all: pretend to be linux/arm in baremetal targets

compiler/compiler.go

@@ -162,11 +162,11 @@ func (c *Compiler) selectGC() string {
 func (c *Compiler) Compile(mainPath string) error {
 	// Prefix the GOPATH with the system GOROOT, as GOROOT is already set to
 	// the TinyGo root.
-	gopath := c.GOPATH
-	if gopath == "" {
-		gopath = runtime.GOROOT()
+	overlayGopath := c.GOPATH
+	if overlayGopath == "" {
+		overlayGopath = runtime.GOROOT()
 	} else {
-		gopath = runtime.GOROOT() + string(filepath.ListSeparator) + gopath
+		overlayGopath = runtime.GOROOT() + string(filepath.ListSeparator) + overlayGopath
 	}
 
 	wd, err := os.Getwd()
@@ -175,15 +175,42 @@ func (c *Compiler) Compile(mainPath string) error {
 	}
 	lprogram := &loader.Program{
 		Build: &build.Context{
+			GOARCH:      c.GOARCH,
+			GOOS:        c.GOOS,
+			GOROOT:      runtime.GOROOT(),
+			GOPATH:      c.GOPATH,
+			CgoEnabled:  true,
+			UseAllFiles: false,
+			Compiler:    "gc", // must be one of the recognized compilers
+			BuildTags:   append([]string{"tinygo", "gc." + c.selectGC()}, c.BuildTags...),
+		},
+		OverlayBuild: &build.Context{
 			GOARCH:      c.GOARCH,
 			GOOS:        c.GOOS,
 			GOROOT:      c.RootDir,
-			GOPATH:      gopath,
+			GOPATH:      overlayGopath,
 			CgoEnabled:  true,
 			UseAllFiles: false,
 			Compiler:    "gc", // must be one of the recognized compilers
 			BuildTags:   append([]string{"tinygo", "gc." + c.selectGC()}, c.BuildTags...),
 		},
+		ShouldOverlay: func(path string) bool {
+			switch path {
+			case "machine", "os", "reflect", "runtime", "sync":
+				return true
+			default:
+				if strings.HasPrefix(path, "device/") || strings.HasPrefix(path, "examples/") {
+					return true
+				} else if path == "syscall" {
+					for _, tag := range c.BuildTags {
+						if tag == "avr" || tag == "cortexm" {
+							return true
+						}
+					}
+				}
+			}
+			return false
+		},
 		TypeChecker: types.Config{
 			Sizes: &StdSizes{
 				IntSize:  int64(c.targetData.TypeAllocSize(c.intType)),

loader/loader.go

@@ -14,13 +14,15 @@ import (
 
 // Program holds all packages and some metadata about the program as a whole.
 type Program struct {
-	Build       *build.Context
-	Packages    map[string]*Package
-	sorted      []*Package
-	fset        *token.FileSet
-	TypeChecker types.Config
-	Dir         string // current working directory (for error reporting)
-	CFlags      []string
+	Build         *build.Context
+	OverlayBuild  *build.Context
+	ShouldOverlay func(path string) bool
+	Packages      map[string]*Package
+	sorted        []*Package
+	fset          *token.FileSet
+	TypeChecker   types.Config
+	Dir           string // current working directory (for error reporting)
+	CFlags        []string
 }
 
 // Package holds a loaded package, its imports, and its parsed files.
@@ -42,7 +44,11 @@ func (p *Program) Import(path, srcDir string) (*Package, error) {
 	}
 
 	// Load this package.
-	buildPkg, err := p.Build.Import(path, srcDir, build.ImportComment)
+	ctx := p.Build
+	if p.ShouldOverlay(path) {
+		ctx = p.OverlayBuild
+	}
+	buildPkg, err := ctx.Import(path, srcDir, build.ImportComment)
 	if err != nil {
 		return nil, err
 	}

src/os/file_wasm.go → src/os/file_other.go

@@ -1,4 +1,4 @@
-// +build wasm
+// +build avr cortexm wasm
 
 package os
 

src/os/file_unix.go

@@ -1,4 +1,4 @@
-// +build darwin linux
+// +build darwin linux,!avr,!cortexm
 
 package os
 

src/runtime/arch_arm.go

@@ -1,3 +1,5 @@
+// +build arm,!avr,!cortexm
+
 package runtime
 
 const GOARCH = "arm"

src/runtime/arch_tinygoarm.go → src/runtime/arch_cortexm.go

@@ -1,4 +1,4 @@
-// +build tinygo.arm
+// +build cortexm
 
 package runtime
 

src/runtime/arch_wasm.go

@@ -1,4 +1,4 @@
-// +build wasm,!tinygo.arm,!avr
+// +build wasm
 
 package runtime
 

src/runtime/runtime_tinygoarm.go → src/runtime/runtime_cortexm.go

@@ -1,4 +1,4 @@
-// +build tinygo.arm
+// +build cortexm
 
 package runtime
 

src/runtime/runtime_unix.go

@@ -1,4 +1,4 @@
-// +build darwin linux
+// +build darwin linux,!avr,!cortexm
 
 package runtime
 

src/runtime/runtime_wasm.go

@@ -1,4 +1,4 @@
-// +build wasm,!tinygo.arm,!avr
+// +build wasm
 
 package runtime
 

src/syscall/str.go

@@ -0,0 +1,24 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package syscall
+
+func itoa(val int) string { // do it here rather than with fmt to avoid dependency
+	if val < 0 {
+		return "-" + uitoa(uint(-val))
+	}
+	return uitoa(uint(val))
+}
+
+func uitoa(val uint) string {
+	var buf [32]byte // big enough for int64
+	i := len(buf) - 1
+	for val >= 10 {
+		buf[i] = byte(val%10 + '0')
+		i--
+		val /= 10
+	}
+	buf[i] = byte(val + '0')
+	return string(buf[i:])
+}

src/syscall/syscall_baremetal.go

@@ -0,0 +1,148 @@
+package syscall
+
+// Most code here has been copied from the Go sources:
+//   https://github.com/golang/go/blob/go1.12/src/syscall/syscall_js.go
+// It has the following copyright note:
+//
+//     Copyright 2018 The Go Authors. All rights reserved.
+//     Use of this source code is governed by a BSD-style
+//     license that can be found in the LICENSE file.
+
+// An Errno is an unsigned number describing an error condition.
+// It implements the error interface. The zero Errno is by convention
+// a non-error, so code to convert from Errno to error should use:
+//      err = nil
+//      if errno != 0 {
+//              err = errno
+//      }
+type Errno uintptr
+
+func (e Errno) Error() string {
+        if 0 <= int(e) && int(e) < len(errorstr) {
+                s := errorstr[e]
+                if s != "" {
+                        return s
+                }
+        }
+        return "errno " + itoa(int(e))
+}
+
+func (e Errno) Temporary() bool {
+        return e == EINTR || e == EMFILE || e.Timeout()
+}
+
+func (e Errno) Timeout() bool {
+        return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
+}
+
+// A Signal is a number describing a process signal.
+// It implements the os.Signal interface.
+type Signal int
+
+const (
+	_ Signal = iota
+	SIGCHLD
+	SIGINT
+	SIGKILL
+	SIGTRAP
+	SIGQUIT
+	SIGTERM
+)
+
+// File system
+
+const (
+	Stdin  = 0
+	Stdout = 1
+	Stderr = 2
+)
+
+const (
+	O_RDONLY = 0
+	O_WRONLY = 1
+	O_RDWR   = 2
+
+	O_CREAT  = 0100
+	O_CREATE = O_CREAT
+	O_TRUNC  = 01000
+	O_APPEND = 02000
+	O_EXCL   = 0200
+	O_SYNC   = 010000
+
+	O_CLOEXEC = 0
+)
+
+func Getenv(key string) (value string, found bool) {
+	return "", false // stub
+}
+
+func Open(path string, mode int, perm uint32) (fd int, err error) {
+	return 0, ENOSYS
+}
+
+func Read(fd int, p []byte) (n int, err error) {
+	return 0, ENOSYS
+}
+
+func Seek(fd int, offset int64, whence int) (off int64, err error) {
+	return 0, ENOSYS
+}
+
+func Close(fd int) (err error) {
+	return ENOSYS
+}
+
+// Processes
+
+type WaitStatus uint32
+
+func (w WaitStatus) Exited() bool       { return false }
+func (w WaitStatus) ExitStatus() int    { return 0 }
+func (w WaitStatus) Signaled() bool     { return false }
+func (w WaitStatus) Signal() Signal     { return 0 }
+func (w WaitStatus) CoreDump() bool     { return false }
+func (w WaitStatus) Stopped() bool      { return false }
+func (w WaitStatus) Continued() bool    { return false }
+func (w WaitStatus) StopSignal() Signal { return 0 }
+func (w WaitStatus) TrapCause() int     { return 0 }
+
+// XXX made up
+type Rusage struct {
+	Utime Timeval
+	Stime Timeval
+}
+
+// XXX made up
+type ProcAttr struct {
+	Dir   string
+	Env   []string
+	Files []uintptr
+	Sys   *SysProcAttr
+}
+
+type SysProcAttr struct {
+}
+
+func Getegid() int                      { return 1 }
+func Geteuid() int                      { return 1 }
+func Getgid() int                       { return 1 }
+func Getgroups() ([]int, error)         { return []int{1}, nil }
+func Getppid() int                      { return 2 }
+func Getpid() int                       { return 3 }
+func Gettimeofday(tv *Timeval) error    { return ENOSYS }
+func Getuid() int                       { return 1 }
+func Kill(pid int, signum Signal) error { return ENOSYS }
+func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
+	return 0, ENOSYS
+}
+func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle uintptr, err error) {
+	return 0, 0, ENOSYS
+}
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
+	return 0, ENOSYS
+}
+
+type Timeval struct {
+	Sec  int64
+	Usec int64
+}