RuntimeError: out of bounds memory access when using plugin on a large nested AST

[jzhan-canva]

Describe the bug

When a large nested file being loaded to swc with plugin, the plugin_runner will crash.
When same file being loaded to swc without plugin, no error is thrown.

Input code

export result = {
      output: outputBuilder()
        .addConfig(1)
        .addConfig(2)
        .addConfig(3)
        .addConfig(4)
        .addConfig(5)
        ....
        .addConfig(1500)
        .build(),
    }

Config

{
  "$schema": "https://swc.rs/schema.json",
  "jsc": {
    "experimental": {
      "plugins": [["@swc/plugin-noop", {}]]
    }
  }
}

Playground link (or link to the minimal reproduction)

https://github.com/jzhan-canva/swc-plugin-bug

SWC Info output

No response

Expected behavior

Same a running swc without plugin, that it should run

Actual behavior

Crash

Version

"@swc/cli": "^0.5.2", "@swc/core": "^1.9.3", "@swc/plugin-noop": "^5.0.0"

Additional context

No response

[jzhan-canva]

upon further investigation, it seems the bug only happen when AST tree is too deep, not the breadth
for example in the reproducible example, I have a builder with 1000+ depth member expression, and it trigger the issue
but if I reduce depth, I can duplicate the builder code many times without any issue

[kdy1]

So my guess is that it's about stack overflow rather than a memory usage. Stack sizes are limited, and I think rkyv is failing due to the nested call level being too deep.

[kwonoj]

I believe we have same issues in the host as well? if depth is deep enough, either host or plugin won't able to traverse down with visitor.

[jzhan-canva]

Right now the host and guest have different limit. I think it makes sense to have same limit for host and guest

[jzhan-canva]

Current host limit is bigger, so the identical file can run without plugin but not with plugin

[kwonoj]

I think it makes sense to have same limit for host and guest

I'm not sure if this is configurable on our end, ideally hope to do so.

[kdy1]

No, I mean it's failing with rkyv. The example plugin does not visit the program.

[jzhan-canva]

I can find this similar issue #1627 and it was resolved by #8867
maybe this maybe_grow_default is needed in rkyv as well?

[jzhan-canva]

I'm able to reproduce this issue in a unit test

[bradzacher]

is there a way that we can workaround this?
for example -- could we pull in SWC into a rust crate to include the plugin natively, rather than as WASM? is there a supported existing pathway for creating a "SWC with custom plugins" build?

[kdy1]

@bradzacher Yes, and I'm actively maintaining it, although it's not in the current repository and there's no clean API for it as it's not designed for a general use.
next-swc is @swc/core with some css-in-js plugins.

The base code of a custom SWC binary with transform() lives at https://github.com/swc-project/swc/blob/5a584078645b8d62df5591a1938be3f0d669c544/bindings/binding_core_node/src/transform.rs and next-swc defines a function named custom_before_pass, and creates a sequence of all custom passes. https://github.com/vercel/next.js/blob/5f455e1a9533f8a29076a30edbaf87a0cccdcdc0/crates/next-custom-transforms/src/chain_transforms.rs#L121-L329

After declaring your own chain of the custom passes, you can pass it to process_js_with_custom_pass like https://github.com/vercel/next.js/blob/5f455e1a9533f8a29076a30edbaf87a0cccdcdc0/crates/napi/src/transform.rs#L138-L147

[kdy1]

@bradzacher Please tell me if you need more guidance