analyze_multics (azm) display request should accept -in control arg

[Gary Dixon]

The dump_segment command currently supports display of a region of memory as holding elements of a PL/I structure. It obtains descriptors for elements of the structure from a source program which declares the structure and is compiled with a symbol table.

help dump_segment -scn "structure display"

>doc>info>dump_segment.info   (24 lines follow; 372 lines in info)

2026-06-12  dump_segment, ds

Control arguments (structure display as a command):
   The following control arguments may not be given when dump_segment
   is invoked as an active function.
-as STRUCTURE_NAME
   displays the data as a PL/I structure defined by STRUCTURE_NAME.
   The STRUCTURE_NAME can be a structure defined in one of the system
   include files supported by the analyze_multics display request.
   See >doc>ss>azm>structure_names.info for a list of supported
   include files and structures.  Or the STRUCTURE_NAME can be a PL/I
   structure declared in an object program specified in the -in control
   argument.  See "Notes for structure display" below.

-in VIRTUAL_ENTRY
   identifies an object program compiled with the -table control
   argument which declares the STRUCTURE_NAME given with the -as
   control argument.  If -in is not given, then STRUCTURE_NAME must be
   found in one of the segments listed in the structure search list.

For example:

dump_segment 234|0 -as stack_header.ect_ptr
000000
  ect_ptr = 247|17240   [pd]>!BBBKbhJCBqLBMM.area.linker

If dump_segment -as is given without using -in control argument, the object segments named in the structure search paths are searched for the given STRUCTURE_NAME.ELEMENT_NAME. These objects are compiled with a symbol table (pl1 -table ...) declaring the STRUCTURE_NAME variable's elements.

psp structure
structure
          >tools>structure_library_1_
          >tools>structure_library_2_
          >tools>structure_library_3_
          >tools>structure_library_4_
          >tools>structure_library_5_
          >tools>structure_library_6_
          >udd>m>gd>lib>gcd_structure_library_1_

If the -in control argument is also given, it specifies the pathname of another object segment compiled with -table which includes the structure variable declared as STRUCTURE_NAME.

The example below shows the ring_zero_dump (rzd) entrypoint of dump_segment specifying location of a pds object segment using the -in control argument.

rzd pds -as pds.process_group_id -in [hd]>lib>structures>pds
000000
  , process_group_id = "GDixon.Multics.a                "

The analyze_multics (azm) display (d) request also supports the -as control argument, but only looks for an object segment using the structure search list. If the desired structure is not declared in one of those object programs, display of the structure (or its elements) cannot be done using the display request.

This ticket requests an enhancement to azm display to support the -in control argument as an additional way to locate descriptors for a structure declaration.