From 22b97005eec83c0da431ccf799ff4104c583ac69 Mon Sep 17 00:00:00 2001
From: Mike Vitousek <mmvitousek@gmail.com>
Date: Thu, 1 Aug 2024 11:24:45 -0700
Subject: [PATCH] [compiler] Bail out and log calls that likely have side
 effects

[ghstack-poisoned]
---
 .../src/Entrypoint/Pipeline.ts                |   3 +
 .../ReactiveScopes/ValidateNoMutationCalls.ts | 127 ++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ValidateNoMutationCalls.ts

diff --git a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
index 6c31306274..192ad03671 100644
--- a/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
+++ b/compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
@@ -98,6 +98,7 @@ import {
 } from '../Validation';
 import {validateLocalsNotReassignedAfterRender} from '../Validation/ValidateLocalsNotReassignedAfterRender';
 import {outlineFunctions} from '../Optimization/OutlineFunctions';
+import {validateNoMutationCalls} from '../ReactiveScopes/ValidateNoMutationCalls';
 
 export type CompilerPipelineValue =
   | {kind: 'ast'; name: string; value: CodegenFunction}
@@ -484,6 +485,8 @@ function* runWithEnvironment(
     validatePreservedManualMemoization(reactiveFunction);
   }
 
+  validateNoMutationCalls(reactiveFunction);
+
   const ast = codegenFunction(reactiveFunction, {
     uniqueIdentifiers,
     fbtOperands,
diff --git a/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ValidateNoMutationCalls.ts b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ValidateNoMutationCalls.ts
new file mode 100644
index 0000000000..480057495a
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-compiler/src/ReactiveScopes/ValidateNoMutationCalls.ts
@@ -0,0 +1,127 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {CompilerError, ErrorSeverity} from '../CompilerError';
+import {Environment} from '../HIR';
+import {
+  Effect,
+  Identifier,
+  IdentifierId,
+  ReactiveFunction,
+  ReactiveInstruction,
+  getHookKind,
+  isSetStateType,
+} from '../HIR/HIR';
+import {
+  ReactiveFunctionVisitor,
+  eachReactiveValueOperand,
+  visitReactiveFunction,
+} from './visitors';
+
+const allowedNames = new Set(['invariant']);
+
+class Visitor extends ReactiveFunctionVisitor<CompilerError> {
+  #env: Environment;
+  #names: Map<IdentifierId, string> = new Map();
+
+  constructor(env: Environment) {
+    super();
+    this.#env = env;
+  }
+
+  getName(id: Identifier): string | undefined {
+    if (id.name?.kind === 'named') {
+      return id.name.value;
+    } else {
+      return this.#names.get(id.id);
+    }
+  }
+
+  setName(id: Identifier, name: string | undefined): void {
+    if (name != null) {
+      this.#names.set(id.id, name);
+    }
+  }
+
+  override visitInstruction(
+    instr: ReactiveInstruction,
+    state: CompilerError,
+  ): void {
+    if (instr.lvalue != null) {
+      switch (instr.value.kind) {
+        case 'LoadGlobal':
+          this.setName(instr.lvalue.identifier, instr.value.binding.name);
+          break;
+        case 'LoadLocal':
+        case 'LoadContext':
+          this.setName(
+            instr.lvalue.identifier,
+            this.getName(instr.value.place.identifier),
+          );
+          break;
+        case 'PropertyLoad': {
+          const name = this.getName(instr.value.object.identifier);
+          if (name != null) {
+            this.setName(
+              instr.lvalue.identifier,
+              name + '.' + instr.value.property,
+            );
+          }
+          break;
+        }
+        case 'ComputedLoad': {
+          const name = this.getName(instr.value.object.identifier);
+          if (name != null) {
+            this.setName(instr.lvalue.identifier, name + '[...]');
+          }
+          break;
+        }
+      }
+    }
+
+    if (
+      instr.value.kind === 'CallExpression' ||
+      instr.value.kind === 'MethodCall'
+    ) {
+      let isException = false;
+      let name = '(unknown)';
+      if (instr.value.kind === 'CallExpression') {
+        isException =
+          getHookKind(this.#env, instr.value.callee.identifier) != null ||
+          isSetStateType(instr.value.callee.identifier);
+        name = this.getName(instr.value.callee.identifier) ?? name;
+      } else {
+        isException =
+          getHookKind(this.#env, instr.value.property.identifier) != null ||
+          isSetStateType(instr.value.property.identifier);
+        name = this.getName(instr.value.property.identifier) ?? name;
+      }
+      if (instr.lvalue === null && !isException && allowedNames.has(name)) {
+        let allReads = true;
+        for (const operand of eachReactiveValueOperand(instr.value)) {
+          allReads &&= operand.effect === Effect.Read;
+        }
+        if (allReads) {
+          state.push({
+            reason: `Likely illegal mutation call \`${name}\``,
+            loc: instr.loc,
+            severity: ErrorSeverity.Todo,
+          });
+        }
+      }
+    }
+    super.visitInstruction(instr, state);
+  }
+}
+
+export function validateNoMutationCalls(fn: ReactiveFunction): void {
+  const error = new CompilerError();
+  visitReactiveFunction(fn, new Visitor(fn.env), error);
+  if (error.hasErrors()) {
+    throw error;
+  }
+}