Symbol Lookup
If an object acquired by
dlopen
(3C) refers to a global symbol,
the runtime linker must locate this symbol from the pool of
objects that make up the process. In the absence of direct
binding, a default symbol search model is applied to objects
obtained by dlopen
(). However, the mode
of a dlopen
() together with the
attributes of the objects that make up the process, provide
for alternative symbol search models.
Objects that required direct binding, although maintaining all the attributes described later, search for symbols directly in the associated dependency. See Direct Bindings.
Note:
Symbols assigned theSTV_SINGLETON
visibility are
bound using the default symbol search, regardless of
any
dlopen
(3C) attributes. See ELF Symbol Visibility.
By default, objects obtained with
dlopen
(3C) are assigned
world symbol search scope, and
local symbol visibility. The
section, Default Symbol Lookup Model, uses this default model to
illustrate typical object group interactions. The sections
Defining a Global Object, Isolating a Group, and Object Hierarchies
show examples of using
dlopen
(3C) modes and file attributes to
extend the default symbol lookup model.