[compiler] Add fallthrough to branch terminal
Branch terminals didn't have a fallthrough because they correspond to an outer terminal (optional, logical, etc) that has the "real" fallthrough. But understanding how branch terminals correspond to these outer terminals requires knowing the branch fallthrough. For example, `foo?.bar?.baz` creates terminals along the lines of: ``` bb0: optional fallthrough=bb4 bb1: optional fallthrough=bb3 bb2: ... branch ... (fallthrough=bb3) ... bb3: ... branch ... (fallthrough=bb4) ... bb4: ... ``` Without a fallthrough on `branch` terminals, it's unclear that the optional from bb0 has its branch node in bb3. With the fallthroughs, we can see look for a branch with the same fallthrough as the outer optional terminal to match them up. ghstack-source-id: d48c6232899864716eef71798a278b487d30eafc Pull Request resolved: https://github.com/facebook/react/pull/30814
Joe Savona committed
Aug 28, 2024 at 10:52 UTC
925c20a20674254391b7752aa216ec417c8f52a3
6 files changed
+77
-11
compiler/packages/babel-plugin-react-compiler/src/HIR/BuildHIR.ts
+10
-4
@@ -607,6 +607,7 @@ function lowerStatement(
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),
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consequent: bodyBlock,
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alternate: continuationBlock.id,
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+ fallthrough: continuationBlock.id,
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id: makeInstructionId(0),
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loc: stmt.node.loc ?? GeneratedSource,
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},
@@ -656,16 +657,13 @@ function lowerStatement(
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},
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conditionalBlock,
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);
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- /*
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- * The conditional block is empty and exists solely as conditional for
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- * (re)entering or exiting the loop
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- */
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const test = lowerExpressionToTemporary(builder, stmt.get('test'));
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const terminal: BranchTerminal = {
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kind: 'branch',
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test,
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consequent: loopBlock,
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alternate: continuationBlock.id,
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+ fallthrough: conditionalBlock.id,
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id: makeInstructionId(0),
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loc: stmt.node.loc ?? GeneratedSource,
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};
@@ -975,6 +973,7 @@ function lowerStatement(
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test,
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consequent: loopBlock,
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alternate: continuationBlock.id,
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+ fallthrough: conditionalBlock.id,
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id: makeInstructionId(0),
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loc,
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};
@@ -1118,6 +1117,7 @@ function lowerStatement(
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consequent: loopBlock,
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alternate: continuationBlock.id,
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loc: stmt.node.loc ?? GeneratedSource,
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+ fallthrough: continuationBlock.id,
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},
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continuationBlock,
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);
@@ -1203,6 +1203,7 @@ function lowerStatement(
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test,
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consequent: loopBlock,
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alternate: continuationBlock.id,
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+ fallthrough: continuationBlock.id,
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loc: stmt.node.loc ?? GeneratedSource,
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},
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continuationBlock,
@@ -1800,6 +1801,7 @@ function lowerExpression(
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test: {...testPlace},
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consequent: consequentBlock,
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alternate: alternateBlock,
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+ fallthrough: continuationBlock.id,
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id: makeInstructionId(0),
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loc: exprLoc,
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},
@@ -1878,6 +1880,7 @@ function lowerExpression(
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test: {...leftPlace},
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consequent,
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alternate,
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+ fallthrough: continuationBlock.id,
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id: makeInstructionId(0),
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loc: exprLoc,
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},
@@ -2611,6 +2614,7 @@ function lowerOptionalMemberExpression(
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test: {...object},
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consequent: consequent.id,
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alternate,
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+ fallthrough: continuationBlock.id,
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id: makeInstructionId(0),
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loc,
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};
@@ -2750,6 +2754,7 @@ function lowerOptionalCallExpression(
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test: {...testPlace},
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consequent: consequent.id,
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alternate,
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+ fallthrough: continuationBlock.id,
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id: makeInstructionId(0),
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loc,
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};
@@ -4025,6 +4030,7 @@ function lowerAssignment(
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test: {...test},
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consequent,
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alternate,
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+ fallthrough: continuationBlock.id,
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id: makeInstructionId(0),
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loc,
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},
compiler/packages/babel-plugin-react-compiler/src/HIR/HIR.ts
+1
-1
@@ -491,7 +491,7 @@ export type BranchTerminal = {
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alternate: BlockId;
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id: InstructionId;
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loc: SourceLocation;
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- fallthrough?: never;
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+ fallthrough: BlockId;
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};
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export type SwitchTerminal = {
compiler/packages/babel-plugin-react-compiler/src/HIR/visitors.ts
+3
-1
@@ -660,11 +660,13 @@ export function mapTerminalSuccessors(
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case 'branch': {
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const consequent = fn(terminal.consequent);
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const alternate = fn(terminal.alternate);
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+ const fallthrough = fn(terminal.fallthrough);
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return {
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kind: 'branch',
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test: terminal.test,
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consequent,
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alternate,
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+ fallthrough,
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id: makeInstructionId(0),
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loc: terminal.loc,
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};
@@ -883,7 +885,6 @@ export function terminalHasFallthrough<
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>(terminal: T): terminal is U {
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switch (terminal.kind) {
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case 'maybe-throw':
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- case 'branch':
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case 'goto':
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case 'return':
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case 'throw':
@@ -892,6 +893,7 @@ export function terminalHasFallthrough<
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const _: undefined = terminal.fallthrough;
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return false;
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}
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+ case 'branch':
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case 'try':
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case 'do-while':
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case 'for-of':
compiler/packages/babel-plugin-react-compiler/src/Inference/DropManualMemoization.ts
+53
-2
@@ -42,6 +42,7 @@ type IdentifierSidemap = {
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react: Set<IdentifierId>;
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maybeDepsLists: Map<IdentifierId, Array<Place>>;
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maybeDeps: Map<IdentifierId, ManualMemoDependency>;
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+ optionals: Set<IdentifierId>;
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};
47
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/**
@@ -52,6 +53,7 @@ type IdentifierSidemap = {
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export function collectMaybeMemoDependencies(
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value: InstructionValue,
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maybeDeps: Map<IdentifierId, ManualMemoDependency>,
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+ optional: boolean,
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): ManualMemoDependency | null {
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switch (value.kind) {
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case 'LoadGlobal': {
@@ -69,7 +71,7 @@ export function collectMaybeMemoDependencies(
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return {
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root: object.root,
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// TODO: determine if the access is optional
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- path: [...object.path, {property: value.property, optional: false}],
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+ path: [...object.path, {property: value.property, optional}],
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};
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}
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break;
@@ -162,7 +164,11 @@ function collectTemporaries(
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break;
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}
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}
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- const maybeDep = collectMaybeMemoDependencies(value, sidemap.maybeDeps);
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+ const maybeDep = collectMaybeMemoDependencies(
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+ value,
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+ sidemap.maybeDeps,
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+ sidemap.optionals.has(lvalue.identifier.id),
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+ );
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// We don't expect named lvalues during this pass (unlike ValidatePreservingManualMemo)
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if (maybeDep != null) {
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sidemap.maybeDeps.set(lvalue.identifier.id, maybeDep);
@@ -338,12 +344,14 @@ export function dropManualMemoization(func: HIRFunction): void {
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func.env.config.validatePreserveExistingMemoizationGuarantees ||
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func.env.config.validateNoSetStateInRender ||
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func.env.config.enablePreserveExistingMemoizationGuarantees;
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+ const optionals = findOptionalPlaces(func);
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const sidemap: IdentifierSidemap = {
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functions: new Map(),
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manualMemos: new Map(),
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react: new Set(),
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maybeDeps: new Map(),
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maybeDepsLists: new Map(),
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+ optionals,
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};
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let nextManualMemoId = 0;
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@@ -476,3 +484,46 @@ export function dropManualMemoization(func: HIRFunction): void {
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}
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}
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}
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+
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+function findOptionalPlaces(fn: HIRFunction): Set<IdentifierId> {
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+ const optionals = new Set<IdentifierId>();
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+ for (const [, block] of fn.body.blocks) {
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+ if (block.terminal.kind === 'optional') {
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+ const optionalTerminal = block.terminal;
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+ let testBlock = fn.body.blocks.get(block.terminal.test)!;
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+ loop: while (true) {
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+ const terminal = testBlock.terminal;
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+ switch (terminal.kind) {
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+ case 'branch': {
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+ if (terminal.fallthrough === optionalTerminal.fallthrough) {
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+ // found it
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+ const consequent = fn.body.blocks.get(terminal.consequent)!;
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+ const last = consequent.instructions.at(-1);
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+ if (last !== undefined && last.value.kind === 'StoreLocal') {
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+ optionals.add(last.value.value.identifier.id);
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+ }
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+ break loop;
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+ } else {
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+ testBlock = fn.body.blocks.get(terminal.fallthrough)!;
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+ }
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+ break;
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+ }
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+ case 'optional':
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+ case 'logical':
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+ case 'sequence':
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+ case 'ternary': {
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+ testBlock = fn.body.blocks.get(terminal.fallthrough)!;
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+ break;
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+ }
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+ default: {
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+ CompilerError.invariant(false, {
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+ reason: `Unexpected terminal in optional`,
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+ loc: terminal.loc,
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+ });
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+ }
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+ }
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+ }
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+ }
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+ }
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+ return optionals;
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+}
compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/AlignReactiveScopesToBlockScopesHIR.ts
+1
-1
@@ -140,7 +140,7 @@ export function alignReactiveScopesToBlockScopesHIR(fn: HIRFunction): void {
140
}
141
142
const fallthrough = terminalFallthrough(terminal);
143
- if (fallthrough !== null) {
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+ if (fallthrough !== null && terminal.kind !== 'branch') {
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/*
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* Any currently active scopes that overlaps the block-fallthrough range
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* need their range extended to at least the first instruction of the
compiler/packages/babel-plugin-react-compiler/src/Validation/ValidatePreservedManualMemoization.ts
+9
-2
@@ -167,7 +167,10 @@ function compareDeps(
167
168
let isSubpath = true;
169
for (let i = 0; i < Math.min(inferred.path.length, source.path.length); i++) {
170
- if (inferred.path[i].property !== source.path[i].property) {
170
+ if (
171
+ inferred.path[i].property !== source.path[i].property ||
172
+ inferred.path[i].optional !== source.path[i].optional
173
+ ) {
174
isSubpath = false;
175
break;
176
}
@@ -339,7 +342,11 @@ class Visitor extends ReactiveFunctionVisitor<VisitorState> {
342
return null;
343
}
344
default: {
342
- const dep = collectMaybeMemoDependencies(value, this.temporaries);
345
+ const dep = collectMaybeMemoDependencies(
346
+ value,
347
+ this.temporaries,
348
+ false,
349
+ );
350
if (value.kind === 'StoreLocal' || value.kind === 'StoreContext') {
351
const storeTarget = value.lvalue.place;
352
state.manualMemoState?.decls.add(