build: Split libtool versioning from project versioning

As described in GNU autotools manuals, libtool versioning is not the
same as the project versioning.

The project versioning string is defined in project_version. meson
uses this string for all operations such a creating the tarball. I
decided against using something fancy as 'git describe' for it,
because meson is not supporting this kind of dynamic project
versioning.

Instead we just need to increment the version after the release and
before the first commit. With this scheme we basically know by looking
at the version string if it is an official released version. If this
is not good enough we can try to adopt the approach other project are
doing such as systemd which introduced an additional package
versioning which depends on 'git describe'.

There is little point in fighting the tool if it can be done quite
easily by the described approach from above.

Signed-off-by: Daniel Wagner <dwagner@suse.de>

diff --git a/meson.build b/meson.build
index 6b4fd7770ed9aa38bbbf49a962655c36bd502bb3..3935cde1143051cccee1440dbb1dc1409f6551c1 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -61,7 +61,7 @@
 project(
     'libnvme', ['c', 'cpp'],
     meson_version: '>= 0.47.0',
-    version: '1.0.1',
+    version: 'v0.1',
     license: 'LGPLv2+',
     default_options: [
         'buildtype=release',
@@ -69,6 +69,22 @@ project(
     ]
 )
 
+# https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
+# https://autotools.io/libtool/version.html
+# The relation between libtool's current:revison:age interface versioning
+# and the .so filename, .so.x.y.z, is
+# x = current - age
+# y = age
+# z = revision
+# If libtool_soversion is updated as described in libtool's documentation,
+# x.y.z will usually *not* be equal to meson.project_version().
+libtool_soversion = [0, 0, 0]
+libnvme_version = '@0@.@1@.@2@'.format(
+  libtool_soversion[0] - libtool_soversion[2],
+  libtool_soversion[2],
+  libtool_soversion[1]
+)
+
 ################################################################################
 cc = meson.get_compiler('c')
 

diff --git a/src/meson.build b/src/meson.build
index 15949c950ad9c0f6b7ab4e1c9987dc83e09fea13..1f932c6db6e58e0ff023c1b8903d70051744f02a 100644 (file)
--- a/src/meson.build
+++ b/src/meson.build
@@ -32,7 +32,7 @@ version_script_arg = join_paths(source_dir, mapfile)
 libnvme_shared = shared_library(
     'nvme', # produces libnvme.so
     sources,
-    version: meson.project_version(),
+    version: libnvme_version,
     soversion: '1',
     link_args: ['-Wl,--version-script=' + version_script_arg],
     dependencies: deps,