Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not"

Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]
2024-07-26 15:52:14 -07:00 · 2024-07-26 15:16:23 -07:00 · 2024-07-26 14:39:18 -07:00 · 2024-07-18 16:14:15 -07:00 · 2024-07-18 13:30:38 -07:00 · 2024-07-18 09:41:55 -07:00
5 changed files with 22 additions and 47 deletions
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
@@ -155,11 +155,7 @@ function* runWithEnvironment(
  validateContextVariableLValues(hir);
  validateUseMemo(hir);

-  if (
-    !env.config.enablePreserveExistingManualUseMemo &&
-    !env.config.disableMemoizationForDebugging &&
-    !env.config.enableChangeDetectionForDebugging
-  ) {
+  if (!env.preserveManualMemo()) {
    dropManualMemoization(hir);
    yield log({kind: 'hir', name: 'DropManualMemoization', value: hir});
  }
--- a/compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts
@@ -765,6 +765,14 @@ export class Environment {
      return DefaultMutatingHook;
    }
  }
+
+  preserveManualMemo(): boolean {
+    return (
+      this.config.enablePreserveExistingManualUseMemo ||
+      this.config.disableMemoizationForDebugging ||
+      this.config.enableChangeDetectionForDebugging != null
+    );
+  }
 }

 // From https://github.com/facebook/react/blob/main/packages/eslint-plugin-react-hooks/src/RulesOfHooks.js#LL18C1-L23C2
--- a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/MemoizeFbtAndMacroOperandsInSameScope.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/MemoizeFbtAndMacroOperandsInSameScope.ts
@@ -45,6 +45,7 @@ export function memoizeFbtAndMacroOperandsInSameScope(
  const fbtMacroTags = new Set([
    ...FBT_TAGS,
    ...(fn.env.config.customMacros ?? []),
+    ...(fn.env.preserveManualMemo() ? ["useMemo", "useCallback"] : []),
  ]);
  const fbtValues: Set<IdentifierId> = new Set();
  while (true) {
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/useMemo-simple-preserved-nomemo.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/useMemo-simple-preserved-nomemo.expect.md
@@ -25,33 +25,18 @@ import { c as _c } from "react/compiler-runtime"; // @disableMemoizationForDebug
 import { useMemo } from "react";

 function Component(t0) {
-  const $ = _c(5);
+  const $ = _c(2);
  const { a } = t0;
+  const x = useMemo(() => [a], []);
  let t1;
-  if ($[0] !== a || true) {
-    t1 = () => [a];
-    $[0] = a;
+  if ($[0] !== x || true) {
+    t1 = <div>{x}</div>;
+    $[0] = x;
    $[1] = t1;
  } else {
    t1 = $[1];
  }
-  let t2;
-  if ($[2] === Symbol.for("react.memo_cache_sentinel") || true) {
-    t2 = [];
-    $[2] = t2;
-  } else {
-    t2 = $[2];
-  }
-  const x = useMemo(t1, t2);
-  let t3;
-  if ($[3] !== x || true) {
-    t3 = <div>{x}</div>;
-    $[3] = x;
-    $[4] = t3;
-  } else {
-    t3 = $[4];
-  }
-  return t3;
+  return t1;
 }

 export const FIXTURE_ENTRYPOINT = {
--- a/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/useMemo-simple-preserved.expect.md
+++ b/compiler/packages/babel-plugin-react-compiler/src/tests/fixtures/compiler/useMemo-simple-preserved.expect.md
@@ -25,33 +25,18 @@ import { c as _c } from "react/compiler-runtime"; // @enablePreserveExistingManu
 import { useMemo } from "react";

 function Component(t0) {
-  const $ = _c(5);
+  const $ = _c(2);
  const { a } = t0;
+  const x = useMemo(() => [a], []);
  let t1;
-  if ($[0] !== a) {
-    t1 = () => [a];
-    $[0] = a;
+  if ($[0] !== x) {
+    t1 = <div>{x}</div>;
+    $[0] = x;
    $[1] = t1;
  } else {
    t1 = $[1];
  }
-  let t2;
-  if ($[2] === Symbol.for("react.memo_cache_sentinel")) {
-    t2 = [];
-    $[2] = t2;
-  } else {
-    t2 = $[2];
-  }
-  const x = useMemo(t1, t2);
-  let t3;
-  if ($[3] !== x) {
-    t3 = <div>{x}</div>;
-    $[3] = x;
-    $[4] = t3;
-  } else {
-    t3 = $[4];
-  }
-  return t3;
+  return t1;
 }

 export const FIXTURE_ENTRYPOINT = {
Author	SHA1	Message	Date
Mike Vitousek	a807bec0e2	Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not" Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]	2024-07-26 15:52:14 -07:00
Mike Vitousek	552ea378bc	Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not" Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]	2024-07-26 15:16:23 -07:00
Mike Vitousek	5c33c81e9f	Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not" Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]	2024-07-26 14:39:18 -07:00
Mike Vitousek	d072be1c87	Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not" Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]	2024-07-18 16:14:15 -07:00
Mike Vitousek	34978c3418	Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not" Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]	2024-07-18 13:30:38 -07:00
Mike Vitousek	1816c663ea	Update base for Update on "[compiler] Make compiler aware of whether a local binding is constlike or not" Summary: Minor change which supports the changeDetection work later on. We can know whether an individual local binding is const or constlike. [ghstack-poisoned]	2024-07-18 09:41:55 -07:00
Mike Vitousek	26a95b10a1	[compiler] When preserving user-level useMemos, don't memoize arguments Summary: This work enhances the don't-drop-memoization mode to not memoize the arguments to useMemo and useCallback (or technically, to memoize them in the same block as the hook call -- but since hooks can't be memoized, this is equivalent to never memoizing them). The advantage here is that we preserve the source-level code structure around memoization callbacks more, and avoid the compiler bug of having function expression dependencies be unconditional when their actual semantics are conditional. This conceptually replaces some of the work of #30177: some of that was motivated by avoiding the deps bug, and the rest of the motivation was to better exercise the compiler's semantics, which was really happening as much as I'd hoped, as @mofeiZ explained to me in that PR and offline! [ghstack-poisoned]	2024-07-18 09:17:50 -07:00