The selftest/sgx/main.c didn't compile with [-Werror=implicit-function-declaration]
[edited]:
make[3]: Entering directory 'tools/testing/selftests/sgx'
gcc -Wall -Werror -g -Itools/testing/selftests/../../../tools/include -fPIC -c main.c \
-o tools/testing/selftests/sgx/main.o
In file included from main.c:21:
../kselftest_harness.h: In function ‘__run_test’:
../kselftest_harness.h:1169:13: error: implicit declaration of function ‘asprintf’; \
did you mean ‘vsprintf’? [-Werror=implicit-function-declaration]
1169 | if (asprintf(&test_name, "%s%s%s.%s", f->name,
| ^~~~~~~~
| vsprintf
cc1: all warnings being treated as errors
make[3]: *** [Makefile:36: tools/testing/selftests/sgx/main.o] Error 1
The cause is in the included <stdio.h> on Ubuntu 22.04 LTS:
19 /*
20 * ISO C99 Standard: 7.19 Input/output <stdio.h>
21 */
.
.
.
387 #if __GLIBC_USE (LIB_EXT2)
388 /* Write formatted output to a string dynamically allocated with `malloc'.
389 Store the address of the string in *PTR. */
390 extern int vasprintf (char **__restrict __ptr, const char *__restrict __f,
391 __gnuc_va_list __arg)
392 __THROWNL __attribute__ ((__format__ (__printf__, 2, 0))) __wur;
393 extern int __asprintf (char **__restrict __ptr,
394 const char *__restrict __fmt, ...)
395 __THROWNL __attribute__ ((__format__ (__printf__, 2, 3))) __wur;
396 extern int asprintf (char **__restrict __ptr,
397 const char *__restrict __fmt, ...)
398 __THROWNL __attribute__ ((__format__ (__printf__, 2, 3))) __wur;
399 #endif
__GLIBC_USE (LIB_EXT2) expands into __GLIBC_USE_LIB_EXT2 as defined here:
/usr/include/features.h:186:#define __GLIBC_USE(F) __GLIBC_USE_ ## F
Now, what is unobvious is that <stdio.h> includes
/usr/include/x86_64-linux-gnu/bits/libc-header-start.h:
------------------------------------------------------
35 /* ISO/IEC TR 24731-2:2010 defines the __STDC_WANT_LIB_EXT2__
36 macro. */
37 #undef __GLIBC_USE_LIB_EXT2
38 #if (defined __USE_GNU \
39 || (defined __STDC_WANT_LIB_EXT2__ && __STDC_WANT_LIB_EXT2__ > 0))
40 # define __GLIBC_USE_LIB_EXT2 1
41 #else
42 # define __GLIBC_USE_LIB_EXT2 0
43 #endif
This makes <stdio.h> exclude line 396 and asprintf() prototype from normal
include file processing.
The fix defines __USE_GNU before including <stdio.h> in case it isn't already
defined. After this intervention the module compiles OK.
Converting snprintf() to asprintf() in selftests/kselftest_harness.h:1169
created this new dependency and the implicit declaration broke the compilation.
Fixes: 809216233555 ("selftests/harness: remove use of LINE_MAX")
Cc: Edward Liaw <edliaw@xxxxxxxxxx>
Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: linux-sgx@xxxxxxxxxxxxxxx
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Mirsad Todorovac <mtodorov69@xxxxxxxxx>
---
tools/testing/selftests/sgx/main.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 9820b3809c69..f5cb426bd797 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -6,6 +6,9 @@
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
+#ifndef __USE_GNU
+#define __USE_GNU
+#endif
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
--
2.34.1
