Fixes#9111.
We have existing packages which have only .js in them, for touch-only
keyboards (mostly legacy but still...), so we need to support the freaky
Javascript regex search which we did in the past for extracting
metadata. While this is not necessarily going to work with hand-crafted
Javascript keyboards, it should work with all kmc- and kmcomp-generated
keyboards, so it will suffice to support these legacy packages.
In the future, we will be giving a hint when a package includes a .js
but not a .kmx, gradually upgrading this to a warning and finally an
error as we attempt to phase out .js-based keyboards in preference for
.kmx keyboards.
Running kmc on a set of keyboards would sporadically fail after some
time. It turns out this was related to memory allocation, specifically,
resizing the WASM module's memory buffer caused `TypedArray` views into
the memory to be reset!
By default, when a `Uint8Array` is created from an `ArrayBuffer` (e.g.
`Module.HEAP8.buffer`), it is a dynamic view into that buffer. This
module buffer can be dynamically reallocated at any time, which can
happen when allocating memory in WASM code (so the change will look
_really_ weird in a stack trace). Thus, to ensure we don't trip over
ourselves, we need to copy the buffer. Fortunately, creating a
`Uint8Array` from a `Uint8Array` copies the data, and is pretty quick.
When we read .kmx files, they have no alignment guarantees, so we need
to tell the compiler to generate unaligned-safe code for accesses to
`COMP_` structure members, because typically we point into the buffer
and read at any offset.
A .kmx file will generally be 2-byte aligned, as there are no structures
or data types with smaller than 2 byte widths. There is no requirement
that this be the case per the .kmx spec, though. So we use a 1 byte
alignment attribute for the compiler, so it will generate safe code when
reading these structs.
Note that we are assuming that `COMP_KEYBOARD` is aligned because it is
always the start of the file, so will be at the start of any buffer
which will automatically be aligned correctly.
We should probably review some of our design decisions and structs for
KMXPlus given this.
Picked this up while running `-fsanitize=address` for trying to track
down another bug.
This fixes a buffer overrun (normally invisible) in kmcmplib, where
`xstrchr` was being called, which takes a string as its second
parameter, but being passed a single character. This was incorrect
behaviour for two reasons:
1. Passing a single character doesn't have null termination (big bug!)
2. We were not wanting xstring semantics on the token being parsed here
Replaced with `u16chr`, which does do what we want. Note the
casting because `u16chr` only has a `const` version of its input/output
at present.
Removed `xstrchr` because it is not used anywhere else in kmcmplib.
The kmcmplib compiler source used `delete` instead of `delete[]` in a
number of locations where the corresponding allocation was an array.
This doesn't appear to matter on arrays of primitives on most platforms
that we are targeting, but it _is_ undefined behaviour so we should
correct it.
https://stackoverflow.com/a/2425749/1836776
