Adopt the pattern in detail_route.tcl to collect parameters instead of using global variables like in global_place.tcl

[oharboe]

Description

In detail_route.tcl, arguments are collected into an array and passed to detailed_route. This way it is clear what is happening and how the information flows and it is all contained to detail_route.tcl

However in global_place, global state is modified by e.g gpl::set_routability_target_rc_metric_cmd and it is not clear who uses this information later on or whether this information can leak outside of replace.tcl.

Suggested Solution

Adopt the pattern of detail_route.tcl and avoid using global state throughout OpenROAD .tcl files like global_place.tcl.

Additional Context

No response

[oharboe]

Another advantage of the detail_route.tcl approach is that it makes it easier to implement logging.

Consider detailed_placement, if all the arguments were on the detailed_placement command, then adding log_cmd would tell the whole story.

The user now has to piece together by careful examination of the logs + variables + reading the .tcl code what is going on. set_placement_padding is another example of global state.