The-OpenROAD-Project / The-OpenROAD-Project/OpenROAD

lefout does not write OBS SPACING / DESIGNRULEWIDTH modifiers

Open
#11,027 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Verilog
Stars
3.1k
Forks
1k
Avg merge
2d 23h
Merged PRs (30d)
136

Description

lefout does not emit the OBS SPACING (or DESIGNRULEWIDTH) modifiers, so a LEF read followed by a LEF write loses the per-box min_spacing_ / design_rule_width_ values stored on dbBox.

getDesignRuleWidth/getMinSpacing are only consumed in src/odb/src/db/; nothing in src/odb/src/lefout/lefout.cpp writes them back out.

Effect: round-trip (read LEF -> write LEF) drops the OBS spacing modifiers. Pre-existing for DESIGNRULEWIDTH; SPACING added in #10856 has the same gap.

Fix: emit the modifiers when writing OBS geometry in lefout.

Follow-up to #10856.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in src/odb/src/lefout/lefout.cpp, where OBS geometry is written, and inspect how dbBox values are available through src/odb/src/db/. Trace getMinSpacing and getDesignRuleWidth, then verify a LEF read followed by a write preserves per-box OBS SPACING and DESIGNRULEWIDTH modifiers.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
databases
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Quiet
Clarity
Clearly specified
Newbie friendliness
72/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.