* Invalidate the literal cache on every mark-and-sweep round, and allow
collection of pinned literals. This approach still allows the literal
cache to be simplistic and without an invalidation mechanism in normal
operation (between mark-and-sweep rounds), but still allows eventual
collection of pinned literals if they stop occurring.
* Log level fixes.
* Automatically pin C literals interned into heap strings. Or if the
literal maps to an already interned string, pin it too. Pinning is
implemented using a duk_hstring flag and a one-off refcount bump.
Mark-and-sweep avoids sweeping pinned strings based on the flag.
* Add a lookup cache for quickly mapping a C literal address (which is
assumed stable) into a duk_hstring pointer. Once a mapping has been
formed, it never needs to be invalidated because the duk_hstring is
always pinned if the cache is used. Only heap destruction will free
the pinned duk_hstrings.
* More internal call site conversion for literals.
* Wording trivia.
* Add internal wrappers also to DUK_MEMMOVE(), DUK_MEMSET(), and
DUK_MEMZERO().
* Use the wrappers everywhere for consistency: the zero-size cases will then
always be safe, and if the target is fine with invalid pointers in the zero
size case, the whole check can be omitted easily.
* Remove a few zero size checks as they're no longer necessary.
* Replace the two alternative algorithms with a single one which works for
both desktop and low memory cases.
* Basic algorithm is a hash table with size 2^N, hash mask is simply
(size - 1), e.g. if size is 0x100, mask is 0xFF. duk_hstring has a 'next'
pointer (single linked list) for chaining strings mapping to the same
slot.
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.
* 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.
Lots of minor string format cleanups (casts mainly).
Add a special check to detect NULL pointers with %s/%p formats in debug
logging to avoid calling the platform sprintf() with a NULL value. This
is especially important for %s + NULL, which is not portable and may crash
on some platforms. Debug logging will now format these specially as "NULL"
and avoid calling the platform for formatting, so debug log call sites don't
need to be careful with NULL pointers any more.
Sami Vaarala