From 2776d2837b8d45a4fb3cda365af8b1c1b6b87531 Mon Sep 17 00:00:00 2001
From: Jim Blandy <jimb@mozilla.com>
Date: Thu, 15 Mar 2018 16:26:09 -0700
Subject: [PATCH] Bug 1444604: Part 6: Add
 LiveSavedFrameCache::findWithoutInvalidation. r=jorendorff

--HG--
extra : rebase_source : bbe26f26f0ae8e0f30e6505e1614c3ae4a320300
extra : histedit_source : fa29282837885902c7a5413cce34ef71e8b444d3
---
 js/src/vm/SavedStacks.cpp | 18 ++++++++++++++++++
 js/src/vm/Stack.h         |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/js/src/vm/SavedStacks.cpp b/js/src/vm/SavedStacks.cpp
index 68f0d70c0547..bdcc7f92f332 100644
--- a/js/src/vm/SavedStacks.cpp
+++ b/js/src/vm/SavedStacks.cpp
@@ -156,6 +156,24 @@ LiveSavedFrameCache::find(JSContext* cx, FramePtr& framePtr, const jsbytecode* p
     frame.set(frames->back().savedFrame);
 }
 
+void
+LiveSavedFrameCache::findWithoutInvalidation(const FramePtr& framePtr,
+                                             MutableHandleSavedFrame frame) const
+{
+    MOZ_ASSERT(initialized());
+    MOZ_ASSERT(framePtr.hasCachedSavedFrame());
+
+    Key key(framePtr);
+    for (auto& entry : (*frames)) {
+        if (entry.key == key) {
+            frame.set(entry.savedFrame);
+            return;
+        }
+    }
+
+    frame.set(nullptr);
+}
+
 struct SavedFrame::Lookup {
     Lookup(JSAtom* source, uint32_t line, uint32_t column,
            JSAtom* functionDisplayName, JSAtom* asyncCause, SavedFrame* parent,
diff --git a/js/src/vm/Stack.h b/js/src/vm/Stack.h
index 2663bd640695..8717a7018f22 100644
--- a/js/src/vm/Stack.h
+++ b/js/src/vm/Stack.h
@@ -1357,6 +1357,11 @@ class LiveSavedFrameCache
     void find(JSContext* cx, FramePtr& framePtr, const jsbytecode* pc,
               MutableHandleSavedFrame frame) const;
 
+    // Search the cache for a frame matching |framePtr|, without removing any
+    // entries. Return the matching saved frame, or nullptr if none is found.
+    // This is used for resolving |evalInFramePrev| links.
+    void findWithoutInvalidation(const FramePtr& framePtr, MutableHandleSavedFrame frame) const;
+
     // Push a cache entry mapping |framePtr| and |pc| to |savedFrame| on the top
     // of the cache's stack. You must insert entries for frames from oldest to
     // youngest. They must all be younger than the frame that the |find| method