Each trace frame now shows the offending source line with a `^` caret
under the column — in the catch-handler formatter, the failable-main C
reporter, and the comptime path.
The source line is embedded at compile time as a 5th Frame field
(line_text), not read from disk at runtime: the file field is a
basename and a runtime read would add a filesystem dependency that
fails under the test harness and on locked-down targets.
- errors.lineAt(src, offset): shared helper for the whole source line.
- Frame gains line_text (mirrored in emit_llvm getFrameStructType,
trace.sx Frame, sx_trace.c SxFrame). emitTraceFrame embeds it; the
interp .trace_resolve extracts it from the source map.
- trace.sx (new spaces helper) and the C reporter render the line +
a col-aligned caret, guarded on a non-empty line_text.
Snapshots 243/244/247/253 regenerated. Gates: zig build, zig build
test, run_examples.sh -> 291 passed.
#run failures now print the same `func at file:line:col` trace as
runtime, resolved in-process via the interpreter's IR/source tables.
- Read-side context-split op `.trace_resolve` (mirror of .trace_frame),
lowered from a name-recognized `__trace_resolve_frame(u64) -> Frame`.
- emit_llvm: inttoptr the operand to *Frame + load (the value
.trace_frame stamped in).
- interp: unpack (func_id << 32 | span.start); resolve func/file from
module.functions and line/col via SourceLoc.compute over a new
source_map (setSourceMap wired at every production interp site).
- trace.sx: frame_at -> u64; to_string routes each frame through
__trace_resolve_frame, so one source works in both machines.
Compiled path behavior unchanged (243/244/247 identical; it now loads
via the op). New examples/253-comptime-trace.sx exercises the comptime
path. Gates: zig build, zig build test, run_examples.sh -> 291 passed.
Architecture spec for the debugging subsystem: error return traces
(embedded Frame table, niladic context-split push op, the thread-local
ring buffer), DWARF debug info as a debugger-only artifact, the exact
wiring (file/function map + trace and DWARF data flows), the rationale
for choosing embedded locations over PC+DWARF symbolization, the
runtime-artifacts split, and the macOS -> iOS-sim -> iOS-device stepping
verification ladder.
