Scanning of allocas was entirely broken on WebAssembly. The code
intended to do this was never run. There were also no tests.
Looking into this further, I found that it is actually not really
necessary to do that: the C stack can be scanned conservatively and in
fact this was already done for goroutine stacks (because they live on
the heap and are always referenced). It wasn't done for the system stack
however.
With these fixes, I believe code should be both faster *and* more
correct.
I found this in my work to get opaque pointers supported in LLVM 15,
because the code that was never reached now finally got run and was
actually quite buggy.
This documents memory constants. Somewhere, we should document what the
default memory size is (seems 2 pages so 128KB), as that determines the
initial heap size (which is a portion of that).
Signed-off-by: Adrian Cole <adrian@tetrate.io>
You can see that it works with the following command:
tinygo run -target=simavr ./testdata/recover.go
This also gets the following tests to pass again:
go test -run=Build -target=simavr -v
Adding support for AVR was a bit more compliated because it's also
necessary to save and restore the Y register.
Do it all at once in preparation for Go 1.18 support.
To make this commit, I've simply modified the `fmt-check` Makefile
target to rewrite files instead of listing the differences. So this is a
fully mechanical change, it should not have introduced any errors.
This would conflict with our own heap. We previously defined all those
functions to make sure it's not used, but with a more recent wasi-libc
version (https://github.com/WebAssembly/wasi-libc/pull/250) we can
simply not compile the wasi-libc heap, which is the proper fix.
When using the latest wasi-libc I experienced a
panic on an attempt to call realloc. My first attempt to
add it to arch_tinygowasm.go was obviously not good (PR #2194). So here
is another suggestion.
This layout parameter is currently always nil and ignored, but will
eventually contain a pointer to a memory layout.
This commit also adds module verification to the transform tests, as I
found out that it didn't (and therefore didn't initially catch all
bugs).
This commit fixes two things:
* It changes the alignment to 16 bytes (from 4), to match max_align_t
in C.
* It manually aligns heapStart on WebAssembly, to work around a bug in
wasm-ld with --stack-first (see https://reviews.llvm.org/D106499).
These two heaps conflict with each other, so that if any function uses
the dlmalloc heap implementation it will eventually result in memory
corruption.
This commit fixes this by implementing all heap-related functions. This
overrides the functions that are implemented in wasi-libc. That's why
all of them are implemented (even if they just panic): to make sure no
program accidentally uses the wrong one.
The wasm build tag together with GOARCH=arm was causing problems in the
internal/cpu package. In general, I think having two architecture build
tag will only cause problems (in this case, wasm and arm) so I've
removed the wasm build tag and replaced it with tinygo.wasm.
This is similar to the tinygo.riscv build tag, which is used for older
Go versions that don't yet have RISC-V support in the standard library
(and therefore pretend to be GOARCH=arm instead).
2021-06-22 09:03:23 +02:00
Переименован с src/runtime/arch_wasm.go (Смотреть далее)
