8 files changed, 122 insertions, 2 deletions
diff --git a/doc/apiref.rst b/doc/apiref.rst
index 3945c11..1b305f5 100644
--- a/doc/apiref.rst
+++ b/doc/apiref.rst
@@ -58,6 +58,25 @@ the library:
       /* Code specific to version 1.3 and above */
       #endif
 
+Additionally, there are functions to determine the version of Jansson at
+runtime:
+
+.. function:: const char *jansson_version_str()
+
+   Return the version of the Jansson library, in the same format as
+   the ``JANSSON_VERSION`` preprocessor constant.
+
+   .. versionadded:: 2.13
+
+.. function:: int jansson_version_cmp(int major, int minor, int micro)
+
+   Returns an integer less than, equal to, or greater than zero if
+   the runtime version of Jansson is found, respectively, to be less
+   than, to match, or be greater than the provided *major*, *minor*, and
+   *micro*.
+
+   .. versionadded:: 2.13
+
 ``JANSSON_THREAD_SAFE_REFCOUNT``
   If this value is defined all read-only operations and reference counting in
   Jansson are thread safe.  This value is not defined for versions older than
diff --git a/src/Makefile.am b/src/Makefile.am
index 37cfaac..bd996cd 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -20,7 +20,8 @@ libjansson_la_SOURCES = \
 	strconv.c \
 	utf.c \
 	utf.h \
-	value.c
+	value.c \
+	version.c
 libjansson_la_LDFLAGS = \
 	-no-undefined \
 	-export-symbols-regex '^json_' \
diff --git a/src/jansson.def b/src/jansson.def
index 15f35c9..ed72829 100644
--- a/src/jansson.def
+++ b/src/jansson.def
@@ -72,4 +72,6 @@ EXPORTS
     json_vunpack_ex
     json_set_alloc_funcs
     json_get_alloc_funcs
+    jansson_version_str
+    jansson_version_cmp
 
diff --git a/src/jansson.h b/src/jansson.h
index e4e73e2..b2b980b 100644
--- a/src/jansson.h
+++ b/src/jansson.h
@@ -360,6 +360,11 @@ typedef void (*json_free_t)(void *);
 void json_set_alloc_funcs(json_malloc_t malloc_fn, json_free_t free_fn);
 void json_get_alloc_funcs(json_malloc_t *malloc_fn, json_free_t *free_fn);
 
+/* runtime version checking */
+
+const char *jansson_version_str(void);
+int jansson_version_cmp(int major, int minor, int micro);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/version.c b/src/version.c
new file mode 100644
index 0000000..11435dd
--- /dev/null
+++ b/src/version.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2019 Sean Bright <sean.bright@gmail.com>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "jansson.h"
+
+const char *jansson_version_str(void)
+{
+    return JANSSON_VERSION;
+}
+
+int jansson_version_cmp(int major, int minor, int micro)
+{
+    int diff;
+
+    if ((diff = JANSSON_MAJOR_VERSION - major)) {
+        return diff;
+    }
+
+    if ((diff = JANSSON_MINOR_VERSION - minor)) {
+        return diff;
+    }
+
+    return JANSSON_MICRO_VERSION - micro;
+}
diff --git a/test/.gitignore b/test/.gitignore
index 401ca5c..d643dc8 100644
--- a/test/.gitignore
+++ b/test/.gitignore
@@ -17,6 +17,7 @@ suites/api/test_pack
 suites/api/test_simple
 suites/api/test_sprintf
 suites/api/test_unpack
+suites/api/test_version
 run-suites.log
 run-suites.trs
 test-suite.log
diff --git a/test/suites/api/Makefile.am b/test/suites/api/Makefile.am
index 63548ac..e109e56 100644
--- a/test/suites/api/Makefile.am
+++ b/test/suites/api/Makefile.am
@@ -16,7 +16,8 @@ check_PROGRAMS = \
 	test_pack \
 	test_simple \
 	test_sprintf \
-	test_unpack
+	test_unpack \
+	test_version
 
 test_array_SOURCES = test_array.c util.h
 test_chaos_SOURCES = test_chaos.c util.h
@@ -32,6 +33,7 @@ test_pack_SOURCES = test_pack.c util.h
 test_simple_SOURCES = test_simple.c util.h
 test_sprintf_SOURCES = test_sprintf.c util.h
 test_unpack_SOURCES = test_unpack.c util.h
+test_version_SOURCES = test_version.c util.h
 
 AM_CPPFLAGS = -I$(top_builddir)/src -I$(top_srcdir)/src
 LDFLAGS = -static  # for speed and Valgrind
diff --git a/test/suites/api/test_version.c b/test/suites/api/test_version.c
new file mode 100644
index 0000000..73c406c
--- /dev/null
+++ b/test/suites/api/test_version.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2019 Sean Bright <sean.bright@gmail.com>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <string.h>
+#include <jansson.h>
+#include "util.h"
+
+static void test_version_str(void)
+{
+    if (strcmp(jansson_version_str(), JANSSON_VERSION)) {
+        fail("jansson_version_str returned invalid version string");
+    }
+}
+
+static void test_version_cmp()
+{
+    if (jansson_version_cmp(JANSSON_MAJOR_VERSION, JANSSON_MINOR_VERSION, JANSSON_MICRO_VERSION)) {
+        fail("jansson_version_cmp equality check failed");
+    }
+
+    if (jansson_version_cmp(JANSSON_MAJOR_VERSION - 1, 0, 0) <= 0) {
+        fail("jansson_version_cmp less than check failed");
+    }
+
+    if (JANSSON_MINOR_VERSION) {
+        if (jansson_version_cmp(JANSSON_MAJOR_VERSION, JANSSON_MINOR_VERSION - 1, JANSSON_MICRO_VERSION) <= 0) {
+            fail("jansson_version_cmp less than check failed");
+        }
+    }
+
+    if (JANSSON_MICRO_VERSION) {
+        if (jansson_version_cmp(JANSSON_MAJOR_VERSION, JANSSON_MINOR_VERSION, JANSSON_MICRO_VERSION - 1) <= 0) {
+            fail("jansson_version_cmp less than check failed");
+        }
+    }
+
+    if (jansson_version_cmp(JANSSON_MAJOR_VERSION + 1, JANSSON_MINOR_VERSION, JANSSON_MICRO_VERSION) >= 0) {
+        fail("jansson_version_cmp greater than check failed");
+    }
+
+    if (jansson_version_cmp(JANSSON_MAJOR_VERSION, JANSSON_MINOR_VERSION + 1, JANSSON_MICRO_VERSION) >= 0) {
+        fail("jansson_version_cmp greater than check failed");
+    }
+
+    if (jansson_version_cmp(JANSSON_MAJOR_VERSION, JANSSON_MINOR_VERSION, JANSSON_MICRO_VERSION + 1) >= 0) {
+        fail("jansson_version_cmp greater than check failed");
+    }
+}
+
+static void run_tests()
+{
+    test_version_str();
+    test_version_cmp();
+}