From c7274165bd25121e2d7562718904f12126bf1b1e Mon Sep 17 00:00:00 2001
From: Marek Polacek <polacek@redhat.com>
Date: Fri, 14 Nov 2014 11:57:05 +0000
Subject: [PATCH] fold-const.c (fold_negate_expr): Don't fold INTEGER_CST if
that overflows when SANITIZE_SI_OVERFLOW is on.
* fold-const.c (fold_negate_expr): Don't fold INTEGER_CST if
that overflows when SANITIZE_SI_OVERFLOW is on. Guard -(-A)
folding with TYPE_OVERFLOW_SANITIZED.
* c-c++-common/ubsan/overflow-negate-3.c: New test.
From-SVN: r217556
---
gcc/ChangeLog | 6 ++++++
gcc/fold-const.c | 7 +++++--
gcc/testsuite/ChangeLog | 4 ++++
.../c-c++-common/ubsan/overflow-negate-3.c | 21 +++++++++++++++++++
4 files changed, 36 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/c-c++-common/ubsan/overflow-negate-3.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 58efc772d66d..976dd3bf51da 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-11-14 Marek Polacek <polacek@redhat.com>
+
+ * fold-const.c (fold_negate_expr): Don't fold INTEGER_CST if
+ that overflows when SANITIZE_SI_OVERFLOW is on. Guard -(-A)
+ folding with TYPE_OVERFLOW_SANITIZED.
+
2014-11-14 Marek Polacek <polacek@redhat.com>
PR sanitizer/63839
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 0170b88daefb..7dbbadd859b3 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -554,7 +554,8 @@ fold_negate_expr (location_t loc, tree t)
case INTEGER_CST:
tem = fold_negate_const (t, type);
if (TREE_OVERFLOW (tem) == TREE_OVERFLOW (t)
- || !TYPE_OVERFLOW_TRAPS (type))
+ || (!TYPE_OVERFLOW_TRAPS (type)
+ && (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0))
return tem;
break;
@@ -611,7 +612,9 @@ fold_negate_expr (location_t loc, tree t)
break;
case NEGATE_EXPR:
- return TREE_OPERAND (t, 0);
+ if (!TYPE_OVERFLOW_SANITIZED (type))
+ return TREE_OPERAND (t, 0);
+ break;
case PLUS_EXPR:
if (!HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1d3ef947bf24..b6a07d3fb129 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2014-11-14 Marek Polacek <polacek@redhat.com>
+
+ * c-c++-common/ubsan/overflow-negate-3.c: New test.
+
2014-11-14 Marek Polacek <polacek@redhat.com>
PR sanitizer/63839
diff --git a/gcc/testsuite/c-c++-common/ubsan/overflow-negate-3.c b/gcc/testsuite/c-c++-common/ubsan/overflow-negate-3.c
new file mode 100644
index 000000000000..e6db394a4f5d
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/overflow-negate-3.c
@@ -0,0 +1,21 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=signed-integer-overflow" } */
+
+#define INT_MIN (-__INT_MAX__ - 1)
+
+int
+main ()
+{
+ int x = INT_MIN;
+ int y;
+ asm ("" : "+g" (x));
+ y = -(-x);
+ asm ("" : "+g" (y));
+ y = -(-INT_MIN);
+ asm ("" : "+g" (y));
+}
+
+/* { dg-output "negation of -2147483648 cannot be represented in type 'int'\[^\n\r]*; cast to an unsigned type to negate this value to itself\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*negation of -2147483648 cannot be represented in type 'int'\[^\n\r]*; cast to an unsigned type to negate this value to itself\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*negation of -2147483648 cannot be represented in type 'int'\[^\n\r]*; cast to an unsigned type to negate this value to itself\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*negation of -2147483648 cannot be represented in type 'int'\[^\n\r]*; cast to an unsigned type to negate this value to itself\[^\n\r]*(\n|\r\n|\r)" } */
--
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