Hi David, > It seems printf() always alloc something and does not free it:
What compiler and what optimizations? Most compilers will optimize a printf without any special formatting into a puts call instead of a printf call. For example clang -O3 -fomit-frame-pointer (which I use for clarity here) outputs this code: .file "leak.c" ... main: # @main # BB#0: # %entry subl $12, %esp movl $str, (%esp) calll puts xorl %eax, %eax addl $12, %esp ret .Ltmp0: ... str: .asciz "Hi" .size str, 3 ... [snip] > ==67840== suppressed: 4,096 bytes in 1 blocks Lets take a look at what valgrind says immediately after this: ==14481== For counts of detected and suppressed errors, rerun with: -v One of the lines we get is --14508-- used_suppression: 1 libc puts leak Which means it is a known issue and has been specially marked as to avoid being reported by valgrind. Lets take a look to see where this suppression happens: in /usr/local/lib/valgrind/default.supp we find { libc puts leak Memcheck:Leak fun:malloc obj:/lib/libc.so.7 obj:/lib/libc.so.7 obj:/lib/libc.so.7 fun:puts fun:main } After some investigation I was able to find the following commit: http://p4db.freebsd.org/chv.cgi?CH=168767 which shows when this suppression was added and by whom. I trust that if you are interested in the details of why this leak is detected you have the skills to follow up on this by yourself :-) Thank you for trying to make FreeBSD better! -- Eitan Adler _______________________________________________ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"