revert_heap_add_checks_position_info.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Keeley Hammond <khammond@slack-corp.com>
Date: Tue, 7 May 2024 15:50:31 -0700
Subject: Revert "[heap] Add checks for ensuring position info slow path is not
 used in heap snapshot"

This reverts commit ca51566b53be5507ff184704767c7a9220a68733.

diff --git a/src/common/assert-scope.cc b/src/common/assert-scope.cc
index 0ea1a04fed062658fa36c239d323e70d0358b57d..1b996b14e490a6fe1b3636f9147728f07cca141f 100644
--- a/src/common/assert-scope.cc
+++ b/src/common/assert-scope.cc
@@ -108,8 +108,6 @@ template class PerThreadAssertScope<CODE_DEPENDENCY_CHANGE_ASSERT, true>;
 template class PerThreadAssertScope<CODE_ALLOCATION_ASSERT, false>;
 template class PerThreadAssertScope<CODE_ALLOCATION_ASSERT, true>;
 template class PerThreadAssertScope<GC_MOLE, false>;
-template class PerThreadAssertScope<POSITION_INFO_SLOW_ASSERT, false>;
-template class PerThreadAssertScope<POSITION_INFO_SLOW_ASSERT, true>;
 
 }  // namespace internal
 }  // namespace v8
diff --git a/src/common/assert-scope.h b/src/common/assert-scope.h
index 27fbc04bc880f2ea68dc7a126b8091a3b5ab4025..42d9649c5250c06a4d39ba0306cbdea0b0e5a8c3 100644
--- a/src/common/assert-scope.h
+++ b/src/common/assert-scope.h
@@ -30,7 +30,6 @@ enum PerThreadAssertType {
   CODE_ALLOCATION_ASSERT,
   // Dummy type for disabling GC mole.
   GC_MOLE,
-  POSITION_INFO_SLOW_ASSERT,
 };
 
 template <PerThreadAssertType kType, bool kAllow>
@@ -258,14 +257,6 @@ using DisallowGarbageCollection =
 // work.
 using DisableGCMole = PerThreadAssertScopeDebugOnly<GC_MOLE, false>;
 
-// Scope to ensure slow path for obtaining position info is not called
-using DisallowPositionInfoSlow =
-    PerThreadAssertScopeDebugOnly<POSITION_INFO_SLOW_ASSERT, false>;
-
-// Scope to add an exception to disallowing position info slow path
-using AllowPositionInfoSlow =
-    PerThreadAssertScopeDebugOnly<POSITION_INFO_SLOW_ASSERT, true>;
-
 // The DISALLOW_GARBAGE_COLLECTION macro can be used to define a
 // DisallowGarbageCollection field in classes that isn't present in release
 // builds.
@@ -337,8 +328,6 @@ extern template class PerThreadAssertScope<CODE_DEPENDENCY_CHANGE_ASSERT, true>;
 extern template class PerThreadAssertScope<CODE_ALLOCATION_ASSERT, false>;
 extern template class PerThreadAssertScope<CODE_ALLOCATION_ASSERT, true>;
 extern template class PerThreadAssertScope<GC_MOLE, false>;
-extern template class PerThreadAssertScope<POSITION_INFO_SLOW_ASSERT, false>;
-extern template class PerThreadAssertScope<POSITION_INFO_SLOW_ASSERT, true>;
 
 }  // namespace internal
 }  // namespace v8
diff --git a/src/objects/objects.cc b/src/objects/objects.cc
index 15e428ad2a870cae1c9efcb7fa2426b88d25b3c7..0794d0346eedd69489f70725d26dc206411d6c8b 100644
--- a/src/objects/objects.cc
+++ b/src/objects/objects.cc
@@ -4357,7 +4357,6 @@ namespace {
 template <typename Char>
 bool GetPositionInfoSlowImpl(base::Vector<Char> source, int position,
                              Script::PositionInfo* info) {
-  DCHECK(DisallowPositionInfoSlow::IsAllowed());
   if (position < 0) {
     position = 0;
   }
diff --git a/src/profiler/heap-snapshot-generator.cc b/src/profiler/heap-snapshot-generator.cc
index 4f3494d4677312ebc6b7e86ef64e08b434e9f77b..ceec8ee0ccf178a5671f760835ac0aad8848b0ea 100644
--- a/src/profiler/heap-snapshot-generator.cc
+++ b/src/profiler/heap-snapshot-generator.cc
@@ -2994,6 +2994,7 @@ bool HeapSnapshotGenerator::GenerateSnapshot() {
   IsolateSafepointScope scope(heap_);
 
   Isolate* isolate = heap_->isolate();
+  v8_heap_explorer_.PopulateLineEnds();
   auto temporary_global_object_tags =
       v8_heap_explorer_.CollectTemporaryGlobalObjectsTags();
 
@@ -3005,7 +3006,6 @@ bool HeapSnapshotGenerator::GenerateSnapshot() {
   // DisallowGarbageCollection scope as the HeapObjectIterator used during
   // snapshot creation enters a safepoint as well. However, in practice we
   // already enter a safepoint above so that should never trigger a GC.
-  DisallowPositionInfoSlow no_position_info_slow;
 
   NullContextForSnapshotScope null_context_scope(isolate);
 
@@ -3016,7 +3016,6 @@ bool HeapSnapshotGenerator::GenerateSnapshot() {
 
   snapshot_->AddSyntheticRootEntries();
 
-  v8_heap_explorer_.PopulateLineEnds();
   if (!FillReferences()) return false;
 
   snapshot_->FillChildren();
@@ -3087,7 +3086,6 @@ bool HeapSnapshotGenerator::FillReferences() {
 const int HeapSnapshotJSONSerializer::kNodeFieldsCount = 7;
 
 void HeapSnapshotJSONSerializer::Serialize(v8::OutputStream* stream) {
-  DisallowHeapAllocation no_heap_allocation;
   v8::base::ElapsedTimer timer;
   timer.Start();
   DCHECK_NULL(writer_);