Update on "[compiler] Rewrite useContext callee"

If a value is specified for the LowerContextAccess environment config,
we rewrite the callee from 'useContext' to the specificed value.

This will allow us run an experiment internally.

[ghstack-poisoned]

.github/workflows/compiler_prereleases.yml

@@ -0,0 +1,52 @@
+name: (Compiler) Publish Prereleases
+
+on:
+  workflow_call:
+    inputs:
+      commit_sha:
+        required: true
+        default: ''
+        type: string
+      release_channel:
+        required: true
+        type: string
+      dist_tag:
+        required: true
+        type: string
+    secrets:
+      NPM_TOKEN:
+        required: true
+
+env:
+  TZ: /usr/share/zoneinfo/America/Los_Angeles
+  # https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout
+  SEGMENT_DOWNLOAD_TIMEOUT_MINS: 1
+  GH_TOKEN: ${{ github.token }}
+  NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+
+defaults:
+  run:
+    working-directory: compiler
+
+jobs:
+  publish_prerelease:
+    name: Publish prelease (${{ inputs.release_channel }}) ${{ inputs.commit_sha }} @${{ inputs.dist_tag }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: '.nvmrc'
+          cache: yarn
+          cache-dependency-path: compiler/yarn.lock
+      - name: Restore cached node_modules
+        uses: actions/cache@v4
+        id: node_modules
+        with:
+          path: "**/node_modules"
+          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('compiler/**/yarn.lock') }}
+      - run: yarn install --frozen-lockfile
+      - name: Publish packages to npm
+        run: |
+          cp ./scripts/release/ci-npmrc ~/.npmrc
+          scripts/release/publish.js --frfr --ci --tags ${{ inputs.dist_tag }}

.github/workflows/compiler_prereleases_manual.yml

@@ -0,0 +1,21 @@
+name: (Compiler) Publish Prereleases Manual
+
+on:
+  workflow_dispatch:
+    inputs:
+      prerelease_commit_sha:
+        required: false
+
+env:
+  TZ: /usr/share/zoneinfo/America/Los_Angeles
+
+jobs:
+  publish_prerelease_experimental:
+    name: Publish to Experimental channel
+    uses: facebook/react/.github/workflows/compiler_prereleases.yml@main
+    with:
+      commit_sha: ${{ inputs.prerelease_commit_sha || github.sha }}
+      release_channel: experimental
+      dist_tag: experimental
+    secrets:
+      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/compiler_prereleases_nightly.yml

@@ -0,0 +1,20 @@
+name: (Compiler) Publish Prereleases Nightly
+
+on:
+  schedule:
+    # At 10 minutes past 16:00 on Mon, Tue, Wed, Thu, and Fri
+    - cron: 10 16 * * 1,2,3,4,5
+
+env:
+  TZ: /usr/share/zoneinfo/America/Los_Angeles
+
+jobs:
+  publish_prerelease_experimental:
+    name: Publish to Experimental channel
+    uses: facebook/react/.github/workflows/compiler_prereleases.yml@main
+    with:
+      commit_sha: ${{ github.sha }}
+      release_channel: experimental
+      dist_tag: experimental
+    secrets:
+      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/shared_lint.yml

@@ -43,7 +43,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: node ./scripts/tasks/eslint
 
@@ -61,7 +61,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: ./scripts/ci/check_license.sh
 
@@ -79,6 +79,6 @@ jobs:
         uses: actions/cache@v4
         with:
           path: "**/node_modules"
-          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+          key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
       - run: yarn install --frozen-lockfile
       - run: ./scripts/ci/test_print_warnings.sh

compiler/crates/react_hir/src/merge_consecutive_blocks.rs

@@ -151,6 +151,7 @@ impl MergedBlocks {
 
 #[derive(Debug, Error)]
 #[error("Expected predecessor {predecessor} to exist")]
+#[allow(dead_code)]
 pub struct ExpectedPredecessorToExist {
     predecessor: BlockId,
 }

compiler/crates/react_semantic_analysis/src/scope_view.rs

@@ -159,6 +159,7 @@ impl<'m> std::fmt::Debug for ScopeView<'m> {
 }
 
 #[derive(Clone, Copy)]
+#[allow(dead_code)]
 pub struct LabelView<'m> {
     #[allow(dead_code)]
     pub(crate) manager: &'m ScopeManager,

compiler/package.json

@@ -25,9 +25,11 @@
     "snap": "yarn workspace babel-plugin-react-compiler run snap",
     "snap:build": "yarn workspace snap run build",
     "postinstall": "perl -p -i -e 's/react\\.element/react.transitional.element/' packages/snap/node_modules/fbt/lib/FbtReactUtil.js && perl -p -i -e 's/didWarnAboutUsingAct = false;/didWarnAboutUsingAct = true;/' packages/babel-plugin-react-compiler/node_modules/react-dom/cjs/react-dom-test-utils.development.js",
-    "npm:publish": "node scripts/release/publish-manual"
+    "npm:publish": "node scripts/release/publish"
+  },
+  "dependencies": {
+    "fs-extra": "^4.0.2"
   },
-  "dependencies": {},
   "devDependencies": {
     "@rollup/plugin-commonjs": "^25.0.7",
     "@rollup/plugin-json": "^6.1.0",

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Options.ts

@@ -194,7 +194,7 @@ export const defaultOptions: PluginOptions = {
   noEmit: false,
   runtimeModule: null,
   eslintSuppressionRules: null,
-  flowSuppressions: false,
+  flowSuppressions: true,
   ignoreUseNoForget: false,
   sources: filename => {
     return filename.indexOf('node_modules') === -1;

compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts

@@ -77,7 +77,11 @@ import {flattenScopesWithHooksOrUseHIR} from '../ReactiveScopes/FlattenScopesWit
 import {pruneAlwaysInvalidatingScopes} from '../ReactiveScopes/PruneAlwaysInvalidatingScopes';
 import pruneInitializationDependencies from '../ReactiveScopes/PruneInitializationDependencies';
 import {stabilizeBlockIds} from '../ReactiveScopes/StabilizeBlockIds';
-import {eliminateRedundantPhi, enterSSA, leaveSSA} from '../SSA';
+import {
+  eliminateRedundantPhi,
+  enterSSA,
+  rewriteInstructionKindsBasedOnReassignment,
+} from '../SSA';
 import {inferTypes} from '../TypeInference';
 import {
   logCodegenFunction,
@@ -98,6 +102,7 @@ import {
 } from '../Validation';
 import {validateLocalsNotReassignedAfterRender} from '../Validation/ValidateLocalsNotReassignedAfterRender';
 import {outlineFunctions} from '../Optimization/OutlineFunctions';
+import {propagatePhiTypes} from '../TypeInference/PropagatePhiTypes';
 import {lowerContextAccess} from '../Optimization/LowerContextAccess';
 
 export type CompilerPipelineValue =
@@ -242,8 +247,19 @@ function* runWithEnvironment(
   inferReactivePlaces(hir);
   yield log({kind: 'hir', name: 'InferReactivePlaces', value: hir});
 
-  leaveSSA(hir);
-  yield log({kind: 'hir', name: 'LeaveSSA', value: hir});
+  rewriteInstructionKindsBasedOnReassignment(hir);
+  yield log({
+    kind: 'hir',
+    name: 'RewriteInstructionKindsBasedOnReassignment',
+    value: hir,
+  });
+
+  propagatePhiTypes(hir);
+  yield log({
+    kind: 'hir',
+    name: 'PropagatePhiTypes',
+    value: hir,
+  });
 
   inferReactiveScopeVariables(hir);
   yield log({kind: 'hir', name: 'InferReactiveScopeVariables', value: hir});

compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts

@@ -1174,11 +1174,19 @@ export type NonLocalBinding =
 
 // Represents a user-defined variable (has a name) or a temporary variable (no name).
 export type Identifier = {
-  /*
-   * unique value to distinguish a variable, since name is not guaranteed to
-   * exist or be unique
+  /**
+   * After EnterSSA, `id` uniquely identifies an SSA instance of a variable.
+   * Before EnterSSA, `id` matches `declarationId`.
    */
   id: IdentifierId;
+
+  /**
+   * Uniquely identifies a given variable in the original program. If a value is
+   * reassigned in the original program each reassigned value will have a distinct
+   * `id` (after EnterSSA), but they will still have the same `declarationId`.
+   */
+  declarationId: DeclarationId;
+
   // null for temporaries. name is primarily used for debugging.
   name: IdentifierName | null;
   // The range for which this variable is mutable
@@ -1212,6 +1220,7 @@ export function makeTemporaryIdentifier(
   return {
     id,
     name: null,
+    declarationId: makeDeclarationId(id),
     mutableRange: {start: makeInstructionId(0), end: makeInstructionId(0)},
     scope: null,
     type: makeType(),
@@ -1239,6 +1248,9 @@ export function makeIdentifierName(name: string): ValidatedIdentifier {
 
 /**
  * Given an unnamed identifier, promote it to a named identifier.
+ *
+ * Note: this uses the identifier's DeclarationId to ensure that all
+ * instances of the same declaration will have the same name.
  */
 export function promoteTemporary(identifier: Identifier): void {
   CompilerError.invariant(identifier.name === null, {
@@ -1249,7 +1261,7 @@ export function promoteTemporary(identifier: Identifier): void {
   });
   identifier.name = {
     kind: 'promoted',
-    value: `#t${identifier.id}`,
+    value: `#t${identifier.declarationId}`,
   };
 }
 
@@ -1260,6 +1272,9 @@ export function isPromotedTemporary(name: string): boolean {
 /**
  * Given an unnamed identifier, promote it to a named identifier, distinguishing
  * it as a value that needs to be capitalized since it appears in JSX element tag position
+ *
+ * Note: this uses the identifier's DeclarationId to ensure that all
+ * instances of the same declaration will have the same name.
  */
 export function promoteTemporaryJsxTag(identifier: Identifier): void {
   CompilerError.invariant(identifier.name === null, {
@@ -1270,7 +1285,7 @@ export function promoteTemporaryJsxTag(identifier: Identifier): void {
   });
   identifier.name = {
     kind: 'promoted',
-    value: `#T${identifier.id}`,
+    value: `#T${identifier.declarationId}`,
   };
 }
 
@@ -1508,6 +1523,23 @@ export function makeIdentifierId(id: number): IdentifierId {
   return id as IdentifierId;
 }
 
+/*
+ * Simulated opaque type for IdentifierId to prevent using normal numbers as ids
+ * accidentally.
+ */
+const opageDeclarationId = Symbol();
+export type DeclarationId = number & {[opageDeclarationId]: 'DeclarationId'};
+
+export function makeDeclarationId(id: number): DeclarationId {
+  CompilerError.invariant(id >= 0 && Number.isInteger(id), {
+    reason: 'Expected declaration id to be a non-negative integer',
+    description: null,
+    loc: null,
+    suggestions: null,
+  });
+  return id as DeclarationId;
+}
+
 /*
  * Simulated opaque type for InstructionId to prevent using normal numbers as ids
  * accidentally.

compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts

@@ -25,6 +25,7 @@ import {
   Terminal,
   VariableBinding,
   makeBlockId,
+  makeDeclarationId,
   makeIdentifierName,
   makeInstructionId,
   makeTemporaryIdentifier,
@@ -320,6 +321,7 @@ export default class HIRBuilder {
         const id = this.nextIdentifierId;
         const identifier: Identifier = {
           id,
+          declarationId: makeDeclarationId(id),
           name: makeIdentifierName(name),
           mutableRange: {
             start: makeInstructionId(0),
@@ -897,3 +899,16 @@ export function createTemporaryPlace(
     loc: GeneratedSource,
   };
 }
+
+/**
+ * Clones an existing Place, returning a new temporary Place that shares the
+ * same metadata properties as the original place (effect, reactive flag, type)
+ * but has a new, temporary Identifier.
+ */
+export function clonePlaceToTemporary(env: Environment, place: Place): Place {
+  const temp = createTemporaryPlace(env, place.loc);
+  temp.effect = place.effect;
+  temp.identifier.type = place.identifier.type;
+  temp.reactive = place.reactive;
+  return temp;
+}

compiler/packages/babel-plugin-react-compiler/src/Inference/AnalyseFunctions.ts

@@ -20,7 +20,7 @@ import {
 } from '../HIR';
 import {deadCodeElimination} from '../Optimization';
 import {inferReactiveScopeVariables} from '../ReactiveScopes';
-import {leaveSSA} from '../SSA';
+import {rewriteInstructionKindsBasedOnReassignment} from '../SSA';
 import {logHIRFunction} from '../Utils/logger';
 import {inferMutableContextVariables} from './InferMutableContextVariables';
 import {inferMutableRanges} from './InferMutableRanges';
@@ -108,7 +108,7 @@ function lower(func: HIRFunction): void {
   inferReferenceEffects(func, {isFunctionExpression: true});
   deadCodeElimination(func);
   inferMutableRanges(func);
-  leaveSSA(func);
+  rewriteInstructionKindsBasedOnReassignment(func);
   inferReactiveScopeVariables(func);
   inferMutableContextVariables(func);
   logHIRFunction('AnalyseFunction (inner)', func);