Files
sx/library/modules/trace.sx
agra b5241243e6 ERR/E3.0 (slice 3b): comptime trace resolution
#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.
2026-06-01 15:33:50 +03:00

80 lines
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#import "std.sx";
// =====================================================================
// trace.sx — error return-trace formatting (ERR step E3.3).
//
// Reads the thread-local return-trace buffer (ERR E3.1, populated by the
// push/clear wiring in E3.2) and renders it. A `raise` / propagating `try`
// pushes a frame; an absorbing site (`catch` / `or value` / destructure)
// clears the buffer. So at format time the buffer holds exactly the frames
// of failures that escaped to where you're formatting — typically inside a
// `catch` handler (the clear fires when the handler completes, so the body
// still sees the chain) or the (future) failable-`main` wrapper.
//
// Frame resolution (ERR E3.0 slice 3a): in compiled code a frame is a pointer
// to an interned `Frame` the compiler stamped in at the push site, so the
// location resolves in-process with no DWARF and no symbolizer. (The comptime
// path — a packed `(func_id, ir_offset)` resolved via the interpreter's IR
// tables — lands with slice 3b.)
// =====================================================================
libc :: #library "c";
// The compiled return-trace frame. Layout MUST match `getFrameStructType` in
// src/ir/emit_llvm.zig and `SxFrame` in library/vendors/sx_trace_runtime/sx_trace.c.
Frame :: struct {
file: string;
line: s32;
col: s32;
func: string;
}
// The error-trace buffer C API (library/vendors/sx_trace_runtime/sx_trace.c),
// linked in for the JIT and auto-injected for AOT when traces are used.
// `frame_at` returns the raw stored `u64`; `__trace_resolve_frame` turns it
// into a `Frame` — by reinterpreting the stamped `*Frame` in compiled code, or
// by resolving the packed `(func_id, span.start)` in the comptime interpreter.
sx_trace_len :: () -> u32 #foreign;
sx_trace_truncated :: () -> u32 #foreign;
sx_trace_frame_at :: (i: u32) -> u64 #foreign;
write :: (fd: s32, buf: [*]u8, count: usize) -> isize #foreign libc;
// Render the current trace buffer to a string (allocated from
// context.allocator). Empty buffer → "" so callers can cheaply skip output.
to_string :: () -> string {
n := sx_trace_len();
if n == 0 { return ""; }
result := "error return trace (most recent call last):\n";
if sx_trace_truncated() != 0 {
result = concat(result, " ... older frames omitted (buffer full)\n");
}
i : u32 = 0;
while i < n {
f := __trace_resolve_frame(sx_trace_frame_at(i));
line := format(" {} at {}:{}:{}\n", f.func, f.file, f.line, f.col);
result = concat(result, line);
i = i + 1;
}
result;
}
// Write the current trace to stderr (fd 2). No-op when the buffer is empty.
print_current :: () {
s := to_string();
if s.len > 0 {
write(2, s.ptr, xx s.len);
}
}
// Dump the comptime (`#run`) interpreter call-frame chain (ERR E4.1). At
// comptime the interpreter walks its active sx frames and appends them to the
// build output; in compiled code this folds to nothing (there is no
// interpreter stack — the only caller is a dead `is_comptime()` branch).
// Frame source locations await IR-offset resolution, so only names print today.
print_interpreter_frames :: () {
__interp_print_frames();
}