The build broke because the images got upgraded from stretch to buster.
Specify the stretch images (for now) so that it works again.
We can upgrade to buster for go1.12 at a later time.
In particular, while LLVM lld supports -L for linker scripts imported
with the `INCLUDE` command, GNU ld does not seem to support this.
This is a prerequisite for supporting the HiFive1 board in the TinyGo
Playground.
In particular, add support for a few math intrinsics for WebAssembly,
but add a few intrinsics to other systems as well at the same time. Some
may be missing still but will be easy to add if needed.
This increases the performance of one example by 50% to 100% depending
on the browser: the bottleneck was the inefficient sqrt implementation.
This makes sure that a stack overflow will cause a "memory access out of
bounds" error instead of a corruption of a global variable.
Here is more background on a very similar stack overflow protection:
https://blog.japaric.io/stack-overflow-protection/
When the target supports it, allow the (initial) heap size to be
configured. Currently only supported in WebAssembly.
This also changes the default heap size of WebAssembly from 64kB to 1MB.
This is a useful optimization for targets with the portable garbage
collector. It isn't as big as you might guess but it does optimize
functions inside the garbage collector itself (which obviously should
not allocate). WebAssembly output in one test is about 1% smaller.
This is directly useful to avoid some unsafety around runtime.alloc and
should be useful in general.
This pragma has the same form as in the main Go compiler:
https://github.com/golang/go/issues/12312
Some instructions do not create new values, they transform existing
values in some way (bitcast, getelementptr, etc.). Do not store them in
the stack object.
This lowers the size of the repulsion demo from 100kB to 98kB (with a
baseline of 72kB for the leaking GC). That's a useful reduction in file
size.
dumb -> leaking:
make it more clear what this "GC" does: leak everything.
marksweep -> conservative:
"marksweep" is too generic, use "conservative" to differentiate
between future garbage collectors: precise marksweep / mark-compact /
refcounting.
Instead of trying to modify periperhals directly, external functions are
called. For example, __tinygo_gpio_set sets a GPIO pin to a specified
value (high or low). It is expected that binaries made this way will be
linked with some extra libraries that implement support for these
functions.
One particularly interesting case is this experimental board simulator:
https://github.com/aykevl/tinygo-play
Compiling code to WebAssembly with the correct build tag for a board
will enable this board to be simulated in the browser.
Atmel/Microchip based SAMD boards are not currently supported, because
their I2C/SPI support is somewhat uncommon and harder to support in the
machine API. They may require a modification to the machine API for
proper support.
The -DLLVM_TOOL_CLANG_TOOLS_EXTRA_BUILD=OFF option turning off the
building of the extra clang tools is required, otherwise linking
the tinygo binary fails.
This is part of a larger rafactor that tries to shrink the ir package
and in general tries to shrink the amount of state that is kept around
in the compiler. The end goal is being able to compile packages
independent of each other, linking them together in a later stage. Along
the way, it cleans up lots of old cruft that has accumulated over the
months.
This refactor also results in globals being loaded lazily. This may be a
problem for some specific programs but will probably change back in a
commit in the near future.
Returning a nil value may lead to problems later on. Just return undef
here, so that further compilation will at least be safe (the result
will be discarded anyway).
