Make fingerprint handling compatible with LTO

Tell the compiler that the fingerprint variable is modified unpredictably.

* lib/fingerprint.h (fingerprint): Remove const.
* lib/fingerprint.c (fingerprint): Likewise.
* src/pdumper.c (Fdump_emacs_portable): Cast fingerprint variable.
(pdumper_load): Likewise.
* lib-src/make-fingerprint.c (main): Likewise.

2 files changed, 2 insertions, 2 deletions

diff --git a/lib/fingerprint.c b/lib/fingerprint.c
index e55de9c6da3..2cc1973428f 100644
--- a/lib/fingerprint.c
+++ b/lib/fingerprint.c
@@ -29,7 +29,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    by a fingerprint of the temporary Emacs executable that was built
    along the way.  */
 
-unsigned char const fingerprint[] =
+volatile unsigned char fingerprint[] =
   {
    0xDE,
    0x86,
diff --git a/lib/fingerprint.h b/lib/fingerprint.h
index 0b195fd0ca7..ba2e740cd9e 100644
--- a/lib/fingerprint.h
+++ b/lib/fingerprint.h
@@ -24,6 +24,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    Emacs.  This way, we have a unique value that we can use to pair
    data files (like a portable dump image) with a specific build of
    Emacs.  */
-extern unsigned char const fingerprint[32];
+extern volatile unsigned char fingerprint[32];
 
 #endif