libunwind 1.2.1 UNW_VERSION_MINOR is not an integer

[orivej]

Configuring libunwind 1.2.1 after autoreconf generates this in include/libunwind-common.h:

#define UNW_VERSION_MAJOR	1
#define UNW_VERSION_MINOR	2.1
#define UNW_VERSION_EXTRA	

Since UNW_VERSION_MINOR is not an integer, it is not comparable in macros.

This happens because configure.ac contains

define(pkg_major, 1)
define(pkg_minor, 2.1)
define(pkg_extra, )

This breaks compilation of julia 0.5.1:

src/julia_internal.h:496:35: error: floating constant in preprocessor expression
        (UNW_VERSION_MAJOR == 1 && UNW_VERSION_MINOR > 1))
                                   ^

Discovered in NixOS/nixpkgs#26891 (comment)

[djwatson]

Sure can change UNW_VERSION_EXTRA to contain the 1 instead, thanks

[orivej]

Looking at mkvers

define(mkvers, $1.$2$3)
dnl Process this file with autoconf to produce a configure script.
AC_INIT([libunwind],[mkvers(pkg_major, pkg_minor, pkg_extra)],[pkg_maintainer])

it might be better to set pkg_extra to .1 so that concatenated version becomes 1.2.1. (Maybe .1 might be omitted at all, as it was in 1.0.1?)
Nethertheless 1.2.1 is already tagged, so I hope for this issue not to reoccur in 1.2.2 and future releases.

[djwatson]

Sure, thanks, will make sure this is correct for the next release.

[orivej]

Thank you!