Compiling tests with GCC 16 results into this warning:
gcc -shared -o libmallocintercept.so -fpic -std=gnu99 -Wall -DFAKE_STAT -Werror -Wextra -U_FILE_OFFSET_BITS -U_TIME_BITS libmallocintercept.c
libmallocintercept.c: In function ‘free’:
libmallocintercept.c:79:12: error: variable ‘ptr2’ set but not used [-Werror=unused-but-set-variable=]
79 | long int ptr2 = (long int) ptr; ptr2 -= (long int) ptr;
| ^~~~
cc1: all warnings being treated as errors
The ptr2 variable was added in the past to silence compiler warnings,
probably for the very same reason (commits
75cbe8e507 and
2bfbe19f71). GCC 16 is smarter and
discovers that the ptr2 variables is not needed.
This patch changes the work around to "(void) unused_variable;" idiom
recommended by GCC manual and already used in print_msg().
We should ignore the return value for logging function, to fix a new gcc ftbfs
libmallocintercept.c: In function ‘print_msg’:
libmallocintercept.c:27:9: error: ignoring return value of ‘write’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
27 | write(0, msg, strlen(msg));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
Backtraces suggest that AddressSanitizer replaces malloc() with a
function that
- locks a mutex and
- calls clock_gettime() while the mutex is held
This commit adds a test that implements a trivial malloc() that behaves
similarly. Currently, this test hangs.
Signed-off-by: Uli Schlachter <psychon@znc.in>
