refactor(exo): patch exo to track endo #2247

Agoric · May 1, 2024 · 8f0f2d5 · 8f0f2d5
1 parent e456308
commit 8f0f2d5
Showing 1 changed file with 276 additions and 0 deletions.
diff --git a/patches/@endo+exo+1.4.0.patch b/patches/@endo+exo+1.4.0.patch
@@ -8,3 +8,279 @@ index 3bc696d..55df34e 100644
 +export * from "./src/types.js";
  //# sourceMappingURL=index.d.ts.map
 \ No newline at end of file
+diff --git a/node_modules/@endo/exo/src/exo-tools.js b/node_modules/@endo/exo/src/exo-tools.js
+index e091adc..20bf28d 100644
+--- a/node_modules/@endo/exo/src/exo-tools.js
++++ b/node_modules/@endo/exo/src/exo-tools.js
+@@ -18,7 +18,7 @@ import { GET_INTERFACE_GUARD } from './get-interface.js';
+
+ /**
+  * @import {InterfaceGuard, Method, MethodGuard, MethodGuardPayload} from '@endo/patterns'
+- * @import {ContextProvider, FacetName, KitContextProvider, MatchConfig, Methods} from './types.js'
++ * @import {ClassContext, ContextProvider, FacetName, KitContext, KitContextProvider, MatchConfig, Methods} from './types.js'
+  */
+
+ const { apply, ownKeys } = Reflect;
+@@ -146,21 +146,28 @@ const buildMatchConfig = methodGuardPayload => {
+ };
+
+ /**
+- * @param {Method} method
++ * @param {(representative: any) => ClassContext | KitContext} getContext
++ * @param {CallableFunction} behaviorMethod
+  * @param {MethodGuardPayload} methodGuardPayload
+  * @param {string} label
+  * @returns {Method}
+  */
+-const defendSyncMethod = (method, methodGuardPayload, label) => {
++const defendSyncMethod = (
++  getContext,
++  behaviorMethod,
++  methodGuardPayload,
++  label,
++) => {
+   const { returnGuard } = methodGuardPayload;
+   const isRawReturn = isRawGuard(returnGuard);
+   const matchConfig = buildMatchConfig(methodGuardPayload);
+   const { syncMethod } = {
+     // Note purposeful use of `this` and concise method syntax
+     syncMethod(...syncArgs) {
++      const context = getContext(this);
+       // Only harden args and return value if not dealing with a raw value guard.
+       const realArgs = defendSyncArgs(syncArgs, matchConfig, label);
+-      const result = apply(method, this, realArgs);
++      const result = apply(behaviorMethod, context, realArgs);
+       if (!isRawReturn) {
+         mustMatch(harden(result), returnGuard, `${label}: result`);
+       }
+@@ -202,11 +209,17 @@ const desync = methodGuardPayload => {
+ };
+
+ /**
+- * @param {(...args: unknown[]) => any} method
++ * @param {(representative: any) => ClassContext | KitContext} getContext
++ * @param {CallableFunction} behaviorMethod
+  * @param {MethodGuardPayload} methodGuardPayload
+  * @param {string} label
+  */
+-const defendAsyncMethod = (method, methodGuardPayload, label) => {
++const defendAsyncMethod = (
++  getContext,
++  behaviorMethod,
++  methodGuardPayload,
++  label,
++) => {
+   const { returnGuard } = methodGuardPayload;
+   const isRawReturn = isRawGuard(returnGuard);
+
+@@ -231,8 +244,11 @@ const defendAsyncMethod = (method, methodGuardPayload, label) => {
+           for (let j = 0; j < awaitedArgs.length; j += 1) {
+             syncArgs[awaitIndexes[j]] = awaitedArgs[j];
+           }
++          // Get the context after all waiting in case we ever do revocation
++          // by removing the context entry. Avoid TOCTTOU!
++          const context = getContext(this);
+           const realArgs = defendSyncArgs(syncArgs, matchConfig, label);
+-          return apply(method, this, realArgs);
++          return apply(behaviorMethod, context, realArgs);
+         },
+       );
+       if (isRawReturn) {
+@@ -249,18 +265,29 @@ const defendAsyncMethod = (method, methodGuardPayload, label) => {
+
+ /**
+  *
+- * @param {Method} method
++ * @param {(representative: any) => ClassContext | KitContext} getContext
++ * @param {CallableFunction} behaviorMethod
+  * @param {MethodGuard} methodGuard
+  * @param {string} label
+  */
+-const defendMethod = (method, methodGuard, label) => {
++const defendMethod = (getContext, behaviorMethod, methodGuard, label) => {
+   const methodGuardPayload = getMethodGuardPayload(methodGuard);
+   const { callKind } = methodGuardPayload;
+   if (callKind === 'sync') {
+-    return defendSyncMethod(method, methodGuardPayload, label);
++    return defendSyncMethod(
++      getContext,
++      behaviorMethod,
++      methodGuardPayload,
++      label,
++    );
+   } else {
+     assert(callKind === 'async');
+-    return defendAsyncMethod(method, methodGuardPayload, label);
++    return defendAsyncMethod(
++      getContext,
++      behaviorMethod,
++      methodGuardPayload,
++      label,
++    );
+   }
+ };
+
+@@ -268,74 +295,43 @@ const defendMethod = (method, methodGuard, label) => {
+  * @param {string} methodTag
+  * @param {ContextProvider} contextProvider
+  * @param {CallableFunction} behaviorMethod
+- * @param {boolean} [thisfulMethods]
+- * @param {MethodGuard} [methodGuard]
+- * @param {import('@endo/patterns').DefaultGuardType} [defaultGuards]
++ * @param {MethodGuard} methodGuard
+  */
+ const bindMethod = (
+   methodTag,
+   contextProvider,
+   behaviorMethod,
+-  thisfulMethods = false,
+-  methodGuard = undefined,
+-  defaultGuards = undefined,
++  methodGuard,
+ ) => {
+   assert.typeof(behaviorMethod, 'function');
+
+-  const getContext = self => {
+-    const context = contextProvider(self);
+-    context ||
+-      Fail`${q(methodTag)} may only be applied to a valid instance: ${self}`;
++  /**
++   * @param {any} representative
++   * @returns {ClassContext | KitContext}
++   */
++  const getContext = representative => {
++    representative ||
++      // separate line to ease breakpointing
++      Fail`Method ${methodTag} called without 'this' object`;
++    const context = contextProvider(representative);
++    if (context === undefined) {
++      throw Fail`${q(
++        methodTag,
++      )} may only be applied to a valid instance: ${representative}`;
++    }
+     return context;
+   };
+
+-  // Violating all Jessie rules to create representatives that inherit
+-  // methods from a shared prototype. The bound method therefore needs
+-  // to mention `this`. We define it using concise method syntax
+-  // so that it will be `this` sensitive but not constructable.
+-  //
+-  // We normally consider `this` unsafe because of the hazard of a
+-  // method of one abstraction being applied to an instance of
+-  // another abstraction. To prevent that attack, the bound method
+-  // checks that its `this` is in the map in which its representatives
+-  // are registered.
+-  let { method } = thisfulMethods
+-    ? {
+-        method(...args) {
+-          this ||
+-            Fail`thisful method ${methodTag} called without 'this' object`;
+-          const context = getContext(this);
+-          return apply(behaviorMethod, context, args);
+-        },
+-      }
+-    : {
+-        method(...args) {
+-          const context = getContext(this);
+-          return apply(behaviorMethod, null, [context, ...args]);
+-        },
+-      };
+-  if (!methodGuard && thisfulMethods) {
+-    switch (defaultGuards) {
+-      case undefined:
+-      case 'passable':
+-        methodGuard = PassableMethodGuard;
+-        break;
+-      case 'raw':
+-        methodGuard = RawMethodGuard;
+-        break;
+-      default:
+-        throw Fail`Unrecognized defaultGuards ${q(defaultGuards)}`;
+-    }
+-  }
+-  if (methodGuard) {
+-    method = defendMethod(method, methodGuard, methodTag);
+-  }
++  const method = defendMethod(
++    getContext,
++    behaviorMethod,
++    methodGuard,
++    methodTag,
++  );
+
+   defineProperties(method, {
+     name: { value: methodTag },
+-    length: {
+-      value: thisfulMethods ? behaviorMethod.length : behaviorMethod.length - 1,
+-    },
++    length: { value: behaviorMethod.length },
+   });
+   return method;
+ };
+@@ -402,14 +398,43 @@ export const defendPrototype = (
+   }
+
+   for (const prop of methodNames) {
++    const originalMethod = behaviorMethods[prop];
++    const { shiftedMethod } = {
++      shiftedMethod(...args) {
++        return originalMethod(this, ...args);
++      },
++    };
++    const behaviorMethod = thisfulMethods ? originalMethod : shiftedMethod;
++    // TODO some tool does not yet understand the `?.[` syntax
++    let methodGuard = methodGuards && methodGuards[prop];
++    if (!methodGuard) {
++      switch (defaultGuards) {
++        case undefined: {
++          if (thisfulMethods) {
++            methodGuard = PassableMethodGuard;
++          } else {
++            methodGuard = RawMethodGuard;
++          }
++          break;
++        }
++        case 'passable': {
++          methodGuard = PassableMethodGuard;
++          break;
++        }
++        case 'raw': {
++          methodGuard = RawMethodGuard;
++          break;
++        }
++        default: {
++          throw Fail`Unrecognized defaultGuards ${q(defaultGuards)}`;
++        }
++      }
++    }
+     prototype[prop] = bindMethod(
+       `In ${q(prop)} method of (${tag})`,
+       contextProvider,
+-      behaviorMethods[prop],
+-      thisfulMethods,
+-      // TODO some tool does not yet understand the `?.[` syntax
+-      methodGuards && methodGuards[prop],
+-      defaultGuards,
++      behaviorMethod,
++      methodGuard,
+     );
+   }
+
+@@ -424,14 +449,13 @@ export const defendPrototype = (
+       `In ${q(GET_INTERFACE_GUARD)} method of (${tag})`,
+       contextProvider,
+       getInterfaceGuardMethod,
+-      thisfulMethods,
+-      undefined,
++      PassableMethodGuard,
+     );
+   }
+
+   return Far(
+     tag,
+-    /** @type {T & import('./get-interface.js').GetInterfaceGuard<T>} */ (
++    /** @type {T & import('./get-interface.js').GetInterfaceGuard<T>} */(
+       prototype
+     ),
+   );