Bug 983598 part 1 - Remove inheritance of the SnapshotReader. r=jandem

js/src/jit/Bailouts.cpp

@@ -37,10 +37,10 @@ using namespace js::jit;
 // bailed out frame.
 
 SnapshotIterator::SnapshotIterator(const IonBailoutIterator &iter)
-  : SnapshotReader(iter.ionScript()->snapshots(),
-                   iter.snapshotOffset(),
-                   iter.ionScript()->snapshotsRVATableSize(),
-                   iter.ionScript()->snapshotsListSize()),
+  : snapshot_(iter.ionScript()->snapshots(),
+              iter.snapshotOffset(),
+              iter.ionScript()->snapshotsRVATableSize(),
+              iter.ionScript()->snapshotsListSize()),
     fp_(iter.jsFrame()),
     machine_(iter.machineState()),
     ionScript_(iter.ionScript())

js/src/jit/IonFrameIterator.h

@@ -246,8 +246,9 @@ class IonBailoutIterator;
 
 // Reads frame information in snapshot-encoding order (that is, outermost frame
 // to innermost frame).
-class SnapshotIterator : public SnapshotReader
+class SnapshotIterator
 {
+    SnapshotReader snapshot_;
     IonJSFrameLayout *fp_;
     MachineState machine_;
     IonScript *ionScript_;
@@ -279,16 +280,56 @@ class SnapshotIterator : public SnapshotReader
     void warnUnreadableAllocation();
 
   public:
+    // Handle iterating over RValueAllocations of the snapshots.
+    inline RValueAllocation readAllocation() {
+        return snapshot_.readAllocation();
+    }
+    Value skip() {
+        readAllocation();
+        return UndefinedValue();
+    }
+
+    inline uint32_t allocations() const {
+        return snapshot_.allocations();
+    }
+    inline bool moreAllocations() const {
+        return snapshot_.moreAllocations();
+    }
+
+  public:
+    // Exhibits frame properties contained in the snapshot.
+    inline uint32_t pcOffset() const {
+        return snapshot_.pcOffset();
+    }
+    inline bool resumeAfter() const {
+        return snapshot_.resumeAfter();
+    }
+    inline BailoutKind bailoutKind() const {
+        return snapshot_.bailoutKind();
+    }
+
+  public:
+    // Handle iterating over frames of the snapshots.
+    inline void nextFrame() {
+        snapshot_.nextFrame();
+    }
+    inline bool moreFrames() const {
+        return snapshot_.moreFrames();
+    }
+    inline uint32_t frameCount() const {
+        return snapshot_.frameCount();
+    }
+
+  public:
+    // Connect all informations about the current script in order to recover the
+    // content of baseline frames.
+
     SnapshotIterator(IonScript *ionScript, SnapshotOffset snapshotOffset,
                      IonJSFrameLayout *fp, const MachineState &machine);
     SnapshotIterator(const IonFrameIterator &iter);
     SnapshotIterator(const IonBailoutIterator &iter);
     SnapshotIterator();
 
-    Value skip() {
-        readAllocation();
-        return UndefinedValue();
-    }
     Value read() {
         return allocationValue(readAllocation());
     }

js/src/jit/IonFrames.cpp

@@ -1291,10 +1291,10 @@ OsiIndex::returnPointDisplacement() const
 
 SnapshotIterator::SnapshotIterator(IonScript *ionScript, SnapshotOffset snapshotOffset,
                                    IonJSFrameLayout *fp, const MachineState &machine)
-  : SnapshotReader(ionScript->snapshots(),
-                   snapshotOffset,
-                   ionScript->snapshotsRVATableSize(),
-                   ionScript->snapshotsListSize()),
+  : snapshot_(ionScript->snapshots(),
+              snapshotOffset,
+              ionScript->snapshotsRVATableSize(),
+              ionScript->snapshotsListSize()),
     fp_(fp),
     machine_(machine),
     ionScript_(ionScript)
@@ -1303,10 +1303,10 @@ SnapshotIterator::SnapshotIterator(IonScript *ionScript, SnapshotOffset snapshot
 }
 
 SnapshotIterator::SnapshotIterator(const IonFrameIterator &iter)
-  : SnapshotReader(iter.ionScript()->snapshots(),
-                   iter.osiIndex()->snapshotOffset(),
-                   iter.ionScript()->snapshotsRVATableSize(),
-                   iter.ionScript()->snapshotsListSize()),
+  : snapshot_(iter.ionScript()->snapshots(),
+              iter.osiIndex()->snapshotOffset(),
+              iter.ionScript()->snapshotsRVATableSize(),
+              iter.ionScript()->snapshotsListSize()),
     fp_(iter.jsFrame()),
     machine_(iter.machineState()),
     ionScript_(iter.ionScript())
@@ -1314,7 +1314,7 @@ SnapshotIterator::SnapshotIterator(const IonFrameIterator &iter)
 }
 
 SnapshotIterator::SnapshotIterator()
-  : SnapshotReader(nullptr, 0, 0, 0),
+  : snapshot_(nullptr, 0, 0, 0),
     fp_(nullptr),
     ionScript_(nullptr)
 {

js/src/jit/Snapshots.h

@@ -394,12 +394,18 @@ class SnapshotReader
     SnapshotReader(const uint8_t *snapshots, uint32_t offset,
                    uint32_t RVATableSize, uint32_t listSize);
 
-    uint32_t pcOffset() const {
-        return pcOffset_;
-    }
     uint32_t allocations() const {
         return allocCount_;
     }
+    RValueAllocation readAllocation();
+
+    bool moreAllocations() const {
+        return allocRead_ < allocCount_;
+    }
+
+    uint32_t pcOffset() const {
+        return pcOffset_;
+    }
     BailoutKind bailoutKind() const {
         return bailoutKind_;
     }
@@ -408,17 +414,13 @@ class SnapshotReader
             return false;
         return resumeAfter_;
     }
+
     bool moreFrames() const {
         return framesRead_ < frameCount_;
     }
     void nextFrame() {
         readFrameHeader();
     }
-    RValueAllocation readAllocation();
-
-    bool moreAllocations() const {
-        return allocRead_ < allocCount_;
-    }
     uint32_t frameCount() const {
         return frameCount_;
     }