(libtool14.info.gz) Libtool versioning

(libtool14.info.gz) Updating version info

 
 6.2 Libtool's versioning system
 ===============================
 
 Libtool has its own formal versioning system.  It is not as flexible as
 some, but it is definitely the simplest of the more powerful versioning
 systems.
 
    Think of a library as exporting several sets of interfaces,
 arbitrarily represented by integers.  When a program is linked against
 a library, it may use any subset of those interfaces.
 
    Libtool's description of the interfaces that a program uses is
 simple: it encodes the least and the greatest interface numbers in the
 resulting binary (FIRST-INTERFACE, LAST-INTERFACE).
 
    The dynamic linker is guaranteed that if a library supports _every_
 interface number between FIRST-INTERFACE and LAST-INTERFACE, then the
 program can be relinked against that library.
 
    Note that this can cause problems because libtool's compatibility
 requirements are actually stricter than is necessary.
 
    Say `libhello' supports interfaces 5, 16, 17, 18, and 19, and that
 libtool is used to link `test' against `libhello'.
 
    Libtool encodes the numbers 5 and 19 in `test', and the dynamic
 linker will only link `test' against libraries that support _every_
 interface between 5 and 19.  So, the dynamic linker refuses to link
 `test' against `libhello'!
 
    In order to eliminate this problem, libtool only allows libraries to
 declare consecutive interface numbers.  So, `libhello' can declare at
 most that it supports interfaces 16 through 19.  Then, the dynamic
 linker will link `test' against `libhello'.
 
    So, libtool library versions are described by three integers:
 
 CURRENT
      The most recent interface number that this library implements.
 
 REVISION
      The implementation number of the CURRENT interface.
 
 AGE
      The difference between the newest and oldest interfaces that this
      library implements.  In other words, the library implements all the
      interface numbers in the range from number `CURRENT - AGE' to
      `CURRENT'.
 
    If two libraries have identical CURRENT and AGE numbers, then the
 dynamic linker chooses the library with the greater REVISION number.

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(libtool14.info.gz) Interfaces

(libtool14.info.gz) Versioning

(libtool14.info.gz) Updating version info

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