feature/asan-gc-poisoning 8043ba186d 2/2: Avoid build failure when building without -fsanitize=address.

[Vibhav Pant]

branch: feature/asan-gc-poisoning
commit 8043ba186dc9d296624d975715938bc4341cc94d
Author: Vibhav Pant <vibhavp@gmail.com>
Commit: Vibhav Pant <vibhavp@gmail.com>

    Avoid build failure when building without -fsanitize=address.
    
    * src/lisp.h (UNALIGNED_LOAD_SIZE): Only use the sanitizer version of
    the macro when USE_SANITIZER_UNALIGNED_LOAD is defined, avoiding link
    errors when building without -fsanitize=address.
---
 src/lisp.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/lisp.h b/src/lisp.h
index f466d4b0da..be511a0eb9 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -5296,8 +5296,12 @@ __lsan_ignore_object (void const *p)
 }
 #endif
 
+/* If built with USE_SANITIZER_UNALIGNED_LOAD defined, use compiler
+   provided ASan functions to perform unaligned loads, allowing ASan
+   to catch bugs which it might otherwise miss.  */
 #if defined HAVE_SANITIZER_COMMON_INTERFACE_DEFS_H \
-  && defined ADDRESS_SANITIZER
+  && defined ADDRESS_SANITIZER                     \
+  && defined USE_SANITIZER_UNALIGNED_LOAD
 # include <sanitizer/common_interface_defs.h>
 # if (SIZE_MAX == UINT64_MAX)
 #  define UNALIGNED_LOAD_SIZE(a, i) \