[PATCH 4/4] Makefile: turn on NO_MMAP when building with LSan

The past few commits fixed some cases where we leak memory allocated by mmap(). Building with SANITIZE=leak doesn't detect these because it covers only heap buffers allocated by malloc().

But if we build with NO_MMAP, our compat mmap() implementation will allocate a heap buffer and pread() into it. And thus Lsan will detect these leaks for free.

Using NO_MMAP is less performant, of course, since we have to use extra memory and read in the whole file, rather than faulting in pages from disk. But LSan builds are already slow, and this doesn't make them measurably worse. Getting extra coverage for our leak-checking is worth it.

Signed-off-by: Jeff King <peff@peff.net>
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 Makefile | 1 +
 1 file changed, 1 insertion(+)