55 lines
2.9 KiB
Diff
55 lines
2.9 KiB
Diff
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Calvin Watford <cwatford@slack-corp.com>
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Date: Wed, 17 Jul 2024 12:52:10 -0600
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Subject: fix: disable scope reuse & associated dchecks
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This change was introduced in https://crrev.com/c/5630974 which reuses
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scope info objects across allocations. Unfortunately, this change seems
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to be not yet fully cooked and causes crashes with normal usage of V8.
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In particular, Node.js call's V8's `v8::ScriptCompiler::CompileFunction`
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method. This ends up wrapping the source code in a function, which this
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code is not yet prepared to handle. The generated function wrapper
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(created by V8) has no source position, so it reports being at the start
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of the source, which may overlap with other scopes that are in the
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original source. This new feature adds a "UniqueIdInScript" concept that
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is derived from the source position of a scope, along with the invariant
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that inner scopes have a higher ID than outer scopes, which does not
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hold for the above situation.
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This patch is not intended to remain indefinitely. Once the upstream
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feature stabilizes, we can remove this patch. Unfortunately, there is no
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public tracking bug for this feature nor the crashes its been causing,
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so we'll have to keep an eye on this for the time being.
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diff --git a/src/ast/scopes.cc b/src/ast/scopes.cc
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index 530a249adde65a47c8e0babf5723b52b8d2a6b1a..fca49d135ad2f23307654e1b0c36e846ca5a6ec6 100644
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--- a/src/ast/scopes.cc
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+++ b/src/ast/scopes.cc
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@@ -2717,9 +2717,9 @@ void Scope::AllocateScopeInfosRecursively(
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// Allocate ScopeInfos for inner scopes.
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for (Scope* scope = inner_scope_; scope != nullptr; scope = scope->sibling_) {
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- DCHECK_GT(scope->UniqueIdInScript(), UniqueIdInScript());
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- DCHECK_IMPLIES(scope->sibling_, scope->sibling_->UniqueIdInScript() !=
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- scope->UniqueIdInScript());
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+ // DCHECK_GT(scope->UniqueIdInScript(), UniqueIdInScript());
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+ // DCHECK_IMPLIES(scope->sibling_, scope->sibling_->UniqueIdInScript() !=
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+ // scope->UniqueIdInScript());
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if (!scope->is_function_scope() ||
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scope->AsDeclarationScope()->ShouldEagerCompile()) {
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scope->AllocateScopeInfosRecursively(isolate, next_outer_scope,
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diff --git a/src/flags/flag-definitions.h b/src/flags/flag-definitions.h
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index 657ac0ebd872d6be4e2fa962a17259dd96f047b7..8e413913048d20b57bdd40807bfa4365e9d9ec77 100644
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--- a/src/flags/flag-definitions.h
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+++ b/src/flags/flag-definitions.h
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@@ -993,6 +993,8 @@ DEFINE_BOOL(trace_track_allocation_sites, false,
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DEFINE_BOOL(trace_migration, false, "trace object migration")
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DEFINE_BOOL(trace_generalization, false, "trace map generalization")
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+// ELECTRON: The following flag should remain false by default until we can
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+// remove `fix_disable_scope_reuse_associated_dchecks.patch`
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DEFINE_BOOL(reuse_scope_infos, false,
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"reuse scope infos from previous compiles")
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