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bootstrap: fixup Error.stackTraceLimit for user-land snapshot
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It's difficult for V8 to handle Error.stackTraceLimit in the snapshot,
so delete it from the Error constructor if it's present before
snapshot serialization, and re-install it after deserialization.
In addition try not to touch it from our internals during snapshot
building in the first place by updating
isErrorStackTraceLimitWritable().

PR-URL: #44203
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
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joyeecheung authored Aug 18, 2022
1 parent 937520a commit 4f1a9fc
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Showing 6 changed files with 46 additions and 16 deletions.
6 changes: 6 additions & 0 deletions lib/internal/errors.js
Original file line number Diff line number Diff line change
Expand Up @@ -191,6 +191,12 @@ function lazyBuffer() {
}

function isErrorStackTraceLimitWritable() {
// Do no touch Error.stackTraceLimit as V8 would attempt to install
// it again during deserialization.
if (require('v8').startupSnapshot.isBuildingSnapshot()) {
return false;
}

const desc = ObjectGetOwnPropertyDescriptor(Error, 'stackTraceLimit');
if (desc === undefined) {
return ObjectIsExtensible(Error);
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34 changes: 32 additions & 2 deletions lib/internal/main/mksnapshot.js
Original file line number Diff line number Diff line change
Expand Up @@ -2,8 +2,11 @@

const {
Error,
ObjectDefineProperty,
ObjectGetOwnPropertyDescriptor,
ObjectSetPrototypeOf,
SafeArrayIterator,
SafeSet,
SafeArrayIterator
} = primordials;

const binding = internalBinding('mksnapshot');
Expand Down Expand Up @@ -125,7 +128,21 @@ function main() {
const source = readFileSync(file, 'utf-8');
const serializeMainFunction = compileSerializeMain(filename, source);

require('internal/v8/startup_snapshot').initializeCallbacks();
const {
initializeCallbacks,
namespace: {
addSerializeCallback,
addDeserializeCallback,
},
} = require('internal/v8/startup_snapshot');
initializeCallbacks();

let stackTraceLimitDesc;
addDeserializeCallback(() => {
if (stackTraceLimitDesc !== undefined) {
ObjectDefineProperty(Error, 'stackTraceLimit', stackTraceLimitDesc);
}
});

if (getOptionValue('--inspect-brk')) {
internalBinding('inspector').callAndPauseOnStart(
Expand All @@ -134,6 +151,19 @@ function main() {
} else {
serializeMainFunction(requireForUserSnapshot, filename, dirname);
}

addSerializeCallback(() => {
stackTraceLimitDesc = ObjectGetOwnPropertyDescriptor(Error, 'stackTraceLimit');

if (stackTraceLimitDesc !== undefined) {
// We want to use null-prototype objects to not rely on globally mutable
// %Object.prototype%.
ObjectSetPrototypeOf(stackTraceLimitDesc, null);
process._rawDebug('Deleting Error.stackTraceLimit from the snapshot. ' +
'It will be re-installed after deserialization');
delete Error.stackTraceLimit;
}
});
}

main();
2 changes: 0 additions & 2 deletions lib/internal/v8/startup_snapshot.js
Original file line number Diff line number Diff line change
Expand Up @@ -54,8 +54,6 @@ function runSerializeCallbacks() {
const { 0: callback, 1: data } = serializeCallbacks.shift();
callback(data);
}
// Remove the hooks from the snapshot.
require('v8').startupSnapshot = undefined;
}

function addSerializeCallback(callback, data) {
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6 changes: 6 additions & 0 deletions test/parallel/test-snapshot-api.js
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,12 @@ const fixtures = require('../common/fixtures');
const path = require('path');
const fs = require('fs');

const v8 = require('v8');

// By default it should be false. We'll test that it's true in snapshot
// building mode in the fixture.
assert(!v8.startupSnapshot.isBuildingSnapshot());

tmpdir.refresh();
const blobPath = path.join(tmpdir.path, 'snapshot.blob');
const entry = fixtures.path('snapshot', 'v8-startup-snapshot-api.js');
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7 changes: 1 addition & 6 deletions test/parallel/test-snapshot-typescript.js
Original file line number Diff line number Diff line change
Expand Up @@ -2,12 +2,7 @@

// This tests the TypeScript compiler in the snapshot.

const common = require('../common');

if (process.features.debug) {
common.skip('V8 snapshot does not work with mutated globals yet: ' +
'https://bugs.chromium.org/p/v8/issues/detail?id=12772');
}
require('../common');

const assert = require('assert');
const { spawnSync } = require('child_process');
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7 changes: 1 addition & 6 deletions test/parallel/test-snapshot-warning.js
Original file line number Diff line number Diff line change
Expand Up @@ -4,12 +4,7 @@
// during snapshot serialization and installed again during
// deserialization.

const common = require('../common');

if (process.features.debug) {
common.skip('V8 snapshot does not work with mutated globals yet: ' +
'https://bugs.chromium.org/p/v8/issues/detail?id=12772');
}
require('../common');

const assert = require('assert');
const { spawnSync } = require('child_process');
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