Add BORINGSSL_API_VERSION.
The BORINGSSL_YYYYMM #defines have served well to coordinate short-term skews
in BoringSSL's public API, but some consumers (notably wpa_supplicant in
Android) wish to build against multiple versions for an extended period of
time. Consumers should not do this unless there is no alternative, but to
accommodate this, start a BORINGSSL_API_VERSION counter. In future, instead of
BORINGSSL_YYYYMM #defines, we'll simply increment the number.
This is specifically called an "API version" rather than a plain "version" as
this number does not denote any particular point in development or stability.
It purely counts how many times we found it convenient to let the preprocessor
observe a public API change up to now.
Change-Id: I39f9740ae8e793cef4c2b5fb5707b9763b3e55ce
Reviewed-on: https://boringssl-review.googlesource.com/7870
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/base.h b/include/openssl/base.h
index 2211920..d4a4eac 100644
--- a/include/openssl/base.h
+++ b/include/openssl/base.h
@@ -117,6 +117,16 @@
#define OPENSSL_VERSION_NUMBER 0x10002000
#define SSLEAY_VERSION_NUMBER OPENSSL_VERSION_NUMBER
+/* BORINGSSL_API_VERSION is a positive integer that increments as BoringSSL
+ * changes over time. The value itself is not meaningful. It will be incremented
+ * whenever is convenient to coordinate an API change with consumers. This will
+ * not denote any special point in development.
+ *
+ * A consumer may use this symbol in the preprocessor to temporarily build
+ * against multiple revisions of BoringSSL at the same time. It is not
+ * recommended to do so for longer than is necessary. */
+#define BORINGSSL_API_VERSION 1
+
#if defined(BORINGSSL_SHARED_LIBRARY)
#if defined(OPENSSL_WINDOWS)
