tor-browser

commit 999dfe06ecfe09211c109ef2902328d464523591
parent 2925df16e930bfb9974ccb22d3bcda61125251e3
Author: Tooru Fujisawa <arai_a@mac.com>
Date:   Tue, 21 Oct 2025 15:14:57 +0000

Bug 1991370 - Part 4: Use FrontendContext-based EncodeStencil in ScriptPreloader. r=bthrall

Differential Revision: https://phabricator.services.mozilla.com/D266625

Diffstat:
M
js/xpconnect/loader/ScriptCacheActors.cpp
 | 
11
++++++++---
M
js/xpconnect/loader/ScriptPreloader.cpp
 | 
18
++++++++++++------
M
js/xpconnect/loader/ScriptPreloader.h
 | 
9
+++++----

3 files changed, 25 insertions(+), 13 deletions(-)
diff --git a/js/xpconnect/loader/ScriptCacheActors.cpp b/js/xpconnect/loader/ScriptCacheActors.cpp
@@ -34,13 +34,16 @@ void ScriptCacheChild::SendScriptsAndFinalize(
     ScriptPreloader::ScriptHash& scripts) {
   MOZ_ASSERT(mWantCacheData);
 
-  AutoSafeJSAPI jsapi;
-
   auto matcher = ScriptPreloader::Match<ScriptPreloader::ScriptStatus::Saved>();
 
+  JS::FrontendContext* fc = JS::NewFrontendContext();
+  if (!fc) {
+    return;
+  }
+
   nsTArray<ScriptData> dataArray;
   for (auto& script : IterHash(scripts, matcher)) {
-    if (!script->mSize && !script->XDREncode(jsapi.cx())) {
+    if (!script->mSize && !script->XDREncode(fc)) {
       continue;
     }
 
@@ -57,6 +60,8 @@ void ScriptCacheChild::SendScriptsAndFinalize(
     }
   }
 
+  JS::DestroyFrontendContext(fc);
+
   Send__delete__(this, dataArray);
 }
 
diff --git a/js/xpconnect/loader/ScriptPreloader.cpp b/js/xpconnect/loader/ScriptPreloader.cpp
@@ -631,8 +631,11 @@ void ScriptPreloader::PrepareCacheWriteInternal() {
     return;
   }
 
-  AutoSafeJSAPI jsapi;
-  JSAutoRealm ar(jsapi.cx(), xpc::PrivilegedJunkScope());
+  JS::FrontendContext* fc = JS::NewFrontendContext();
+  if (!fc) {
+    return;
+  }
+
   bool found = false;
   for (auto& script : IterHash(mScripts, Match<ScriptStatus::Saved>())) {
     // Don't write any scripts that are also in the child cache. They'll be
@@ -652,11 +655,13 @@ void ScriptPreloader::PrepareCacheWriteInternal() {
       found = true;
     }
 
-    if (!script->mSize && !script->XDREncode(jsapi.cx())) {
+    if (!script->mSize && !script->XDREncode(fc)) {
       script.Remove();
     }
   }
 
+  JS::DestroyFrontendContext(fc);
+
   if (!found) {
     mSaveComplete = true;
     return;
@@ -1268,19 +1273,20 @@ ScriptPreloader::CachedStencil::CachedStencil(ScriptPreloader& cache,
   mProcessTypes = {};
 }
 
-bool ScriptPreloader::CachedStencil::XDREncode(JSContext* cx) {
+bool ScriptPreloader::CachedStencil::XDREncode(JS::FrontendContext* aFc) {
   auto cleanup = MakeScopeExit([&]() { MaybeDropStencil(); });
 
   mXDRData.construct<JS::TranscodeBuffer>();
 
-  JS::TranscodeResult code = JS::EncodeStencil(cx, mStencil, Buffer());
+  JS::TranscodeResult code = JS::EncodeStencil(aFc, mStencil, Buffer());
+
   if (code == JS::TranscodeResult::Ok) {
     mXDRRange.emplace(Buffer().begin(), Buffer().length());
     mSize = Range().length();
     return true;
   }
   mXDRData.destroy();
-  JS_ClearPendingException(cx);
+  JS::ClearFrontendErrors(aFc);
   return false;
 }
 
diff --git a/js/xpconnect/loader/ScriptPreloader.h b/js/xpconnect/loader/ScriptPreloader.h
@@ -31,9 +31,10 @@
 #include "nsITimer.h"
 
 #include "js/CompileOptions.h"  // JS::DecodeOptions, JS::ReadOnlyDecodeOptions
-#include "js/experimental/JSStencil.h"  // JS::Stencil
-#include "js/GCAnnotations.h"           // for JS_HAZ_NON_GC_POINTER
-#include "js/RootingAPI.h"              // for Handle, Heap
+#include "js/experimental/CompileScript.h"  // JS::FrontendContext
+#include "js/experimental/JSStencil.h"      // JS::Stencil
+#include "js/GCAnnotations.h"               // for JS_HAZ_NON_GC_POINTER
+#include "js/RootingAPI.h"                  // for Handle, Heap
 #include "js/Transcoding.h"  // for TranscodeBuffer, TranscodeRange, TranscodeSource
 #include "js/TypeDecls.h"  // for HandleObject, HandleScript
 
@@ -273,7 +274,7 @@ class ScriptPreloader : public nsIObserver,
 
     // Encodes this script into XDR data, and stores the result in mXDRData.
     // Returns true on success, false on failure.
-    bool XDREncode(JSContext* cx);
+    bool XDREncode(JS::FrontendContext* cx);
 
     // Encodes or decodes this script, in the storage format required by the
     // script cache file.