vm-ext: phase B — extension registry module

sx_vm_extension.ml: handler type, extensible extension_state variant,
EXTENSION first-class module signature.

sx_vm_extensions.ml: register / dispatch / id_of_name /
state_of_extension. install_dispatch () runs at module init,
swapping Phase A's stub for the real registry. Rejects out-of-range
opcode IDs (must be 200-247), duplicate IDs, duplicate names, and
duplicate extension names.

Tests: 9 new foundation cases — lookup hits/misses, end-to-end VM
dispatch including opcode composition, all four rejection paths.
+9 pass vs Phase A baseline, no regressions across 11 conformance
suites.
This commit is contained in:
2026-05-14 23:28:24 +00:00
parent cf597f1b5f
commit 8c33a6f8d5
4 changed files with 305 additions and 4 deletions

View File

@@ -67,6 +67,14 @@ let rec deep_equal a b =
| NativeFn _, NativeFn _ -> a == b
| _ -> false
(* ====================================================================== *)
(* Test extensions for the VM extension registry suite (Phase B) *)
(* ====================================================================== *)
(* Extend the extensible variant from sx_vm_extension.ml so the test
extensions below can carry their own private state. *)
type Sx_vm_extension.extension_state += TestRegState of int ref
(* ====================================================================== *)
(* Build evaluator environment with test platform functions *)
(* ====================================================================== *)
@@ -1323,7 +1331,145 @@ let run_foundation_tests () =
Printf.printf " PASS: opcode 199 stays in core (catch-all)\n"
| exn ->
incr fail_count;
Printf.printf " FAIL: opcode 199 — unexpected: %s\n" (Printexc.to_string exn))
Printf.printf " FAIL: opcode 199 — unexpected: %s\n" (Printexc.to_string exn));
Printf.printf "\nSuite: vm-extension-registry\n";
(* Sx_vm_extensions self-installs its dispatcher at module init. Reset
the registry so prior loaded extensions don't interfere with this
test. *)
Sx_vm_extensions._reset_for_tests ();
let module TestExt : Sx_vm_extension.EXTENSION = struct
let name = "test_reg"
let init () = TestRegState (ref 0)
let opcodes _st = [
(210, "test_reg.OP_PUSH_42", (fun vm _frame ->
Sx_vm.push vm (Sx_types.Integer 42)));
(211, "test_reg.OP_DOUBLE_TOS", (fun vm _frame ->
let v = Sx_vm.pop vm in
match v with
| Sx_types.Integer n -> Sx_vm.push vm (Sx_types.Integer (n * 2))
| _ -> failwith "OP_DOUBLE_TOS: not an integer"));
]
end in
Sx_vm_extensions.register (module TestExt);
(match Sx_vm_extensions.id_of_name "test_reg.OP_PUSH_42" with
| Some 210 ->
incr pass_count;
Printf.printf " PASS: id_of_name resolves opcode\n"
| other ->
incr fail_count;
Printf.printf " FAIL: id_of_name: got %s\n"
(match other with Some n -> string_of_int n | None -> "None"));
(match Sx_vm_extensions.id_of_name "nonexistent.OP" with
| None ->
incr pass_count;
Printf.printf " PASS: id_of_name returns None for unknown\n"
| Some _ ->
incr fail_count;
Printf.printf " FAIL: id_of_name should return None for unknown\n");
(match Sx_vm_extensions.state_of_extension "test_reg" with
| Some (TestRegState _) ->
incr pass_count;
Printf.printf " PASS: state_of_extension returns extension state\n"
| _ ->
incr fail_count;
Printf.printf " FAIL: state_of_extension lookup\n");
(match Sx_vm_extensions.state_of_extension "nonexistent" with
| None ->
incr pass_count;
Printf.printf " PASS: state_of_extension None for unknown\n"
| Some _ ->
incr fail_count;
Printf.printf " FAIL: state_of_extension should be None\n");
(* End-to-end dispatch through the VM. Bytecode runs OP_PUSH_42 then
OP_RETURN (50); execute_module pops the result. *)
let make_bc_seq bytes = ({
vc_arity = 0; vc_rest_arity = -1; vc_locals = 0;
vc_bytecode = bytes; vc_constants = [||];
vc_bytecode_list = None; vc_constants_list = None;
} : Sx_types.vm_code) in
(let globals = Hashtbl.create 1 in
try
match Sx_vm.execute_module (make_bc_seq [| 210; 50 |]) globals with
| Integer 42 ->
incr pass_count;
Printf.printf " PASS: dispatch routes opcode 210 -> push 42\n"
| other ->
incr fail_count;
Printf.printf " FAIL: dispatch opcode 210: got %s\n"
(Sx_types.inspect other)
with exn ->
incr fail_count;
Printf.printf " FAIL: dispatch opcode 210 raised: %s\n"
(Printexc.to_string exn));
(* Compose two extension opcodes: PUSH_42 then DOUBLE_TOS then RETURN.
Verifies that successive extension dispatches share VM state. *)
(let globals = Hashtbl.create 1 in
try
match Sx_vm.execute_module (make_bc_seq [| 210; 211; 50 |]) globals with
| Integer 84 ->
incr pass_count;
Printf.printf " PASS: extension opcodes compose (42 -> 84)\n"
| other ->
incr fail_count;
Printf.printf " FAIL: composed opcodes: got %s\n"
(Sx_types.inspect other)
with exn ->
incr fail_count;
Printf.printf " FAIL: composed opcodes raised: %s\n"
(Printexc.to_string exn));
(* Duplicate opcode-id detection. *)
let module DupExt : Sx_vm_extension.EXTENSION = struct
let name = "dup_check"
let init () = TestRegState (ref 0)
let opcodes _st = [
(210, "dup_check.OP_X", (fun _vm _frame -> ()));
]
end in
(try
Sx_vm_extensions.register (module DupExt);
incr fail_count;
Printf.printf " FAIL: duplicate opcode id should have raised\n"
with Failure _ ->
incr pass_count;
Printf.printf " PASS: duplicate opcode id rejected\n");
(* Out-of-range opcode-id detection. *)
let module OutExt : Sx_vm_extension.EXTENSION = struct
let name = "out_of_range"
let init () = TestRegState (ref 0)
let opcodes _st = [
(300, "out_of_range.OP_X", (fun _vm _frame -> ()));
]
end in
(try
Sx_vm_extensions.register (module OutExt);
incr fail_count;
Printf.printf " FAIL: out-of-range opcode should have raised\n"
with Failure _ ->
incr pass_count;
Printf.printf " PASS: out-of-range opcode rejected\n");
(* Duplicate extension-name detection. *)
let module SameNameExt : Sx_vm_extension.EXTENSION = struct
let name = "test_reg" (* same as TestExt above *)
let init () = TestRegState (ref 0)
let opcodes _st = []
end in
(try
Sx_vm_extensions.register (module SameNameExt);
incr fail_count;
Printf.printf " FAIL: duplicate extension name should have raised\n"
with Failure _ ->
incr pass_count;
Printf.printf " PASS: duplicate extension name rejected\n")
(* ====================================================================== *)