[λ] Remove broken support for identifiers defined after use
This also adds some book keeping to throw if ever define identifiers after use to make sure we don't generate incorrect code.
Sathya Gunasekaran committed
Feb 7, 2023 at 18:25 UTC
24b28ae25748098f025892cdd23c776203f73367
4 files changed
+39
-46
compiler/forget/src/SSA/EnterSSA.ts
+13
-8
@@ -1,4 +1,5 @@
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import invariant from "invariant";
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+import { CompilerError } from "../CompilerError";
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import {
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BasicBlock,
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BlockId,
@@ -18,6 +19,7 @@ import {
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mapInstructionOperands,
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mapTerminalOperands,
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} from "../HIR/visitors";
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+import { todoInvariant } from "../Utils/todo";
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type IncompletePhi = {
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oldId: Identifier;
@@ -35,6 +37,7 @@ class SSABuilder {
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unsealedPreds: Map<BasicBlock, number> = new Map();
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#blocks: Map<BlockId, BasicBlock>;
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#env: Environment;
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+ #unknown: Set<Identifier> = new Set();
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constructor(env: Environment, blocks: Map<BlockId, BasicBlock>) {
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this.#blocks = blocks;
@@ -68,6 +71,15 @@ class SSABuilder {
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definePlace(oldPlace: Place): Place {
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const oldId = oldPlace.identifier;
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+ if (this.#unknown.has(oldId)) {
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+ CompilerError.invariant(
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+ `identifier ${printIdentifier(
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+ oldId
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+ )} should have been defined before use`,
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+ oldPlace.loc
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+ );
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+ }
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+
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const newId = this.makeId(oldId);
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this.state().defs.set(oldId, newId);
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return {
@@ -98,6 +110,7 @@ class SSABuilder {
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// console.log(
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// `Unable to find "${printIdentifier(oldId)}", assuming it's a global`
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// );
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+ this.#unknown.add(oldId);
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return oldId;
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}
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@@ -224,12 +237,4 @@ export default function enterSSA(func: HIRFunction) {
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}
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}
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}
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-
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- for (const [_, block] of func.body.blocks) {
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- for (const instr of block.instructions) {
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- if (instr.value.kind === "FunctionExpression") {
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- mapInstructionOperands(instr, (place) => builder.getPlace(place));
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- }
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- }
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- }
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}
compiler/forget/src/__tests__/fixtures/hir/error.mutate-captured-arg-separately.expect.md
new
+25
@@ -0,0 +1,25 @@
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+
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+## Input
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+
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+```javascript
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+// Let's not support identifiers defined after use for now.
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+function component(a) {
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+ let y = function () {
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+ m(x);
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+ };
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+
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+ let x = { a };
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+ m(x);
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+ return y;
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+}
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+
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+```
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+
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+
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+## Error
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+
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+```
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+[ReactForget] Invariant: identifier x$2 should have been defined before use (7:7)
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+```
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+
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+
\ No newline at end of file
compiler/forget/src/__tests__/fixtures/hir/error.mutate-captured-arg-separately.js
renamed
+1
@@ -1,3 +1,4 @@
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+// Let's not support identifiers defined after use for now.
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function component(a) {
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let y = function () {
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m(x);
compiler/forget/src/__tests__/fixtures/hir/mutate-captured-arg-separately.expect.md
deleted
-38
@@ -1,38 +0,0 @@
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-
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-## Input
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-
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-```javascript
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-function component(a) {
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- let y = function () {
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- m(x);
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- };
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-
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- let x = { a };
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- m(x);
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- return y;
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-}
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-
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-```
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-
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-## Code
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-
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-```javascript
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-function component(a) {
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- const $ = React.unstable_useMemoCache();
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- let y;
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- if ($[0] === Symbol.for("react.memo_cache_sentinel")) {
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- y = function () {
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- m(x);
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- };
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- $[0] = y;
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- } else {
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- y = $[0];
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- }
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-
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- const x = { a: a };
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- m(x);
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- return y;
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-}
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-
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-```
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-
\ No newline at end of file