|LIBRARY-SPECS(7)||Miscellaneous Information Manual||LIBRARY-SPECS(7)|
shared library name specifications
WANTLIB item in the ports tree
All libraries that a package needs must be mentioned in that list.
Except for system and X11 libraries, they all must be reachable through
directly, or indirectly through recursive dependencies.
Conversely, the ports tree uses
check whether a given
LIB_DEPENDS will be required
at runtime for shared libraries, and thus turn it into a
@depend line (see
The package system will embed correct dependency checks in the
built package in the form of
according to the normal shared library semantics: any library with the same
major number, and a greater or equal minor number will do.
Note that static libraries can only satisfy a library specification if no shared library has been found. Thus, if WANTLIB = foo>=5, and both libfoo.so.4.0 and libfoo.a are present, the check will fail.
Therefore, porters must strive to respect correct shared library semantics in their own ports: by bumping the minor number each time the interface is augmented, and by bumping the major number each time the interface changes. Note that adding functions to a library is an interface augmentation. Removing functions is an interface change.
The major.minor components of the library specification are used only as a build-time check, the run-time checks are computed by resolve-lib(1). For ‘libname>=major[.minor]’, any library which is more recent than the given major.minor version will do. If a specific major number is needed, use the form ‘libname=major[.minor]’. If the minor component is left empty, any minor will do. If both components are left empty, any version will do.
Most specifications won't mention a path: resolve-lib(1) will look in the default ldconfig(8) path automatically, namely /usr/local/lib, /usr/X11R6/lib, /usr/lib. It is generally a bad idea to put libraries elsewhere as they won't be reached directly.
However, distinct ports may install different major versions of the same library in /usr/local/lib, and disambiguate the build by creating a link in a separate directory, and specifying the right options to the linker.
These libraries will require a path
component in the corresponding
WANTLIB to make sure
the right library is resolved. This path is rooted under
/usr/local. For instance, to refer to
/usr/local/lib/qt3/libqt-mt.so.33.0, one would use
Full support for library specifications first appeared in
OpenBSD 3.1. The format of specifications changed
slightly to include ‘>=’ before OpenBSD
4.0. The interactions between
WANTLIB were modified and clarified for
OpenBSD 4.8. The format of specifications changed
again before OpenBSD 4.9 to remove extra noise.
|April 17, 2016||OpenBSD-6.1|