6.9.2 Customizing the Debugged Runtime System

It is possible to fine-tune the behavior of the debugged runtime system in various ways, both at compile time (setting C pre-processor symbols and passing system properties to SP_initialize()) and at runtime (passing system properties as environment variables).

The system properties and environment variables that affect the debugged runtime system are,

SP_USE_DEVSYS

if set to yes, the runtime system will try to start a development system, as described above.

SP_ATTACH_SPIDER

if set to yes, has the same effect as SP_USE_DEVSYS=yes and in addition tries to attach to the SICStus Prolog IDE (SPIDER). You have to tell SPIDER to `Attach to Prolog Process', i.e. listen for an incoming connection. This command is available from the SICStus top-level view menu in SPIDER.

SP_DEVSYS_NO_TRACE

if set to yes, will prevent the runtime system from calling trace/0 at initialization. This is useful if you prefer to manually enable the debugger later from your C or Prolog code.

SP_ALLOW_DEVSYS

if set to no, will prevent the runtime system from starting as a development system. This may be useful in order to prevent inheriting SP_USE_DEVSYS or SP_ATTACH_SPIDER from the environment. The same effect can be obtained by passing the option --no-allow-devsys to spld when building the runtime system.

SP_LICENSE_FILE

SP_LICENSE_SITE

SP_LICENSE_CODE

SP_LICENSE_EXPIRATION

These are described in Locating the License Information, above.

If your C code calls SP_initialize() you can pass these system properties in the call to SP_initialize() (see SP_initialize). You can also pass these options to SP_initialize() by setting the SPLD_DSP C macro. See the definition of SP_initialize() in the header file sictus/sicstus.h for details.