[compiler] Add new ValidateNoVoidUseMemo pass (#33990)

Adds a new validation pass to validate against `useMemo`s that don't
return anything. This usually indicates some kind of "useEffect"-like
code that has side effects that need to be memoized to prevent
overfiring, and is an anti-pattern.

A follow up validation could also look at the return value of `useMemo`s
to see if they are being used.

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/33990).
* #34022
* #34002
* #34001
* __->__ #33990
* #33989

DiffTrain build for [c60eebf](c60eebf)

Author: poteto

compiled/eslint-plugin-react-hooks/index.js

@@ -30734,6 +30734,7 @@ const EnvironmentConfigSchema = zod.z.object({
     hookPattern: zod.z.string().nullable().default(null),
     enableTreatRefLikeIdentifiersAsRefs: zod.z.boolean().default(false),
     lowerContextAccess: ExternalFunctionSchema.nullable().default(null),
+    validateNoVoidUseMemo: zod.z.boolean().default(false),
 });
 class Environment {
     constructor(scope, fnType, compilerMode, config, contextIdentifiers, parentFunction, logger, filename, code, programContext) {
@@ -43754,7 +43755,7 @@ function collectMaybeMemoDependencies(value, maybeDeps, optional) {
     }
     return null;
 }
-function collectTemporaries(instr, env, sidemap) {
+function collectTemporaries$1(instr, env, sidemap) {
     const { value, lvalue } = instr;
     switch (value.kind) {
         case 'FunctionExpression': {
@@ -43945,7 +43946,7 @@ function dropManualMemoization(func) {
                 }
             }
             else {
-                collectTemporaries(instr, func.env, sidemap);
+                collectTemporaries$1(instr, func.env, sidemap);
             }
         }
     }
@@ -47617,6 +47618,107 @@ function visit(identifiers, place, kind) {
     identifiers.set(place.identifier.id, { place, kind });
 }
 
+function validateNoVoidUseMemo(fn) {
+    const errors = new CompilerError();
+    const sidemap = {
+        useMemoHooks: new Map(),
+        funcExprs: new Map(),
+        react: new Set(),
+    };
+    for (const [, block] of fn.body.blocks) {
+        for (const instr of block.instructions) {
+            collectTemporaries(instr, fn.env, sidemap);
+        }
+    }
+    for (const [, block] of fn.body.blocks) {
+        for (const instr of block.instructions) {
+            if (instr.value.kind === 'CallExpression') {
+                const callee = instr.value.callee.identifier;
+                const useMemoHook = sidemap.useMemoHooks.get(callee.id);
+                if (useMemoHook !== undefined && instr.value.args.length > 0) {
+                    const firstArg = instr.value.args[0];
+                    if (firstArg.kind !== 'Identifier') {
+                        continue;
+                    }
+                    let funcToCheck = sidemap.funcExprs.get(firstArg.identifier.id);
+                    if (!funcToCheck) {
+                        for (const [, searchBlock] of fn.body.blocks) {
+                            for (const searchInstr of searchBlock.instructions) {
+                                if (searchInstr.lvalue &&
+                                    searchInstr.lvalue.identifier.id === firstArg.identifier.id &&
+                                    searchInstr.value.kind === 'FunctionExpression') {
+                                    funcToCheck = searchInstr.value;
+                                    break;
+                                }
+                            }
+                            if (funcToCheck)
+                                break;
+                        }
+                    }
+                    if (funcToCheck) {
+                        const hasReturn = checkFunctionHasNonVoidReturn(funcToCheck.loweredFunc.func);
+                        if (!hasReturn) {
+                            errors.push({
+                                severity: ErrorSeverity.InvalidReact,
+                                reason: `React Compiler has skipped optimizing this component because ${useMemoHook.name} doesn't return a value. ${useMemoHook.name} should only be used for memoizing values, not running arbitrary side effects.`,
+                                loc: useMemoHook.loc,
+                                suggestions: null,
+                                description: null,
+                            });
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return errors.asResult();
+}
+function checkFunctionHasNonVoidReturn(func) {
+    for (const [, block] of func.body.blocks) {
+        if (block.terminal.kind === 'return') {
+            if (block.terminal.returnVariant === 'Explicit' ||
+                block.terminal.returnVariant === 'Implicit') {
+                return true;
+            }
+        }
+    }
+    return false;
+}
+function collectTemporaries(instr, env, sidemap) {
+    const { value, lvalue } = instr;
+    switch (value.kind) {
+        case 'FunctionExpression': {
+            sidemap.funcExprs.set(lvalue.identifier.id, value);
+            break;
+        }
+        case 'LoadGlobal': {
+            const global = env.getGlobalDeclaration(value.binding, value.loc);
+            const hookKind = global !== null ? getHookKindForType(env, global) : null;
+            if (hookKind === 'useMemo') {
+                sidemap.useMemoHooks.set(lvalue.identifier.id, {
+                    name: value.binding.name,
+                    loc: instr.loc,
+                });
+            }
+            else if (value.binding.name === 'React') {
+                sidemap.react.add(lvalue.identifier.id);
+            }
+            break;
+        }
+        case 'PropertyLoad': {
+            if (sidemap.react.has(value.object.identifier.id)) {
+                if (value.property === 'useMemo') {
+                    sidemap.useMemoHooks.set(lvalue.identifier.id, {
+                        name: value.property,
+                        loc: instr.loc,
+                    });
+                }
+            }
+            break;
+        }
+    }
+}
+
 function computeUnconditionalBlocks(fn) {
     const unconditionalBlocks = new Set();
     const dominators = computePostDominatorTree(fn, {
@@ -50709,6 +50811,9 @@ function runWithEnvironment(func, env) {
     log({ kind: 'hir', name: 'PruneMaybeThrows', value: hir });
     validateContextVariableLValues(hir);
     validateUseMemo(hir).unwrap();
+    if (env.config.validateNoVoidUseMemo) {
+        validateNoVoidUseMemo(hir).unwrap();
+    }
     if (env.isInferredMemoEnabled &&
         !env.config.enablePreserveExistingManualUseMemo &&
         !env.config.disableMemoizationForDebugging &&

compiled/facebook-www/REVISION

@@ -1 +1 @@
-5dd622eabe38e01781b3699d0d81c4a16e302f09
+c60eebffea94a67f35c6ebbf7019e5b2145d4284

compiled/facebook-www/REVISION_TRANSFORMS

@@ -1 +1 @@
-5dd622eabe38e01781b3699d0d81c4a16e302f09
+c60eebffea94a67f35c6ebbf7019e5b2145d4284

compiled/facebook-www/React-dev.classic.js

@@ -1434,7 +1434,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.2.0-www-classic-5dd622ea-20250728";
+    exports.version = "19.2.0-www-classic-c60eebff-20250728";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-dev.modern.js

@@ -1434,7 +1434,7 @@ __DEV__ &&
     exports.useTransition = function () {
       return resolveDispatcher().useTransition();
     };
-    exports.version = "19.2.0-www-modern-5dd622ea-20250728";
+    exports.version = "19.2.0-www-modern-c60eebff-20250728";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-prod.classic.js

@@ -610,4 +610,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-classic-5dd622ea-20250728";
+exports.version = "19.2.0-www-classic-c60eebff-20250728";

compiled/facebook-www/React-prod.modern.js

@@ -610,4 +610,4 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-modern-5dd622ea-20250728";
+exports.version = "19.2.0-www-modern-c60eebff-20250728";

compiled/facebook-www/React-profiling.classic.js

@@ -614,7 +614,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-classic-5dd622ea-20250728";
+exports.version = "19.2.0-www-classic-c60eebff-20250728";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/React-profiling.modern.js

@@ -614,7 +614,7 @@ exports.useSyncExternalStore = function (
 exports.useTransition = function () {
   return ReactSharedInternals.H.useTransition();
 };
-exports.version = "19.2.0-www-modern-5dd622ea-20250728";
+exports.version = "19.2.0-www-modern-c60eebff-20250728";
 "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
   "function" ===
     typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&

compiled/facebook-www/ReactART-dev.classic.js

@@ -19305,10 +19305,10 @@ __DEV__ &&
     (function () {
       var internals = {
         bundleType: 1,
-        version: "19.2.0-www-classic-5dd622ea-20250728",
+        version: "19.2.0-www-classic-c60eebff-20250728",
         rendererPackageName: "react-art",
         currentDispatcherRef: ReactSharedInternals,
-        reconcilerVersion: "19.2.0-www-classic-5dd622ea-20250728"
+        reconcilerVersion: "19.2.0-www-classic-c60eebff-20250728"
       };
       internals.overrideHookState = overrideHookState;
       internals.overrideHookStateDeletePath = overrideHookStateDeletePath;
@@ -19342,7 +19342,7 @@ __DEV__ &&
     exports.Shape = Shape;
     exports.Surface = Surface;
     exports.Text = Text;
-    exports.version = "19.2.0-www-classic-5dd622ea-20250728";
+    exports.version = "19.2.0-www-classic-c60eebff-20250728";
     "undefined" !== typeof __REACT_DEVTOOLS_GLOBAL_HOOK__ &&
       "function" ===
         typeof __REACT_DEVTOOLS_GLOBAL_HOOK__.registerInternalModuleStop &&