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

src/debug/liveedit.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // LiveEdit feature implementation. The script should be executed after
 // debug.js.
 
 // A LiveEdit namespace. It contains functions that modifies JavaScript code
 // according to changes of script source (if possible).
 //
@@ skipping 11 matching lines @@
 
 (function(global, utils) {
   "use strict";
 
   // -------------------------------------------------------------------
   // Imports
 
   var FindScriptSourcePosition = global.Debug.findScriptSourcePosition;
   var GlobalArray = global.Array;
   var MathFloor = global.Math.floor;
+  var MathMax = global.Math.max;
   var SyntaxError = global.SyntaxError;
 
   // -------------------------------------------------------------------
 
   // Forward declaration for minifier.
   var FunctionStatus;
 
   // Applies the change to the script.
   // The change is in form of list of chunks encoded in a single array as
   // a series of triplets (pos1_start, pos1_end, pos2_end)
@@ skipping 26 matching lines @@
       if (e instanceof SyntaxError) {
         var details = {
           type: "liveedit_compile_error",
           syntaxErrorMessage: e.message
         };
         CopyErrorPositionToDetails(e, details);
         failure.details = details;
       }
       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.
     FindCorrespondingFunctions(root_old_node, root_new_node);
 
     // Prepare to-do lists.
     var replace_code_list = new GlobalArray();
     var link_to_old_script_list = new GlobalArray();
     var link_to_original_script_list = new GlobalArray();
     var update_positions_list = new GlobalArray();
@@ skipping 82 matching lines @@
     // Create an old script only if there are function that should be linked
     // to old version.
     if (link_to_old_script_list.length == 0) {
       %LiveEditReplaceScript(script, new_source, null);
       old_script = UNDEFINED;
     } else {
       var old_script_name = CreateNameForOldScript(script);
 
       // 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 } );
 
       // We need to link to old script all former nested functions.
       for (var i = 0; i < link_to_old_script_list.length; i++) {
         LinkToOldScript(link_to_old_script_list[i], old_script,
             link_to_old_script_report);
       }
 
       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);
     }
 
     var position_patch_report = new GlobalArray();
     change_log.push( {position_patched: position_patch_report} );
 
     for (var i = 0; i < update_positions_list.length; i++) {
       // TODO(LiveEdit): take into account whether it's source_changed or
       // unchanged and whether positions changed at all.
       PatchPositions(update_positions_list[i], diff_array,
           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;
   }
 
   // Fully compiles source string as a script. Returns Array of
   // FunctionCompileInfo -- a descriptions of all functions of the script.
   // Elements of array are ordered by start positions of functions (from top
   // to bottom) in the source. Fields outer_index and next_sibling_index help
   // to navigate the nesting structure of functions.
   //
@@ skipping 522 matching lines @@
   // An object describing function compilation details. Its index fields
   // apply to indexes inside array that stores these objects.
   function FunctionCompileInfo(raw_array) {
     this.function_name = raw_array[0];
     this.start_position = raw_array[1];
     this.end_position = raw_array[2];
     this.param_num = raw_array[3];
     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;
   }
 
   function SharedInfoWrapper(raw_array) {
     this.function_name = raw_array[0];
     this.start_position = raw_array[1];
     this.end_position = raw_array[2];
     this.info = raw_array[3];
     this.raw_array = raw_array;
@@ skipping 257 matching lines @@
 
   LiveEdit.TestApi = {
     PosTranslator: PosTranslator,
     CompareStrings: CompareStrings,
     ApplySingleChunkPatch: ApplySingleChunkPatch
   };
 
   global.Debug.LiveEdit = LiveEdit;
 
 })