From 00611d86c66f4230eb229b2b7dc5ac413aef2221 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 5 Mar 2026 18:13:05 -0500 Subject: [PATCH] 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 Signed-off-by: Junio C Hamano --- Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/Makefile b/Makefile index 8aa489f3b6..6b121daf1e 100644 --- a/Makefile +++ b/Makefile @@ -1594,6 +1594,7 @@ BASIC_CFLAGS += -DSHA1DC_FORCE_ALIGNED_ACCESS endif ifneq ($(filter leak,$(SANITIZERS)),) BASIC_CFLAGS += -O0 +NO_MMAP = CatchMapLeaks SANITIZE_LEAK = YesCompiledWithIt endif ifneq ($(filter address,$(SANITIZERS)),)