ExtUtils::Mksymlists produces files used by the linker under
some OSs during the creation of shared libraries for dynamic
extensions. It is normally called from a MakeMaker-
generated Makefile when the extension is built. The linker
option file is generated by calling the function Mksymlists,
which is exported by default from ExtUtils::Mksymlists. It
takes one argument, a list of key-value pairs, in which the
following keys are recognized:
DLBASE
This item specifies the name by which the linker knows
the extension, which may be different from the name of
the extension itself (for instance, some linkers add an
'_' to the name of the extension). If it is not
specified, it is derived from the NAME attribute. It
is presently used only by OS2 and Win32.
DL_FUNCS
This is identical to the DL_FUNCS attribute available
via MakeMaker, from which it is usually taken. Its
value is a reference to an associative array, in which
each key is the name of a package, and each value is an
a reference to an array of function names which should
be exported by the extension. For instance, one might
say DL_FUNCS => { Homer::Iliad => [ qw(trojans greeks)
], Homer::Odyssey => [ qw(travellers family suitors) ]
}. The function names should be identical to those in
the XSUB code; Mksymlists will alter the names written
to the linker option file to match the changes made by
xsubpp. In addition, if none of the functions in a
list begin with the string boot_, Mksymlists will add a
bootstrap function for that package, just as xsubpp
does. (If a boot_<pkg> function is present in the
list, it is passed through unchanged.) If DL_FUNCS is
not specified, it defaults to the bootstrap function
for the extension specified in NAME.
DL_VARS
This is identical to the DL_VARS attribute available
via MakeMaker, and, like DL_FUNCS, it is usually
specified via MakeMaker. Its value is a reference to
an array of variable names which should be exported by
the extension.
FILE This key can be used to specify the name of the linker
option file (minus the OS-specific extension), if for
some reason you do not want to use the default value,
which is the last word of the NAME attribute (e.g. for
Tk::Canvas, FILE defaults to Canvas).
FUNCLIST
This provides an alternate means to specify function
names to be exported from the extension. Its value is
a reference to an array of function names to be
exported by the extension. These names are passed
through unaltered to the linker options file.
Specifying a value for the FUNCLIST attribute
suppresses automatic generation of the bootstrap
function for the package. To still create the bootstrap
name you have to specify the package name in the
DL_FUNCS hash:
Mksymlists({ NAME => $name ,
FUNCLIST => [ $func1, $func2 ],
DL_FUNCS => { $pkg => [] } });
IMPORTS
This attribute is used to specify names to be imported
into the extension. It is currently only used by OS/2
and Win32.
NAME This gives the name of the extension (e.g. Tk::Canvas)
for which the linker option file will be produced.
When calling Mksymlists, one should always specify the NAME
attribute. In most cases, this is all that's necessary. In
the case of unusual extensions, however, the other
attributes can be used to provide additional information to
the linker.