Files
sx/examples/1051-errors-cleanup-closure-boundary.sx
agra 2d2bfafa29 test(ir): pin both lambda arms of the error-flow pass (A5.2 scaffolding review fix)
Codex review of 95895a3 found 1051 reached neither lambda arm it claimed to
pin: the lambda arrived only as a var_decl initializer, which routes through
checkCleanupNode's `.var_decl` arm -> cleanupReject(lambda) -> early-return
(a lambda literal is not failable), so the `.lambda` stop never ran; and its
accepted-direction `if !err` guard would still pass with flowExpr's lambda
recursion removed.

Scaffolding-only fix (no compiler change):
- 1051: add a bare lambda STATEMENT `() -> !E { failing(); };` in the cleanup
  body so checkCleanupNode sees a `.lambda` node directly and stops (the bare
  failable inside is accepted; were the arm to recurse it would reject like
  1052). Output byte-identical — only the .sx gained the statement.
- 1053-errors-nested-lambda-liveness-reject (exit 1): an E1.8 value-slot read
  inside a never-called nested lambda, rejected only because flowExpr recurses
  via `.lambda => analyzeFnBody`. Remove that arm and the diagnostic vanishes
  -> suite fails. This is the discriminating negative 1051 lacked.

Gate: zig build test, bash tests/run_examples.sh -> 361/0.
2026-06-03 06:42:51 +03:00

49 lines
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// A closure literal inside a `defer` / `onfail` body is its OWN function
// boundary (ERR step E1.7). Two boundary effects, both pinned here:
//
// (a) `checkCleanupNode` sees a bare lambda STATEMENT as a `.lambda` node and
// STOPS — it does not descend into the lambda body. So the bare failable
// inside the lambda is the lambda's concern, not a cleanup violation
// (were the `.lambda` arm to recurse, this bare `failing()` would reject
// like the ones in 1052).
//
// (b) value-slot liveness (E1.8) is analysed per-boundary: `flowExpr` recurses
// into the lambda via `analyzeFnBody`, so a value slot read inside the
// lambda must prove its own error absent — `v` here is live under its
// `if !err` guard. (The rejecting counterpart is 1053.)
//
// Also: `try` is legal inside the lambda (it propagates through the lambda's own
// `!E` channel) even though it is parser-banned in the cleanup body directly.
//
// Locks the closure-boundary arms of the error-flow pass before A5.2 extracts it
// into its own module. Constructible since issue 0073 (closure literal in a
// `defer` body no longer segfaults lowering — see 0310).
#import "modules/std.sx";
E :: error { Bad }
failing :: () -> !E { raise error.Bad; }
recover :: () -> (s32, !E) { return 21; }
work :: () {
defer {
// (a) bare lambda statement — checkCleanupNode stops at the `.lambda`.
() -> !E { failing(); };
// (b) called closure — its body is analysed as its own boundary.
emit := () -> !E {
v, err := recover();
if !err { print("defer closure: v={}\n", v); } // E1.8: live under guard
try failing();
};
emit() catch e print("defer closure: raised\n");
}
print("body\n");
}
main :: () -> s32 {
work();
return 0;
}