7c21f84151
Add an .optional arm to regToValue in comptime_vm.zig: read the
has_value flag at offset sizeof(child), bridge the payload recursively
into a { payload, i1=true } aggregate when set, yield .null_val (zero
{T,i1}) when clear or the bare null sentinel. Matching serialize arm in
serializeAggregateValue (emit_llvm.zig). Pointer/?Closure/?Protocol-child
optionals and array-payload aggregates bail loudly, not silently.
Regression: examples/comptime/0643-comptime-run-optional-aggregate.sx
(present ?T, present ?i64, null ?i64). Verified by 3 adversarial reviews.
39 lines
1.6 KiB
Plaintext
39 lines
1.6 KiB
Plaintext
// `#run` of a function returning an OPTIONAL value must bridge the comptime
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// VM register → host Value through the reg→value optional arm.
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//
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// Regression (issue 0162): a `#run` whose function returned `?T` / `?i64`
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// previously failed comptime evaluation with
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// "reg→value: aggregate shape not bridged yet"
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// because the VM's regToValue bridge handled scalars/structs/slices/tuples
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// but bailed on an OPTIONAL-typed result. The fix reads the optional's
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// has_value flag (at offset sizeof(child)); when set it bridges the payload
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// recursively into a `{ payload, i1=true }` aggregate (the host serializes
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// that to `{T, i1}`), and when clear (or the value is the bare null sentinel)
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// it yields `.null_val` (serialized to a zero `{T, i1}` = absent).
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//
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// Exercises: present `?T` (optional of struct), present `?i64` (optional of
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// scalar), and a NULL-returning `?i64`. The values are read via `!` (unwrap)
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// and `??` (coalesce), which read the has_value flag correctly.
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#import "modules/std.sx";
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T :: struct { a: i64 = 0; b: i64 = 0; }
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mk_struct :: () -> ?T { t : T = .{ a = 7, b = 11 }; return t; }
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mk_scalar :: () -> ?i64 { return 5; }
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mk_null :: () -> ?i64 { return null; }
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X :: #run mk_struct(); // present ?T
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Y :: #run mk_scalar(); // present ?i64
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N :: #run mk_null(); // null ?i64
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main :: () {
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// Present optional-of-struct: payload bridged field-by-field.
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print("X.a = {}\n", X!.a);
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print("X.b = {}\n", X!.b);
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// Present optional-of-scalar.
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print("Y = {}\n", Y ?? -1);
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// Null optional: coalesce takes the default.
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print("N = {}\n", N ?? -1);
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}
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