validateNoSetStateInRenderImpl() — react Function Reference

Source Code

compiler/packages/babel-plugin-react-compiler/src/Validation/ValidateNoSetStateInRender.ts lines 53–187

function validateNoSetStateInRenderImpl(
  fn: HIRFunction,
  unconditionalSetStateFunctions: Set<IdentifierId>,
): Result<void, CompilerError> {
  const unconditionalBlocks = computeUnconditionalBlocks(fn);
  let activeManualMemoId: number | null = null;
  const errors = new CompilerError();
  for (const [, block] of fn.body.blocks) {
    for (const instr of block.instructions) {
      switch (instr.value.kind) {
        case 'LoadLocal': {
          if (
            unconditionalSetStateFunctions.has(instr.value.place.identifier.id)
          ) {
            unconditionalSetStateFunctions.add(instr.lvalue.identifier.id);
          }
          break;
        }
        case 'StoreLocal': {
          if (
            unconditionalSetStateFunctions.has(instr.value.value.identifier.id)
          ) {
            unconditionalSetStateFunctions.add(
              instr.value.lvalue.place.identifier.id,
            );
            unconditionalSetStateFunctions.add(instr.lvalue.identifier.id);
          }
          break;
        }
        case 'ObjectMethod':
        case 'FunctionExpression': {
          if (
            // faster-path to check if the function expression references a setState
            [...eachInstructionValueOperand(instr.value)].some(
              operand =>
                isSetStateType(operand.identifier) ||
                unconditionalSetStateFunctions.has(operand.identifier.id),
            ) &&
            // if yes, does it unconditonally call it?
            validateNoSetStateInRenderImpl(
              instr.value.loweredFunc.func,
              unconditionalSetStateFunctions,
            ).isErr()
          ) {
            // This function expression unconditionally calls a setState
            unconditionalSetStateFunctions.add(instr.lvalue.identifier.id);
          }
          break;
        }
        case 'StartMemoize': {
          CompilerError.invariant(activeManualMemoId === null, {
            reason: 'Unexpected nested StartMemoize instructions',
            loc: instr.value.loc,
          });
          activeManualMemoId = instr.value.manualMemoId;
          break;
        }
        case 'FinishMemoize': {
          CompilerError.invariant(
            activeManualMemoId === instr.value.manualMemoId,
            {
              reason:
                'Expected FinishMemoize to align with previous StartMemoize instruction',
              loc: instr.value.loc,
            },
          );
          activeManualMemoId = null;
          break;
        }
        case 'CallExpression': {
          const callee = instr.value.callee;
          if (
            isSetStateType(callee.identifier) ||
            unconditionalSetStateFunctions.has(callee.identifier.id)
          ) {
            if (activeManualMemoId !== null) {
              errors.pushDiagnostic(
                CompilerDiagnostic.create({
                  category: ErrorCategory.RenderSetState,
                  reason:
                    'Calling setState from useMemo may trigger an infinite loop',