Unwanted code elimination when using a component in `getStaticProps`

What version of Next.js are you using?

12.0.4

What version of Node.js are you using?

v14.15.0

What browser are you using?

Chrome

What operating system are you using?

macOS

How are you deploying your application?

Describe the Bug

I’m encountering a runtime error, since Next.js seems to be eliminating a component from a function where it is needed.

It seems to occur when a component is used both on the page and in getStaticProps.

function PageLayout({children}) {
  return <div style={{background: 'gray'}}>{children}</div>;
}

export default function Index() {
  // ReferenceError: PageLayout is not defined
  return <PageLayout>Index</PageLayout>
}

export function getStaticProps() {
  // When this line is removed, the page no longer breaks
  console.log(PageLayout.name);
  
  return {
    props: {}
  };
}

Note that the example is intended to be minimal, in my application the usage of the layout component in getStaticProps serves a meaningful purpose. In Next.js 11 the above code works flawlessly.

Expected Behavior

No runtime error

To Reproduce

1. Clone https://github.com/amannn/next-compile-bug
2. Follow the reproduction steps in the README

[pveyes]

I’m not confident with my rust skill, so I just created a draft PR as a proof of concept. The test is very basic (only covers JSXElement AST)

[pveyes]

Upon investigating further, this is a regression in the swc-based compiler. If you add babel.config.js to disable SWC, the code works even in latest next.js version (12.0.7)

Here’s a repro with swc disabled https://github.com/pveyes/next-swc-ssg-code-elimination