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Prevent an implicit int promotion in malloc/tst-alloc_buffer.c

Message ID 20170623203736.16876-1-tuliom@linux.vnet.ibm.com
State New
Headers show

Commit Message

Tulio Magno Quites Machado Filho June 23, 2017, 8:37 p.m. UTC 
According to ISO C11, section 6.5.3.3 "Unary arithmetic operators", the
result of the ~ operator is the bitwise complement of its (promoted)
operand.
This can lead to a comparison of a char with another integer type.

Tested on powerpc, powerpc64 and powerpc64le.

2017-06-23  Tulio Magno Quites Machado Filho  <tuliom@linux.vnet.ibm.com>

	* malloc/tst-alloc_buffer.c (test_misaligned): Cast to char
	before comparing with another char.
---
 malloc/tst-alloc_buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Florian Weimer June 23, 2017, 8:42 p.m. UTC | #1 
On 06/23/2017 10:37 PM, Tulio Magno Quites Machado Filho wrote:
> 2017-06-23  Tulio Magno Quites Machado Filho  <tuliom@linux.vnet.ibm.com>
> 
> 	* malloc/tst-alloc_buffer.c (test_misaligned): Cast to char
> 	before comparing with another char.

Oops, thanks.  Please commit.

Florian
diff mbox

Patch

diff --git a/malloc/tst-alloc_buffer.c b/malloc/tst-alloc_buffer.c
index 1c14399..9b2bd20 100644
--- a/malloc/tst-alloc_buffer.c
+++ b/malloc/tst-alloc_buffer.c
@@ -429,7 +429,7 @@  test_misaligned (char pad)
   }
 
   /* Verify that padding was not overwritten.  */
-  TEST_VERIFY (backing[0] == ~pad);
+  TEST_VERIFY (backing[0] == (char) ~pad);
   TEST_VERIFY (backing[SIZE + 1] == pad);
   free (backing);
 }