Skip to content

NOTES.md

Latest commit

 

History

History
43 lines (38 loc) · 2.1 KB

NOTES.md

File metadata and controls

43 lines (38 loc) · 2.1 KB
Raw

Notes

  • Any benefit to saving (DECSC) and restoring (DECRC) cursor rather than placing it back manually?
  • Rendering optimisation ideas:
    • Use repeat (REP) when implementing splat?
    • Move cursor instead of sending multiple spaces (splat special case)?

TODO

  • Replace FRNG fuzzer with non-stop in-process fuzzer.
  • Add AFL++ fuzzer.
  • Add metrics to fuzzer: show live metrics and optionally includein trace.json.
  • Add timing instrumentation. Is 2ms max reasonable per-tick?

Bugs caught by fuzzer

  • Didn't handle empty files. When indexing lines, file_bytes[file_bytes.len -1] overflowed. There were a few other places that didn't handle empty files.
  • Crashed on long file names. Integer overflow when calculating padding size. In other words because it couldn't fit everything on the status line.
  • Crashed on long lines. Haven't implemented wrappings so was just asserting on line length. Going to avoid wrapping and just only print what fits. Will add horizontal scroll later.
  • Crashed on too many lines. This was asserted in indexLines. Instead, should return an error. Reasonable that we might manually edit a file and leave it with more lines than before.
  • Crashed because viewport was too small. Minimum viewport width depends on gutter width which depends on number of lines so can't easily generate valid dimensions. Just catch error in the fuzzer.
  • A couple overflow bugs to do with the status line once I started fuzzing the dimensions. Just hiding the filename and then the cursor indicator if they don't fit in the viewport.
  • Loads of overflows in tick(). Ended up moving checks into a validate() function. Called in init() so that we know the first render() call will be safe then called at end of tick() to check state after input processed.
  • Interesting one. See 7170bd2a79b7418ce78ac649b3d0d2e834feecc2. In cases where we have a huge viewport we were overflowing when checking if the cursor was within bounds. This was because the last visible line is the current line plus row_count. Both are stored as u16. If row_count is huge we can overflow.