This means that it will be possible to generate a Darwin binary on any
platform (Windows, Linux, and MacOS of course), including CGo. Of
course, the resulting binaries can only run on MacOS itself.
The binary links against libSystem.dylib, which is a shared library. The
macos-minimal-sdk repository contains open source header files and
generated symbol stubs so we can generate a stub libSystem.dylib without
copying any closed source code.
Some clang builds (e.g., Fedora's) enable unwind tables by default. As
tinygo does not need nor support them, that leads to undefined symbols
when linking.
This adds support for building with `-tags=llvm13` and switches to LLVM
13 for tinygo binaries that are statically linked against LLVM.
Some notes on this commit:
* Added `-mfloat-abi=soft` to all Cortex-M targets because otherwise
nrfx would complain that floating point was enabled on Cortex-M0.
That's not the case, but with `-mfloat-abi=soft` the `__SOFTFP__`
macro is defined which silences this warning.
See: https://reviews.llvm.org/D100372
* Changed from `--sysroot=<root>` to `-nostdlib -isystem <root>` for
musl because with Clang 13, even with `--sysroot` some system
libraries are used which we don't want.
* Changed all `-Xclang -internal-isystem -Xclang` to simply
`-isystem`, for consistency with the above change. It appears to
have the same effect.
* Moved WebAssembly function declarations to the top of the file in
task_asyncify_wasm.S because (apparently) the assembler has become
more strict.
This environment variable can be set to 5, 6, or 7 and controls which
ARM version (ARMv5, ARMv6, ARMv7) is used when compiling for GOARCH=arm.
I have picked the default value ARMv6, which I believe is supported on
most common single board computers including all Raspberry Pis. The
difference in code size is pretty big.
We could even go further and support ARMv4 if anybody is interested. It
should be pretty simple to add this if needed.
This change implements a new "scheduler" for WebAssembly using binaryen's asyncify transform.
This is more reliable than the current "coroutines" transform, and works with non-Go code in the call stack.
runtime (js/wasm): handle scheduler nesting
If WASM calls into JS which calls back into WASM, it is possible for the scheduler to nest.
The event from the callback must be handled immediately, so the task cannot simply be deferred to the outer scheduler.
This creates a minimal scheduler loop which is used to handle such nesting.
This makes sure that the LLVM target features match the one generated by
Clang:
- This fixes a bug introduced when setting the target CPU for all
targets: Cortex-M4 would now start using floating point operations
while they were disabled in C.
- This will make it possible in the future to inline C functions in Go
and vice versa. This will need some more work though.
There is a code size impact. Cortex-M4 targets are increased slightly in
binary size while Cortex-M0 targets tend to be reduced a little bit.
Other than that, there is little impact.
With this fix, `cflags` in the target JSON files is correctly ordered.
Previously, the cflags of a parent JSON file would come after the ones
in the child JSON file, which makes it hard to override properties in
the child JSON file.
Specifically, this fixes the case where targets/riscv32.json sets
`-march=rv32imac` and targets/esp32c3.json wants to override this using
`-march=rv32imc` but can't do this because its `-march` comes before the
riscv32.json one.
The target triples have to match mostly to be able to link LLVM modules.
Linking LLVM modules is already possible (the triples already match),
but testing becomes much easier when they match exactly.
For macOS, I picked "macosx10.12.0". That's an old and unsupported
version, but I had to pick _something_. Clang by default uses
"macos10.4.0", which is much older.
This commit adds support for musl-libc and uses it by default on Linux.
The main benefit of it is that binaries are always statically linked
instead of depending on the host libc, even when using CGo.
Advantages:
- The resulting binaries are always statically linked.
- No need for any tools on the host OS, like a compiler, linker, or
libc in a release build of TinyGo.
- This also simplifies cross compilation as no cross compiler is
needed (it's all built into the TinyGo release build).
Disadvantages:
- Binary size increases by 5-6 kilobytes if -no-debug is used. Binary
size increases by a much larger margin when debugging symbols are
included (the default behavior) because musl is built with debugging
symbols enabled.
- Musl does things a bit differently than glibc, and some CGo code
might rely on the glibc behavior.
- The first build takes a bit longer because musl needs to be built.
As an additional bonus, time is now obtained from the system in a way
that fixes the Y2038 problem because musl has been a bit more agressive
in switching to 64-bit time_t.
This is for consistency with Clang, which always adds a CPU flag even if
it's not specified in CFLAGS.
This commit also adds some tests to make sure the Clang target-cpu
matches the CPU property in the JSON files.
This does have an effect on the generated binaries. The effect is very
small though: on average just 0.2% increase in binary size, apparently
because Cortex-M3 and Cortex-M4 are compiled a bit differently. However,
when rebased on top of https://github.com/tinygo-org/tinygo/pull/2218
(minsize), the difference drops to -0.1% (a slight decrease on average).
It is better to use environment variables (GOOS and GOARCH) for
consistency instead of providing two slightly incompatible ways. This
-target flag should only be used to specify a .json file (either
directly or in the TinyGo targets directory). Previously it was possible
to specify the LLVM target as well but that was never really fully
supported.
So:
- To specify a different OS/arch like you would in regular Go, use
GOOS and GOARCH.
- To specify a microcontroller chip or board, use the -target flag.
Also remove the old `os.Setenv` which might have had a purpose long ago
but doesn't have a purpose now.
... instead of setting a special -target= value. This is more robust and
makes sure that the test actually tests different arcitectures as they
would be compiled by TinyGo. As an example, the bug of the bugfix in the
previous commit ("arm: use armv7 instead of thumbv7") would have been
caught if this change was applied earlier.
I've decided to put GOOS/GOARCH in compileopts.Options, as it makes
sense to me to treat them the same way as command line parameters.
At the moment, thumbv7 is crashing. I'm not exactly sure why, but it
appears that there is an unknown instruction in __aeabi_uldivmod
(probably from libgcc).
I've fixed this by switching to armv7, which is also somewhat modern.
Maybe we can switch back to Thumb2 (aka thumbv7) once we start using
musl and compiler-rt. In the meantime, this does fix a miscompilation
(illegal instruction).
This commit changes a target triple like "armv6m-none-eabi" to
"armv6m-unknown-unknow-eabi". The reason is that while the former is
correctly parsed in Clang (due to normalization), it wasn't parsed
correctly in LLVM meaning that the environment wasn't set to EABI.
This change normalizes all target triples and uses the EABI environment
(-eabi in the triple) for Cortex-M targets.
This change also drops the `--target=` flag in the target JSON files,
the flag is now added implicitly in `(*compileopts.Config).CFlags()`.
This removes some duplication in target JSON files.
Unfortunately, this change also increases code size for Cortex-M
targets. It looks like LLVM now emits calls like __aeabi_memmove instead
of memmove, which pull in slightly more code (they basically just call
the regular C functions) and the calls themself don't seem to be as
efficient as they could be. Perhaps this is a LLVM bug that will be
fixed in the future, as this is a very common occurrence.
This reduces binary size substantially, for two reasons:
- It switches to a much more architecture ARMv4 vs ARMv7.
- It switches to Thumb2, which is a lot denser than regular ARM.
Practically all modern and not-so-modern ARM chips support Thumb2, so
this seems like a safe change to me.
The size in numbers:
- Code size for testdata/stdlib.go is reduced by about 35%.
- Binary size for testdata/stdlib.go (when compiling with -no-debug to
strip debug information) is reduced by about 16%.
Previously we used the i386 target, probably with all optional features
disabled. However, the Pentium 4 has been released a _long_ time ago and
it seems reasonable to me to take that as a minimum requirement.
Upstream Go now also seems to move in this direction:
https://github.com/golang/go/issues/40255
The main motivation for this is that there were floating point issues
when running the tests for the math package:
GOARCH=386 tinygo test math
I haven't investigated what's the issue, but I strongly suspect it's
caused by the weird x87 80-bit floating point format. This could perhaps
be fixed in a different way (by setting the FPU precision to 64 bits)
but I figured that just setting the minimum requirement to the Pentium 4
would probably be fine. If needed, we can respect the GO386 environment
variable to support these very old CPUs.
To support this newer CPU, I had to make sure that the stack is aligned
to 16 bytes everywhere. This was not yet always the case.
This can be very useful for some purposes:
* It makes it possible to disable the UART in cases where it is not
needed or needs to be disabled to conserve power.
* It makes it possible to disable the serial output to reduce code
size, which may be important for some chips. Sometimes, a few kB can
be saved this way.
* It makes it possible to override the default, for example you might
want to use an actual UART to debug the USB-CDC implementation.
It also lowers the dependency on having machine.Serial defined, which is
often not defined when targeting a chip. Eventually, we might want to
make it possible to write `-target=nrf52` or `-target=atmega328p` for
example to target the chip itself with no board specific assumptions.
The defaults don't change. I checked this by running `make smoketest`
before and after and comparing the results.
This makes it possible to flash a board even when there are multiple
different kinds of boards attached, e.g. an Arduino Uno and a Circuit
Playground Express. You can find the VID/PID pair in several ways:
1. By running `lsusb` before and after attaching the board and looking
at the new USB device.
2. By grepping for `usb_PID` and `usb_VID` in the TinyGo source code.
3. By checking the Arduino IDE boards.txt from the vendor.
Note that one board may have multiple VID/PID pairs:
* The bootloader and main program may have a different PID, so far
I've seen that the main program generally has the bootloader PID
with 0x8000 added.
* The software running on the board may have an erroneous PID, for
example from a different board. I've seen this happen a few times.
* A single board may have had some revisions which changed the PID.
This is particularly true for the Arduino Uno.
As a fallback, if the given VID/PID pair isn't found, the whole set of
serial ports will be used.
There are many boards which I haven't included yet simply because I
couldn't test them.
This results in smaller and likely more efficient code. It does require
some architecture specific code for each architecture, but I've kept the
amount of code as small as possible.
The CircleCI macOS builds are failing, probably due to the old macOS
version that's used. This version (10.13 High Sierra) isn't supported
anymore on Homebrew so it seems best to me to simply bump the version.
I picked Xcode 11.1.0 because 10.3.0 is somehow triggering an error
while trying to install QEMU (the Python install fails).
Because of this newer Xcode version, I had to add an extra flag
(-isysroot) to the default command line for MacOS. The reason is that
this newer Xcode version no longer stores header files in /usr/local, an
SDK must be specified manually. With this change, the default SDK is
used.
At the moment, all targets use the Clang compiler to compile C and
assembly files. There is no good reason to make this configurable
anymore and in fact it will make future changes more complicated (and
thus more likely to have bugs). Therefore, I've removed support for
setting the compiler.
Note that the same is not true for the linker. While it makes sense to
standardize on the Clang compiler (because if Clang doesn't support a
target, TinyGo is unlikely to support it either), linkers will remain
configurable for the foreseeable future. One example is Xtensa, which is
supported by the Xtensa LLVM fork but doesn't have support in ld.lld
yet.
I've also fixed a bug in compileAndCacheCFile: it wasn't using the right
CFlags for caching purposes. This could lead to using stale caches. This
commit fixes that too.
The only architecture that actually needs special support for scanning
the stack is WebAssembly. All others allow raw access to the stack with
a small bit of assembly. Therefore, don't manually keep track of all
these objects on the stack manually and instead just use conservative
stack scanning.
This results in a massive code size decrease in the affected targets
(only tested linux/amd64 for code size) - sometimes around 33%. It also
allows for future improvements such as using proper stackful goroutines.
This commit allows debugging like the following:
GOARCH=arm tinygo gdb ./testdata/alias.go
This can be very useful to debug issues on a different instruction set
architecture but still on a host system.
I tested the following 7 configurations to make sure it works and I
didn't break anything:
GOOS=amd64
GOOS=386
GOOS=arm
GOOS=arm64
tinygo gdb -target=hifive1-qemu
tinygo gdb -target=cortex-m-qemu
tinygo gdb -target=microbit
To avoid breaking this, make sure we actually test x86-32 (aka i386 aka
GOARCH=386) support in CI.
Also remove the now-unnecessary binutils-arm-none-eabi package to speed
up CI a bit.
This is a big change that will determine the stack size for many
goroutines automatically. Functions that aren't recursive and don't call
function pointers can in many cases have an automatically determined
worst case stack size. This is useful, as the stack size is usually much
lower than the previous hardcoded default of 1024 bytes: somewhere
around 200-500 bytes is common.
A side effect of this change is that the default stack sizes (including
the stack size for other architectures such as AVR) can now be changed
in the config JSON file, making it tunable per application.
This is necessary for better CGo support on bare metal. Existing
libraries expect to be able to include parts of libc and expect to be
able to link to those symbols.
Because with this all targets have a working libc, it is now possible to
add tests to check that a libc in fact works basically.
Not all parts of picolibc are included, such as the math or stdio parts.
These should be added later, when needed.
This commit also avoids the need for the custom memcpy/memset/memcmp
symbols that are sometimes emitted by LLVM. The C library will take care
of that.
Use the cross compiling toolchains for compiling/linking. This fixes CGo
support, and therefore allows CGo to be used when cross compiling to
Linux on a different architecture.
This commit also removes some redundant testing code.
Add a target for the Adafruit Circuit Playground Bluefruit, which is
based on the nRF52840. Adds the necessary code for the machine
package and the json and linker script files in the targets directory.
The machine package code is based on board_circuitplay_express.go,
with modifications made by consulting the wiring diagram on the
adafruit website here:
https://learn.adafruit.com/adafruit-circuit-playground-bluefruit/downloads
Also adds support to the uf2 conversion packacge to set the familyID
field. The Circuit Playground Bluefruit firmware rejects uf2 files
without the family id set to 0xADA52840 (and without the flag specifying
that the family id is present).
This flag is overloaded. It can be used in two ways:
* Choosing the flash method to use (openocd, msd, command).
* Choosing the OpenOCD programmer name.
For example, you can use one of these to use OpenOCD instead of the
mass-storage device programmer:
tinygo flash -target=microbit -programmer=openocd
tinygo flash -target=microbit -programmer=cmsis-dap
Setting the linker script as one property (instead of as part of the
generic ldflags property) allows it to be overriden.
This is important for the SoftDevice on Nordic chips, because the
SoftDevice takes up a fixed part of the flash/RAM and the application
must be flashed at a different position. With this linkerscript option,
it is possible to create (for example) a pca10040-s132v6 that overrides
the default linker script.
