bb20339691
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).
41 lines
1.6 KiB
Plaintext
41 lines
1.6 KiB
Plaintext
// Error return-trace buffer push/clear wiring (ERR step E3.2). A `raise` and a
|
|
// propagating `try` each push a frame; an absorbing site (`catch`, `or value`,
|
|
// a destructure that binds the error) clears the buffer. In debug builds
|
|
// (`sx run` defaults to -O0) these calls are emitted; in release they're
|
|
// skipped entirely (zero overhead). Until E3.3 ships `trace.print_current`,
|
|
// this example observes the buffer directly via the runtime's `sx_trace_len`
|
|
// (linked in for the JIT) — a white-box probe, not the eventual public API.
|
|
|
|
#import "modules/std.sx";
|
|
|
|
// Internal runtime symbol (library/vendors/sx_trace_runtime/sx_trace.c).
|
|
sx_trace_len :: () -> u32 #foreign;
|
|
|
|
E :: error { Bad }
|
|
|
|
fail :: (n: s32) -> !E {
|
|
if n < 0 { raise error.Bad; } // pushes a frame
|
|
return;
|
|
}
|
|
|
|
propagate :: (n: s32) -> !E {
|
|
try fail(n); // on failure: pushes a frame, propagates
|
|
return;
|
|
}
|
|
|
|
main :: () -> s32 {
|
|
// `catch` lets the handler INSPECT the trace, then absorbs: the buffer is
|
|
// cleared when the handler completes (a non-diverging exit), not on entry.
|
|
// So inside the handler the frames are still visible (here: the `raise` in
|
|
// `fail` + the `try fail` propagation in `propagate` = 2 frames)...
|
|
propagate(-1) catch e {
|
|
print("in catch: len={}\n", sx_trace_len()); // 2 (handler sees the chain)
|
|
};
|
|
print("after catch: len={}\n", sx_trace_len()); // 0 (absorbed at handler exit)
|
|
|
|
// A success leaves the buffer empty (nothing pushed).
|
|
propagate(1) catch e { };
|
|
print("after success: len={}\n", sx_trace_len()); // 0
|
|
return 0;
|
|
}
|