Verilog Testcase Runner

Overview

This skill runs every IP-level testcase listed in tc_list.md through the Makefile-driven bench that vtestgen scaffolded, captures the build/simulation logs, and writes a structured issue report for each failure.

The input is an IP name. The outputs are:

1. ./issue/<ip>/issue_NNN_<tcname>.md — one file per failing testcase
2. ./issue/<ip>/run_summary.md — overall pass/fail count and failure index

This skill reports failure context only. It does not analyze root cause, propose fixes, or suggest code changes.

Prerequisites

Tool	Purpose	Check
xvlog	compile / lint	xvlog --version
xelab	elaborate	xelab --version
xsim	simulate	xsim --version
make	build orchestration	make --version

Step 1 - Read the testcase list

Read tb/<ip>/tc_list.md and parse the testcase table into a run list. Include only rows with status OK; skip rows with status SKIPPED.

For each entry record: file (the .sv), module (the tb_* module, equal to the file base name), category, and description. Confirm tb/<ip>/Makefile and tb/<ip>/script/rtl.f exist before proceeding.

Step 2 - Create the output directory

Create ./issue/<ip>/ if absent. Do not delete existing issue files; new files use the next available NNN index (continue from the highest existing index, else start at 001).

Step 3 - Run each testcase

Run from inside tb/<ip>/. vtestrun is the authoritative pass/fail, but it does not need to re-simulate testcases that vtestgen already ran — the verdict is the same [FINISH] token. Re-running everything would just repeat vtestgen's self-check sims. The one thing it must never do is trust a stale result (a simulate.log older than an RTL/TB source it depends on — e.g. after a Phase 6 RTL fix), because the build rule no-ops while a simulate.log exists and make cleanf keeps prior PASS dirs.

So reuse a fresh result, rebuild only a stale (or missing) one — per testcase:

# fresh = simulate.log exists AND no RTL/TB source is newer than it
if [ -f sim/tb_<module>/simulate.log ] && \
   [ -z "$(find ../../rtl ../../lib *.vh sti_*.sv sco_*.sv tb_<module>.sv \
                -newer sim/tb_<module>/simulate.log 2>/dev/null)" ]; then
    : # fresh — read its [FINISH] verdict directly, no re-sim
else
    rm -rf sim/tb_<module> && make tb_<module>   # stale/missing — rebuild fresh
fi

This makes the first run right after vtestgen a pure verdict-collection pass (no second simulation), while a post-fix re-test rebuilds every testcase whose RTL/TB changed (a fix touches ../../rtl, so all dependent testcases re-run and a regression is still caught). If you ever want to force the whole suite fresh regardless of mtimes, use make retest (= clean all).

make tb_<module> produces sim/tb_<module>/ containing compile.log, elaborate.log, and simulate.log. After all testcases, make report prints a one-line PASS/FAIL per testcase; use it to cross-check.

Pass/fail decision

The decision is based solely on the [FINISH] verdict token in simulate.log (see .claude/skills/shared/CodingStyle.md). Do not decide from the presence of [ERROR] text — [ERROR] lines are collected only for the issue report, not for the verdict.

A testcase is a FAIL if any of the following is true:

• compile.log (xvlog) or elaborate.log (xelab) reports an error / the build step failed
• simulate.log contains [FINISH] FAIL
• simulate.log contains no [FINISH] line at all (crash, or the run was killed by the timeout)

A testcase is a PASS only if simulate.log contains [FINISH] PASS.

Step 4 - Write issue reports

For each FAIL, assign the next sequential issue number (zero-padded to 3 digits) and write ./issue/<ip>/issue_NNN_<module>.md. Fill every section from the captured logs. Do not add analysis, speculation, or fix suggestions.

Section: Testcase A table: File (tb/<ip>/<file>), Module, Category, Description.

Section: Failure Summary The verbatim first [ERROR] line from simulate.log (the most diagnostic message). If there is no [ERROR] line — e.g. timeout or crash — use the [FINISH] FAIL line, or the first error line from compile.log/elaborate.log if the build failed. One line only.

Section: Simulation Log A fenced code block containing, in order of occurrence, up to the first 10 [ERROR] lines from simulate.log and the [FINISH] FAIL line. If the build failed, include the xvlog/xelab error lines from compile.log/elaborate.log instead and leave the simulation portion empty. If the testcase timed out, include the last 10 lines of simulate.log before termination.

Section: Reproduction A fenced bash block:

cd tb/<ip>
make cleanf
make tb_<module>
# logs: sim/tb_<module>/{compile,elaborate,simulate}.log

Closing note End the file with: > This report documents observed failure context only. No fix is proposed.

Rules for the Simulation Log section:

• Include up to the first 10 [ERROR] lines produced by cpu_read_check or explicit checks.
• Do not include [INFO] lines or Vivado tool banners.
• For a build failure, include the full xvlog/xelab error output.

Step 5 - Write the run summary

After all testcases run, write ./issue/<ip>/run_summary.md. Keep the Results table as the one-metric-per-row shape below: vflow's scanner (scan.sh) reads the Failed count from the | Failed | N | row to decide whether Phase 6 is needed, so the count must stay in the second column of that row.

# Test Run Summary: <ip>

## Results

| Metric             | Count |
|--------------------|-------|
| Total run          | N     |
| Passed             | N     |
| Failed             | N     |
| Skipped (vtestgen) | N     |

## Failures

| Issue | Testcase | Category | Failure Summary |
|-------|----------|----------|-----------------|
| [001](issue_001_<module>.md) | tb_<name> | <category> | <first [ERROR] or [FINISH] FAIL line, truncated to 80 chars> |

## Skipped Testcases

| Testcase | Reason |
|----------|--------|
| tb_<name> | Skipped self-check in vtestgen |

---
> Run completed: <date and time>

If all testcases passed, write the summary with zero failures and omit the Failures table.

Known Issues and Fixes

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