99
However, linking a “work that uses the Library” with the Library creates an executable that is a
derivative of the Library (because it contains portions of the Library), rather than a “work that uses
the library”. The executable is therefore covered by this License. Section 6 states terms for
distribution of such executables.
When a “work that uses the Library” uses material from a header file that is part of the Library, the
object code for the work may be a derivative work of the Library even though the source code is
not. Whether this is true is especially significant if the work can be linked without the Library, or if
the work is itself a library. The threshold for this to be true is not precisely defined by law.
If such an object file uses only numerical parameters, data structure layouts and accessors, and
small macros and small inline functions (ten lines or less in length), then the use of the object file is
unrestricted, regardless of whether it is legally a derivative work. (Executables containing this
object code plus portions of the Library will still fall under Section 6.)
Otherwise, if the work is a derivative of the Library, you may distribute the object code for the work
under the terms of Section 6. Any executables containing that work also fall under Section 6,
whether or not they are linked directly with the Library itself.
6. As an exception to the Sections above, you may also combine or link a “work that uses the Library”
with the Library to produce a work containing portions of the Library, and distribute that work
under terms of your choice, provided that the terms permit modification of the work for the
customer’s own use and reverse engineering for debugging such modifications.
You must give prominent notice with each copy of the work that the Library is used in it and that
the Library and its use are covered by this License. You must supply a copy of this License. If the
work during execution displays copyright notices, you must include the copyright notice for the
Library among them, as well as a reference directing the user to the copy of this License. Also, you
must do one of these things:
a) Accompany the work with the complete corresponding machine-readable source code for the
Library including whatever changes were used in the work (which must be distributed under
Sections 1 and 2 above); and, if the work is an executable linked with the Library, with the
complete machine-readable “work that uses the Library”, as object code and/or source code,
so that the user can modify the Library and then relink to produce a modified executable
containing the modified Library. (It is understood that the user who changes the contents of
definitions files in the Library will not necessarily be able to recompile the application to use the
modified definitions.)
b) Use a suitable shared library mechanism for linking with the Library. A suitable mechanism is
one that (1) uses at run time a copy of the library already present on the user’s computer
system, rather than copying library functions into the executable, and (2) will operate properly
with a modified version of the library, if the user installs one, as long as the modified version is
interface-compatible with the version that the work was made with.
c) Accompany the work with a written offer, valid for at least three years, to give the same user the
materials specified in Subsection 6a, above, for a charge no more than the cost of performing
this distribution.
d) If distribution of the work is made by offering access to copy from a designated place, offer
equivalent access to copy the above specified materials from the same place.
e) Verify that the user has already received a copy of these materials or that you have already sent
this user a copy.
