========================= Duktape 1.4 release notes ========================= Release overview ================ This release provides small feature and performance improvements (see RELEASES.rst for full details): * Error handling improvements: better error messages for e.g. property operations and function calls; improved .fileName and .lineNumber attribution; directly writable .fileName, .lineNumber, and .stack properties. * Stronger finalizer guarantees: a finalizer is called exactly once, unless the object is rescued in which case the finalizer is called exactly once per rescue cycle. * Typed array constructors now accept a plain buffer with the same semantics as a Duktape.Buffer argument. * Debugger improvements: Throw notify for error about to be thrown; option for automatically pausing on an uncaught error; Detaching notify; correct line number for "debugger" statement. * Initial support for using C++ exceptions instead of setjmp()/longjmp() for internal long control transfers. This change is minimally functional but still a work in progress. * Support indentation and JX/JC formats in the JSON.stringify() fast path. The fast path should now, when enabled, cover a much larger set of use cases. * Performance improvements affecting call handling, string handling, reference counting, hex and base64 encoding and decoding, JSON.stringify() fast and slow paths, and more. * Combined duktape.c without #line directives into the dist package. * Minor API improvements, bug fixes, and compilation warning fixes. Upgrading from Duktape 1.3.x ============================ No action (other than recompiling) should be needed for most users to upgrade from Duktape v1.3.x. Note the following: * Typed array constructors (like Uint16Array) now accept a plain buffer, with behavior matching a Duktape.Buffer argument: the argument is treated as an array of initialization values. There are bug fixes and other minor behavioral changes which may affect some applications, see ``RELEASES.rst`` for details. Known issues ============ This release has the following known issues worth noting. ECMAScript features ------------------- * Non-compliant behavior for array indices near 2G or 4G elements. * RegExp parser is strict and won't accept some real world RegExps which are technically not compliant with ECMAScript E5/E5.1 specification. * Final mantissa bit rounding issues in the internal number-to-string conversion. Portability and platforms ------------------------- * On some older clang/llvm versions (e.g. Clang 3.3 on FreeBSD 10): when ``-m32`` is used, Duktape will end up using the 8-byte packed value representation but clang will generate incorrect code for union assignment (see ``misc/clang_aliasing.c``). The issue can be detected by defining ``DUK_OPT_SELF_TESTS``. A workaround is to avoid packed types in this case by defining ``DUK_OPT_NO_PACKED_TVAL``. * On some older clang/llvm versions (e.g. Clang 3.3 on FreeBSD 10): compilation may produce a warning "generic selections are a C11-specific feature". The warning should be harmless. * On some older clang/llvm versions (e.g. Clang 3.3 on FreeBSD 10): harmless compilation warning for "duk_repl_isinf" being unused. * On some GCC versions and compilation options you may get a warning "variable idx_func might be clobbered by longjmp or vfork [-Wclobbered]". This warning seems spurious and causes no known problems. * GCC ``-O4`` may produce a warning "assuming signed overflow does not occur when assuming that (X - c) > X is always false" for some assertions. This warning seems spurious and causes no known problems. * GCC ``-pedantic`` without ``-std=c99`` causes the ``unsigned long long`` type to be used by Duktape, and an associated warning about the type. This is harmless and most easily fixed by simply using ``-std=c99``. * MSVC ``/Wp64`` produces harmless warnings when compiling for x86. The warnings are caused by 64-bit incompatible code enabled for 32-bit targets; when you actually compile for a 64-bit target, those code paths are not used so the warnings are irrelevant. * MSVC ``/W4`` produces a harmless "conditional expression is constant" warning caused by a sizeof() comparison. * MinGW produces harmless "visibility attribute not supported in this configuration" warnings when compiling from separate sources. * An older mixed endian ARM toolchain (based on gcc-3.x) produces "xxx declared inline after being called" warnings. * The JSON.stringify() fast path (DUK_USE_JSON_STRINGIFY_FASTPATH) assumes that "%lld" format specifier is correct for the "unsigned long long" type. Raw issues from test runs ========================= API tests --------- See ``testcase-known-issues.yaml``:: test-to-number.c: fail; 15 diff lines; known issue: number parsing bug for strings containing NUL characters (e.g. '\u0000') ECMAScript tests ---------------- See ``testcase-known-issues.yaml``:: test-bi-array-proto-push: fail; 30 diff lines; known issue: array length above 2^32-1 not supported test-bi-array-push-maxlen: fail; 17 diff lines; known issue: array length above 2^32-1 not supported test-bi-date-tzoffset-brute-fi: fail; 12 diff lines; known issue: year 1970 deviates from expected, Duktape uses equiv. year for 1970 on purpose at the moment; requires special feature options: test case has been written for Finnish locale test-bi-function-nonstd-caller-prop: fail; 178 diff lines; requires special feature options: DUK_OPT_NONSTD_FUNC_CALLER_PROPERTY test-bi-global-parseint: fail; 108 diff lines; known issue: rounding differences for parsing integers larger than 2^53 test-bi-json-dec-types: fail; 21 diff lines; known issue: '\x' should be allowed by eval() but not by JSON.parse(), Duktape rejects '\x' in both test-bi-json-enc-proplist-dups: fail; 8 diff lines; known issue: JSON.stringify() can be given a property list to serialize; duplicates should be eliminated but Duktape (and other engines) will happily serialize a property multiple times test-bi-json-enc-proxy: fail; 18 diff lines; known issue: JSON enumeration behavior for Proxy targets is incomplete and uses 'enumerate' trap instead of 'ownKeys' trap test-bi-number-proto-toexponential: fail; 75 diff lines; known issue: corner case rounding errors in toExponential() test-bi-number-proto-tostring: fail; 46 diff lines; known issue: expect strings to be checked, but probably Duktape rounding issues test-bi-regexp-gh39: fail; 5 diff lines; known issue: requires leniency for non-standard regexps test-bug-dataview-buffer-prop: fail; 20 diff lines; known issue: DataView .buffer property misleading when DataView argument is not an ArrayBuffer (custom behavior) test-bug-date-timeval-edges: fail; 17 diff lines; known issue: test case depends on current timezone offset test-bug-enum-shadow-nonenumerable: fail; 12 diff lines; known issue: corner case enumeration semantics, not sure what correct behavior is (test262 ch12/12.6/12.6.4/12.6.4-2) test-bug-invalid-oct-as-dec: fail; 16 diff lines; known issue: V8/Rhino parse invalid octal constants as decimal values, Duktape doesn't at the moment test-bug-json-parse-__proto__: fail; 18 diff lines; known issue: when ES6 __proto__ enabled, JSON.parse() parses '__proto__' property incorrectly when a specially crafted reviver is used test-bug-numconv-1e23: fail; 10 diff lines; known issue: corner case in floating point parse rounding test-bug-numconv-denorm-toprec: fail; 7 diff lines; known issue: in a denormal corner case toPrecision() can output a zero leading digit test-bug-tonumber-u0000: fail; 7 diff lines; known issue: '\u0000' should ToNumber() coerce to NaN, but now coerces to zero like an empty string test-dev-bound-thread-start-func: fail; 13 diff lines; known issue: initial function of a new coroutine cannot be bound test-dev-func-cons-args: fail; 18 diff lines; known issue: corner cases for 'new Function()' when arguments and code are given as strings test-dev-lightfunc-accessor: fail; 50 diff lines; requires special feature options: DUK_OPT_LIGHTFUNC_BUILTINS test-dev-lightfunc-finalizer: fail; 8 diff lines; requires special feature options: DUK_OPT_LIGHTFUNC_BUILTINS test-dev-lightfunc: fail; 462 diff lines; requires special feature options: DUK_OPT_LIGHTFUNC_BUILTINS test-dev-yield-after-callapply: fail; 8 diff lines; known issue: yield() not allowed when function called via Function.prototype.(call|apply)() test-lex-unterminated-hex-uni-escape: fail; 29 diff lines; known issue: unterminated hex escapes should be parsed leniently, e.g. '\uX' -> 'uX' but Duktape now refuses to parse them test-numconv-parse-misc: fail; 12 diff lines; known issue: rounding corner case for 1e+23 (parses/prints as 1.0000000000000001e+23) test-numconv-tostring-gen: fail; 257 diff lines; known issue: rounding corner cases in number-to-string coercion test-numconv-tostring-misc: fail; 6 diff lines; known issue: rounding corner case, 1e+23 string coerces to 1.0000000000000001e+23 test-regexp-empty-quantified: fail; 15 diff lines; known issue: a suitable empty quantified (e.g. '(x*)*') causes regexp parsing to terminate due to step limit test-regexp-invalid-charclass: fail; 7 diff lines; known issue: some invalid character classes are accepted (e.g. '[\d-z]' and '[z-x]') test-regexp-nonstandard-patternchar: fail; 6 diff lines; known issue: other engines allow an unescaped brace to appear literally (e.g. /{/), Duktape does not (which seems correct but is against real world behavior) test-stmt-for-in-lhs: fail; 29 diff lines; known issue: for-in allows some invalid left-hand-side expressions which cause a runtime ReferenceError instead of a compile-time SyntaxError (e.g. 'for (a+b in [0,1]) {...}') test262 ------- See ``test262-status.rst`` and ``test262-known-issues.yaml``. With ECMAScript 6 and Intl module tests removed:: ch12/12.6/12.6.4/12.6.4-2 in non-strict mode // diagnosed: enumeration corner case issue, see test-bug-enum-shadow-nonenumerable.js ch15/15.10/15.10.2/15.10.2.5/S15.10.2.5_A1_T5 in non-strict mode // diagnosed: Duktape bug, matching /(a*)b\1+/ against 'baaaac' causes first capture to match the empty string; the '\1+' part will then use the '+' quantifier over the empty string. As there is no handling to empty quantified now, Duktape bails out with a RangeError. ch15/15.10/15.10.2/15.10.2.9/S15.10.2.9_A1_T5 in non-strict mode // diagnosed: Duktape bug, matching /(a*)b\1+/ against 'baaac' causes first capture to be empty, the '\1+' part will then quantify over an empty string leading to Duktape RangeError (there is no proper handling for an empty quantified now) ch15/15.4/15.4.4/15.4.4.10/S15.4.4.10_A3_T3 in non-strict mode // diagnosed: probably Duktape bug related to long array corner cases or 'length' sign handling (C typing?) ch15/15.4/15.4.4/15.4.4.12/S15.4.4.12_A3_T3 in non-strict mode // diagnosed: probably Duktape bug related to long array corner cases or 'length' sign handling (C typing?) ch15/15.4/15.4.4/15.4.4.14/15.4.4.14-5-12 in non-strict mode // diagnosed: Array length over 2G, not supported right now ch15/15.4/15.4.4/15.4.4.14/15.4.4.14-5-16 in non-strict mode // diagnosed: Array length over 2G, not supported right now ch15/15.4/15.4.4/15.4.4.14/15.4.4.14-9-9 in non-strict mode // diagnosed: a.indexOf(,4294967290) returns -1 for all indices n=2,3,4,5 but is supposed to return 4294967294 for n=2. The cause is long array corner case handling, possibly signed length handling (C typing?) ch15/15.4/15.4.4/15.4.4.15/15.4.4.15-5-12 in non-strict mode // diagnosed: probably Duktape bug: long array corner cases (C typing?) ch15/15.4/15.4.4/15.4.4.15/15.4.4.15-5-16 in non-strict mode // diagnosed: probably Duktape bug: long array corner cases (C typing?) ch15/15.4/15.4.4/15.4.4.15/15.4.4.15-8-9 in non-strict mode // diagnosed: probably Duktape bug: long array corner cases (C typing?)