From fe463276d72663e9939dce5202fee7789fee0f1e Mon Sep 17 00:00:00 2001
From: Jon Shallow <supjps-libcoap@jpshallow.com>
Date: Fri, 15 Sep 2023 15:36:06 +0100
Subject: [PATCH] CMakeLists.txt: Create .so files using the ABI

configure.ac: Report the ABI version.
---
 CMakeLists.txt |  7 +++++++
 configure.ac   | 13 ++++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6ce90fef..48568140 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,6 +16,8 @@ project(
   LANGUAGES CXX C)
 
 set(LIBCOAP_API_VERSION 3)
+set(LIBCOAP_ABI_VERSION 3.1.0)
+
 set(COAP_LIBRARY_NAME "coap-${LIBCOAP_API_VERSION}")
 
 option(
@@ -75,6 +77,9 @@ if(${CMAKE_VERSION} VERSION_GREATER "3.20.0")
   cmake_policy(SET CMP0115 OLD) # Supresses libcoap configuration warning
 endif()
 
+set_target_properties(${COAP_LIBRARY_NAME} PROPERTIES SOVERSION ${LIBCOAP_API_VERSION})
+set_target_properties(${COAP_LIBRARY_NAME} PROPERTIES VERSION ${LIBCOAP_ABI_VERSION})
+
 #
 # options to tweak the library
 #
@@ -590,6 +595,8 @@ message(STATUS "libcoap Configuration Summary:")
 message(STATUS "")
 message(STATUS "PACKAGE VERSION..................${PACKAGE_VERSION}")
 message(STATUS "PACKAGE SOURCE...................${LIBCOAP_PACKAGE_BUILD}")
+message(STATUS "LIBRARY API VERSION..............${LIBCOAP_API_VERSION}")
+message(STATUS "LIBRARY ABI VERSION..............${LIBCOAP_ABI_VERSION}")
 message(STATUS "ENABLE_DTLS:.....................${ENABLE_DTLS}")
 message(STATUS "ENABLE_TCP:......................${ENABLE_TCP}")
 message(STATUS "ENABLE_IPV4:.....................${ENABLE_IPV4}")
diff --git a/configure.ac b/configure.ac
index 37176413..dd4d090a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -150,6 +150,16 @@ AC_SUBST(LIBCOAP_SO_VERSION)
 
 # Defining the API Version
 LIBCOAP_API_VERSION=3
+
+# calculate the ABI version
+m4_pattern_allow(LT_TEMP)
+LT_TEMP=$LT_LIBCOAP_CURRENT
+LT_TEMP=`expr $LT_TEMP - $LT_LIBCOAP_AGE`
+if [ "$LT_TEMP" != "LIBCOAP_API_VERSION" ] ; then
+   AC_MSG_ERROR([==> API version does not match base ABI version.])
+fi
+LIBCOAP_ABI_VERSION=$LT_TEMP.$LT_LIBCOAP_AGE.$LT_LIBCOAP_REVISION
+AC_SUBST(LIBCOAP_ABI_VERSION)
 AC_SUBST(LIBCOAP_API_VERSION)
 
 # Define a numeric version string
@@ -1163,8 +1173,9 @@ AC_MSG_RESULT([
 libcoap Configuration Summary:
       libcoap package version        : "$PACKAGE_VERSION"
       libcoap package source         : "$LIBCOAP_BUILD"
-      libcoap library version        : "$LIBCOAP_SO_VERSION"
       libcoap API version            : "$LIBCOAP_API_VERSION"
+      libcoap ABI version            : "$LIBCOAP_ABI_VERSION"
+      libcoap libtool SO version     : "$LIBCOAP_SO_VERSION"
       libcoap DTLS lib extn          : "$LIBCOAP_DTLS_LIB_EXTENSION_NAME"
       host system                    : "$host"]);
 if test "x$enable_server_mode" = "xyes"; then