From becd5e1ac92ad5e24222d474970c017b81e99c1d Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Fri, 14 Nov 2014 11:57:05 +0000 Subject: * 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. git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@217556 138bc75d-0d04-0410-961f-82ee72b054a4 --- 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 58efc772d66..976dd3bf51d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2014-11-14 Marek Polacek + + * 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 PR sanitizer/63839 diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 0170b88daef..7dbbadd859b 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 1d3ef947bf2..b6a07d3fb12 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2014-11-14 Marek Polacek + + * c-c++-common/ubsan/overflow-negate-3.c: New test. + 2014-11-14 Marek Polacek 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 00000000000..e6db394a4f5 --- /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)" } */ -- cgit v1.2.3