Restrictions on setting breakpoints in the prologue of Language Environment assembler programs

The following restrictions apply when you attempt to set explicit or implicit breakpoints in the prologue of a Language Environment® assembler program:

• If you try to step across the portion of the prologue code that is between the point where the stack extend routine is called and the LR 13,x instruction that loads the address of the new DSA into register 13, the STEP command stops at the instruction immediately following the LR 13,x instruction.
• If you try to set a breakpoint in the portion of the prologue code between the point where the stack extend routine is called and the LR 13,x instruction that loads the address of the new DSA into register 13, z/OS® Debugger will not set the breakpoint.