+++ /dev/null
-// 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);
-}
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