gtpi1m0t | System Installation Support Reference |
User exit routine UCCCREB is called if the exit point named CREB is
active. UCCCREB is invoked at the end of macro processing and just
before control is passed to the destination program for:
- Enter-type macros going to a core-resident program
- BACKC macro from a core-resident program.
UCCCREB can be called from an ISO-C environment.
Exit point CREB is located in copy segment CCEB of CSECT CCENBK and in copy
segment CLHL of CSECT CCCLHR.
Multifunction user exit linkage is assembled into this exit point.
This user exit is activated by the ZDBUG command (with the START parameter
specified), which calls the UXITC macro with the IUX_VADB function set
on.
General Conditions at Entry
The registers at entry to UCCCREB are:
- R0-R7
- When the user exit is called from a non-ISO-C environment, the
contents have been restored from the ECB and contain the values that are to be
passed to the E-type program that will receive control. When the user
exit is called from an ISO-C environment, the application registers are stored
in the data save area (DSA) and have not yet been restored.
- R8
- Base of E-type program to receive control.
- R9
- Address of the ECB.
- R10
- Contains 0 if the user exit is called from an ISO-C environment, otherwise
it contains a non-zero value.
- R11-R15
- See User Exit Routines - Common Entry Conditions.
System Conditions at Entry
- System state
- Problem (see Programming Considerations at Entry, item 1)
- System mask
- Unmasked (see Programming Considerations at Entry, item 1)
- Protect key
- Working storage.
- Address Space
- EVM.
Programming Considerations at Entry
- Usually, the system state, system mask, and protection key
are as stated. However, there can be exceptions if system programs
issued MONTC to get to supervisor state, changed the system mask, or changed
the protection key.
- You activate the TPF Assembler Debugger for VisualAge Client or TPF C
Debugger for VisualAge Client code from this user exit by calling the UXMAC
macro. Program load event detection code (the IUX_VADB UXMAC call) must
be the last exit routine to be called in the exit. The
debugger will not return to this user exit when it determines that
the debugger must receive control. If you do not want the debugger to
trace the program that will be entered, set the CE3_NO_DEBUG indicator in byte
CE3DBCR (page 3 of the ECB) before the debugger is called. The debugger
always sets this indicator off before activating the program.
- See User Exit Routines - Common Entry Conditions.
- See User Exit Routines - Common Programming Considerations for other considerations.
Programming Considerations on Return
See User Exit Routines - Common Return Conditions.
General Conditions on Return
See User Exit Routines - Common Return Conditions.