MPE/iX Intrinsics Reference Manual (32650-90905)

54 Chapter4

Command Deﬁnitions (ABORTSESS - FCLOSE)

ARITRAP

NM and CM callable (differences noted below).

Collectively enables all arithmetic traps (except the IEEE inexact result trap) or disables

all arithmetic traps.

Syntax

I*V

ARITRAP(

trapstate

);

Parameters

trapstate

(NM) 32-bit signed integer by value (required)

(CM) 16-bit signed integer by value (required)

(NM) Enables/disables arithmetic traps:

Value Meaning

Disable all arithmetic traps

1 Enable all arithmetic traps (except the IEEE inexact

result trap)

(CM) Enables/disables CM arithmetic traps.

Operation Notes

There is a difference between arming and enabling traps. Enabling a trap means that the

occurrence of a trap condition is not ignored. Arming a trap is required so that, on a trap

condition, a user-written routine is invoked and can take appropriate recovery actions. The

following list summarizes what can happen when an arithmetic trap condition occurs:

• If a trap is both enabled and armed, the user-written trap handler is invoked.

• If a trap is enabled but not armed, one of two situations apply:

• If a Pascal/XL TRY statement was executed, pass control to the RECOVER block by

doing an ESCAPE.

• If a Pascal/XL TRY statement was not executed, an error message is output and the

process aborts.

• If a trap is disabled, even though it is armed, the trap is ignored, and execution of the

process continues without any interruption.

NOTE By default, all traps (except the IEEE inexact result trap) are enabled and

the system trap handler is armed.