re PR sanitizer/60613 (Invalid signed subtraction ubsan diagnostics)

	PR sanitizer/60613
	* internal-fn.c (ubsan_expand_si_overflow_addsub_check): For
	code == MINUS_EXPR, never swap op0 with op1.

	* c-c++-common/ubsan/pr60613-1.c: New test.
	* c-c++-common/ubsan/pr60613-2.c: New test.

From-SVN: r208766

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dbd497177bb7fc6b08b868f8c1a88553234829da..e085b2ac681193fab0a482c5ad6e9f76c972a303 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2014-03-22  Jakub Jelinek  <jakub@redhat.com>
 
+       PR sanitizer/60613
+       * internal-fn.c (ubsan_expand_si_overflow_addsub_check): For
+       code == MINUS_EXPR, never swap op0 with op1.
+
        * toplev.c (init_local_tick): Avoid signed integer multiplication
        overflow.
        * genautomata.c (reserv_sets_hash_value): Fix rotate idiom, avoid

diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index 9926ec2808be9134cd2f8d1cb45d57225deca734..1062ea84705d6105150aa78a5584f2b8200e03c2 100644 (file)
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -221,14 +221,15 @@ ubsan_expand_si_overflow_addsub_check (tree_code code, gimple stmt)
       res = expand_binop (mode, code == PLUS_EXPR ? add_optab : sub_optab,
                          op0, op1, NULL_RTX, false, OPTAB_LIB_WIDEN);
 
-      /* If we can prove one of the arguments is always non-negative
-        or always negative, we can do just one comparison and
-        conditional jump instead of 2 at runtime, 3 present in the
+      /* If we can prove one of the arguments (for MINUS_EXPR only
+        the second operand, as subtraction is not commutative) is always
+        non-negative or always negative, we can do just one comparison
+        and conditional jump instead of 2 at runtime, 3 present in the
         emitted code.  If one of the arguments is CONST_INT, all we
         need is to make sure it is op1, then the first
         emit_cmp_and_jump_insns will be just folded.  Otherwise try
         to use range info if available.  */
-      if (CONST_INT_P (op0))
+      if (code == PLUS_EXPR && CONST_INT_P (op0))
        {
          rtx tem = op0;
          op0 = op1;
@@ -236,7 +237,7 @@ ubsan_expand_si_overflow_addsub_check (tree_code code, gimple stmt)
        }
       else if (CONST_INT_P (op1))
        ;
-      else if (TREE_CODE (arg0) == SSA_NAME)
+      else if (code == PLUS_EXPR && TREE_CODE (arg0) == SSA_NAME)
        {
          double_int arg0_min, arg0_max;
          if (get_range_info (arg0, &arg0_min, &arg0_max) == VR_RANGE)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 210dbf564a66b22fe648c5b982609a2ee7aa6422..f95f4bd23c772c2c7770e1261f1a72a4aa534bb7 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2014-03-22  Jakub Jelinek  <jakub@redhat.com>
+
+       PR sanitizer/60613
+       * c-c++-common/ubsan/pr60613-1.c: New test.
+       * c-c++-common/ubsan/pr60613-2.c: New test.
+
 2014-03-22  Matthias Klose  <doko@ubuntu.com>
 
        * g++.dg/cpp0x/regress: Remove empty directory.

diff --git a/gcc/testsuite/c-c++-common/ubsan/pr60613-1.c b/gcc/testsuite/c-c++-common/ubsan/pr60613-1.c
new file mode 100644 (file)
index 0000000..2161e0b
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/pr60613-1.c
@@ -0,0 +1,33 @@
+/* PR sanitizer/60613 */
+/* { dg-do run } */
+/* { dg-options "-fsanitize=undefined" } */
+
+long long y;
+
+__attribute__((noinline, noclone)) long long
+foo (long long x)
+{
+  asm ("");
+  if (x >= 0 || x < -2040)
+    return 23;
+  x += 2040;
+  return x - y;
+}
+
+__attribute__((noinline, noclone)) long long
+bar (long long x)
+{
+  asm ("");
+  return 8LL - x;
+}
+
+int
+main ()
+{
+  y = 1;
+  if (foo (8 - 2040) != 8 - 1)
+    __builtin_abort ();
+  if (bar (1) != 8 - 1)
+    __builtin_abort ();
+  return 0;
+}

diff --git a/gcc/testsuite/c-c++-common/ubsan/pr60613-2.c b/gcc/testsuite/c-c++-common/ubsan/pr60613-2.c
new file mode 100644 (file)
index 0000000..92c2de8
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/pr60613-2.c
@@ -0,0 +1,36 @@
+/* PR sanitizer/60613 */
+/* { dg-do run } */
+/* { dg-options "-fsanitize=undefined" } */
+
+long long y;
+
+__attribute__((noinline, noclone)) long long
+foo (long long x)
+{
+  asm ("");
+  if (x >= 0 || x < -2040)
+    return 23;
+  x += 2040;
+  return x - y;
+}
+
+__attribute__((noinline, noclone)) long long
+bar (long long x)
+{
+  asm ("");
+  return 8LL - x;
+}
+
+int
+main ()
+{
+  y = -__LONG_LONG_MAX__ + 6;
+  if (foo (8 - 2040) != -__LONG_LONG_MAX__)
+    __builtin_abort ();
+  if (bar (-__LONG_LONG_MAX__ + 5) != -__LONG_LONG_MAX__ + 1)
+    __builtin_abort ();
+  return 0;
+}
+
+/* { dg-output "signed integer overflow: 8 \\- -9223372036854775801 cannot be represented in type 'long long int'(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: 8 \\- -9223372036854775802 cannot be represented in type 'long long int'" } */