & SANITIZE_BOUNDS)
- {
- tree xop0 = op0;
- while (CONVERT_EXPR_P (xop0))
- xop0 = TREE_OPERAND (xop0, 0);
- if (TREE_CODE (xop0) == ARRAY_REF)
- {
- TREE_SIDE_EFFECTS (xop0) = 1;
- TREE_SIDE_EFFECTS (op0) = 1;
- }
- }
+ make sure it gets evaluated before the condition. */
t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), unshare_expr (op0), t);
t = fold_build2 (TRUTH_OR_EXPR, boolean_type_node, t,
tt ? tt : integer_zero_node);
diff --git gcc/testsuite/c-c++-common/ubsan/bounds-11.c gcc/testsuite/c-c++-common/ubsan/bounds-11.c
index e69de29..c3e0f22 100644
--- gcc/testsuite/c-c++-common/ubsan/bounds-11.c
+++ gcc/testsuite/c-c++-common/ubsan/bounds-11.c
@@ -0,0 +1,23 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=bounds" } */
+
+struct S
+{
+ unsigned long a[1];
+ int l;
+};
+
+static inline unsigned long
+fn (const struct S *s, int i)
+{
+ return s->a[i] / i;
+}
+
+int
+main ()
+{
+ struct S s;
+ fn (&s, 1);
+}
+
+/* { dg-output "index 1 out of bounds for type 'long unsigned int \\\[1\\\]'" } */
diff --git gcc/testsuite/c-c++-common/ubsan/bounds-12.c gcc/testsuite/c-c++-common/ubsan/bounds-12.c
index e69de29..3cd3a4a 100644
--- gcc/testsuite/c-c++-common/ubsan/bounds-12.c
+++ gcc/testsuite/c-c++-common/ubsan/bounds-12.c
@@ -0,0 +1,23 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=bounds" } */
+
+struct S
+{
+ unsigned long a[1];
+ int l;
+};
+
+static inline unsigned long
+fn (const struct S *s, int i)
+{
+ return s->a[i] << i;
+}
+
+int
+main ()
+{
+ struct S s;
+ fn (&s, 1);
+}
+
+/* { dg-output "index 1 out of bounds for type 'long unsigned int \\\[1\\\]'" } */
Marek
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