如何在底层定位到导致崩溃的js？

[zjt123]

Affected version

main

No same issues found.

• Yes, I search all issues but not found.

Steps to Reproduce

2023-03-01 20:19:06.690 12121-12121/? A/DEBUG: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
2023-03-01 20:19:06.690 12121-12121/? A/DEBUG: Build fingerprint: 'Redmi/ares/ares:11/RP1A.200720.011/V12.5.3.0.RKJCNXM:user/release-keys'
2023-03-01 20:19:06.690 12121-12121/? A/DEBUG: Revision: '0'
2023-03-01 20:19:06.690 12121-12121/? A/DEBUG: ABI: 'arm64'
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: Timestamp: 2023-03-01 20:19:06+0800
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: pid: 12053, tid: 12084, name: 1.ui >>> com.example.webfsample.webf_sample <<<
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: uid: 10881
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x8
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: Cause: null pointer dereference
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x0 b40000734c99a300 x1 b400007340edc328 x2 ffffffffffffffff x3 0000000000000000
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x4 0000000000000003 x5 0000000000000000 x6 0000000000000001 x7 0000000000000000
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x8 0000000000000000 x9 0000000000000000 x10 000000734c159374 x11 0000000000000000
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x12 000000736afdd540 x13 000000736afdd670 x14 000000736afdd3d0 x15 0000000000000004
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x16 000000734c1e8380 x17 000000734c159340 x18 000000736a914000 x19 b40000734c99a300
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x20 b40000734c99a398 x21 0000000000000001 x22 000000736afdd7f0 x23 000000736afdd800
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x24 0000000000000001 x25 0000000000000001 x26 0000000000000000 x27 b4000073cd1c8d8e
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: x28 b4000073cd1c8d8e x29 000000736afdd750
2023-03-01 20:19:06.691 12121-12121/? A/DEBUG: lr 000000734c166084 sp 000000736afdd750 pc 000000734c15938c pst 0000000080001000
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: backtrace:
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #00 pc 000000000004c38c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (__JS_FreeValueRT+76) (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #1 pc 0000000000059080 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #2 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #3 pc 0000000000059018 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #4 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #5 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #6 pc 00000000000beedc /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #7 pc 0000000000045c20 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #8 pc 0000000000057744 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #9 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #10 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #11 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #12 pc 00000000000beedc /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #13 pc 0000000000045c20 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #14 pc 0000000000057744 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #15 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #16 pc 000000000005920c /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #17 pc 000000000008e484 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #18 pc 0000000000046870 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libquickjs.so (JS_ExecutePendingJob+76) (BuildId: 35b47a52a8e61f4f004d5ce83902cc1972e703c4)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #19 pc 000000000008f0c4 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libwebf.so (webf::binding::qjs::ExecutionContext::drainPendingPromiseJobs()+40) (BuildId: 100b8cae992b02b4816a547147d8c6c2747c9c85)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #20 pc 0000000000098c84 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libwebf.so (BuildId: 100b8cae992b02b4816a547147d8c6c2747c9c85)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #21 pc 0000000000098be0 /data/app/~~lTNpl8f_0lvQmmiLc7vrGg==/com.example.webfsample.webf_sample-hnVsbRGMfvsMooUMytmO2A==/lib/arm64/libwebf.so (BuildId: 100b8cae992b02b4816a547147d8c6c2747c9c85)
2023-03-01 20:19:06.736 12121-12121/? A/DEBUG: #22 pc 0000000000006db4 [anon:dart-codespace]

Code example

目前不知道哪块代码有问题。想问下在quickjs怎么知道执行哪个js导致的崩溃。我用的是kbc1文件。

Expected results

异常没有说明是哪块js导致的

Actual results

期望抛类似这种异常的时候，能打印出相关的js，或者指导下如何打印相关的js

[andycall]

Can you provide the JS code caused this crash?

[zjt123]

Can you provide the JS code caused this crash?

我整理下看看，在quickjs.c那可以加打印信息输出相关的js吗？如果可以请问具体怎么加?

[zjt123]

Can you provide the JS code caused this crash?
@andycall 类似这种的

async function createTask () {
return new Promise((resolve) => {
Promise.resolve().then(function () {
const buf = new Uint8Array(1000000)
resolve(buf)
})
})
}

run()

async function run () {
let fn = () => {}

let done = () => {
fn()
}

createTask().then(done)

const p = new Promise(() => {})

console.log('pre await')
await p
console.log('post done')
}

[andycall]

Need to use xcode or Clion to attach webf process and debug the crashed stacktraces.

https://www.jetbrains.com/help/clion/attaching-to-local-process.html

[andycall]

const buf = new Uint8Array(1000000)

It looks like the new Uint8Array(1000000) caused an overflow in other code's memory and crashed the system.

[zjt123]

想问下，执行js选择quickjs是基于什么考虑的？为什么不用v8，看微信小程序用的是v8引擎执行的

[andycall]

Miniapps run based on WebView, which means that the application code runs on V8 in Android and JavaScriptCore in iOS. However, both JavaScriptCore and V8 are large, and JIT mode cannot be enabled on iOS devices.

[andycall]

Therefore, we have opted to use QuickJS, which is lighter than V8 and is only 40% slower than V8 in JIT-less mode.

[zjt123]

Miniapps run based on WebView, which means that the application code runs on V8 in Android and JavaScriptCore in iOS. However, both JavaScriptCore and V8 are large, and JIT mode cannot be enabled on iOS devices.

小程序的渲染引擎如果是skyline的话 内部是基于flutter渲染的，计算样式那些是通过v8 来做的。ios的话不太清楚。
可以看看这个文档，https://developers.weixin.qq.com/miniprogram/dev/framework/runtime/skyline/introduction.html

[zjt123]

Therefore, we have opted to use QuickJS, which is lighter than V8 and is only 40% slower than V8 in JIT-less mode.

之前做过demo，感觉列表的流畅度好像小程序skyline模式下比kraken的好一些。估计是计算样式的用了v8，这块不太确定

[andycall]

JS threads on Kraken/WebF are running on the Flutter UI thread, so executing JS code can block the rendering phase. This problem can be solved by adding multiple thread mode.

You can find more information on this topic in the following link:

openwebf/rfc#4"