Output Directory Structure

All generated files live under .clash/ in the workspace root.

Because that lands inside your repository, the extension offers once per workspace to add .clash/ to an existing .gitignore — Yes writes the entry with a comment saying what it is, No is remembered and never asked again, and Not right now leaves the question open for the next session. The offer is skipped entirely when the workspace has no .gitignore (the extension does not create one) or when the file already mentions .clash. To change a No later, add the entry yourself; the extension will then see it and stay quiet.

Each invocation writes into its own timestamped run directory, so previous results are never overwritten. This is what the History section of the sidebar reads.

.clash/
  debug.log                          Debug log for all tool invocations
  debug.log.old                      Previous session's log, rotated on activation
  synth-project/                     Cabal project that depends on your package
    cabal.project
    clash-synth.cabal
    bin/Clash.hs
    src/                             Generated wrapper modules
  {Module}.{Function}/               One directory per synthesised function
    runs/
      {YYYY-MM-DD_HH-MM-SS}/         One directory per run, id is its timestamp
        run.json                     Run summary — command, target, stats, Fmax
        02-verilog/                  Clash Verilog output
          {Module}.topEntity/
            function_name.v          Main Verilog
            clash-manifest.json      Clash metadata
            *.sdc                    Timing constraints
            …
        03-yosys/                    Yosys synthesis results
          function_name_synth.v      Synthesized Verilog
          function_name.json         JSON netlist (for nextpnr and diagrams)
          function_name.svg          Schematic diagram (netlistsvg)
          diagrams/                  Sub-component diagrams, rendered on demand
            {Module}.svg
          stats.json                 Machine-readable statistics (`stat -json`)
          statistics.txt             Human-readable statistics report
          logic_depth.txt            Longest topological path (`ltp`)
          synth.ys                   Yosys script
          yosys.log                  Complete Yosys output
          per-module/                Per-module synthesis outputs
            hierarchy.json           Component graph + out-of-context flag
            {Module}/
              {Module}.il            RTLIL
              {Module}.json          JSON netlist
              {Module}.svg           Schematic diagram (netlistsvg)
              synth.ys
              yosys.log
        04-nextpnr/                  Place & route output
          function_name.config       Textual FPGA configuration
          function_name.routed.svg   Routed-layout SVG (when pnrWriteRoutedSvg)
          report.json                Machine-readable timing/utilisation report
          nextpnr.log

The run id is a local-time timestamp (formatRunId), so runs sort chronologically by name. synth-project/ is deliberately excluded when the Run History view enumerates function directories.