3c738695dc
Erasing a type to a protocol when it conforms only via a free function (not an explicit impl P for T) built a vtable of unreachable thunks -> SIGABRT on first dispatch, with no diagnostic. Per specs.md erasure is impl-driven, not structural, so the erasure was never valid. Add a conformance gate (firstUnimplementedMethod in buildProtocolValue, src/ir/lower/protocol.zig): emit a located diagnostic when a protocol method has no reachable impl, or when an impl method introduces its own type params (signature mismatch — it bails lazyLowerFunction and would reach the unreachable thunk). A std.debug.panic tripwire guards the diagnostics==null path so a non-conforming erasure can never silently ship as undef. Gate<->thunk equivalence verified bidirectional. Regressions: protocols/0419 (positive struct-field dispatch), diagnostics/1197 (no-impl) + 1198 (generic-method signature mismatch). Updated memory/0808 (it erased a non-conforming type that never dispatched). Verified by 3+1 adversarial reviews, suite 788/0. Filed adjacent bug 0178 (protocol impl method type-mismatch silent miscompile).
47 lines
1.6 KiB
Plaintext
47 lines
1.6 KiB
Plaintext
// Phase 1.1 — the compiler-internal heap-copy that backs `xx <rvalue>`
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// protocol erasure must dispatch through `context.allocator`, not call
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// libc malloc directly. So when a `push Context.{ allocator = tracer }`
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// block is active, a `xx StructLiteral.{}` inside it MUST be allocated
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// by the tracker.
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//
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// Note: `xx` only heap-copies for RVALUES (struct literals, call results).
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// `xx <lvalue>` (an identifier, field access, index, or deref) borrows
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// the operand's storage, so it never allocates and never reaches this
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// path. See specs.md §3 — Protocol value ownership and lifetime.
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#import "modules/std.sx";
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#import "modules/std/mem.sx"; // `Allocator` is non-transitive: name it, import it.
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Tracer :: struct {
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count: i64;
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init :: () -> *Tracer {
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t : *Tracer = xx libc_malloc(size_of(Tracer));
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t.count = 0;
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t
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}
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}
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impl Allocator for Tracer {
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alloc_bytes :: (self: *Tracer, size: i64) -> *void {
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self.count += 1;
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return libc_malloc(size);
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}
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dealloc_bytes :: (self: *Tracer, ptr: *void) {
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libc_free(ptr);
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}
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}
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main :: () -> i32 {
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tracer := Tracer.init();
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push Context.{ allocator = xx tracer, data = null } {
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// Struct-literal operand: rvalue → heap-copy through context.allocator.
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// The erased type must actually `impl Allocator` (erasure is
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// impl-driven, issue 0176), so use a fresh `Tracer.{}` rvalue — the
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// copy is what we want routed through the active allocator.
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ignore : Allocator = xx Tracer.{ count = 0 };
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_ = ignore;
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}
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print("Tracer.count = {}\n", tracer.count);
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0
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}
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