Saves a few hundred bytes of footprint:
* duk_dup_0() = duk_dup(ctx, 0), duk_dup_1() = duk_dup(ctx, 1), etc.
* duk_dup_m2() = duk_dup(ctx, -2), etc.
* duk_dup_m1() is not added, because duk_dup_top() is the same thing
* Plain buffers still inherit from ArrayBuffer.prototype.
* Plain buffers won't object coerce, so Object(plainBuffer) fails.
* All buffer object related methods throw an error; their function bodies
are essentially empty. Note that this includes bindings such as
String.fromBuffer(), ArrayBuffer.allocPlain(), ArrayBuffer.plainOf(),
and so on. In essence, you can index plain buffers in Ecmascript but
the buffer values must be created via the C API.
* Duktape custom bindings like Duktape.dec('hex', 'deadbeef') still work
and produce plain buffers.
Change handling of plain buffers so that they behave like ArrayBuffer
instances to Ecmascript code, with limitations such as not being
extensible and all properties being virtualized. This simplifies
Ecmascript code as plain buffers are just lightweight ArrayBuffers
(similarly to how lightfuncs appear as function objects). There are
a lot of small changes in how the built-in objects and methods, and
the C API deals with plain buffer values.
Also make a few small changes to plain pointer and lightfunc handling
to improve consistency with how plain buffers are now handled.
These don't play well with the API currently: the Duktape specific error
codes don't have Ecmascript Error class counterparts so they don't get
represented usefully as Ecmascript objects (e.g. AllocError is a plain
Error from Ecmascript point of view).
There's no real need for Duktape specific error code. Some of the codes
had become unused; a couple were used but Ecmascript standard types can
be used instead.
Also minor error message tweaking.
Improve readability by doing the following renames:
* duk_hcompiledfunction -> duk_hcompfunc
* duk_hnativefunction -> duk_hnatfunc
* duk_hbufferobject -> duk_hbufobj
Corresponding renames for all caps defines.
This makes it easier to pass C pointers to state structs etc without having
to use duk_push_pointer() and the value stack.
Change internal duk_safe_call() sites to use udata where appropriate.
* Use shared error macros and shared error handler to reduce the size of call
sites of common errors.
* Make zero argument DUK_ERROR() calls non-vararg calls to reduce call site
footprint. Non-vararg calls have smaller call sites and because there are
a lot of call sites, this turns out to be significant.
* Remove variadic macros from internal DUK_ERROR() macro set and add separate
macros for argument counts 0 to 4; this is more portable and requires less
conditional code, and works well when a non-vararg call is used for most
error call sites.
* Rework macro / function argument order for the error path, try to keep 'thr'
in the same argument slot to avoid unnecessary register moves.
* Pack linenumber and error code into a single 32-bit argument when possible,
removes one more constant load from the call site.
* Convert some internal errors to RangeErrors when the underlying cause is an
implementation limit (such as a compiler temp limit) rather than an actual
unexpected internal situation.
* Simplify and share a few error messages to reduce string count.
* Use a single step value encoding approach instead of a two-step one
* Rework slow path value encoding to rewind: by simply rewinding the
ufwriter the awkward two-step approach can be avoided.
* Also rework automatic "naked" key escape code to be a bit simpler.
* Fix automatic unboxing of strings, numbers, etc in JSON.stringify()
fast path; it needs to invoke .toString() / .valueOf() explicitly
if they have been replaced in the object itself or in the prototype
chain.
- Faster hex decode invalid input check for duk_hex_decode() fast path
- Faster JX/JC hex encode
- Slightly faster JX/JC hex decode (avoid string intern for temp value)
- Relocate decode tables, they may be useful in other files later
- Loop typing changes
Also fix a minor fast path bug when unboxing String, Number, or Boolean.
Recursion depth was not decremented so it would accumulate and potentially
cause the fast path to fail unnecessarily. Outwardly this has no other
impact than the serialization being slower than intended.
Reorder tags to accommodate a separate 'unused' tag so that 'undefined' can
become a single tag write (instead of tag + value like booleans). This is
good because 'undefined' values are involved in e.g. value stack resizes and
are performance relevant.
Also reorder tags so that "is heap allocated" check can be a single bit test
instead of a comparison when using non-packed duk_tval. This makes every
DECREF potentially faster because an "is heap allocated" test appears in
every DECREF.
Because "unused" is not intended to appear anywhere in actual use (e.g. as
a value stack value, as a property value, etc), "unused" values will fall
into the default clause of DUK_TAG_xxx switch case statements. Add an assert
to every such default clause that the value is not intended to be "unused".
Remove duk_push_unused() as it should no longer be used. It was only used
by the debugger protocol; refuse an inbound "unused" value in the debugger.
This is not breaking compatibility because there was no legitimate usage for
the debug client sending requests with "unused" values.
Remove support for 'full tval' init. It was never enabled, and there was no
'full tval' support for non-packed duk_tval anyway.
Add fastint marker to Duktape.env.
Also remove mostly unused old debug code.
Debug code doesn't have access to 'heap' so it cannot decode pointers.
Cause an #error for now if both debug prints and pointer compression
are enabled at the same time.
Remove duk_debug_hobject.c from make and dist. It was out of date and
not used in practice anymore.
- Avoid warning for unreferenced variables
- Fix incorrect (non-existent) macro name (DUK_NEVER_HERE)
- Fix built-in missing prototype
- Fix C++ static variable issue
- Avoid pc2line lookup when not enabled
- Change combine_src.py order to match C++ static var requirements
- Use volatile in cause segfault to avoid clang warning
Add a C API binding for Object.defineProperty(): duk_def_prop().
In addition to Object.defineProperty() features, the API call provides a
"force" flag which allows properties to be added to non-extensible objects
and non-configurable properties to be changed (except virtual properties
which are immutable).
Because the name duk_def_prop() conflicts with internal calls, rename them
from duk_def_prop*() to duk_xdef_prop*(). This rename also makes it clearer
that the internal duk_xdef_prop*() calls have non-compliant, internal
semantics.
Also reimplement Object.defineProperty() and Object.defineProperties() (and
duk_def_prop()) so that they share the same internal helpers, and there is
no need for a temporary property descriptor object which is unnecessary churn.
Detailed changes:
- New helper to prepare (validate and normalize) property descriptors
- New helper to implement Object.defineProperty() internals, leaving
out validation of the property descriptor
- Reimplement Object.defineProperty() using the new helpers
- Reimplement Object.defineProperties() using the new helpers
- Reimplement duk_define_property() using the new helpers, so that a
temporary property descriptor object is no longer created
- Add support for "force" flag to Object.defineProperty()
* Fix outstanding FIXME issues for lightfunc semantics.
* Improve API and Ecmascript testcases to match.
* Clarify lightfunc limitations, e.g. finalizer limitations.
* Guide and API documentation changes for lightfuncs.
* Fix compile warning: duk_str_not_object unused.
A lot of changes to add preliminary lightfunc support:
* Add LIGHTFUNC tagged type to duk_tval.h and API.
* Internal changes for preliminary to support lightfuncs in call handling
and other operations (FIXMEs left in obvious places where support is
still missing after this commit)
* Preliminary Ecmascript and API testcases for lightfuncs
Detailed notes:
* Because magic is signed, reading it back involves sign extension which is
quite verbose to do in C. Use macros for reading the magic value and other
bit fields encoded in the flags.
* Function.prototype.bind(): the 'length' property of a bound function now
comes out wrong. We could simply look up the virtual 'length' property
even if h_target is NULL: no extra code and binding is relatively rare in
hot paths. Rewrite more cleanly in any case.
* The use flag DUK_USE_LIGHTFUNC_BUILTINS controls the forced lightfunc
conversion of built-ins. This results in non-compliant built-ins but
significant memory savings in very memory poor environments.
* Reject eval(), Thread.yield/resume as lightfuncs. These functions have
current assertions that they must be called as fully fledged functions.
* Lightfuncs are serialized like ordinary functions for JSON, JX, and JC
by this diff.
* Add 'magic' to activation for lightfuncs. It will be needed for lightweight
functions: we don't have the duk_tval related to the lightfunc, so we must
copy the magic value to the activation when a call is made.
* When lightfuncs are used as property lookup base values, continue property
lookup from the Function.prototype object. This is necessary to allow e.g.
``func.call()`` and ``func.apply()`` to be used.
* Call handling had to be reworked for lightfuncs, especially how bound
function chains are handled. This is a relatively large change but is
necessary to support lightweight functions properly in bound function
resolution.
The current solution is not ideal. The bytecode executor will first try an
ecma-to-ecma call setup which resolves the bound function chain first. If
the final, unbound function is not viable (a native function) the call setup
returns with an error code. The caller will then perform a normal call.
Although bound function resolution has already been done, the normal call
handling code will re-do it (and detect there is nothing to do).
This situation could be avoided by decoupling bound function handling and
effective this binding computation from the actual call setup. The caller
could then to do this prestep first, and only then decide whether to use an
ecma-to-ecma call or an ordinary heavyweight call.
Remove duk__find_nonbound_function as unused.
* Use indirect magic to allow LIGHTFUNCs for Date. Most of the built-in
functions not directly eligible as lightfuncs are the Date built-in methods,
whose magic values contain too much information to fit into the 8-bit magic
of a LIGHTFUNC value.
To work around this, add an array (duk__date_magics[]) containing the
actual control flags needed by the built-ins, and make the Date built-in
magic value an index into this table. With this change Date built-ins are
successfully converted to lightfuncs.
Testcase fixes:
- Whitespace fixes
- Print error for indirect eval error to make diagnosis easier
- Fix error string to match errmsg updated in this branch
Sami Vaarala