Index: src/liveedit-delay.js |
=================================================================== |
--- src/liveedit-delay.js (revision 4217) |
+++ src/liveedit-delay.js (working copy) |
@@ -1,431 +0,0 @@ |
-// 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); |
-} |