* Use same "proxy rejected" for all Proxy invariant rejects.
* #ifdef guard for proxy policy checks.
* Test coverage for 'preventExtensions' trap.
* Convert many duk_hobject.h macro calls into function calls.
* Add functions to interact with idx_props allocation.
* Compile warning fixes.
* Fix Proxy.revocable() revoker function .name and .length properties
(empty name, 0 length).
* Summarize a revoked proxy as '[object RevokedProxy]' in internal readable
summary string, and add test coverage.
* Rename internal duk_push_class_string() as duk_push_objproto_tostring()
for clarity, the helper has Object.prototype.toString() semantics
(except when avoid_side_effects = 1).
* Fix duk_push_objproto_tostring() behavior for revoked Proxies, required
behavior is to throw (this happens in the @@toStringTag lookup which is
unconditional).
* Rename duk_get_top_index_unsafe() -> duk_get_top_index_known() for clarity.
* Add more duk_get_top_index_known() call sites when value stack is known
to have >= 1 entries.
* Rename duk_pop_unsafe() and variants to duk_pop_known() which is more
descriptive.
* Use duk_push_{undefined,tval}_unsafe() instead of direct valstack_top
manipulation in executor and a few other places.
* Add test coverage for chained Proxies in call setup.
* Minor code improvements.
Change function .arguments and .caller behavior to be in line with the
latest specification:
* No own .arguments or .caller property for Function instances. V8 provides
non-strict functions with null .caller and .arguments properties (but they
are not required by the specification).
* Inherit .arguments and .caller thrower from Function.prototype.
Also change %ThrowTypeError%.name to the empty string to match V8.
Isolate all char-offset-to-byte-offset and character access calls
behind helpers to help prepare for a switch to WTF-8 representation.
This change should have no visible effect yet.
Input 'val' pointer may be a value stack pointer, which may become
stale if the variable lookup reallocates the current value stack.
This can happen e.g. in a with(proxy).
* Rename hobject helper functions for property entry access.
* Add helpers for looking up _Formals and _Varmap without inheritance.
* Add duk_xget_owndataprop() + variants for internal property lookups
without inheritance or side effects.
* Date built-in fix for .setTime(), .setYear(), etc on a frozen Date
instance. These should be allowed because they operate on an internal
slot which is not under normal property access control. Previously
the operations were incorrectly rejected with a TypeError.
* Changes to internal property definition and lookup here and there.
Mostly the changes should be no-op because e.g. inheritance only
matters if the internal property might be missing (which is not
usually the case).
* Rework duk_heaphdr and subclass assertions into functions to
reduce debug build size.
* Add explicit object validity assert passes to mark-and-sweep.
This allows detection of invalid internal structures especially
when used with GC torture.
* Rename assertion macros for consistency, e.g. from
DUK_ASSERT_HSTRING_VALID to DUK_HSTRING_ASSERT_VALID.
* Change duk_bool_to to duk_small_uint_t from duk_small_int_t. This may
cause some sign warnings in calling code.
* Reject attempt to unpack an array-like value whose length is 2G or over;
previously was not checked explicitly, and the length was cast to duk_idx_t
with a sign change and the unpack would then later fail. Now it fails with
a clean RangeError.
* Add wrap check for Node.js Buffer.concat().
* API DUK_TYPE_xxx, DUK_TYPE_MASK_xxx, flag constants etc are now unsigned.
Both duk_hthread and duk_context typedefs resolve to struct duk_hthread
internally. In external API duk_context resolves to struct duk_hthread
which is intentionally left undefined as the struct itself is not
dereferenced. Change internal code to use duk_hthread exclusively which
removes unnecessary and awkward thr <-> ctx casts from internals.
The basic guidelines are:
* Public API uses duk_context in prototype declarations. The intent is to
hide the internal type, and there's already a wide dependency on the
type name.
* All internal code, both declarations and definitions, use duk_hthread
exclusively. This is done even for API functions, i.e. an API function
declared as "void duk_foo(duk_context *ctx);" is then defined as
"void duk_foo(duk_hthread *thr);".
* Make value stack and call stack limits configurable via DUK_USE_xxx
options. Also make value stack grow/shrink constants configurable.
* Rewrite value stack grow/shrink check primitives for better hot/cold path
handling.
* Use a proportional spare for grow and shrink sizes so that applications
needing a large value stack have fewer value stack resizes.
* Grow value stack allocation when entering a call or when explicitly requested
via e.g. duk_require_stack().
* Never shrink the value stack when entering a call, so that the unwind path
is guaranteed to have value stack to handle a protected call return. This
guarantee is only needed for protected call but is now applied to all calls
for simplicity.
* Don't perform a value stack shrink check at all in function return anymore.
It would be OK from protected call semantics perspective to do a shrink
attempt without throwing if it fails.
* Perform a value stack shrink check in mark-and-sweep only for now. When
emergency GC is running, shrink to a minimal size respecting current value
stack reserve.
Remove thr->callstack as a monolithic array and replace it with a linked list
of duk_activations. thr->callstack_curr is the current call (or NULL if no
call is in progress), and act->parent chains to a previous call or NULL.
thr->callstack_top is kept because it's needed by some internals at present;
it may be removed in the future.
When the flag is set, there is either no subclass C struct for the
duk_hobject, or there is a subclass C struct but there are no references
needing DECREF/marking in the struct.
This allows DECREF and mark-and-sweep to handle duk_hobjects with less
overhead for the common cases of plain objects and arrays (and some other
less commonly collected structs like duk_hnatfunc).
Also change Duktape.Thread.prototype internal class from Thread to Object:
with the other changes internal code now assumes that if an object's class
is Thread, it has the duk_hthread memory layout which wouldn't be the case
for Duktape.Thread.prototype.
One bottleneck in refzero and mark-and-sweep handling is checking whether an
object has an own or inherited _Finalizer property. This check walked the
prototype chain and did a property lookup for every object. Because a
finalizer is usually not present, the prototype chain would almost always be
walked to completion.
Improve this behavior by:
* Adding a DUK_HOBJECT_FLAG_HAVE_FINALIZER flag. The flag is set when the
object has an own _Finalizer property with a callable value, and cleared
otherwise. The flag is *only* set by duk_set_finalizer(), so any other
means of changing the internal _Finalizer property will leave the flag out
of sync (which causes a finalizer run to be skipped).
* Adding duk_hobject_has_finalizer_fast() which checks for finalizer existence
by walking the prototype chain, but only checking the flag, not the property
table.
* Use the fast finalizer check in refzero and mark-and-sweep.
Out-of sync cases:
* If the flag is set but there is no actual finalizer, the object will go
through finalizer processing when garbage collecting. This is harmless:
the finalizer call will fail and the object will be garbage collected, but
with some potential delay (especially for mark-and-sweep).
* If the flag is cleared but there is an actual finalizer, the finalizer will
be ignored.
Related changes:
* When duk_dump_function() is called, zero DUK_HOBJECT_FLAG_HAVE_FINALIZER on
serialization, so it won't be set when the function is loaded back. If this
is not done, the loaded function will (harmlessly) go through finalizer
processing when garbage collected.
* Update debugger artificial properties to include "have_finalizer" flag.
Other changes:
* A few DUK_UNLIKELY() attributes for prototype sanity limits which are
almost never hit.
* Allow duplicates keys, even in strict mode (ES6).
* Add identifier reference shorthand: { Math }.
* Add method definition shorthand: { foo(a,b) { return a + b; } }.
* Eval/program code no longer has the CONSTRUCTABLE flag which was
previously set. Calling an eval/program function as a constructor
makes no sense and wasn't really supported previously. This change
has no compliance impact because eval/program code doesn't exist as
an unexecuted function in Ecmascript.
* Eval/program code no longer has a NAMEBINDING flag which was previously
set. The revised behavior is cleaner because eval/program code must
not have a name binding. However, the flag is only consulted if NEWENV
is also set, and NEWENV is never set for eval/program code. So this
change has no other effect other than affecting dumped bytecode.
* Anonymous functions don't have an own '.name' property but inherit
an empty string .name from Function.prototype.
* new Function() returns a function whose name is 'anonymous'.
These can be used whenever we're 100% certain that the value stack index
exists and the type matches expected type. When these are true, a
duk_hstring, duk_hbuffer, or duk_hobject pointer fetch can be inlined to
small code.
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
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.
Eval code doesn't need an automatic prototype object, so avoid creating one.
This also avoids making the internal function which eval compiles to part of
a reference loop so that eval functions collect immediately.
* 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.
Sami Vaarala