Instead of putting tinygo_scanCurrentStack in scheduler_*.S files, put
them in dedicated files. The function tinygo_scanCurrentStack has
nothing to do with scheduling and so doesn't belong there. Additionally,
while scheduling code is made specific for the Cortex-M, the
tinygo_scanCurrentStack is generic to all ARM targets so this move
removes some duplication there.
Specifically:
* tinygo_scanCurrentStack is moved out of scheduler_cortexm.S as it
isn't really part of the scheduler. It is now gc_arm.S.
* Same for the AVR target.
* Same for the RISCV target.
* scheduler_gba.S is removed, using gc_arm.S instead as it only
contains tinygo_scanCurrentStack.
* initial commit for WASI support
* merge "time" package with wasi build tag
* override syscall package with wasi build tag
* create runtime_wasm_{js,wasi}.go files
* create syscall_wasi.go file
* create time/zoneinfo_wasi.go file as the replacement of zoneinfo_js.go
* add targets/wasi.json target
* set visbility hidden for runtime extern variables
Accodring to the WASI docs (https://github.com/WebAssembly/WASI/blob/master/design/application-abi.md#current-unstable-abi),
none of exports of WASI executable(Command) should no be accessed.
v0.19.0 of bytecodealliance/wasmetime, which is often refered to as the reference implementation of WASI,
does not accept any exports except functions and the only limited variables like "table", "memory".
* merge syscall_{baremetal,wasi}.go
* fix js target build
* mv wasi functions to syscall/wasi && implement sleepTicks
* WASI: set visibility hidden for globals variables
* mv back syscall/wasi/* to runtime package
* WASI: add test
* unexport wasi types
* WASI test: fix wasmtime path
* stop changing visibility of runtime.alloc
* use GOOS=linux, GOARCH=arm for wasi target
Signed-off-by: mathetake <takeshi@tetrate.io>
* WASI: fix build tags for os/runtime packages
Signed-off-by: mathetake <takeshi@tetrate.io>
* run WASI test only on Linux
Signed-off-by: mathetake <takeshi@tetrate.io>
* set InternalLinkage instead of changing visibility
Signed-off-by: mathetake <takeshi@tetrate.io>
For example, for running tests with -target=wasm or
-target=cortex-m-qemu. It looks at the output to determine whether tests
were successful in the absence of a status code.
The algorithm now checks for invalid UTF-8 sequences, which is required
by the Go spec.
This gets the tests of the unicode/utf8 package to pass.
Also add bytes.Equal for Go 1.11, which again is necessary for the
unicode/utf8 package.
There were a few problems with the go/packages package. While it is more
or less designed for our purpose, it didn't work quite well as it didn't
provide access to indirectly imported packages (most importantly the
runtime package). This led to a workaround that sometimes broke
`tinygo test`.
This PR contains a number of related changes:
* It uses `go list` directly to retrieve the list of packages/files to
compile, instead of relying on the go/packages package.
* It replaces our custom TestMain replace code with the standard code
for running tests (generated by `go list`).
* It adds a dummy runtime/pprof package and modifies the testing
package, to get tests to run again with the code generated by
`go list`.
This is only very minimal support. More support (such as tinygo flash,
or peripheral access) should be added in later commits, to keep this one
focused.
Importantly, this commit changes the LLVM repo from llvm/llvm-project to
tinygo-org/llvm-project. This provides a little bit of versioning in
case something changes in the Espressif fork. If we want to upgrade to
LLVM 11 it's easy to switch back to llvm/llvm-project until Espressif
has updated their fork.
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 reduces current consumption from 500-1000µA to very low (<10µA)
current consumption. This change is important for battery powered
devices, especially devices that may be running for long periods of
time.
Call Frame Information is stored in the .debug_frame section and is used
by debuggers for unwinding. For assembly, this information is not known.
Debuggers will normally use heuristics to figure out the parent function
in the absence of call frame information.
This usually works fine, but is not enough for determining stack sizes.
Instead, I hardcoded the stack size information in
stacksize/stacksize.go, which is somewhat fragile. This change uses CFI
assembly directives to store this information instead of hardcoding it.
This change also fixes the following error message that would appear in
GDB:
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
More information on CFI:
* https://sourceware.org/binutils/docs/as/CFI-directives.html
* https://www.imperialviolet.org/2017/01/18/cfi.html
For now, this is just an extra flag that can be used to print stack
frame information, but this is intended to provide a way to determine
stack sizes for goroutines at compile time in many cases.
Stack sizes are often somewhere around 350 bytes so are in fact not all
that big usually. Once this can be determined at compile time in many
cases, it is possible to use this information when available and as a
result increase the fallback stack size if the size cannot be determined
at compile time. This should reduce stack overflows while at the same
time reducing RAM consumption in many cases.
Interesting output for testdata/channel.go:
function stack usage (in bytes)
Reset_Handler 332
.Lcommand-line-arguments.fastreceiver 220
.Lcommand-line-arguments.fastsender 192
.Lcommand-line-arguments.iterator 192
.Lcommand-line-arguments.main$1 184
.Lcommand-line-arguments.main$2 200
.Lcommand-line-arguments.main$3 200
.Lcommand-line-arguments.main$4 328
.Lcommand-line-arguments.receive 176
.Lcommand-line-arguments.selectDeadlock 72
.Lcommand-line-arguments.selectNoOp 72
.Lcommand-line-arguments.send 184
.Lcommand-line-arguments.sendComplex 192
.Lcommand-line-arguments.sender 192
.Lruntime.run$1 548
This shows that the stack size (if these numbers are correct) can in
fact be determined automatically in many cases, especially for small
goroutines. One of the great things about Go is lightweight goroutines,
and reducing stack sizes is very important to make goroutines
lightweight on microcontrollers.
- Fix UART & putChar
- Timer-based sleep
- Enable systick in abort
- Buffered, interrupt-based UART TX
- Use the new interrupt API and fix sleepTicks
- Make pins behave more like other boards
- Use the MCU's UART numbering
- Allow interrupts to wake the scheduler (#1214)
Commit fc4857e98c (runtime: avoid recursion in printuint64 function)
caused a regression for AVR. I have tried locally with LLVM 11 (which
contains a number of codegen bugs) and the issue is no longer present,
so I'm assuming it's a codegen bug that is now fixed. However, LLVM 11
is not yet released so it seems best to me to work around this
temporarily (for the next few months).
This commit can easily be reverted when we start using LLVM 11.
Previously, chansend and chanrecv allocated a heap object before blocking on a channel.
This object was used to implement a linked list of goroutines blocked on the channel.
The chansend and chanrecv now instead accept a buffer to store this object in as an argument.
The compiler now creates a stack allocation for this object and passes it in.
