Remove the last of the obsolete *-delay.js files. This one...

src/liveedit-delay.js

-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// LiveEdit feature implementation. The script should be executed after
-// debug-delay.js.
-
-
-// Changes script text and recompiles all relevant functions if possible.
-// The change is always a substring (change_pos, change_pos + change_len)
-// being replaced with a completely different string new_str.
-// 
-// Only one function will have its Code changed in result of this function.
-// All nested functions (should they have any instances at the moment) are left
-// unchanged and re-linked to a newly created script instance representing old
-// version of the source. (Generally speaking,
-// during the change all nested functions are erased and completely different
-// set of nested functions are introduced.) All other functions just have
-// their positions updated. 
-//
-// @param {Script} script that is being changed
-// @param {Array} change_log a list that collects engineer-readable description
-//     of what happened.
-Debug.LiveEditChangeScript = function(script, change_pos, change_len, new_str,
-    change_log) {
-
-  // So far the function works as namespace.
-  var liveedit = Debug.LiveEditChangeScript;
-  var Assert = liveedit.Assert;
-
-  // 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.
-  // 
-  // The script is used for compilation, because it produces code that 
-  // needs to be linked with some particular script (for nested functions). 
-  function DebugGatherCompileInfo(source) {
-    // Get function info, elements are partially sorted (it is a tree
-    // of nested functions serialized as parent followed by serialized children.
-    var raw_compile_info = %LiveEditGatherCompileInfo(script, source);
-
-    // Sort function infos by start position field.
-    var compile_info = new Array();
-    var old_index_map = new Array();
-    for (var i = 0; i < raw_compile_info.length; i++) {
-        compile_info.push(new liveedit.FunctionCompileInfo(raw_compile_info[i]));
-        old_index_map.push(i);
-    }
-    
-    for (var i = 0; i < compile_info.length; i++) {
-      var k = i;
-      for (var j = i + 1; j < compile_info.length; j++) {
-        if (compile_info[k].start_position > compile_info[j].start_position) {
-          k = j;
-        }
-      }
-      if (k != i) {
-        var temp_info = compile_info[k];
-        var temp_index = old_index_map[k];
-        compile_info[k] = compile_info[i];
-        old_index_map[k] = old_index_map[i];
-        compile_info[i] = temp_info;
-        old_index_map[i] = temp_index;
-      }
-    }
-
-    // After sorting update outer_inder field using old_index_map. Also
-    // set next_sibling_index field.
-    var current_index = 0;
-
-    // The recursive function, that goes over all children of a particular
-    // node (i.e. function info).
-    function ResetIndexes(new_parent_index, old_parent_index) {
-      var previous_sibling = -1;
-      while (current_index < compile_info.length &&
-          compile_info[current_index].outer_index == old_parent_index) {
-        var saved_index = current_index;
-        compile_info[saved_index].outer_index = new_parent_index;
-        if (previous_sibling != -1) {
-          compile_info[previous_sibling].next_sibling_index = saved_index;
-        }
-        previous_sibling = saved_index;
-        current_index++;
-        ResetIndexes(saved_index, old_index_map[saved_index]);
-      }
-      if (previous_sibling != -1) {
-        compile_info[previous_sibling].next_sibling_index = -1;
-      }
-    }
-    
-    ResetIndexes(-1, -1);
-    Assert(current_index == compile_info.length);
-    
-    return compile_info;
-  }  
-
-  // Given a positions, finds a function that fully includes the entire change.
-  function FindChangedFunction(compile_info, offset, len) {
-    // First condition: function should start before the change region.
-    // Function #0 (whole-script function) always does, but we want
-    // one, that is later in this list.
-    var index = 0;
-    while (index + 1 < compile_info.length &&
-        compile_info[index + 1].start_position <= offset) {
-      index++;
-    }
-    // Now we are at the last function that begins before the change
-    // region. The function that covers entire change region is either
-    // this function or the enclosing one.
-    for (; compile_info[index].end_position < offset + len;
-        index = compile_info[index].outer_index) {
-      Assert(index != -1);
-    }
-    return index;
-  }
-
-  // Variable forward declarations. Preprocessor "Minifier" needs them.
-  var old_compile_info;
-  var shared_infos;
-  // Finds SharedFunctionInfo that corresponds compile info with index
-  // in old version of the script.
-  function FindFunctionInfo(index) {
-    var old_info = old_compile_info[index];
-    for (var i = 0; i < shared_infos.length; i++) {
-      var info = shared_infos[i];
-      if (info.start_position == old_info.start_position && 
-          info.end_position == old_info.end_position) {
-        return info;
-      }
-    }
-  }
-
-  // Replaces function's Code.
-  function PatchCode(new_info, shared_info) {
-    %LiveEditReplaceFunctionCode(new_info.raw_array, shared_info.raw_array);
-
-    change_log.push( {function_patched: new_info.function_name} );
-  }
-  
-  var change_len_old;
-  var change_len_new;
-  // Translate position in old version of script into position in new
-  // version of script.
-  function PosTranslator(old_pos) {
-    if (old_pos <= change_pos) {
-      return old_pos;
-    }
-    if (old_pos >= change_pos + change_len_old) {
-      return old_pos + change_len_new - change_len_old;
-    }
-    return -1;
-  }
-  
-  var position_change_array;
-  var position_patch_report;
-  function PatchPositions(new_info, shared_info) {
-    if (!shared_info) {
-      // TODO: explain what is happening.
-      return;
-    }
-    %LiveEditPatchFunctionPositions(shared_info.raw_array,
-        position_change_array);
-    position_patch_report.push( { name: new_info.function_name } );
-  }
-  
-  var link_to_old_script_report;
-  var old_script;
-  // Makes a function associated with another instance of a script (the
-  // one representing its old version). This way the function still
-  // may access its own text.
-  function LinkToOldScript(shared_info) {
-    %LiveEditRelinkFunctionToScript(shared_info.raw_array, old_script);
-    
-    link_to_old_script_report.push( { name: shared_info.function_name } );
-  }
-
-
-  
-  var old_source = script.source;
-  var change_len_old = change_len;
-  var change_len_new = new_str.length;
-  
-  // Prepare new source string.
-  var new_source = old_source.substring(0, change_pos) +
-      new_str + old_source.substring(change_pos + change_len);
-
-  // Find all SharedFunctionInfo's that are compiled from this script.
-  var shared_raw_list = %LiveEditFindSharedFunctionInfosForScript(script);
-
-  var shared_infos = new Array();
-
-  for (var i = 0; i < shared_raw_list.length; i++) {
-    shared_infos.push(new liveedit.SharedInfoWrapper(shared_raw_list[i]));
-  }
-  
-  // Gather compile information about old version of script.
-  var old_compile_info = DebugGatherCompileInfo(old_source);
-  
-  // Gather compile information about new version of script.
-  var new_compile_info;
-  try {
-    new_compile_info = DebugGatherCompileInfo(new_source);
-  } catch (e) {
-    throw new liveedit.Failure("Failed to compile new version of script: " + e);
-  }
-
-  // An index of a single function, that is going to have its code replaced.
-  var function_being_patched =
-      FindChangedFunction(old_compile_info, change_pos, change_len_old);
-
-  // In old and new script versions function with a change should have the
-  // same indexes.
-  var function_being_patched2 =
-      FindChangedFunction(new_compile_info, change_pos, change_len_new);
-  Assert(function_being_patched == function_being_patched2,
-         "inconsistent old/new compile info");
-
-  // Check that function being patched has the same expectations in a new
-  // version. Otherwise we cannot safely patch its behavior and should
-  // choose the outer function instead.
-  while (!liveedit.CompareFunctionExpectations(
-      old_compile_info[function_being_patched],
-      new_compile_info[function_being_patched])) {
-
-    Assert(old_compile_info[function_being_patched].outer_index == 
-        new_compile_info[function_being_patched].outer_index);
-    function_being_patched =
-        old_compile_info[function_being_patched].outer_index;
-    Assert(function_being_patched != -1);
-  }
-  
-  // Check that function being patched is not currently on stack.
-  liveedit.CheckStackActivations(
-      [ FindFunctionInfo(function_being_patched) ], change_log );
-  
-
-  // Committing all changes.
-  var old_script_name = liveedit.CreateNameForOldScript(script); 
-
-  // Update the script text and create a new script representing an old
-  // version of the script.
-  var old_script = %LiveEditReplaceScript(script, new_source, old_script_name);
-
-  PatchCode(new_compile_info[function_being_patched],
-      FindFunctionInfo(function_being_patched));
-
-  var position_patch_report = new Array();
-  change_log.push( {position_patched: position_patch_report} );
-  
-  var position_change_array = [ change_pos,
-                                change_pos + change_len_old,
-                                change_pos + change_len_new ];
-  
-  // Update positions of all outer functions (i.e. all functions, that
-  // are partially below the function being patched).
-  for (var i = new_compile_info[function_being_patched].outer_index;
-      i != -1;
-      i = new_compile_info[i].outer_index) {
-    PatchPositions(new_compile_info[i], FindFunctionInfo(i));
-  }
-
-  // Update positions of all functions that are fully below the function
-  // being patched.
-  var old_next_sibling =
-      old_compile_info[function_being_patched].next_sibling_index;
-  var new_next_sibling =
-      new_compile_info[function_being_patched].next_sibling_index;
-
-  // We simply go over the tail of both old and new lists. Their tails should
-  // have an identical structure.
-  if (old_next_sibling == -1) {
-    Assert(new_next_sibling == -1);
-  } else {
-    Assert(old_compile_info.length - old_next_sibling ==
-        new_compile_info.length - new_next_sibling);
-
-    for (var i = old_next_sibling, j = new_next_sibling;
-        i < old_compile_info.length; i++, j++) {
-      PatchPositions(new_compile_info[j], FindFunctionInfo(i));
-    }
-  }
-
-  var link_to_old_script_report = new Array();
-  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 = function_being_patched + 1; i < old_next_sibling; i++) {
-    LinkToOldScript(FindFunctionInfo(i), old_script);
-  }
-}
-
-Debug.LiveEditChangeScript.Assert = function(condition, message) {
-  if (!condition) {
-    if (message) {
-      throw "Assert " + message;
-    } else {
-      throw "Assert";
-    }
-  }
-}
-    
-// An object describing function compilation details. Its index fields
-// apply to indexes inside array that stores these objects.
-Debug.LiveEditChangeScript.FunctionCompileInfo = function(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.code = raw_array[4];
-  this.scope_info = raw_array[5];
-  this.outer_index = raw_array[6];
-  this.next_sibling_index = null;
-  this.raw_array = raw_array;
-}
-  
-// A structure describing SharedFunctionInfo.
-Debug.LiveEditChangeScript.SharedInfoWrapper = function(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;
-}
-
-// Adds a suffix to script name to mark that it is old version.
-Debug.LiveEditChangeScript.CreateNameForOldScript = function(script) {
-  // TODO(635): try better than this; support several changes.
-  return script.name + " (old)";
-}
-
-// Compares a function interface old and new version, whether it
-// changed or not.
-Debug.LiveEditChangeScript.CompareFunctionExpectations =
-    function(function_info1, function_info2) {
-  // Check that function has the same number of parameters (there may exist
-  // an adapter, that won't survive function parameter number change).
-  if (function_info1.param_num != function_info2.param_num) {
-    return false;
-  }
-  var scope_info1 = function_info1.scope_info;
-  var scope_info2 = function_info2.scope_info;
-  
-  if (!scope_info1) {
-    return !scope_info2;
-  }
-  
-  if (scope_info1.length != scope_info2.length) {
-    return false;
-  }
-
-  // Check that outer scope structure is not changed. Otherwise the function
-  // will not properly work with existing scopes.
-  return scope_info1.toString() == scope_info2.toString(); 
-}
-
-// For array of wrapped shared function infos checks that none of them
-// have activations on stack (of any thread). Throws a Failure exception
-// if this proves to be false.
-Debug.LiveEditChangeScript.CheckStackActivations = function(shared_wrapper_list,
-                                                            change_log) {
-  var liveedit = Debug.LiveEditChangeScript;
-      
-  var shared_list = new Array();
-  for (var i = 0; i < shared_wrapper_list.length; i++) {
-    shared_list[i] = shared_wrapper_list[i].info;
-  }
-  var result = %LiveEditCheckStackActivations(shared_list);
-  var problems = new Array();
-  for (var i = 0; i < shared_list.length; i++) {
-    if (result[i] == liveedit.FunctionPatchabilityStatus.FUNCTION_BLOCKED_ON_STACK) {
-      var shared = shared_list[i];
-      var description = {
-          name: shared.function_name,
-          start_pos: shared.start_position, 
-          end_pos: shared.end_position
-      };
-      problems.push(description);
-    }
-  }
-  if (problems.length > 0) {
-    change_log.push( { functions_on_stack: problems } );
-    throw new liveedit.Failure("Blocked by functions on stack");
-  }
-}
-
-// A copy of the FunctionPatchabilityStatus enum from liveedit.h
-Debug.LiveEditChangeScript.FunctionPatchabilityStatus = {
-    FUNCTION_AVAILABLE_FOR_PATCH: 0,
-    FUNCTION_BLOCKED_ON_STACK: 1
-}
-
-
-// A logical failure in liveedit process. This means that change_log
-// is valid and consistent description of what happened.
-Debug.LiveEditChangeScript.Failure = function(message) {
-  this.message = message;
-}
-
-Debug.LiveEditChangeScript.Failure.prototype.toString = function() {
-  return "LiveEdit Failure: " + this.message;     
-}
-
-// A testing entry.
-Debug.LiveEditChangeScript.GetPcFromSourcePos = function(func, source_pos) {
-  return %GetFunctionCodePositionFromSource(func, source_pos);
-}