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 the STV_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.