feat: new polkadot wasm target and custom gc (#22)

* polkawasm: add dockerfile and build script
* polkawasm: add new target separate from the existing wasm/wasi
* polkawasm: import memory, allow undefined, export globals and tables, disable scheduler, specify gc
* polkawasm: switch wasi-libc and wasm-opt to MVP instructions set
* polkawasm: remove _start export. remove wasm-libc allocation functions
* polkawasm: add custom gc that relies on an external allocator

.gitmodules

@@ -13,7 +13,7 @@
 	branch = main
 [submodule "lib/wasi-libc"]
 	path = lib/wasi-libc
-	url = https://github.com/WebAssembly/wasi-libc
+	url = https://github.com/LimeChain/wasi-libc
 [submodule "lib/picolibc"]
 	path = lib/picolibc
 	url = https://github.com/keith-packard/picolibc.git

Dockerfile.polkawasm

@@ -0,0 +1,33 @@
+# Diffs:
+# - prebuild LLVM
+
+FROM golang:1.21-bullseye AS tinygo-base
+
+ENV GO111MODULE=on
+ENV GOFLAGS="-buildvcs=false"
+
+# Add the LLVM 16 repo for Debian 11 Bullseye
+RUN wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add - && \
+  echo "deb http://apt.llvm.org/bullseye/ llvm-toolchain-bullseye-16 main" | tee /etc/apt/sources.list.d/llvm.list
+
+# Install LLVM toolchain packages
+RUN apt-get update && apt-get install -y \
+  clang-16 lld-16 llvm-16-dev libclang-16-dev cmake ninja-build
+
+# Copy TinyGo repo
+COPY . /tinygo
+
+WORKDIR /tinygo/lib/binaryen
+
+# Install binaryen(wasm-opt) 
+RUN cmake . && make
+
+ENV WASMOPT="/tinygo/lib/binaryen/bin/wasm-opt"
+
+WORKDIR /tinygo
+
+# Build wasi-libc and tinygo compiler
+RUN make wasi-libc && \
+  go install .
+
+CMD ["tinygo"]

builder/build.go

@@ -816,12 +816,26 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 					args = append(args, "--asyncify")
 				}
 
-				args = append(args,
-					opt,
-					"-g",
-					result.Executable,
-					"--output", result.Executable,
-				)
+				if config.Target.Triple == "wasm32-unknown-polkawasm" {
+					args = append(args,
+						opt,
+						"--signext-lowering",
+						// "--signature-pruning",
+						// "--const-hoisting",
+						// "--mvp-features",
+						result.Executable,
+						"--output",
+						result.Executable,
+					)
+				} else {
+					args = append(args,
+						opt,
+						"-g",
+						result.Executable,
+						"--output",
+						result.Executable,
+					)
+				}
 
 				cmd := exec.Command(goenv.Get("WASMOPT"), args...)
 				cmd.Stdout = os.Stdout

compileopts/config.go

@@ -104,7 +104,7 @@ func (c *Config) GC() string {
 // that can be traced by the garbage collector.
 func (c *Config) NeedsStackObjects() bool {
 	switch c.GC() {
-	case "conservative", "custom", "precise":
+	case "conservative", "custom", "extalloc", "extalloc_leaking", "precise":
 		for _, tag := range c.BuildTags() {
 			if tag == "tinygo.wasm" {
 				return true

compileopts/options.go

@@ -8,7 +8,7 @@ import (
 )
 
 var (
-	validGCOptions            = []string{"none", "leaking", "conservative", "custom", "precise"}
+	validGCOptions            = []string{"none", "leaking", "conservative", "custom", "extalloc", "extalloc_leaking", "precise"}
 	validSchedulerOptions     = []string{"none", "tasks", "asyncify"}
 	validSerialOptions        = []string{"none", "uart", "usb", "rtt"}
 	validPrintSizeOptions     = []string{"none", "short", "full"}

compileopts/options_test.go

@@ -9,7 +9,7 @@ import (
 
 func TestVerifyOptions(t *testing.T) {
 
-	expectedGCError := errors.New(`invalid gc option 'incorrect': valid values are none, leaking, conservative, custom, precise`)
+	expectedGCError := errors.New(`invalid gc option 'incorrect': valid values are none, leaking, conservative, custom, extalloc, extalloc_leaking, precise`)
 	expectedSchedulerError := errors.New(`invalid scheduler option 'incorrect': valid values are none, tasks, asyncify`)
 	expectedPrintSizeError := errors.New(`invalid size option 'incorrect': valid values are none, short, full`)
 	expectedPanicStrategyError := errors.New(`invalid panic option 'incorrect': valid values are print, trap`)

polkawasm.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+docker build --tag tinygo/polkawasm:0.31.0-dev -f Dockerfile.polkawasm .
+docker run --rm -it tinygo/polkawasm:0.31.0-dev bash

src/os/dir_other.go

@@ -1,4 +1,4 @@
-//go:build baremetal || js || windows
+//go:build baremetal || js || windows || polkawasm
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/dir_unix.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && !baremetal && !wasi && !wasip1
+//go:build linux && !baremetal && !wasi && !wasip1 && !polkawasm
 
 package os
 

src/os/dirent_linux.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && !js && !wasi
+//go:build !baremetal && !js && !wasi && !polkawasm
 
 // Copyright 2020 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/env_unix_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build darwin || linux || wasip1
+//go:build darwin || (linux && !polkawasm) || wasip1
 
 package os_test
 

src/os/exec_posix.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris || wasip1 || windows
+//go:build aix || darwin || dragonfly || freebsd || (js && wasm) || (linux && !polkawasm) || netbsd || openbsd || solaris || wasip1 || windows
 
 package os
 

src/os/executable_other.go

@@ -1,4 +1,4 @@
-//go:build !linux || baremetal
+//go:build !linux || baremetal || polkawasm
 
 package os
 

src/os/executable_procfs.go

@@ -4,7 +4,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux && !baremetal
+//go:build linux && !baremetal && !polkawasm
 
 package os
 

src/os/file_anyos.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && !js
+//go:build !baremetal && !js && !polkawasm
 
 // Portions copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/file_anyos_test.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && !js
+//go:build !baremetal && !js && !polkawasm
 
 package os_test
 

src/os/file_other.go

@@ -1,4 +1,4 @@
-//go:build baremetal || (wasm && !wasi && !wasip1)
+//go:build baremetal || polkawasm || (wasm && !wasi && !wasip1)
 
 package os
 

src/os/file_unix.go

@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal) || wasip1
+//go:build darwin || (linux && !baremetal && !polkawasm) || wasip1
 
 // target wasi sets GOOS=linux and thus the +linux build tag,
 // even though it doesn't show up in "tinygo info target -wasi"

src/os/getpagesize_test.go

@@ -1,4 +1,4 @@
-//go:build windows || darwin || (linux && !baremetal) || wasip1
+//go:build windows || darwin || (linux && !baremetal && !polkawasm) || wasip1
 
 package os_test
 

src/os/os_anyos_test.go

@@ -1,4 +1,4 @@
-//go:build windows || darwin || (linux && !baremetal) || wasip1
+//go:build windows || darwin || (linux && !baremetal && !polkawasm) || wasip1
 
 package os_test
 

src/os/os_chmod_test.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && !js && !wasi && !wasip1
+//go:build !baremetal && !js && !wasi && !wasip1 && !polkawasm
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/os_symlink_test.go

@@ -1,4 +1,4 @@
-//go:build !windows && !baremetal && !js && !wasi && !wasip1
+//go:build !windows && !baremetal && !js && !wasi && !wasip1 && !polkawasm
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/pipe_test.go

@@ -1,4 +1,4 @@
-//go:build windows || darwin || (linux && !baremetal && !wasi)
+//go:build windows || darwin || (linux && !baremetal && !wasi && !polkawasm)
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/read_test.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && !js && !wasi && !wasip1
+//go:build !baremetal && !js && !wasi && !wasip1 && !polkawasm
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/removeall_noat.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !baremetal && !js && !wasi && !wasip1
+//go:build !baremetal && !js && !wasi && !wasip1 && !polkawasm
 
 package os
 

src/os/removeall_other.go

@@ -1,4 +1,4 @@
-//go:build baremetal || js || wasi || wasip1
+//go:build baremetal || polkawasm || js || wasi || wasip1
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/removeall_test.go

@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal && !js && !wasi)
+//go:build darwin || (linux && !baremetal && !js && !wasi && !polkawasm)
 
 // TODO: implement ReadDir on windows
 

src/os/seek_unix_bad.go

@@ -1,4 +1,4 @@
-//go:build (linux && !baremetal && 386) || (linux && !baremetal && arm && !wasi)
+//go:build (linux && !baremetal && 386) || (linux && !baremetal && arm && !wasi && !polkawasm)
 
 package os
 

src/os/stat_linuxlike.go

@@ -1,4 +1,4 @@
-//go:build (linux && !baremetal) || wasip1
+//go:build (linux && !baremetal && !polkawasm) || wasip1
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/stat_other.go

@@ -1,4 +1,4 @@
-//go:build baremetal || (wasm && !wasi && !wasip1)
+//go:build baremetal || polkawasm || (wasm && !wasi && !wasip1)
 
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/stat_unix.go

@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal) || wasip1
+//go:build darwin || (linux && !baremetal && !polkawasm) || wasip1
 
 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/types_anyos.go

@@ -1,4 +1,4 @@
-//go:build !baremetal && !js
+//go:build !baremetal && !js && !polkawasm
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/os/types_unix.go

@@ -1,4 +1,4 @@
-//go:build darwin || (linux && !baremetal) || wasip1
+//go:build darwin || (linux && !baremetal && !polkawasm) || wasip1
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

src/runtime/arch_tinygowasm.go

@@ -66,7 +66,7 @@ var (
 func align(ptr uintptr) uintptr {
 	// Align to 16, which is the alignment of max_align_t:
 	// https://godbolt.org/z/dYqTsWrGq
-	const heapAlign = 16
+	const heapAlign = 8 // matches the allocator's alignment (consumes less memory)
 	return (ptr + heapAlign - 1) &^ (heapAlign - 1)
 }
 

src/runtime/arch_tinygowasm_malloc.go

@@ -1,4 +1,4 @@
-//go:build tinygo.wasm && !custommalloc
+//go:build tinygo.wasm && !custommalloc && !polkawasm
 
 package runtime
 

src/runtime/gc_custom.go

@@ -1,5 +1,4 @@
 //go:build gc.custom
-// +build gc.custom
 
 package runtime
 

src/runtime/gc_debug.go

@@ -0,0 +1,47 @@
+//go:build gc.extalloc || gc.extalloc_leaking
+
+package runtime
+
+const gcDebug = false
+
+func printnum(num int) {
+	if num == 0 {
+		printstr("0")
+		return
+	}
+
+	digits := [16]int{} // store up to 16 digits
+	digitStrings := [10]string{"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"}
+	count := 0 // count of digits
+
+	// extract digits from the number
+	for ; num > 0; num /= 10 {
+		digits[count] = num % 10
+		count++
+	}
+
+	// reverse the digits
+	for i := 0; i < count/2; i++ {
+		j := count - i - 1
+		digits[i], digits[j] = digits[j], digits[i]
+	}
+
+	// print each digit
+	for i := 0; i < count; i++ {
+		printstr(digitStrings[digits[i]])
+	}
+}
+
+func printstr(str string) {
+	if !gcDebug {
+		return
+	}
+
+	for i := 0; i < len(str); i++ {
+		if putcharPosition >= putcharBufferSize {
+			break
+		}
+
+		putchar(str[i])
+	}
+}