# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/lto-wrapper
Target: x86_64--netbsd
Configured with: /usr/src/tools/gcc/../../external/gpl3/gcc/dist/configure --target=x86_64--netbsd --enable-long-long --enable-threads --with-bugurl=http://www.NetBSD.org/support/send-pr.html --with-pkgversion='NetBSD nb1 20200907' --with-system-zlib --without-isl --enable-__cxa_atexit --enable-libstdcxx-time=rt --enable-libstdcxx-threads --with-diagnostics-color=auto-if-env --with-tune=nocona --with-default-libstdcxx-abi=new --with-mpc-lib=/var/obj/mknative/amd64-x86_64/usr/src/external/lgpl3/mpc/lib/libmpc --with-mpfr-lib=/var/obj/mknative/amd64-x86_64/usr/src/external/lgpl3/mpfr/lib/libmpfr --with-gmp-lib=/var/obj/mknative/amd64-x86_64/usr/src/external/lgpl3/gmp/lib/libgmp --with-mpc-include=/usr/src/external/lgpl3/mpc/dist/src --with-mpfr-include=/usr/src/external/lgpl3/mpfr/dist/src --with-gmp-include=/usr/src/external/lgpl3/gmp/lib/libgmp/arch/x86_64 --enable-tls --disable-multilib --disable-libstdcxx-pch --build=x86_64--netbsd --host=x86_64--netbsd --with-sysroot=/var/obj/mknative/amd64-x86_64/usr/src/destdir.amd64
Thread model: posix
gcc version 9.3.0 (nb1 20200907) 
# gcc -fsanitize=leak test.c                                                                                                                     
# ./a.out                                                                                                                                        

=================================================================
==3113==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1 byte(s) in 1 object(s) allocated from:
    #0 0x7f7ff70062d7 in __interceptor_malloc /usr/src/external/gpl3/gcc/dist/libsanitizer/lsan/lsan_interceptors.cc:53
    #1 0x400a74 in main ??:?
    #2 0x40095b in ___start ??:?

SUMMARY: LeakSanitizer: 1 byte(s) leaked in 1 allocation(s).
# ./a.out  1 2 3

=================================================================
==16675==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 16 byte(s) in 4 object(s) allocated from:
    #0 0x7f7ff70062d7 in __interceptor_malloc /usr/src/external/gpl3/gcc/dist/libsanitizer/lsan/lsan_interceptors.cc:53
    #1 0x400a74 in main ??:?
    #2 0x40095b in ___start ??:?

SUMMARY: LeakSanitizer: 16 byte(s) leaked in 4 allocation(s).
# ./a.out  1 2 3 4 5

=================================================================
==24914==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 36 byte(s) in 6 object(s) allocated from:
    #0 0x7f7ff70062d7 in __interceptor_malloc /usr/src/external/gpl3/gcc/dist/libsanitizer/lsan/lsan_interceptors.cc:53
    #1 0x400a74 in main ??:?
    #2 0x40095b in ___start ??:?

SUMMARY: LeakSanitizer: 36 byte(s) leaked in 6 allocation(s).
# gcc -fsanitize=leak test.c -g
# ./a.out  1 2 3 4 5            

=================================================================
==4763==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 36 byte(s) in 6 object(s) allocated from:
    #0 0x7f7ff70062d7 in __interceptor_malloc /usr/src/external/gpl3/gcc/dist/libsanitizer/lsan/lsan_interceptors.cc:53
    #1 0x400a74 in main /tmp/test.c:9 (discriminator 3)
    #2 0x40095b in ___start ??:?

SUMMARY: LeakSanitizer: 36 byte(s) leaked in 6 allocation(s).
# ./a.out            

=================================================================
==6199==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1 byte(s) in 1 object(s) allocated from:
    #0 0x7f7ff70062d7 in __interceptor_malloc /usr/src/external/gpl3/gcc/dist/libsanitizer/lsan/lsan_interceptors.cc:53
    #1 0x400a74 in main /tmp/test.c:9 (discriminator 3)
    #2 0x40095b in ___start ??:?

SUMMARY: LeakSanitizer: 1 byte(s) leaked in 1 allocation(s).
# cat test.c                                                                                                                                     
#include <stdlib.h>

int
main(int argc, char **argv)
{
        int i;
        volatile void *ptr;
        for (i = 0; i < argc; i++)
                ptr = malloc(argc);
        return 0;
}