[newlib-cygwin] Don't sanitize linker_set

[Sebastian Huber <sh@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=b9967c3f9040c25efe0a67b59dbd05ee79d0a97d

commit b9967c3f9040c25efe0a67b59dbd05ee79d0a97d
Author: dab <dab@FreeBSD.org>
Date:   Tue Nov 19 14:46:28 2019 +0000

    Don't sanitize linker_set
    
    The assumptions of linker_set don't play nicely with
    AddressSanitizer. AddressSanitizer adds a 'redzone' of zeros around
    globals (including those in named sections), whereas linker_set
    assumes they are all packed consecutively like a pointer array. So:
    let's annotate linker_set so that AddressSanitizer ignores it.
    
    Submitted by:   Matthew Bryan <matthew.bryan@isilon.com>
    Reviewed by:    kib, rang_acm.org
    Sponsored by:   Dell EMC Isilon
    Differential Revision:  https://reviews.freebsd.org/D22239

Diff:
---
 newlib/libc/include/sys/cdefs.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index 9a0466fff..1f2ce063d 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -709,6 +709,13 @@
 /* Function should not be analyzed. */
 #define	__no_lock_analysis	__lock_annotate(no_thread_safety_analysis)
 
+/* Function or variable should not be sanitized, ie. by AddressSanitizer */
+#if __has_attribute(no_sanitize)
+#define __nosanitizeaddress	__attribute__((no_sanitize("address")))
+#else
+#define __nosanitizeaddress
+#endif
+
 /* Guard variables and structure members by lock. */
 #define	__guarded_by(x)		__lock_annotate(guarded_by(x))
 #define	__pt_guarded_by(x)	__lock_annotate(pt_guarded_by(x))