Javascript
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1226行
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44.7 KB
// Copyright 2012 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.
// -------------------------------------------------------------------
//
// If this object gets passed to an error constructor the error will
// get an accessor for .message that constructs a descriptive error
// message on access.
var kAddMessageAccessorsMarker = { };
// This will be lazily initialized when first needed (and forcibly
// overwritten even though it's const).
var kMessages = 0;
function FormatString(format, message) {
var args = %MessageGetArguments(message);
var result = "";
var arg_num = 0;
for (var i = 0; i < format.length; i++) {
var str = format[i];
if (str.length == 2 && %_StringCharCodeAt(str, 0) == 0x25) {
// Two-char string starts with "%".
var arg_num = (%_StringCharCodeAt(str, 1) - 0x30) >>> 0;
if (arg_num < 4) {
// str is one of %0, %1, %2 or %3.
try {
str = ToDetailString(args[arg_num]);
} catch (e) {
str = "#<error>";
}
}
}
result += str;
}
return result;
}
// To check if something is a native error we need to check the
// concrete native error types. It is not enough to check "obj
// instanceof $Error" because user code can replace
// NativeError.prototype.__proto__. User code cannot replace
// NativeError.prototype though and therefore this is a safe test.
function IsNativeErrorObject(obj) {
return (obj instanceof $Error) ||
(obj instanceof $EvalError) ||
(obj instanceof $RangeError) ||
(obj instanceof $ReferenceError) ||
(obj instanceof $SyntaxError) ||
(obj instanceof $TypeError) ||
(obj instanceof $URIError);
}
// When formatting internally created error messages, do not
// invoke overwritten error toString methods but explicitly use
// the error to string method. This is to avoid leaking error
// objects between script tags in a browser setting.
function ToStringCheckErrorObject(obj) {
if (IsNativeErrorObject(obj)) {
return %_CallFunction(obj, ErrorToString);
} else {
return ToString(obj);
}
}
function ToDetailString(obj) {
if (obj != null && IS_OBJECT(obj) && obj.toString === ObjectToString) {
var constructor = obj.constructor;
if (typeof constructor == "function") {
var constructorName = constructor.name;
if (IS_STRING(constructorName) && constructorName !== "") {
return "#<" + constructorName + ">";
}
}
}
return ToStringCheckErrorObject(obj);
}
function MakeGenericError(constructor, type, args) {
if (IS_UNDEFINED(args)) {
args = [];
}
var e = new constructor(kAddMessageAccessorsMarker);
e.type = type;
e.arguments = args;
return e;
}
/**
* Set up the Script function and constructor.
*/
%FunctionSetInstanceClassName(Script, 'Script');
%SetProperty(Script.prototype, 'constructor', Script,
DONT_ENUM | DONT_DELETE | READ_ONLY);
%SetCode(Script, function(x) {
// Script objects can only be created by the VM.
throw new $Error("Not supported");
});
// Helper functions; called from the runtime system.
function FormatMessage(message) {
if (kMessages === 0) {
var messagesDictionary = [
// Error
"cyclic_proto", ["Cyclic __proto__ value"],
"code_gen_from_strings", ["Code generation from strings disallowed for this context"],
// TypeError
"unexpected_token", ["Unexpected token ", "%0"],
"unexpected_token_number", ["Unexpected number"],
"unexpected_token_string", ["Unexpected string"],
"unexpected_token_identifier", ["Unexpected identifier"],
"unexpected_reserved", ["Unexpected reserved word"],
"unexpected_strict_reserved", ["Unexpected strict mode reserved word"],
"unexpected_eos", ["Unexpected end of input"],
"malformed_regexp", ["Invalid regular expression: /", "%0", "/: ", "%1"],
"unterminated_regexp", ["Invalid regular expression: missing /"],
"regexp_flags", ["Cannot supply flags when constructing one RegExp from another"],
"incompatible_method_receiver", ["Method ", "%0", " called on incompatible receiver ", "%1"],
"invalid_lhs_in_assignment", ["Invalid left-hand side in assignment"],
"invalid_lhs_in_for_in", ["Invalid left-hand side in for-in"],
"invalid_lhs_in_postfix_op", ["Invalid left-hand side expression in postfix operation"],
"invalid_lhs_in_prefix_op", ["Invalid left-hand side expression in prefix operation"],
"multiple_defaults_in_switch", ["More than one default clause in switch statement"],
"newline_after_throw", ["Illegal newline after throw"],
"redeclaration", ["%0", " '", "%1", "' has already been declared"],
"no_catch_or_finally", ["Missing catch or finally after try"],
"unknown_label", ["Undefined label '", "%0", "'"],
"uncaught_exception", ["Uncaught ", "%0"],
"stack_trace", ["Stack Trace:\n", "%0"],
"called_non_callable", ["%0", " is not a function"],
"undefined_method", ["Object ", "%1", " has no method '", "%0", "'"],
"property_not_function", ["Property '", "%0", "' of object ", "%1", " is not a function"],
"cannot_convert_to_primitive", ["Cannot convert object to primitive value"],
"not_constructor", ["%0", " is not a constructor"],
"not_defined", ["%0", " is not defined"],
"non_object_property_load", ["Cannot read property '", "%0", "' of ", "%1"],
"non_object_property_store", ["Cannot set property '", "%0", "' of ", "%1"],
"non_object_property_call", ["Cannot call method '", "%0", "' of ", "%1"],
"with_expression", ["%0", " has no properties"],
"illegal_invocation", ["Illegal invocation"],
"no_setter_in_callback", ["Cannot set property ", "%0", " of ", "%1", " which has only a getter"],
"apply_non_function", ["Function.prototype.apply was called on ", "%0", ", which is a ", "%1", " and not a function"],
"apply_wrong_args", ["Function.prototype.apply: Arguments list has wrong type"],
"invalid_in_operator_use", ["Cannot use 'in' operator to search for '", "%0", "' in ", "%1"],
"instanceof_function_expected", ["Expecting a function in instanceof check, but got ", "%0"],
"instanceof_nonobject_proto", ["Function has non-object prototype '", "%0", "' in instanceof check"],
"null_to_object", ["Cannot convert null to object"],
"reduce_no_initial", ["Reduce of empty array with no initial value"],
"getter_must_be_callable", ["Getter must be a function: ", "%0"],
"setter_must_be_callable", ["Setter must be a function: ", "%0"],
"value_and_accessor", ["Invalid property. A property cannot both have accessors and be writable or have a value, ", "%0"],
"proto_object_or_null", ["Object prototype may only be an Object or null"],
"property_desc_object", ["Property description must be an object: ", "%0"],
"redefine_disallowed", ["Cannot redefine property: ", "%0"],
"define_disallowed", ["Cannot define property:", "%0", ", object is not extensible."],
"non_extensible_proto", ["%0", " is not extensible"],
"handler_non_object", ["Proxy.", "%0", " called with non-object as handler"],
"proto_non_object", ["Proxy.", "%0", " called with non-object as prototype"],
"trap_function_expected", ["Proxy.", "%0", " called with non-function for '", "%1", "' trap"],
"handler_trap_missing", ["Proxy handler ", "%0", " has no '", "%1", "' trap"],
"handler_trap_must_be_callable", ["Proxy handler ", "%0", " has non-callable '", "%1", "' trap"],
"handler_returned_false", ["Proxy handler ", "%0", " returned false from '", "%1", "' trap"],
"handler_returned_undefined", ["Proxy handler ", "%0", " returned undefined from '", "%1", "' trap"],
"proxy_prop_not_configurable", ["Proxy handler ", "%0", " returned non-configurable descriptor for property '", "%2", "' from '", "%1", "' trap"],
"proxy_non_object_prop_names", ["Trap '", "%1", "' returned non-object ", "%0"],
"proxy_repeated_prop_name", ["Trap '", "%1", "' returned repeated property name '", "%2", "'"],
"invalid_weakmap_key", ["Invalid value used as weak map key"],
// RangeError
"invalid_array_length", ["Invalid array length"],
"stack_overflow", ["Maximum call stack size exceeded"],
"invalid_time_value", ["Invalid time value"],
// SyntaxError
"unable_to_parse", ["Parse error"],
"invalid_regexp_flags", ["Invalid flags supplied to RegExp constructor '", "%0", "'"],
"invalid_regexp", ["Invalid RegExp pattern /", "%0", "/"],
"illegal_break", ["Illegal break statement"],
"illegal_continue", ["Illegal continue statement"],
"illegal_return", ["Illegal return statement"],
"illegal_let", ["Illegal let declaration outside extended mode"],
"error_loading_debugger", ["Error loading debugger"],
"no_input_to_regexp", ["No input to ", "%0"],
"invalid_json", ["String '", "%0", "' is not valid JSON"],
"circular_structure", ["Converting circular structure to JSON"],
"called_on_non_object", ["%0", " called on non-object"],
"called_on_null_or_undefined", ["%0", " called on null or undefined"],
"array_indexof_not_defined", ["Array.getIndexOf: Argument undefined"],
"object_not_extensible", ["Can't add property ", "%0", ", object is not extensible"],
"illegal_access", ["Illegal access"],
"invalid_preparser_data", ["Invalid preparser data for function ", "%0"],
"strict_mode_with", ["Strict mode code may not include a with statement"],
"strict_catch_variable", ["Catch variable may not be eval or arguments in strict mode"],
"too_many_arguments", ["Too many arguments in function call (only 32766 allowed)"],
"too_many_parameters", ["Too many parameters in function definition (only 32766 allowed)"],
"too_many_variables", ["Too many variables declared (only 32767 allowed)"],
"strict_param_name", ["Parameter name eval or arguments is not allowed in strict mode"],
"strict_param_dupe", ["Strict mode function may not have duplicate parameter names"],
"strict_var_name", ["Variable name may not be eval or arguments in strict mode"],
"strict_function_name", ["Function name may not be eval or arguments in strict mode"],
"strict_octal_literal", ["Octal literals are not allowed in strict mode."],
"strict_duplicate_property", ["Duplicate data property in object literal not allowed in strict mode"],
"accessor_data_property", ["Object literal may not have data and accessor property with the same name"],
"accessor_get_set", ["Object literal may not have multiple get/set accessors with the same name"],
"strict_lhs_assignment", ["Assignment to eval or arguments is not allowed in strict mode"],
"strict_lhs_postfix", ["Postfix increment/decrement may not have eval or arguments operand in strict mode"],
"strict_lhs_prefix", ["Prefix increment/decrement may not have eval or arguments operand in strict mode"],
"strict_reserved_word", ["Use of future reserved word in strict mode"],
"strict_delete", ["Delete of an unqualified identifier in strict mode."],
"strict_delete_property", ["Cannot delete property '", "%0", "' of ", "%1"],
"strict_const", ["Use of const in strict mode."],
"strict_function", ["In strict mode code, functions can only be declared at top level or immediately within another function." ],
"strict_read_only_property", ["Cannot assign to read only property '", "%0", "' of ", "%1"],
"strict_cannot_assign", ["Cannot assign to read only '", "%0", "' in strict mode"],
"strict_poison_pill", ["'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them"],
"strict_caller", ["Illegal access to a strict mode caller function."],
"unprotected_let", ["Illegal let declaration in unprotected statement context."],
"unprotected_const", ["Illegal const declaration in unprotected statement context."],
"cant_prevent_ext_external_array_elements", ["Cannot prevent extension of an object with external array elements"],
"redef_external_array_element", ["Cannot redefine a property of an object with external array elements"],
"harmony_const_assign", ["Assignment to constant variable."],
"invalid_module_path", ["Module does not export '", "%0", "', or export is not itself a module"],
"module_type_error", ["Module '", "%0", "' used improperly"],
];
var messages = { __proto__ : null };
for (var i = 0; i < messagesDictionary.length; i += 2) {
var key = messagesDictionary[i];
var format = messagesDictionary[i + 1];
for (var j = 0; j < format.length; j++) {
%IgnoreAttributesAndSetProperty(format, %_NumberToString(j), format[j],
DONT_DELETE | READ_ONLY | DONT_ENUM);
}
%IgnoreAttributesAndSetProperty(format, 'length', format.length,
DONT_DELETE | READ_ONLY | DONT_ENUM);
%PreventExtensions(format);
%IgnoreAttributesAndSetProperty(messages,
key,
format,
DONT_DELETE | DONT_ENUM | READ_ONLY);
}
%PreventExtensions(messages);
%IgnoreAttributesAndSetProperty(builtins, "kMessages",
messages,
DONT_DELETE | DONT_ENUM | READ_ONLY);
}
var message_type = %MessageGetType(message);
var format = kMessages[message_type];
if (!format) return "<unknown message " + message_type + ">";
return FormatString(format, message);
}
function GetLineNumber(message) {
var start_position = %MessageGetStartPosition(message);
if (start_position == -1) return kNoLineNumberInfo;
var script = %MessageGetScript(message);
var location = script.locationFromPosition(start_position, true);
if (location == null) return kNoLineNumberInfo;
return location.line + 1;
}
// Returns the source code line containing the given source
// position, or the empty string if the position is invalid.
function GetSourceLine(message) {
var script = %MessageGetScript(message);
var start_position = %MessageGetStartPosition(message);
var location = script.locationFromPosition(start_position, true);
if (location == null) return "";
location.restrict();
return location.sourceText();
}
function MakeTypeError(type, args) {
return MakeGenericError($TypeError, type, args);
}
function MakeRangeError(type, args) {
return MakeGenericError($RangeError, type, args);
}
function MakeSyntaxError(type, args) {
return MakeGenericError($SyntaxError, type, args);
}
function MakeReferenceError(type, args) {
return MakeGenericError($ReferenceError, type, args);
}
function MakeEvalError(type, args) {
return MakeGenericError($EvalError, type, args);
}
function MakeError(type, args) {
return MakeGenericError($Error, type, args);
}
/**
* Find a line number given a specific source position.
* @param {number} position The source position.
* @return {number} 0 if input too small, -1 if input too large,
else the line number.
*/
function ScriptLineFromPosition(position) {
var lower = 0;
var upper = this.lineCount() - 1;
var line_ends = this.line_ends;
// We'll never find invalid positions so bail right away.
if (position > line_ends[upper]) {
return -1;
}
// This means we don't have to safe-guard indexing line_ends[i - 1].
if (position <= line_ends[0]) {
return 0;
}
// Binary search to find line # from position range.
while (upper >= 1) {
var i = (lower + upper) >> 1;
if (position > line_ends[i]) {
lower = i + 1;
} else if (position <= line_ends[i - 1]) {
upper = i - 1;
} else {
return i;
}
}
return -1;
}
/**
* Get information on a specific source position.
* @param {number} position The source position
* @param {boolean} include_resource_offset Set to true to have the resource
* offset added to the location
* @return {SourceLocation}
* If line is negative or not in the source null is returned.
*/
function ScriptLocationFromPosition(position,
include_resource_offset) {
var line = this.lineFromPosition(position);
if (line == -1) return null;
// Determine start, end and column.
var line_ends = this.line_ends;
var start = line == 0 ? 0 : line_ends[line - 1] + 1;
var end = line_ends[line];
if (end > 0 && %_CallFunction(this.source, end - 1, StringCharAt) == '\r') {
end--;
}
var column = position - start;
// Adjust according to the offset within the resource.
if (include_resource_offset) {
line += this.line_offset;
if (line == this.line_offset) {
column += this.column_offset;
}
}
return new SourceLocation(this, position, line, column, start, end);
}
/**
* Get information on a specific source line and column possibly offset by a
* fixed source position. This function is used to find a source position from
* a line and column position. The fixed source position offset is typically
* used to find a source position in a function based on a line and column in
* the source for the function alone. The offset passed will then be the
* start position of the source for the function within the full script source.
* @param {number} opt_line The line within the source. Default value is 0
* @param {number} opt_column The column in within the line. Default value is 0
* @param {number} opt_offset_position The offset from the begining of the
* source from where the line and column calculation starts.
* Default value is 0
* @return {SourceLocation}
* If line is negative or not in the source null is returned.
*/
function ScriptLocationFromLine(opt_line, opt_column, opt_offset_position) {
// Default is the first line in the script. Lines in the script is relative
// to the offset within the resource.
var line = 0;
if (!IS_UNDEFINED(opt_line)) {
line = opt_line - this.line_offset;
}
// Default is first column. If on the first line add the offset within the
// resource.
var column = opt_column || 0;
if (line == 0) {
column -= this.column_offset;
}
var offset_position = opt_offset_position || 0;
if (line < 0 || column < 0 || offset_position < 0) return null;
if (line == 0) {
return this.locationFromPosition(offset_position + column, false);
} else {
// Find the line where the offset position is located.
var offset_line = this.lineFromPosition(offset_position);
if (offset_line == -1 || offset_line + line >= this.lineCount()) {
return null;
}
return this.locationFromPosition(
this.line_ends[offset_line + line - 1] + 1 + column); // line > 0 here.
}
}
/**
* Get a slice of source code from the script. The boundaries for the slice is
* specified in lines.
* @param {number} opt_from_line The first line (zero bound) in the slice.
* Default is 0
* @param {number} opt_to_column The last line (zero bound) in the slice (non
* inclusive). Default is the number of lines in the script
* @return {SourceSlice} The source slice or null of the parameters where
* invalid
*/
function ScriptSourceSlice(opt_from_line, opt_to_line) {
var from_line = IS_UNDEFINED(opt_from_line) ? this.line_offset
: opt_from_line;
var to_line = IS_UNDEFINED(opt_to_line) ? this.line_offset + this.lineCount()
: opt_to_line;
// Adjust according to the offset within the resource.
from_line -= this.line_offset;
to_line -= this.line_offset;
if (from_line < 0) from_line = 0;
if (to_line > this.lineCount()) to_line = this.lineCount();
// Check parameters.
if (from_line >= this.lineCount() ||
to_line < 0 ||
from_line > to_line) {
return null;
}
var line_ends = this.line_ends;
var from_position = from_line == 0 ? 0 : line_ends[from_line - 1] + 1;
var to_position = to_line == 0 ? 0 : line_ends[to_line - 1] + 1;
// Return a source slice with line numbers re-adjusted to the resource.
return new SourceSlice(this,
from_line + this.line_offset,
to_line + this.line_offset,
from_position, to_position);
}
function ScriptSourceLine(opt_line) {
// Default is the first line in the script. Lines in the script are relative
// to the offset within the resource.
var line = 0;
if (!IS_UNDEFINED(opt_line)) {
line = opt_line - this.line_offset;
}
// Check parameter.
if (line < 0 || this.lineCount() <= line) {
return null;
}
// Return the source line.
var line_ends = this.line_ends;
var start = line == 0 ? 0 : line_ends[line - 1] + 1;
var end = line_ends[line];
return %_CallFunction(this.source, start, end, StringSubstring);
}
/**
* Returns the number of source lines.
* @return {number}
* Number of source lines.
*/
function ScriptLineCount() {
// Return number of source lines.
return this.line_ends.length;
}
/**
* Returns the name of script if available, contents of sourceURL comment
* otherwise. See
* http://fbug.googlecode.com/svn/branches/firebug1.1/docs/ReleaseNotes_1.1.txt
* for details on using //@ sourceURL comment to identify scritps that don't
* have name.
*
* @return {?string} script name if present, value for //@ sourceURL comment
* otherwise.
*/
function ScriptNameOrSourceURL() {
if (this.name) {
return this.name;
}
// The result is cached as on long scripts it takes noticable time to search
// for the sourceURL.
if (this.hasCachedNameOrSourceURL)
return this.cachedNameOrSourceURL;
this.hasCachedNameOrSourceURL = true;
// TODO(608): the spaces in a regexp below had to be escaped as \040
// because this file is being processed by js2c whose handling of spaces
// in regexps is broken. Also, ['"] are excluded from allowed URLs to
// avoid matches against sources that invoke evals with sourceURL.
// A better solution would be to detect these special comments in
// the scanner/parser.
var source = ToString(this.source);
var sourceUrlPos = %StringIndexOf(source, "sourceURL=", 0);
this.cachedNameOrSourceURL = this.name;
if (sourceUrlPos > 4) {
var sourceUrlPattern =
/\/\/@[\040\t]sourceURL=[\040\t]*([^\s\'\"]*)[\040\t]*$/gm;
// Don't reuse lastMatchInfo here, so we create a new array with room
// for four captures (array with length one longer than the index
// of the fourth capture, where the numbering is zero-based).
var matchInfo = new InternalArray(CAPTURE(3) + 1);
var match =
%_RegExpExec(sourceUrlPattern, source, sourceUrlPos - 4, matchInfo);
if (match) {
this.cachedNameOrSourceURL =
SubString(source, matchInfo[CAPTURE(2)], matchInfo[CAPTURE(3)]);
}
}
return this.cachedNameOrSourceURL;
}
SetUpLockedPrototype(Script,
$Array("source", "name", "line_ends", "line_offset", "column_offset",
"cachedNameOrSourceURL", "hasCachedNameOrSourceURL" ),
$Array(
"lineFromPosition", ScriptLineFromPosition,
"locationFromPosition", ScriptLocationFromPosition,
"locationFromLine", ScriptLocationFromLine,
"sourceSlice", ScriptSourceSlice,
"sourceLine", ScriptSourceLine,
"lineCount", ScriptLineCount,
"nameOrSourceURL", ScriptNameOrSourceURL
)
);
/**
* Class for source location. A source location is a position within some
* source with the following properties:
* script : script object for the source
* line : source line number
* column : source column within the line
* position : position within the source
* start : position of start of source context (inclusive)
* end : position of end of source context (not inclusive)
* Source text for the source context is the character interval
* [start, end[. In most cases end will point to a newline character.
* It might point just past the final position of the source if the last
* source line does not end with a newline character.
* @param {Script} script The Script object for which this is a location
* @param {number} position Source position for the location
* @param {number} line The line number for the location
* @param {number} column The column within the line for the location
* @param {number} start Source position for start of source context
* @param {number} end Source position for end of source context
* @constructor
*/
function SourceLocation(script, position, line, column, start, end) {
this.script = script;
this.position = position;
this.line = line;
this.column = column;
this.start = start;
this.end = end;
}
var kLineLengthLimit = 78;
/**
* Restrict source location start and end positions to make the source slice
* no more that a certain number of characters wide.
* @param {number} opt_limit The with limit of the source text with a default
* of 78
* @param {number} opt_before The number of characters to prefer before the
* position with a default value of 10 less that the limit
*/
function SourceLocationRestrict(opt_limit, opt_before) {
// Find the actual limit to use.
var limit;
var before;
if (!IS_UNDEFINED(opt_limit)) {
limit = opt_limit;
} else {
limit = kLineLengthLimit;
}
if (!IS_UNDEFINED(opt_before)) {
before = opt_before;
} else {
// If no before is specified center for small limits and perfer more source
// before the the position that after for longer limits.
if (limit <= 20) {
before = $floor(limit / 2);
} else {
before = limit - 10;
}
}
if (before >= limit) {
before = limit - 1;
}
// If the [start, end[ interval is too big we restrict
// it in one or both ends. We make sure to always produce
// restricted intervals of maximum allowed size.
if (this.end - this.start > limit) {
var start_limit = this.position - before;
var end_limit = this.position + limit - before;
if (this.start < start_limit && end_limit < this.end) {
this.start = start_limit;
this.end = end_limit;
} else if (this.start < start_limit) {
this.start = this.end - limit;
} else {
this.end = this.start + limit;
}
}
}
/**
* Get the source text for a SourceLocation
* @return {String}
* Source text for this location.
*/
function SourceLocationSourceText() {
return %_CallFunction(this.script.source,
this.start,
this.end,
StringSubstring);
}
SetUpLockedPrototype(SourceLocation,
$Array("script", "position", "line", "column", "start", "end"),
$Array(
"restrict", SourceLocationRestrict,
"sourceText", SourceLocationSourceText
)
);
/**
* Class for a source slice. A source slice is a part of a script source with
* the following properties:
* script : script object for the source
* from_line : line number for the first line in the slice
* to_line : source line number for the last line in the slice
* from_position : position of the first character in the slice
* to_position : position of the last character in the slice
* The to_line and to_position are not included in the slice, that is the lines
* in the slice are [from_line, to_line[. Likewise the characters in the slice
* are [from_position, to_position[.
* @param {Script} script The Script object for the source slice
* @param {number} from_line
* @param {number} to_line
* @param {number} from_position
* @param {number} to_position
* @constructor
*/
function SourceSlice(script, from_line, to_line, from_position, to_position) {
this.script = script;
this.from_line = from_line;
this.to_line = to_line;
this.from_position = from_position;
this.to_position = to_position;
}
/**
* Get the source text for a SourceSlice
* @return {String} Source text for this slice. The last line will include
* the line terminating characters (if any)
*/
function SourceSliceSourceText() {
return %_CallFunction(this.script.source,
this.from_position,
this.to_position,
StringSubstring);
}
SetUpLockedPrototype(SourceSlice,
$Array("script", "from_line", "to_line", "from_position", "to_position"),
$Array("sourceText", SourceSliceSourceText)
);
// Returns the offset of the given position within the containing
// line.
function GetPositionInLine(message) {
var script = %MessageGetScript(message);
var start_position = %MessageGetStartPosition(message);
var location = script.locationFromPosition(start_position, false);
if (location == null) return -1;
location.restrict();
return start_position - location.start;
}
function GetStackTraceLine(recv, fun, pos, isGlobal) {
return FormatSourcePosition(new CallSite(recv, fun, pos));
}
// ----------------------------------------------------------------------------
// Error implementation
// Defines accessors for a property that is calculated the first time
// the property is read.
function DefineOneShotAccessor(obj, name, fun) {
// Note that the accessors consistently operate on 'obj', not 'this'.
// Since the object may occur in someone else's prototype chain we
// can't rely on 'this' being the same as 'obj'.
var hasBeenSet = false;
var value;
var getter = function() {
if (hasBeenSet) {
return value;
}
hasBeenSet = true;
value = fun(obj);
return value;
};
var setter = function(v) {
hasBeenSet = true;
value = v;
};
%DefineOrRedefineAccessorProperty(obj, name, getter, setter, DONT_ENUM);
}
function CallSite(receiver, fun, pos) {
this.receiver = receiver;
this.fun = fun;
this.pos = pos;
}
function CallSiteGetThis() {
return this.receiver;
}
function CallSiteGetTypeName() {
var constructor = this.receiver.constructor;
if (!constructor) {
return %_CallFunction(this.receiver, ObjectToString);
}
var constructorName = constructor.name;
if (!constructorName) {
return %_CallFunction(this.receiver, ObjectToString);
}
return constructorName;
}
function CallSiteIsToplevel() {
if (this.receiver == null) {
return true;
}
return IS_GLOBAL(this.receiver);
}
function CallSiteIsEval() {
var script = %FunctionGetScript(this.fun);
return script && script.compilation_type == COMPILATION_TYPE_EVAL;
}
function CallSiteGetEvalOrigin() {
var script = %FunctionGetScript(this.fun);
return FormatEvalOrigin(script);
}
function CallSiteGetScriptNameOrSourceURL() {
var script = %FunctionGetScript(this.fun);
return script ? script.nameOrSourceURL() : null;
}
function CallSiteGetFunction() {
return this.fun;
}
function CallSiteGetFunctionName() {
// See if the function knows its own name
var name = this.fun.name;
if (name) {
return name;
} else {
return %FunctionGetInferredName(this.fun);
}
// Maybe this is an evaluation?
var script = %FunctionGetScript(this.fun);
if (script && script.compilation_type == COMPILATION_TYPE_EVAL) {
return "eval";
}
return null;
}
function CallSiteGetMethodName() {
// See if we can find a unique property on the receiver that holds
// this function.
var ownName = this.fun.name;
if (ownName && this.receiver &&
(%_CallFunction(this.receiver,
ownName,
ObjectLookupGetter) === this.fun ||
%_CallFunction(this.receiver,
ownName,
ObjectLookupSetter) === this.fun ||
this.receiver[ownName] === this.fun)) {
// To handle DontEnum properties we guess that the method has
// the same name as the function.
return ownName;
}
var name = null;
for (var prop in this.receiver) {
if (this.receiver.__lookupGetter__(prop) === this.fun ||
this.receiver.__lookupSetter__(prop) === this.fun ||
(!this.receiver.__lookupGetter__(prop) &&
this.receiver[prop] === this.fun)) {
// If we find more than one match bail out to avoid confusion.
if (name) {
return null;
}
name = prop;
}
}
if (name) {
return name;
}
return null;
}
function CallSiteGetFileName() {
var script = %FunctionGetScript(this.fun);
return script ? script.name : null;
}
function CallSiteGetLineNumber() {
if (this.pos == -1) {
return null;
}
var script = %FunctionGetScript(this.fun);
var location = null;
if (script) {
location = script.locationFromPosition(this.pos, true);
}
return location ? location.line + 1 : null;
}
function CallSiteGetColumnNumber() {
if (this.pos == -1) {
return null;
}
var script = %FunctionGetScript(this.fun);
var location = null;
if (script) {
location = script.locationFromPosition(this.pos, true);
}
return location ? location.column + 1: null;
}
function CallSiteIsNative() {
var script = %FunctionGetScript(this.fun);
return script ? (script.type == TYPE_NATIVE) : false;
}
function CallSiteGetPosition() {
return this.pos;
}
function CallSiteIsConstructor() {
var constructor = this.receiver ? this.receiver.constructor : null;
if (!constructor) {
return false;
}
return this.fun === constructor;
}
SetUpLockedPrototype(CallSite, $Array("receiver", "fun", "pos"), $Array(
"getThis", CallSiteGetThis,
"getTypeName", CallSiteGetTypeName,
"isToplevel", CallSiteIsToplevel,
"isEval", CallSiteIsEval,
"getEvalOrigin", CallSiteGetEvalOrigin,
"getScriptNameOrSourceURL", CallSiteGetScriptNameOrSourceURL,
"getFunction", CallSiteGetFunction,
"getFunctionName", CallSiteGetFunctionName,
"getMethodName", CallSiteGetMethodName,
"getFileName", CallSiteGetFileName,
"getLineNumber", CallSiteGetLineNumber,
"getColumnNumber", CallSiteGetColumnNumber,
"isNative", CallSiteIsNative,
"getPosition", CallSiteGetPosition,
"isConstructor", CallSiteIsConstructor
));
function FormatEvalOrigin(script) {
var sourceURL = script.nameOrSourceURL();
if (sourceURL) {
return sourceURL;
}
var eval_origin = "eval at ";
if (script.eval_from_function_name) {
eval_origin += script.eval_from_function_name;
} else {
eval_origin += "<anonymous>";
}
var eval_from_script = script.eval_from_script;
if (eval_from_script) {
if (eval_from_script.compilation_type == COMPILATION_TYPE_EVAL) {
// eval script originated from another eval.
eval_origin += " (" + FormatEvalOrigin(eval_from_script) + ")";
} else {
// eval script originated from "real" source.
if (eval_from_script.name) {
eval_origin += " (" + eval_from_script.name;
var location = eval_from_script.locationFromPosition(
script.eval_from_script_position, true);
if (location) {
eval_origin += ":" + (location.line + 1);
eval_origin += ":" + (location.column + 1);
}
eval_origin += ")";
} else {
eval_origin += " (unknown source)";
}
}
}
return eval_origin;
}
function FormatSourcePosition(frame) {
var fileName;
var fileLocation = "";
if (frame.isNative()) {
fileLocation = "native";
} else if (frame.isEval()) {
fileName = frame.getScriptNameOrSourceURL();
if (!fileName) {
fileLocation = frame.getEvalOrigin();
}
} else {
fileName = frame.getFileName();
}
if (fileName) {
fileLocation += fileName;
var lineNumber = frame.getLineNumber();
if (lineNumber != null) {
fileLocation += ":" + lineNumber;
var columnNumber = frame.getColumnNumber();
if (columnNumber) {
fileLocation += ":" + columnNumber;
}
}
}
if (!fileLocation) {
fileLocation = "unknown source";
}
var line = "";
var functionName = frame.getFunction().name;
var addPrefix = true;
var isConstructor = frame.isConstructor();
var isMethodCall = !(frame.isToplevel() || isConstructor);
if (isMethodCall) {
var methodName = frame.getMethodName();
line += frame.getTypeName() + ".";
if (functionName) {
line += functionName;
if (methodName && (methodName != functionName)) {
line += " [as " + methodName + "]";
}
} else {
line += methodName || "<anonymous>";
}
} else if (isConstructor) {
line += "new " + (functionName || "<anonymous>");
} else if (functionName) {
line += functionName;
} else {
line += fileLocation;
addPrefix = false;
}
if (addPrefix) {
line += " (" + fileLocation + ")";
}
return line;
}
function FormatStackTrace(error, frames) {
var lines = [];
try {
lines.push(error.toString());
} catch (e) {
try {
lines.push("<error: " + e + ">");
} catch (ee) {
lines.push("<error>");
}
}
for (var i = 0; i < frames.length; i++) {
var frame = frames[i];
var line;
try {
line = FormatSourcePosition(frame);
} catch (e) {
try {
line = "<error: " + e + ">";
} catch (ee) {
// Any code that reaches this point is seriously nasty!
line = "<error>";
}
}
lines.push(" at " + line);
}
return lines.join("\n");
}
function FormatRawStackTrace(error, raw_stack) {
var frames = [ ];
for (var i = 0; i < raw_stack.length; i += 4) {
var recv = raw_stack[i];
var fun = raw_stack[i + 1];
var code = raw_stack[i + 2];
var pc = raw_stack[i + 3];
var pos = %FunctionGetPositionForOffset(code, pc);
frames.push(new CallSite(recv, fun, pos));
}
if (IS_FUNCTION($Error.prepareStackTrace)) {
return $Error.prepareStackTrace(error, frames);
} else {
return FormatStackTrace(error, frames);
}
}
function captureStackTrace(obj, cons_opt) {
var stackTraceLimit = $Error.stackTraceLimit;
if (!stackTraceLimit || !IS_NUMBER(stackTraceLimit)) return;
if (stackTraceLimit < 0 || stackTraceLimit > 10000) {
stackTraceLimit = 10000;
}
var raw_stack = %CollectStackTrace(obj,
cons_opt ? cons_opt : captureStackTrace,
stackTraceLimit);
DefineOneShotAccessor(obj, 'stack', function (obj) {
return FormatRawStackTrace(obj, raw_stack);
});
}
function SetUpError() {
// Define special error type constructors.
var DefineError = function(f) {
// Store the error function in both the global object
// and the runtime object. The function is fetched
// from the runtime object when throwing errors from
// within the runtime system to avoid strange side
// effects when overwriting the error functions from
// user code.
var name = f.name;
%SetProperty(global, name, f, DONT_ENUM);
%SetProperty(builtins, '$' + name, f, DONT_ENUM | DONT_DELETE | READ_ONLY);
// Configure the error function.
if (name == 'Error') {
// The prototype of the Error object must itself be an error.
// However, it can't be an instance of the Error object because
// it hasn't been properly configured yet. Instead we create a
// special not-a-true-error-but-close-enough object.
var ErrorPrototype = function() {};
%FunctionSetPrototype(ErrorPrototype, $Object.prototype);
%FunctionSetInstanceClassName(ErrorPrototype, 'Error');
%FunctionSetPrototype(f, new ErrorPrototype());
} else {
%FunctionSetPrototype(f, new $Error());
}
%FunctionSetInstanceClassName(f, 'Error');
%SetProperty(f.prototype, 'constructor', f, DONT_ENUM);
// The name property on the prototype of error objects is not
// specified as being read-one and dont-delete. However, allowing
// overwriting allows leaks of error objects between script blocks
// in the same context in a browser setting. Therefore we fix the
// name.
%SetProperty(f.prototype, "name", name,
DONT_ENUM | DONT_DELETE | READ_ONLY) ;
%SetCode(f, function(m) {
if (%_IsConstructCall()) {
// Define all the expected properties directly on the error
// object. This avoids going through getters and setters defined
// on prototype objects.
%IgnoreAttributesAndSetProperty(this, 'stack', void 0, DONT_ENUM);
%IgnoreAttributesAndSetProperty(this, 'arguments', void 0, DONT_ENUM);
%IgnoreAttributesAndSetProperty(this, 'type', void 0, DONT_ENUM);
if (m === kAddMessageAccessorsMarker) {
// DefineOneShotAccessor always inserts a message property and
// ignores setters.
DefineOneShotAccessor(this, 'message', function (obj) {
return FormatMessage(%NewMessageObject(obj.type, obj.arguments));
});
} else if (!IS_UNDEFINED(m)) {
%IgnoreAttributesAndSetProperty(this,
'message',
ToString(m),
DONT_ENUM);
}
captureStackTrace(this, f);
} else {
return new f(m);
}
});
%SetNativeFlag(f);
};
DefineError(function Error() { });
DefineError(function TypeError() { });
DefineError(function RangeError() { });
DefineError(function SyntaxError() { });
DefineError(function ReferenceError() { });
DefineError(function EvalError() { });
DefineError(function URIError() { });
}
SetUpError();
$Error.captureStackTrace = captureStackTrace;
%SetProperty($Error.prototype, 'message', '', DONT_ENUM);
// Global list of error objects visited during ErrorToString. This is
// used to detect cycles in error toString formatting.
var visited_errors = new InternalArray();
var cyclic_error_marker = new $Object();
function ErrorToStringDetectCycle(error) {
if (!%PushIfAbsent(visited_errors, error)) throw cyclic_error_marker;
try {
var type = error.type;
var name = error.name;
name = IS_UNDEFINED(name) ? "Error" : TO_STRING_INLINE(name);
var message = error.message;
var hasMessage = %_CallFunction(error, "message", ObjectHasOwnProperty);
if (type && !hasMessage) {
message = FormatMessage(%NewMessageObject(type, error.arguments));
}
message = IS_UNDEFINED(message) ? "" : TO_STRING_INLINE(message);
if (name === "") return message;
if (message === "") return name;
return name + ": " + message;
} finally {
visited_errors.length = visited_errors.length - 1;
}
}
function ErrorToString() {
if (!IS_SPEC_OBJECT(this)) {
throw MakeTypeError("called_on_non_object", ["Error.prototype.toString"]);
}
try {
return ErrorToStringDetectCycle(this);
} catch(e) {
// If this error message was encountered already return the empty
// string for it instead of recursively formatting it.
if (e === cyclic_error_marker) {
return '';
}
throw e;
}
}
InstallFunctions($Error.prototype, DONT_ENUM, ['toString', ErrorToString]);
// Boilerplate for exceptions for stack overflows. Used from
// Isolate::StackOverflow().
var kStackOverflowBoilerplate = MakeRangeError('stack_overflow', []);