FILTER
Attribute
The FILTER
attribute indicates that this symbol is a filter
to another shared object. It shares the same syntax as the
FILTER
directive, differing in that it works at the
per-symbol level rather than the entire object.
FILTER
accepts the following attributes.
-
STANDARD
-
A standard filter. Standard filter symbols do not require any backing implementation to be provided from an input relocatable object. Therefore, use this directive together with defining the symbol's type, to create an absolute symbol table entry. See Generating Standard Filters.
-
AUXILIARY
-
An auxiliary filter. See Generating Auxiliary Filters.
-
WEAK
-
A weak standard filter. Weak filters are identical to standard filters at runtime. At link-edit time, if unused dependency processing is active, a weak filter symbol from a dependency can be ignored in favor of the same symbol from the target filtee. Weak filters are the preferred type when using filters to provide backward compatibility when code moves between libraries. See Generating Weak Filters.
The simplified form of the FILTER
attribute has the
following form.
FILTER = soname;
This creates a standard filter, and is equivalent to the following.
FILTER {
FILTEE = soname;
TYPE = STANDARD;
};