LeakSanitizer not working in gcc 4.8.2

[yyh-graphsql]

First I just hard code a memory leak in the program. After I compiled the binary with -fsanitize=address. It showed nothing. Is it normal situation or Did I miss something?

[yugr]

It's hard to say without an example. Note that leak detector is disabled on 32-bit platforms as it's considered to not be reliable there.

[yyh-graphsql]

@yugr The platform of our system is 64bits. It's centos 7.1.（Linux localhost.localdomain 3.10.0-327.el7.x86_64 #1 SMP Thu Nov 19 22:10:57 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux）. And the hacked leak code is just "int *a = new int (4);" in a function definitely will invoked

[yugr]

Just to check, could you try with

volatile int *a = new int (4);
a = 0;

?

[yyh-graphsql]

The code:
#include
int main() {
volatile int *a = new int(3);
a = 0;
return 0;
}

compile: g++ -fsanitize=address -o 1 /tmp/1.cpp
run: ASAN_OPTIONS='detect_leaks=1' ./1
output: 'nothing'

[yyh-graphsql]

Is it related to the libasan's version ?

[chefmax]

Yes, AFAIK LSan is available in GCC 4.9+.

[chefmax]

gcc-4_8-branch doesn't even contain libsanitizer/lsan/ directory. Please try more recent GCC versions.

[yyh-graphsql]

Let me try gcc 4.9. Thanks a lot!

[chefmax]

Closing then.

[rootkea]

I'm using gcc 4.9.2 and no. -fsanitizer=address doesn't report memory leak. You need -fsanitizer=leak for that.

Here is an interesting bit (bug?) with gcc 4.9.2 though. -fsanitizer=leak doesn't work with -fsanitizer=address. Yes! Weird!

[kcc]

@rootkea lsan is enabled as part of asan, so if you have -fsanitizer=address leak detection is enabled.
(not sure about 4.9.2, maybe it's too old).
-fsanitizer=leak is a way to enable just lsan, w/o asan.
You can not pass both -fsanitizer=leak and -fsanitizer=address

[chefmax]

Hm, it seems that for gcc 4.9 LSan is disabled by default when using with ASan. Use ASAN_OPTIONS=detect_leaks=1 to enable leak detection.

[rootkea]

Use ASAN_OPTIONS=detect_leaks=1 to enable leak detection

I did ASAN_OPTIONS=detect_leaks=1. Then gcc foo.c -fsanitize=address -o foo. After which ./foo gets executed smoothly. It's only when I use -fsanitize=leak it shows memory leak.

[hyyeah]

I have the same problem with rootkea