Store SharedFunctionInfos of a Script in a FixedArray indexed by their ID

src/debug/liveedit.js

Index: src/debug/liveedit.js
diff --git a/src/debug/liveedit.js b/src/debug/liveedit.js
index d85e827115bbe3b68f648ce7730d90a92f57f78a..fd24ab2144a1ac5a00ffd639e440829810294d90 100644
--- a/src/debug/liveedit.js
+++ b/src/debug/liveedit.js
@@ -29,6 +29,7 @@
   var FindScriptSourcePosition = global.Debug.findScriptSourcePosition;
   var GlobalArray = global.Array;
   var MathFloor = global.Math.floor;
+  var MathMax = global.Math.max;
   var SyntaxError = global.SyntaxError;
 
   // -------------------------------------------------------------------
@@ -75,6 +76,10 @@
       }
       throw failure;
     }
+
+    var max_function_literal_id = new_compile_info.reduce(
+        (max, info) => MathMax(max, info.function_literal_id), 0);
+
     var root_new_node = BuildCodeInfoTree(new_compile_info);
 
     // Link recompiled script data with other data.
@@ -177,8 +182,7 @@
 
       // Update the script text and create a new script representing an old
       // version of the script.
-      old_script = %LiveEditReplaceScript(script, new_source,
-          old_script_name);
+      old_script = %LiveEditReplaceScript(script, new_source, old_script_name);
 
       var link_to_old_script_report = new GlobalArray();
       change_log.push( { linked_to_old_script: link_to_old_script_report } );
@@ -192,12 +196,6 @@
       preview_description.created_script_name = old_script_name;
     }
 
-    // Link to an actual script all the functions that we are going to use.
-    for (var i = 0; i < link_to_original_script_list.length; i++) {
-      %LiveEditFunctionSetScript(
-          link_to_original_script_list[i].info.shared_function_info, script);
-    }
-
     for (var i = 0; i < replace_code_list.length; i++) {
       PatchFunctionCode(replace_code_list[i], change_log);
     }
@@ -212,13 +210,25 @@
           position_patch_report);
 
       if (update_positions_list[i].live_shared_function_infos) {
-        update_positions_list[i].live_shared_function_infos.
-            forEach(function (info) {
-                %LiveEditFunctionSourceUpdated(info.raw_array);
-              });
+        var new_function_literal_id =
+            update_positions_list[i]
+                .corresponding_node.info.function_literal_id;

[kozy, 2016/12/14 01:09:51]

It could be no corresponding_node here as mentioned in comment:
  // For each old function (if it is not damaged) tries to find a corresponding
  // function in new script. Typically it should succeed (non-damaged functions
  // by definition may only have changes inside their bodies). However there are
  // reasons for correspondence not to be found; function with unmodified text
  // in new script may become enclosed into other function; the innocent change
  // inside function body may in fact be something like "} function B() {" that
  // splits a function into 2 functions.
Complicated repro case is described in crbug.com/673950

+        update_positions_list[i].live_shared_function_infos.forEach(function(
+            info) {
+          %LiveEditFunctionSourceUpdated(
+              info.raw_array, new_function_literal_id);
+        });
       }
     }
 
+    %LiveEditFixupScript(script, max_function_literal_id);
+
+    // Link all the functions we're going to use to an actual script.
+    for (var i = 0; i < link_to_original_script_list.length; i++) {
+      %LiveEditFunctionSetScript(
+          link_to_original_script_list[i].info.shared_function_info, script);
+    }
+
     preview_description.updated = true;
     return preview_description;
   }
@@ -761,6 +771,7 @@
     this.scope_info = raw_array[4];
     this.outer_index = raw_array[5];
     this.shared_function_info = raw_array[6];
+    this.function_literal_id = raw_array[8];
     this.next_sibling_index = null;
     this.raw_array = raw_array;
   }