Resolve -Wextern-c-compat warnings with OPENSSL_NO_THREADS.
C and C++ disagree on the sizes of empty structs, which can be rather bad for
structs embedded in public headers. Stick a char in them to avoid issues. (It
doesn't really matter for CRYPTO_STATIC_MUTEX, but it's easier to add a char in
there too.)
Thanks to Andrew Chi for reporting this issue.
Change-Id: Ic54fff710b688decaa94848e9c7e1e73f0c58fd3
Reviewed-on: https://boringssl-review.googlesource.com/7760
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/include/openssl/thread.h b/include/openssl/thread.h
index 568a858..ac4ced0 100644
--- a/include/openssl/thread.h
+++ b/include/openssl/thread.h
@@ -67,7 +67,9 @@
#if defined(OPENSSL_NO_THREADS)
-typedef struct crypto_mutex_st {} CRYPTO_MUTEX;
+typedef struct crypto_mutex_st {
+ char padding; /* Empty structs have different sizes in C and C++. */
+} CRYPTO_MUTEX;
#elif defined(OPENSSL_WINDOWS)
/* CRYPTO_MUTEX can appear in public header files so we really don't want to
* pull in windows.h. It's statically asserted that this structure is large
