The last E4 item: a comptime call-frame dump.
- New nullary `interp_print_frames` IR op (inst/print). The interpreter
maintains a `call_chain` side-stack (push/pop a FuncId around each sx-bodied
`call`, freed in deinit) and `printInterpFrames` appends the chain to its
output — most-recent-last, with the dump frame itself skipped. emit_llvm
makes the op a no-op: compiled code has no interpreter stack, and the only
caller is `process.exit`'s dead `is_comptime()` branch.
- Lowered from a name-recognized `__interp_print_frames()` builtin
(tryLowerReflectionCall + inferExprType → void).
- `trace.print_interpreter_frames()` wraps the builtin; wired into
`process.exit`'s comptime branch (process.sx now imports trace.sx).
- Frame source locations await IR-offset resolution (the comptime analog of
DWARF), so only function names print today.
examples/252-interp-frames.sx (top-level `#run` drives the dump; exit 0).
Phase E4 (entry-point + stdlib error story) is now 100% complete.
The trace formatter, unblocked now that 0057 is fixed.
- library/modules/trace.sx: to_string() walks the trace buffer (sx_trace_len /
frame_at / truncated) and renders "error return trace ..." with one line per
frame; print_current() writes it to stderr (libc write(2, ...)). Frame
locations are "<location pending DWARF>" until E3.0 resolves PCs; count +
ordering + the overflow note are already meaningful.
- Catch-clear timing fix (lowerCatch): move the absorption clear from
runCatchBody ENTRY to the handler's non-diverging EXIT (both the pure and
value-carrying paths). This reconciles the two PLAN-ERR statements that
conflicted — §clear-points "buffer cleared before the catch body" vs
§catch-over-or "frames still in the buffer when the body runs". Exit-clear
satisfies both: the handler can inspect the trace (trace.print_current()
shows the chain), and the buffer is empty once the handler completes. A
diverging body (raise/return) keeps/discards on its own path.
- examples/243-trace-format.sx: catch handler prints the tag + the 2-frame
trace, then shows the buffer is empty after. examples/241 updated: the
handler now observes len=2 (was 0 under the buggy entry-clear).
Gates: zig build, zig build test, bash tests/run_examples.sh (280 passed; lone
failure is the user's uncommitted 213-canonical-map pack WIP).
