Link AbortController without the fetch unit

AbortController and AbortSignal lowered to fetch.abort* entry points, so
a program that only used them linked the fetch unit with its socket,
HTTP, TLS and zlib dependencies. They now lower to the abort.* entry
points on every target, a new abortSignal feature links scr_abort.c (the
fetch unit's signal implementation built without its transport, which
WASI already ships) and the EventTarget unit, and programs that also
fetch keep the fetch unit's copy.

packages/compiler/src/backend/executable-features.ts

@@ -36,6 +36,7 @@ export function executableLinkFeatures(mod: IrModule, largePages = false): Nativ
     ...(features.dynForAwait ? { dynForAwait: true } : {}),
     ...(features.eventsOnceSignal ? { eventsOnceSignal: true } : {}),
     ...(features.mime ? { mime: true } : {}),
+    ...(features.abortSignal ? { abortSignal: true } : {}),
     ...(features.utilTiming ? { utilTiming: true } : {}),
     ...(features.dynBuffer ? { dynBuffer: true } : {}),
     ...(features.builtinValues ? { builtinValues: true } : {}),

packages/compiler/src/backend/llvm/lib-shared.ts

@@ -1030,10 +1030,6 @@ export const LIB_FN_SYMS: Record<string, string> = {
   "fetch.responseJson": "scr_fetch_response_json",
   "fetch.responseText": "scr_fetch_response_text",
   "fetch.responseBytes": "scr_fetch_response_bytes",
-  "fetch.abortControllerNew": "scr_fetch_abort_controller_new",
-  "fetch.abortTimeout": "scr_fetch_abort_timeout",
-  "fetch.abortNow": "scr_fetch_abort_now",
-  "fetch.abortAny": "scr_fetch_abort_any",
   "fetch.webIs": "scr_fetch_web_is",
   "fetch.streamIs": "scr_fetch_stream_is",
   "zlib.streamIs": "scr_zlib_stream_is",
@@ -1838,14 +1834,11 @@ export const USES_TIMERS_LIB_FNS = new Set<string>([
   "fetch.input",
   "fetch.function",
   "fetch.requestNew",
-  "fetch.abortTimeout",
   "abort.timeout",
   // EventTarget listeners report their exceptions from a nextTick.
   "event.targetNew",
   "abort.controllerNew",
   "abort.any",
-  "fetch.abortControllerNew",
-  "fetch.abortAny",
   "fetch.streamNew",
   "fetch.streamFrom",
   "fetch.transformNew",

packages/compiler/src/backend/native-link-info-core.ts

@@ -67,6 +67,9 @@ export interface NativeLinkFeatures {
   /** `--large-pages`: scr_text_pages.c, which moves the executable's code
    * onto transparent huge pages at startup. Absent (false) without it. */
   largePages?: boolean;
+  /** AbortController and AbortSignal: scr_abort.c, unless the program
+   * links the fetch unit, which has them. */
+  abortSignal?: boolean;
   /** util.debounce and util.throttle: scr_util_timing.c. */
   utilTiming?: boolean;
   /** Buffer.prototype methods called on checked-dynamic values link

packages/compiler/src/backend/native/contracts.ts

@@ -131,6 +131,9 @@ export interface CcOptions {
   mime?: boolean;
   /** `--large-pages`: compiles scr_text_pages.c. */
   largePages?: boolean;
+  /** AbortController and AbortSignal: compiles scr_abort.c, unless the
+   * program compiles the fetch unit, which has them. */
+  abortSignal?: boolean;
   /** util.debounce and util.throttle: compiles scr_util_timing.c. */
   utilTiming?: boolean;
   /** Buffer.prototype methods called on checked-dynamic values:

packages/compiler/src/backend/native/executable.ts

@@ -195,7 +195,10 @@ const RUNTIME_UNITS: readonly RuntimeUnit[] = [
   unit((u) => u.opts.computedRequire === true, "scr_require.c"),
   unit((u) => u.opts.dc, "scr_dc.c"),
   unit((u) => u.opts.dynTier, "scr_js_value.c", "scr_js_object.c"),
-  unit((u) => u.opts.eventTarget || u.nativeFetch, "scr_event_target.c"),
+  unit(
+    (u) => u.opts.eventTarget || u.nativeFetch || u.opts.abortSignal === true,
+    "scr_event_target.c",
+  ),
   unit((u) => u.opts.wasm, "scr_wasm.c"),
   // Module namespace objects as checked-dynamic values.
   unit((u) => u.opts.moduleNamespace === true, "scr_module_namespace.c"),
@@ -248,6 +251,7 @@ const RUNTIME_UNITS: readonly RuntimeUnit[] = [
   unit((u) => u.opts.eventsOnceSignal === true, "scr_events_once_signal.c"),
   unit((u) => u.opts.mime === true, "scr_mime.c"),
   unit((u) => u.opts.largePages === true, "scr_text_pages.c"),
+  unit((u) => u.opts.abortSignal === true && !u.nativeFetch, "scr_abort.c"),
   unit((u) => u.opts.utilTiming === true, "scr_util_timing.c"),
   // The checked-dynamic HANDLE support unit (listener gate + runtime
   // adapter closures): every referencing unit is one of the emitter or

packages/compiler/src/backend/runtime-pack-core.ts

@@ -92,6 +92,7 @@ export interface RuntimeFeatureSet extends NativeLinkFeatures {
   eventsOnceSignal: boolean;
   mime: boolean;
   largePages: boolean;
+  abortSignal: boolean;
   utilTiming: boolean;
   dynBuffer: boolean;
   builtinValues: boolean;
@@ -101,6 +102,7 @@ export interface RuntimeFeatureSet extends NativeLinkFeatures {
   brotli: boolean;
   moduleNamespace: boolean;
   nativeFetch: boolean;
+  abortSignalOnly: boolean;
   netEffective: boolean;
   httpEffective: boolean;
   tlsEffective: boolean;
@@ -297,6 +299,7 @@ export function effectiveRuntimeFeatures(
     eventsOnceSignal: features.eventsOnceSignal === true,
     mime: features.mime === true,
     largePages: features.largePages === true,
+    abortSignal: features.abortSignal === true,
     utilTiming: features.utilTiming === true,
     dynBuffer: features.dynBuffer === true,
     builtinValues: features.builtinValues === true,
@@ -306,6 +309,9 @@ export function effectiveRuntimeFeatures(
     brotli: features.brotli === true,
     moduleNamespace: features.moduleNamespace === true,
     nativeFetch,
+    // The fetch unit has AbortController and AbortSignal; scr_abort.c is
+    // the same implementation without the fetch transport.
+    abortSignalOnly: features.abortSignal === true && !nativeFetch,
     netEffective,
     httpEffective,
     tlsEffective,

packages/compiler/src/backend/target-diagnostics.test.ts

@@ -117,7 +117,7 @@ test("prototype tables store optional methods without invoking their host capabi
 test("local abort signals remain available without a reflection dispatcher", () => {
   const mod = module();
   mod.functions = [
-    fn("%main", [{ kind: "libCall", fn: "fetch.abortControllerNew", args: [], type: DYN, loc }]),
+    fn("%main", [{ kind: "libCall", fn: "abort.controllerNew", args: [], type: DYN, loc }]),
   ];
   fenceSpeculativeWasiFunctions(mod);
   expect(moduleWasiUnavailableSurface(mod)).toBeNull();

packages/compiler/src/backend/target-diagnostics.ts

@@ -1,4 +1,4 @@
-import { everyModuleNode, everyStmtList, transformStmtList } from "../ir/traverse.js";
+import { everyModuleNode, everyStmtList } from "../ir/traverse.js";
 import type { LlvmUnsupportedError } from "./llvm/emitter.js";
 import type { ScrDiagnostic } from "../diagnostics/diagnostic.js";
 import { type IrModule, type SrcLoc } from "../ir/ir.js";
@@ -14,24 +14,6 @@ import {
  * calls, escaped callables, constructors, and exported roots still retain
  * the ordinary target diagnostic. ABI types remain checked by the gate. */
 export function fenceSpeculativeWasiFunctions(mod: IrModule): void {
-  for (const fn of mod.functions)
-    fn.body = transformStmtList(fn.body, {
-      stmt: (statement) => statement,
-      expr: (expr) => {
-        if (expr.kind !== "libCall") return expr;
-        const portable =
-          expr.fn === "fetch.abortControllerNew"
-            ? "abort.controllerNew"
-            : expr.fn === "fetch.abortTimeout"
-              ? "abort.timeout"
-              : expr.fn === "fetch.abortNow"
-                ? "abort.now"
-                : expr.fn === "fetch.abortAny"
-                  ? "abort.any"
-                  : null;
-        return portable ? { ...expr, fn: portable } : expr;
-      },
-    });
   if (!mod.functions.some((fn) => fn.speculativeDispatch)) return;
   const functions = new Map(mod.functions.map((fn) => [fn.name, fn]));
   const classes = new Map((mod.classes ?? []).map((info) => [info.name, info]));

packages/compiler/src/executable/executable-cache.ts

@@ -81,6 +81,7 @@ export interface EarlyExecutableNativeFeatures {
   dynForAwait?: boolean;
   eventsOnceSignal?: boolean;
   mime?: boolean;
+  abortSignal?: boolean;
   utilTiming?: boolean;
   dynBuffer?: boolean;
   builtinValues?: boolean;

packages/compiler/src/frontend/lowering/lower-stdlib.ts

@@ -1500,7 +1500,7 @@ export function lowerStaticFetchCompanionCall(
             : dynUndefinedExpr(loc),
           (first) => ({
             kind: "libCall",
-            fn: "fetch.abortTimeout",
+            fn: "abort.timeout",
             args: [first],
             type: DYN,
             loc,
@@ -1510,7 +1510,7 @@ export function lowerStaticFetchCompanionCall(
         if (call.arguments.nodes.length === 0) {
           return {
             kind: "libCall",
-            fn: "fetch.abortNow",
+            fn: "abort.now",
             args: [dynUndefinedExpr(loc)],
             type: DYN,
             loc,
@@ -1523,7 +1523,7 @@ export function lowerStaticFetchCompanionCall(
           lowerLiveWebValue(lowerer, call.arguments.nodes[0]!),
           (first) => ({
             kind: "libCall",
-            fn: "fetch.abortNow",
+            fn: "abort.now",
             args: [first],
             type: DYN,
             loc,
@@ -1541,7 +1541,7 @@ export function lowerStaticFetchCompanionCall(
             : dynUndefinedExpr(loc),
           (first) => ({
             kind: "libCall",
-            fn: "fetch.abortAny",
+            fn: "abort.any",
             args: [first],
             type: DYN,
             loc,
@@ -1886,7 +1886,7 @@ export function lowerAbortControllerNew(lowerer: Lowerer, expr: ts.NewExpression
 
   const result: IrExpr = {
     kind: "libCall",
-    fn: "fetch.abortControllerNew",
+    fn: "abort.controllerNew",
     args: [],
     type: DYN,
     loc,

packages/compiler/src/frontend/lowering/lower-stream.ts

@@ -5176,7 +5176,7 @@ function lowerPipelineStages(
           {
             kind: "varDecl",
             localId: ac.id,
-            init: { kind: "libCall", fn: "fetch.abortControllerNew", args: [], type: DYN, loc },
+            init: { kind: "libCall", fn: "abort.controllerNew", args: [], type: DYN, loc },
             loc,
           },
         ],
@@ -5502,7 +5502,7 @@ function duplexFromBody(lowerer: Lowerer, node: ts.Expression, loc: SrcLoc): IrE
         {
           kind: "varDecl",
           localId: acLocal.id,
-          init: { kind: "libCall", fn: "fetch.abortControllerNew", args: [], type: DYN, loc },
+          init: { kind: "libCall", fn: "abort.controllerNew", args: [], type: DYN, loc },
           loc,
         },
       ];
@@ -5954,7 +5954,7 @@ export function operatorSignalOptions(lowerer: Lowerer, options: IrExpr, loc: Sr
     type: DYN,
     loc,
   };
-  const signal: IrExpr = { kind: "libCall", fn: "fetch.abortAny", args: [list], type: DYN, loc };
+  const signal: IrExpr = { kind: "libCall", fn: "abort.any", args: [list], type: DYN, loc };
   return { kind: "libCall", fn: "readable.opSignalOpts", args: [signal], type: DYN, loc };
 }
 
@@ -5978,7 +5978,7 @@ export function reduceSignalSetup(
     {
       kind: "varDecl",
       localId: acLocal.id,
-      init: { kind: "libCall", fn: "fetch.abortControllerNew", args: [], type: DYN, loc },
+      init: { kind: "libCall", fn: "abort.controllerNew", args: [], type: DYN, loc },
       loc,
     },
     {

packages/compiler/src/index.ts

@@ -702,6 +702,7 @@ async function compileExecutableNative(
     ...(features.eventsOnceSignal ? { eventsOnceSignal: true } : {}),
     ...(features.mime ? { mime: true } : {}),
     ...(features.largePages ? { largePages: true } : {}),
+    ...(features.abortSignal ? { abortSignal: true } : {}),
     ...(features.utilTiming ? { utilTiming: true } : {}),
     ...(features.dynBuffer ? { dynBuffer: true } : {}),
     ...(features.builtinValues ? { builtinValues: true } : {}),

packages/compiler/src/ir/builtin-effects.ts

@@ -151,8 +151,6 @@ export const MAY_THROW_LIB_FNS: ReadonlySet<IrLibFn> = new Set([
   "fetch.headersNew",
   "fetch.responseNew",
   "fetch.responseJsonStatic",
-  "fetch.abortTimeout",
-  "fetch.abortAny",
   "abort.timeout",
   "abort.any",
   "event.new",

packages/compiler/src/ir/builtin-signatures.ts

@@ -159,10 +159,6 @@ function buildLibFnSignatures() {
     "fetch.responseJson": { argTypes: [DYN], result: { kind: "promise", inner: DYN } },
     "fetch.responseText": { argTypes: [DYN], result: { kind: "promise", inner: STRING } },
     "fetch.responseBytes": { argTypes: [DYN], result: { kind: "promise", inner: BYTES_U8 } },
-    "fetch.abortControllerNew": { argTypes: [], result: DYN },
-    "fetch.abortTimeout": { argTypes: [DYN], result: DYN },
-    "fetch.abortNow": { argTypes: [DYN], result: DYN },
-    "fetch.abortAny": { argTypes: [DYN], result: DYN },
     "fetch.streamNew": { argTypes: [DYN], result: DYN },
     "fetch.transformNew": { argTypes: [], result: DYN },
     // Program-dependent iterable: typed arrays/bytes/string stay intact so

packages/compiler/src/ir/runtime-features.ts

@@ -1033,6 +1033,8 @@ const RUNTIME_FEATURE_RULES = {
   }),
   /** util.MIMEType and util.MIMEParams (scr_mime.c). */
   mime: rule({ prefixes: ["mime."] }),
+  /** AbortController and AbortSignal (scr_abort.c, or the fetch unit). */
+  abortSignal: rule({ prefixes: ["abort."] }),
   /** util.debounce and util.throttle (scr_util_timing.c). */
   utilTiming: rule({ fns: ["util.debounce", "util.throttle"] }),
   /** events.once(emitter, name, { signal }) (scr_events_once_signal.c). */
@@ -1254,6 +1256,7 @@ function noRuntimeFeatures(): RuntimeFeatures {
     inspect: false,
     legacyTextDecoder: false,
     mime: false,
+    abortSignal: false,
     utilTiming: false,
     mockTimers: false,
     net: false,

packages/compiler/src/native/sanitizer.test.ts

@@ -23,6 +23,7 @@ const features = {
   eventsOnceSignal: false,
   mime: false,
   largePages: false,
+  abortSignal: false,
   utilTiming: false,
   dynBuffer: false,
   builtinValues: false,
@@ -74,6 +75,7 @@ const features = {
   webcrypto: false,
   perfLoop: false,
   nativeFetch: false,
+  abortSignalOnly: false,
   netEffective: false,
   httpEffective: false,
   tlsEffective: false,

packages/runtime-pack-common/runtime-pack-matrix.mjs

@@ -80,7 +80,7 @@ export const OPTIONAL_RUNTIME_SOURCES = [
   // programs whose IR has dynamic-tier operations.
   ["scr_js_value.c", "dynTier"],
   ["scr_js_object.c", "dynTier"],
-  ["scr_event_target.c", any("eventTarget", "nativeFetch")],
+  ["scr_event_target.c", any("eventTarget", "nativeFetch", "abortSignal")],
   ["scr_async_dyn.c", any("dynAsync", "dynInvoke", "dc", "fileHandle", "nativeFetch")],
   // The crypto global's object extends scr_async_dyn.c's crypto object.
   ["scr_webcrypto_object.c", all("webcrypto", "dynAsync")],
@@ -184,6 +184,7 @@ export const OPTIONAL_RUNTIME_SOURCES = [
   ["scr_tls_x509.c", all("tlsEffective", "x509")],
   // WebCrypto's AES ciphers run over the cipher feature's mbedTLS archive.
   ["scr_webcrypto_aes.c", all("cipher", "webcrypto")],
+  ["scr_abort.c", "abortSignalOnly"],
   ["scr_fetch.c", "nativeFetch"],
   ["scr_stream_from_web.c", all("stream", "nativeFetch")],
 ];

packages/runtime-wasm32-wasi/scripts/build.mjs

@@ -8,6 +8,7 @@ process.env.SCRIPTC_RUNTIME_PACK_CONFIG = JSON.stringify({
   runtimeDefines: ["_GNU_SOURCE", "_WASI_EMULATED_SIGNAL", "_WASI_EMULATED_PROCESS_CLOCKS"],
   omitRuntimeSources: ["scr_child.c"],
   omitOptionalSources: [
+    "scr_abort.c",
     "scr_event_target.c",
     "scr_loop_kqueue.c",
     "scr_loop_epoll.c",