GCC and -fsanitize=leak

Question

I'm working and on a large C++ project and making it compile with clang would be painful, so I'm stuck with GCC.

I want to use the nice -fsanitize=leak flag that I already used with clang on a previous job, but it does not seem to work.

I made a very simple example to test it:

#include <stdlib.h>
void FooBar() {
  malloc(7);
}
int main() {
  FooBar();
  return 0;
}

With clang it works as expected:

>> clang -fsanitize=leak main.cpp
>> LSAN_OPTIONS=detect_leaks=1 ./a.out
=================================================================
==18052==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 7 byte(s) in 1 object(s) allocated from:
#0 0x41dcbc  (~/dev/addresssanitizertest/a.out+0x41dcbc)
#1 0x431ac3  (~/dev/addresssanitizertest/a.out+0x431ac3)
#2 0x431ae3  (~/dev/addresssanitizertest/a.out+0x431ae3)
#3 0x7f8077e71a3f  (/lib/x86_64-linux-gnu/libc.so.6+0x20a3f)
SUMMARY: LeakSanitizer: 7 byte(s) leaked in 1 allocation(s).
>>

But with gcc it does not seem to detect anything:

>> gcc -fsanitize=leak main.cpp
>> LSAN_OPTIONS=detect_leaks=1 ./a.out
>>

Did I miss something like a nice environment variable? Did someone ever made it work with gcc?

EDIT: This works for instance:

g++ -fsanitize=address main.cpp
ASAN_OPTIONS=detect_leaks=1 ./a.out

But I can't do that: the perf drawback is too much. I only want leak detection.

Answer 1

You must read this and use the patch :

https://gcc.gnu.org/ml/gcc-patches/2013-11/msg01874.html