Ensure that cryptor, hmac, and xxhash always define at least one symbol. This prevents headaches with compilers and linkers that choke on empty object files.

1 files changed, 14 insertions, 0 deletions

diff --git a/libarchive/archive_hmac.c b/libarchive/archive_hmac.c
index 12fca456..7857c0ff 100644
--- a/libarchive/archive_hmac.c
+++ b/libarchive/archive_hmac.c
@@ -31,6 +31,20 @@
 #include "archive.h"
 #include "archive_hmac_private.h"
 
+/*
+ * On systems that do not support any recognized crypto libraries,
+ * the archive_hmac.c file is expected to define no usable symbols.
+ *
+ * But some compilers and linkers choke on empty object files, so
+ * define a public symbol that will always exist.  This could
+ * be removed someday if this file gains another always-present
+ * symbol definition.
+ */
+int __libarchive_hmac_build_hack(void) {
+	return 0;
+}
+
+
 #ifdef ARCHIVE_HMAC_USE_Apple_CommonCrypto
 
 static int