From 17de77bbc1f300573ab13cad2e1a210097539ca4 Mon Sep 17 00:00:00 2001
From: Ted Campbell <tcampbell@mozilla.com>
Date: Wed, 7 Oct 2020 22:20:15 +0000
Subject: [PATCH] Bug 1669847 - Make ScopeStencil instantiation const. r=arai

Depends on D92827

Differential Revision: https://phabricator.services.mozilla.com/D92828
---
 js/src/frontend/Stencil.cpp |  7 ++++---
 js/src/frontend/Stencil.h   | 10 +++++-----
 js/src/vm/Scope.cpp         | 24 ++++++++++++------------
 3 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/js/src/frontend/Stencil.cpp b/js/src/frontend/Stencil.cpp
index b4bfab83d8f6..7bd354f6eeeb 100644
--- a/js/src/frontend/Stencil.cpp
+++ b/js/src/frontend/Stencil.cpp
@@ -37,7 +37,8 @@
 using namespace js;
 using namespace js::frontend;
 
-AbstractScopePtr ScopeStencil::enclosing(CompilationInfo& compilationInfo) {
+AbstractScopePtr ScopeStencil::enclosing(
+    CompilationInfo& compilationInfo) const {
   if (enclosing_) {
     return AbstractScopePtr(compilationInfo, *enclosing_);
   }
@@ -47,7 +48,7 @@ AbstractScopePtr ScopeStencil::enclosing(CompilationInfo& compilationInfo) {
 
 Scope* ScopeStencil::createScope(JSContext* cx,
                                  CompilationInfo& compilationInfo,
-                                 CompilationGCOutput& gcOutput) {
+                                 CompilationGCOutput& gcOutput) const {
   Scope* scope = nullptr;
   switch (kind()) {
     case ScopeKind::Function: {
@@ -310,7 +311,7 @@ static bool InstantiateScopes(JSContext* cx, CompilationInfo& compilationInfo,
     return false;
   }
 
-  for (auto& scd : compilationInfo.stencil.scopeData) {
+  for (const ScopeStencil& scd : compilationInfo.stencil.scopeData) {
     Scope* scope = scd.createScope(cx, compilationInfo, gcOutput);
     if (!scope) {
       return false;
diff --git a/js/src/frontend/Stencil.h b/js/src/frontend/Stencil.h
index 5e628592e1d4..3939425033de 100644
--- a/js/src/frontend/Stencil.h
+++ b/js/src/frontend/Stencil.h
@@ -244,7 +244,7 @@ class ScopeStencil {
                                  mozilla::Maybe<ScopeIndex> enclosing,
                                  ScopeIndex* index);
 
-  AbstractScopePtr enclosing(CompilationInfo& compilationInfo);
+  AbstractScopePtr enclosing(CompilationInfo& compilationInfo) const;
 
   ScopeKind kind() const { return kind_; }
 
@@ -258,7 +258,7 @@ class ScopeStencil {
   bool isArrow() const { return isArrow_; }
 
   Scope* createScope(JSContext* cx, CompilationInfo& compilationInfo,
-                     CompilationGCOutput& gcOutput);
+                     CompilationGCOutput& gcOutput) const;
 
   uint32_t nextFrameSlot() const;
 
@@ -284,7 +284,7 @@ class ScopeStencil {
   template <typename SpecificScopeType>
   UniquePtr<typename SpecificScopeType::Data> createSpecificScopeData(
       JSContext* cx, CompilationInfo& compilationInfo,
-      CompilationGCOutput& gcOutput);
+      CompilationGCOutput& gcOutput) const;
 
   template <typename SpecificScopeType>
   uint32_t nextFrameSlot() const {
@@ -296,11 +296,11 @@ class ScopeStencil {
   template <typename SpecificEnvironmentType>
   MOZ_MUST_USE bool createSpecificShape(JSContext* cx, ScopeKind kind,
                                         BaseScopeData* scopeData,
-                                        MutableHandleShape shape);
+                                        MutableHandleShape shape) const;
 
   template <typename SpecificScopeType, typename SpecificEnvironmentType>
   Scope* createSpecificScope(JSContext* cx, CompilationInfo& compilationInfo,
-                             CompilationGCOutput& gcOutput);
+                             CompilationGCOutput& gcOutput) const;
 };
 
 // As an alternative to a ScopeIndex (which references a ScopeStencil), we may
diff --git a/js/src/vm/Scope.cpp b/js/src/vm/Scope.cpp
index 2911bffd44fd..43dd5a4a1baf 100644
--- a/js/src/vm/Scope.cpp
+++ b/js/src/vm/Scope.cpp
@@ -2164,7 +2164,7 @@ bool ScopeStencil::createForModuleScope(JSContext* cx,
 template <typename SpecificEnvironmentT>
 bool ScopeStencil::createSpecificShape(JSContext* cx, ScopeKind kind,
                                        BaseScopeData* scopeData,
-                                       MutableHandleShape shape) {
+                                       MutableHandleShape shape) const {
   const JSClass* cls = &SpecificEnvironmentT::class_;
   uint32_t baseShapeFlags = SpecificEnvironmentT::BASESHAPE_FLAGS;
 
@@ -2203,7 +2203,7 @@ bool ScopeStencil::createForWithScope(JSContext* cx,
 template <typename SpecificScopeT>
 UniquePtr<typename SpecificScopeT::Data> ScopeStencil::createSpecificScopeData(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput) {
+    CompilationGCOutput& gcOutput) const {
   return LiftParserScopeData<SpecificScopeT>(cx, compilationInfo,
                                              &data<SpecificScopeT>());
 }
@@ -2212,7 +2212,7 @@ template <>
 UniquePtr<FunctionScope::Data>
 ScopeStencil::createSpecificScopeData<FunctionScope>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput) {
+    CompilationGCOutput& gcOutput) const {
   // Allocate a new vm function-scope.
   UniquePtr<FunctionScope::Data> data = LiftParserScopeData<FunctionScope>(
       cx, compilationInfo, &this->data<FunctionScope>());
@@ -2229,7 +2229,7 @@ ScopeStencil::createSpecificScopeData<FunctionScope>(
 template <>
 UniquePtr<ModuleScope::Data> ScopeStencil::createSpecificScopeData<ModuleScope>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput) {
+    CompilationGCOutput& gcOutput) const {
   // Allocate a new vm module-scope.
   UniquePtr<ModuleScope::Data> data = LiftParserScopeData<ModuleScope>(
       cx, compilationInfo, &this->data<ModuleScope>());
@@ -2247,7 +2247,7 @@ UniquePtr<ModuleScope::Data> ScopeStencil::createSpecificScopeData<ModuleScope>(
 template <>
 Scope* ScopeStencil::createSpecificScope<WithScope, std::nullptr_t>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput) {
+    CompilationGCOutput& gcOutput) const {
   RootedScope enclosingScope(
       cx, enclosing(compilationInfo).existingScope(gcOutput));
   return Scope::create(cx, ScopeKind::With, enclosingScope, nullptr);
@@ -2257,7 +2257,7 @@ Scope* ScopeStencil::createSpecificScope<WithScope, std::nullptr_t>(
 template <>
 Scope* ScopeStencil::createSpecificScope<GlobalScope, std::nullptr_t>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput) {
+    CompilationGCOutput& gcOutput) const {
   Rooted<UniquePtr<GlobalScope::Data>> rootedData(
       cx, createSpecificScopeData<GlobalScope>(cx, compilationInfo, gcOutput));
   if (!rootedData) {
@@ -2273,7 +2273,7 @@ Scope* ScopeStencil::createSpecificScope<GlobalScope, std::nullptr_t>(
 template <typename SpecificScopeT, typename SpecificEnvironmentT>
 Scope* ScopeStencil::createSpecificScope(JSContext* cx,
                                          CompilationInfo& compilationInfo,
-                                         CompilationGCOutput& gcOutput) {
+                                         CompilationGCOutput& gcOutput) const {
   Rooted<UniquePtr<typename SpecificScopeT::Data>> rootedData(
       cx,
       createSpecificScopeData<SpecificScopeT>(cx, compilationInfo, gcOutput));
@@ -2297,20 +2297,20 @@ Scope* ScopeStencil::createSpecificScope(JSContext* cx,
 
 template Scope* ScopeStencil::createSpecificScope<FunctionScope, CallObject>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput);
+    CompilationGCOutput& gcOutput) const;
 template Scope*
 ScopeStencil::createSpecificScope<LexicalScope, LexicalEnvironmentObject>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput);
+    CompilationGCOutput& gcOutput) const;
 template Scope*
 ScopeStencil::createSpecificScope<EvalScope, VarEnvironmentObject>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput);
+    CompilationGCOutput& gcOutput) const;
 template Scope*
 ScopeStencil::createSpecificScope<VarScope, VarEnvironmentObject>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput);
+    CompilationGCOutput& gcOutput) const;
 template Scope*
 ScopeStencil::createSpecificScope<ModuleScope, ModuleEnvironmentObject>(
     JSContext* cx, CompilationInfo& compilationInfo,
-    CompilationGCOutput& gcOutput);
+    CompilationGCOutput& gcOutput) const;