Previously, `*macro-lints*` was set after the `macroexpand1` fiber was
resumed, rather than just before. And, `*macro-lints*` was never
cleared. This behavior was typically fine since the main users of
`compile` pass the same lint array repeatedly, and the first macro
expansion (somewhere in boot.janet) never produces a lint. But, when
compiling with a fresh lint array, if the first macro invocation
produced a lint, the lint was always lost.
Coming from commit 77189b6e66, relating
to changes in source mapping debug info, this caused a segfault when
traversing a stack frame where the birth_pc was incredibly large due
to wrap around. This fix prevents the wrap around and does saturating
subtraction to 0.
This removes unnecessary movn, movf, lds, and a few other instructions.
Any instructions that has not side effects and writes to a slot that
isn't used can be removed. A number of other optimizations can follow
from this:
- Implement the def-aliasing-var optimization better
- This function can be iterated as a fix point until no more
instructions are removed.
- If we implement slot renaming, then we no longer need to free slots
and can simplify the initial code generation a lot.
This turns splices that are ignored into compiler errors. Other
alternatives here should also be considered, for example making this
a compiler warning rather than an error. For example, the latest
spork as of a3ee63c137ee3234987dbbca71b566994ff8ae8c has an error of this
kind, but the resulting program does work correctly.
Also disallow splice propagation - code of the
form (+ 1 (do ;[2 3 4]) 5).
Upvalues are stored in the symbol slots structure as well, but
since they are always live, we repurpose the death_pc field to
refer to the environment index that we want to look at at runtime.
This has a lot of possible uses, and would let users add a macro-based
type system on top of Janet that would integrate with the usual linting
and warning system.
This is the beginning of a system for compiler warnings. This includes
linting, deprecation notices, and other compiler warnings that are best
detected by the `compile` function and don't require the partial
evalutaion of the flychecker.
Structs and tuples composed entirely out of constant values
will themselves be considered constant values during compilation.
This reduces the amount of generated code.
Also fix marshalling functions without full
sourcemapping information, as well as thread/receive
ignoring bad messages. Instead, thread/receive will error
on bad messages.
Be really sure we don't pass too large of a size to memcpy.
There seem to be some situations where the slotcount and the ua.count
do not match at all, so use the mimimum for copying.
Using a bitset to indicate which stack values are upvalues, we
can more accurately track when a reference to a stack value
persists after the stack frame exits.
The %q formatter for janet_formatc now expects a Janet, not a JanetString or
JanetSymbol or JanetKeyword.
Also fix some reference counting issues with threads when destroying
threads, which should fix#287's
SIGSEGV. Still fails to send messages sometimes, though.
This should help when redefining certain forms. Will also
not do functional arity checking against nil forms, as that
is the default value when a def doesn't evaluate.
This way we can support fewer build configurations. Also, remove
all undefined behavior due to use of memcpy with NULL pointers. GCC
was exploiting this to remove NULL checks in some builds.
Also make integer to size_t casts explicit rather than relying on
int32_t * sizeof(x) = size_t. This is kind of a personal preference for
this problem.
