9.8.1 Runtime Systems

Stand-alone applications containing debugged Prolog code and destined for end-users are typically packaged as runtime systems. No SICStus license is needed by a runtime system. A runtime system has the following limitations:

• No top-level. The executable will restore a saved-state and/or load code, and call user:runtime_entry(start). Alternatively, you may supply a main program and explicitly initialize the Prolog engine with SP_initialize(). break/0 and require/1 are unavailable.
• No debugger. The Prolog flags debug and debugger_print_options have no effect. The predicates debugging/0, debug/0, nodebug/0, trace/0, notrace/0, zip/0, nozip/0, unknown/2, leash/1, spy/[1,2], nospy/1, nospyall/0, add_breakpoints/2, remove_breakpoints/1, current_breakpoint/5, disable_breakpoints/1, enable_breakpoints/1, and execution_state/[1,2] are unavailable.
• Except in extended runtime systems: no compiler; compiling is replaced by consulting. fcompile/1 is unavailable. Extended runtime system contain the compiler.
• The Prolog flags discontiguous_warnings, redefine_warnings, single_var_warnings have no effect. The user is not prompted in the event of name clashes.
• The informational Prolog flag is off by default, suppressing informational messages.
• The predicates version/[0,1] and help/0 are unavailable.
• The compile-time part of the foreign language interface, e.g. load_foreign_files/2, is unavailable.
• No profiler. The predicates profile_data/4 and profile_reset/1 are unavailable.
• No signal handling except as installed by SP_signal().