1 files changed, 35 insertions, 14 deletions

diff --git a/js/src/jsscript.h b/js/src/jsscript.h
index 87da79901..bb8635581 100644
--- a/js/src/jsscript.h
+++ b/js/src/jsscript.h
@@ -575,10 +575,6 @@ class ScriptSource
         introductionOffset_ = offset;
         hasIntroductionOffset_ = true;
     }
-
-    uint32_t parameterListEnd() const {
-        return parameterListEnd_;
-    }
 };
 
 class ScriptSourceHolder
@@ -857,9 +853,19 @@ class JSScript : public js::gc::TenuredCell
 
     uint32_t        bodyScopeIndex_; /* index into the scopes array of the body scope */
 
-    /* Range of characters in scriptSource which contains this script's source. */
+    // Range of characters in scriptSource which contains this script's source.
+    // each field points the following location.
+    //
+    //   function * f(a, b) { return a + b; }
+    //   ^          ^                        ^
+    //   |          |                        |
+    //   |          sourceStart_             sourceEnd_
+    //   |
+    //   preludeStart_
+    //
     uint32_t        sourceStart_;
     uint32_t        sourceEnd_;
+    uint32_t        preludeStart_;
 
     // Number of times the script has been called or has had backedges taken.
     // When running in ion, also increased for any inlined scripts. Reset if
@@ -1020,7 +1026,7 @@ class JSScript : public js::gc::TenuredCell
     // instead of private to suppress -Wunused-private-field compiler warnings.
   protected:
 #if JS_BITS_PER_WORD == 32
-    // Currently no padding is needed.
+    uint32_t padding;
 #endif
 
     //
@@ -1031,7 +1037,7 @@ class JSScript : public js::gc::TenuredCell
     static JSScript* Create(js::ExclusiveContext* cx,
                             const JS::ReadOnlyCompileOptions& options,
                             js::HandleObject sourceObject, uint32_t sourceStart,
-                            uint32_t sourceEnd);
+                            uint32_t sourceEnd, uint32_t preludeStart);
 
     void initCompartment(js::ExclusiveContext* cx);
 
@@ -1178,6 +1184,10 @@ class JSScript : public js::gc::TenuredCell
         return sourceEnd_;
     }
 
+    size_t preludeStart() const {
+        return preludeStart_;
+    }
+
     bool noScriptRval() const {
         return noScriptRval_;
     }
@@ -1501,7 +1511,8 @@ class JSScript : public js::gc::TenuredCell
     bool mayReadFrameArgsDirectly();
 
     JSFlatString* sourceData(JSContext* cx);
-
+    JSFlatString* sourceDataWithPrelude(JSContext* cx);
+    
     static bool loadSource(JSContext* cx, js::ScriptSource* ss, bool* worked);
 
     void setSourceObject(JSObject* object);
@@ -1920,7 +1931,8 @@ class LazyScript : public gc::TenuredCell
     // instead of private to suppress -Wunused-private-field compiler warnings.
   protected:
 #if JS_BITS_PER_WORD == 32
-    uint32_t padding;
+    // uint32_t padding;
+    // Currently no padding is needed.
 #endif
 
   private:
@@ -1960,20 +1972,25 @@ class LazyScript : public gc::TenuredCell
     };
 
     // Source location for the script.
+    // See the comment in JSScript for the details.
     uint32_t begin_;
     uint32_t end_;
+    uint32_t preludeStart_;
+    // Line and column of |begin_| position, that is the position where we
+    // start parsing.
     uint32_t lineno_;
     uint32_t column_;
 
     LazyScript(JSFunction* fun, void* table, uint64_t packedFields,
-               uint32_t begin, uint32_t end, uint32_t lineno, uint32_t column);
+               uint32_t begin, uint32_t end, uint32_t preludeStart,
+               uint32_t lineno, uint32_t column);
 
     // Create a LazyScript without initializing the closedOverBindings and the
     // innerFunctions. To be GC-safe, the caller must initialize both vectors
     // with valid atoms and functions.
     static LazyScript* CreateRaw(ExclusiveContext* cx, HandleFunction fun,
                                  uint64_t packedData, uint32_t begin, uint32_t end,
-                                 uint32_t lineno, uint32_t column);
+                                 uint32_t preludeStart, uint32_t lineno, uint32_t column);
 
   public:
     static const uint32_t NumClosedOverBindingsLimit = 1 << NumClosedOverBindingsBits;
@@ -1985,7 +2002,7 @@ class LazyScript : public gc::TenuredCell
                               const frontend::AtomVector& closedOverBindings,
                               Handle<GCVector<JSFunction*, 8>> innerFunctions,
                               JSVersion version, uint32_t begin, uint32_t end,
-                              uint32_t lineno, uint32_t column);
+                              uint32_t preludeStart, uint32_t lineno, uint32_t column);
 
     // Create a LazyScript and initialize the closedOverBindings and the
     // innerFunctions with dummy values to be replaced in a later initialization
@@ -2000,7 +2017,7 @@ class LazyScript : public gc::TenuredCell
                               HandleScript script, HandleScope enclosingScope,
                               HandleScript enclosingScript,
                               uint64_t packedData, uint32_t begin, uint32_t end,
-                              uint32_t lineno, uint32_t column);
+                              uint32_t preludeStart, uint32_t lineno, uint32_t column);
 
     void initRuntimeFields(uint64_t packedFields);
 
@@ -2173,6 +2190,9 @@ class LazyScript : public gc::TenuredCell
     uint32_t end() const {
         return end_;
     }
+    uint32_t preludeStart() const {
+        return preludeStart_;
+    }
     uint32_t lineno() const {
         return lineno_;
     }
@@ -2199,7 +2219,8 @@ class LazyScript : public gc::TenuredCell
 };
 
 /* If this fails, add/remove padding within LazyScript. */
-JS_STATIC_ASSERT(sizeof(LazyScript) % js::gc::CellSize == 0);
+static_assert(sizeof(LazyScript) % js::gc::CellSize == 0,
+              "Size of LazyScript must be an integral multiple of js::gc::CellSize");
 
 struct ScriptAndCounts
 {