[PATCHv3] S390: Fix build failure in test string/tst-endian.c with gcc 6.
Commit Message
On 01/21/2016 05:44 PM, Mike Frysinger wrote:
> On 21 Jan 2016 17:38, Stefan Liebler wrote:
>> This patch suppresses these warnings with DIAG_* macros.
>> The conditional #if __GNUC_PREREQ (6, 0) is needed, because an older gcc
>> would warn about:
>> tst-endian.c: In function ‘do_test’:
>> tst-endian.c:18:4: warning: unknown option after ‘#pragma GCC
>> diagnostic’ kind [-Wpragmas]
>> DIAG_IGNORE_NEEDS_COMMENT (6, "-Wtautological-compare");
>> ^
>
> you can at least do it once at the top via a local define:
> /* big comment block */
> #if __GNUC_PREREQ (6, 0)
> # define DIAG_IGNORE_NEEDS_COMMENT_AUTOLOGICAL_COMPARE() \
> DIAG_IGNORE_NEEDS_COMMENT (6, "-Wtautological-compare");
> #else
> # define DIAG_IGNORE_NEEDS_COMMENT_AUTOLOGICAL_COMPARE()
> #endif
>
> then the inline usage is simple
> -mike
>
That's a good point.
Here is the updated patch.
Ok to commit?
Bye Stefan
ChangeLog:
* string/tst-endian.c: Include <libc-internal.h>
(do_test): Ignore tautological-compare warnings around
"htobeXX (beXXtoh (i)) != i" and
"htoleXX (leXXtoh (i)) != i" if-statements.
Comments
On 22 Jan 2016 13:28, Stefan Liebler wrote:
> Ok to commit?
seems fine to me
-mike
@@ -3,6 +3,20 @@
#include <inttypes.h>
#include <stdio.h>
#include <stdint.h>
+#include <libc-internal.h>
+
+#if __GNUC_PREREQ (6, 0)
+/* GCC 6.0 warns on big endian systems about:
+ htobeXX (beXXtoh (i)) != i
+ warning: self-comparison always evaluates to false [-Wtautological-compare]
+ because htobeXX(x) and beXXtoh(x) is defined to (x)
+ in string/endian.h on big endian systems.
+ The same applies to htoleXX/leXXtoh on little endian systems. */
+# define DIAG_IGNORE_NEEDS_COMMENT_TAUTOLOGICAL_COMPARE() \
+ DIAG_IGNORE_NEEDS_COMMENT (6, "-Wtautological-compare")
+#else
+# define DIAG_IGNORE_NEEDS_COMMENT_TAUTOLOGICAL_COMPARE()
+#endif
static int
do_test (void)
@@ -13,6 +27,8 @@ do_test (void)
{
if (i < UINT64_C (65536))
{
+ DIAG_PUSH_NEEDS_COMMENT;
+ DIAG_IGNORE_NEEDS_COMMENT_TAUTOLOGICAL_COMPARE ();
if (htobe16 (be16toh (i)) != i)
{
printf ("htobe16 (be16toh (%" PRIx64 ")) == %" PRIx16 "\n",
@@ -25,6 +41,7 @@ do_test (void)
i, (uint16_t) htole16 (le16toh (i)));
result = 1;
}
+ DIAG_POP_NEEDS_COMMENT;
uint16_t n[2];
n[__BYTE_ORDER == __LITTLE_ENDIAN] = bswap_16 (i);
@@ -45,6 +62,8 @@ do_test (void)
if (i < UINT64_C (4294967296))
{
+ DIAG_PUSH_NEEDS_COMMENT;
+ DIAG_IGNORE_NEEDS_COMMENT_TAUTOLOGICAL_COMPARE ();
if (htobe32 (be32toh (i)) != i)
{
printf ("htobe32 (be32toh (%" PRIx64 ")) == %" PRIx32 "\n",
@@ -57,6 +76,7 @@ do_test (void)
i, (uint32_t) htole32 (le32toh (i)));
result = 1;
}
+ DIAG_POP_NEEDS_COMMENT;
uint32_t n[2];
n[__BYTE_ORDER == __LITTLE_ENDIAN] = bswap_32 (i);
@@ -75,6 +95,8 @@ do_test (void)
}
}
+ DIAG_PUSH_NEEDS_COMMENT;
+ DIAG_IGNORE_NEEDS_COMMENT_TAUTOLOGICAL_COMPARE ();
if (htobe64 (be64toh (i)) != i)
{
printf ("htobe64 (be64toh (%" PRIx64 ")) == %" PRIx64 "\n",
@@ -87,6 +109,7 @@ do_test (void)
i, htole64 (le64toh (i)));
result = 1;
}
+ DIAG_POP_NEEDS_COMMENT;
uint64_t n[2];
n[__BYTE_ORDER == __LITTLE_ENDIAN] = bswap_64 (i);