[Libguestfs] [nbdkit PATCH 1/2] include: Expose nbdkit version information to public

[Eric Blake]

Internally, our plugins and filters can (and do!) use PACKAGE_VERSION
to populate the .version field.  But this macro is defined in
config.h, which is unsuitable for installation in /usr/include, so
external plugin authors cannot use it.  It is worth letting our public
interface include a version designation (ideally, users should NOT be
basing compile-time decisions solely on what version they are
compiling against, but instead using actual feature tests, but we
weren't even allowing for a version check).

The addition is done in such as way as to continue to allow version
bumps to touch a single place in configure.ac and have that propagate
to all affected files.

Signed-off-by: Eric Blake <eblake at redhat.com>
---
 configure.ac                | 15 ++++++++++++-
 include/nbdkit-common.h     |  2 ++
 .gitignore                  |  1 +
 include/Makefile.am         |  1 +
 include/nbdkit-version.h.in | 45 +++++++++++++++++++++++++++++++++++++
 5 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 include/nbdkit-version.h.in

diff --git a/configure.ac b/configure.ac
index ac8b4ba7..1667cb3f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,7 +29,11 @@
 # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.

-AC_INIT([nbdkit], [1.13.9])
+m4_define([NBDKIT_VERSION_MAJOR], [1])
+m4_define([NBDKIT_VERSION_MINOR], [13])
+m4_define([NBDKIT_VERSION_MICRO], [9])
+AC_INIT([nbdkit],
+        NBDKIT_VERSION_MAJOR.NBDKIT_VERSION_MINOR.NBDKIT_VERSION_MICRO)
 AC_CONFIG_MACRO_DIR([m4])
 m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],[],
          [m4_define([AC_USE_SYSTEM_EXTENSIONS],[])])
@@ -45,6 +49,14 @@ AC_CANONICAL_HOST

 AC_PROG_SED

+dnl Expose version information to the public headers
+[NBDKIT_]VERSION_MAJOR=NBDKIT_VERSION_MAJOR
+[NBDKIT_]VERSION_MINOR=NBDKIT_VERSION_MINOR
+[NBDKIT_]VERSION_MICRO=NBDKIT_VERSION_MICRO
+AC_SUBST([NBDKIT_VERSION_MAJOR])
+AC_SUBST([NBDKIT_VERSION_MINOR])
+AC_SUBST([NBDKIT_VERSION_MICRO])
+
 dnl Check for basic C environment.
 AC_PROG_CC_STDC
 AC_PROG_INSTALL
@@ -891,6 +903,7 @@ AC_CONFIG_FILES([Makefile
                  common/utils/Makefile
                  docs/Makefile
                  include/Makefile
+                 include/nbdkit-version.h
                  plugins/Makefile
                  plugins/curl/Makefile
                  plugins/data/Makefile
diff --git a/include/nbdkit-common.h b/include/nbdkit-common.h
index e004aa18..3a62b47e 100644
--- a/include/nbdkit-common.h
+++ b/include/nbdkit-common.h
@@ -41,6 +41,8 @@
 #include <stdint.h>
 #include <errno.h>

+#include <nbdkit-version.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/.gitignore b/.gitignore
index 15620626..464a860d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -51,6 +51,7 @@ Makefile.in
 /docs/plugin-links.pod
 /fuzzing/sync_dir/
 /html/*.html
+/include/nbdkit-version.h
 /INSTALL
 /install-sh
 /libtool
diff --git a/include/Makefile.am b/include/Makefile.am
index 3a293359..cf46abc6 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -35,4 +35,5 @@ include_HEADERS = \
 	nbdkit-common.h \
 	nbdkit-plugin.h \
 	nbdkit-filter.h \
+	nbdkit-version.h \
 	$(NULL)
diff --git a/include/nbdkit-version.h.in b/include/nbdkit-version.h.in
new file mode 100644
index 00000000..38bbf0d2
--- /dev/null
+++ b/include/nbdkit-version.h.in
@@ -0,0 +1,45 @@
+/* nbdkit
+ * Copyright (C) 2013-2019 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of Red Hat nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef NBDKIT_VERSION_H
+#define NBDKIT_VERSION_H
+
+#if !defined (NBDKIT_PLUGIN_H) && !defined (NBDKIT_FILTER_H)
+#error this header file should not be directly included
+#endif
+
+#define NBDKIT_VERSION_MAJOR @NBDKIT_VERSION_MAJOR@
+#define NBDKIT_VERSION_MINOR @NBDKIT_VERSION_MINOR@
+#define NBDKIT_VERSION_MICRO @NBDKIT_VERSION_MICRO@
+#define NBDKIT_VERSION_STRING "@NBDKIT_VERSION_MAJOR at .@NBDKIT_VERSION_MINOR at .@NBDKIT_VERSION_MICRO@"
+
+#endif /* NBDKIT_VERSION_H */
-- 
2.21.0