removeDeadDoWhileStatements() — react Function Reference

Source Code

compiler/packages/babel-plugin-react-compiler/src/HIR/HIRBuilder.ts lines 681–705

export function removeDeadDoWhileStatements(func: HIR): void {
  const visited: Set<BlockId> = new Set();
  for (const [_, block] of func.blocks) {
    visited.add(block.id);
  }

  /*
   * If the test condition of a DoWhile is unreachable, the terminal is effectively deadcode and we
   * can just inline the loop body. We replace the terminal with a goto to the loop block and
   * MergeConsecutiveBlocks figures out how to merge as appropriate.
   */
  for (const [_, block] of func.blocks) {
    if (block.terminal.kind === 'do-while') {
      if (!visited.has(block.terminal.test)) {
        block.terminal = {
          kind: 'goto',
          block: block.terminal.loop,
          variant: GotoVariant.Break,
          id: block.terminal.id,
          loc: block.terminal.loc,
        };
      }
    }
  }
}