ABI breakage of libmircore.so.1 with v2.8.0 vs v1.8.2

[JamiKettunen]

Attempting to launch Lomiri shell with libmircore.so.1 from v2.8.0 (same, conflicting soname with v1.8.2) causes the following error:

lomiri: symbol lookup error: /usr/lib64/libmirplatform.so.18: undefined symbol: _ZN3mir8geometrylsERSoRKNS0_5PointE, version MIR_CORE_0.25

Simply replacing the shared library file with a known working one from v1.8.2 resolves the issue immediately (with everything else being libraries from v1.8.2).

Here's my x86_64 glibc samples of the libraries if they could be useful: libmircore-shared-libraries.zip

My suggestion: bump soname of libmircore.so.1 to libmircore.so.2 on main, but perhaps there's something I'm missing

[AlanGriffiths]

$ c++filt _ZN3mir8geometrylsERSoRKNS0_5PointE
mir::geometry::operator<<(std::basic_ostream<char, std::char_traits<char> >&, mir::geometry::Point const&)

[AlanGriffiths]

Yes, this looks like an ABI break to me:

$ git diff release/1.8 release/2.8 include/core/mir/geometry/point.h 
diff --git a/include/core/mir/geometry/point.h b/include/core/mir/geometry/point.h
index 943f8e8893..e9ee971c13 100644
--- a/include/core/mir/geometry/point.h
+++ b/include/core/mir/geometry/point.h
@@ -12,58 +12,26 @@
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- * Authored by: Alexandros Frantzis <alexandros.frantzis@canonical.com>
  */
 
 #ifndef MIR_GEOMETRY_POINT_H_
 #define MIR_GEOMETRY_POINT_H_
 
+#include "point_generic.h"
 #include "dimensions.h"
-#include <iosfwd>
 
 namespace mir
 {
 namespace geometry
 {
-
-struct Point
+struct Size;
+struct Displacement;
+struct Point : generic::Point<detail::IntWrapper>
 {
-    constexpr Point() = default;
-    constexpr Point(Point const&) = default;
-    Point& operator=(Point const&) = default;
-
-    template<typename XType, typename YType>
-    constexpr Point(XType&& x, YType&& y) : x(x), y(y) {}
-
-    X x;
-    Y y;
+    using SizeType = Size;
+    using DisplacementType = Displacement;
+    using generic::Point<detail::IntWrapper>::Point;
 };
-
-inline constexpr bool operator == (Point const& lhs, Point const& rhs)
-{
-    return lhs.x == rhs.x && lhs.y == rhs.y;
-}
-
-inline constexpr bool operator != (Point const& lhs, Point const& rhs)
-{
-    return lhs.x != rhs.x || lhs.y != rhs.y;
-}
-
-inline constexpr Point operator+(Point lhs, DeltaX rhs) { return{lhs.x + rhs, lhs.y}; }
-inline constexpr Point operator+(Point lhs, DeltaY rhs) { return{lhs.x, lhs.y + rhs}; }
-
-inline constexpr Point operator-(Point lhs, DeltaX rhs) { return{lhs.x - rhs, lhs.y}; }
-inline constexpr Point operator-(Point lhs, DeltaY rhs) { return{lhs.x, lhs.y - rhs}; }
-
-inline Point& operator+=(Point& lhs, DeltaX rhs) { lhs.x += rhs; return lhs; }
-inline Point& operator+=(Point& lhs, DeltaY rhs) { lhs.y += rhs; return lhs; }
-
-inline Point& operator-=(Point& lhs, DeltaX rhs) { lhs.x -= rhs; return lhs; }
-inline Point& operator-=(Point& lhs, DeltaY rhs) { lhs.y -= rhs; return lhs; }
-
-std::ostream& operator<<(std::ostream& out, Point const& value);
 }
 }
-
 #endif /* MIR_GEOMETRY_POINT_H_ */

[AlanGriffiths]

FWIW, this breakage comes from #1858 (after which we ought to have bumped the soname)