From 86f87787489be061698bb03cc9fb5e7e3be65cb3 Mon Sep 17 00:00:00 2001 From: Ayke van Laethem Date: Sun, 24 Mar 2019 12:59:09 +0100 Subject: [PATCH] darwin: use custom syscall pkg that uses libsystem Go 1.12 switched to using libSystem.dylib for system calls, because Apple recommends against doing direct system calls that Go 1.11 and earlier did. For more information, see: https://github.com/golang/go/issues/17490 https://developer.apple.com/library/archive/qa/qa1118/_index.html While the old syscall package was relatively easy to support in TinyGo (just implement syscall.Syscall*), this got a whole lot harder with Go 1.12 as all syscalls now go through CGo magic to call the underlying libSystem functions. Therefore, this commit overrides the stdlib syscall package with a custom package that performs calls with libc (libSystem). This may be useful not just for darwin but for other platforms as well that do not place the stable ABI at the syscall boundary like Linux but at the libc boundary. Only a very minimal part of the syscall package has been implemented, to get the tests to pass. More calls can easily be added in the future. --- .travis.yml | 2 +- Makefile | 2 +- compiler/compiler.go | 2 +- src/syscall/errno.go | 30 ++++++++ src/syscall/syscall_baremetal.go | 29 +------- src/syscall/syscall_darwin.go | 51 +++++++++++++ src/syscall/syscall_libc.go | 57 +++++++++++++++ src/syscall/tables_baremetal.go | 119 ------------------------------- 8 files changed, 143 insertions(+), 149 deletions(-) create mode 100644 src/syscall/errno.go create mode 100644 src/syscall/syscall_darwin.go create mode 100644 src/syscall/syscall_libc.go diff --git a/.travis.yml b/.travis.yml index 995884d105..acec65141e 100644 --- a/.travis.yml +++ b/.travis.yml @@ -3,7 +3,7 @@ language: go matrix: include: - os: osx - go: "1.11" + go: "1.12" env: PATH="/usr/local/opt/llvm/bin:$PATH" before_install: - mkdir -p /Users/travis/gopath/bin diff --git a/Makefile b/Makefile index 93db041200..e89c38f03b 100644 --- a/Makefile +++ b/Makefile @@ -82,7 +82,7 @@ clean: @rm -rf build fmt: - @go fmt . ./compiler ./interp ./loader ./ir ./src/device/arm ./src/examples/* ./src/machine ./src/os ./src/runtime ./src/sync + @go fmt . ./compiler ./interp ./loader ./ir ./src/device/arm ./src/examples/* ./src/machine ./src/os ./src/runtime ./src/sync ./src/syscall @go fmt ./testdata/*.go test: diff --git a/compiler/compiler.go b/compiler/compiler.go index 93b3f22456..13a29d4361 100644 --- a/compiler/compiler.go +++ b/compiler/compiler.go @@ -203,7 +203,7 @@ func (c *Compiler) Compile(mainPath string) error { return true } else if path == "syscall" { for _, tag := range c.BuildTags { - if tag == "avr" || tag == "cortexm" { + if tag == "avr" || tag == "cortexm" || tag == "darwin" { return true } } diff --git a/src/syscall/errno.go b/src/syscall/errno.go new file mode 100644 index 0000000000..b67a685c85 --- /dev/null +++ b/src/syscall/errno.go @@ -0,0 +1,30 @@ +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 { + 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 +} diff --git a/src/syscall/syscall_baremetal.go b/src/syscall/syscall_baremetal.go index 05b0e57db2..fe17fcabb4 100644 --- a/src/syscall/syscall_baremetal.go +++ b/src/syscall/syscall_baremetal.go @@ -1,3 +1,5 @@ +// +build avr cortexm + package syscall // Most code here has been copied from the Go sources: @@ -8,33 +10,6 @@ package syscall // 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 diff --git a/src/syscall/syscall_darwin.go b/src/syscall/syscall_darwin.go new file mode 100644 index 0000000000..27e73733df --- /dev/null +++ b/src/syscall/syscall_darwin.go @@ -0,0 +1,51 @@ +package syscall + +// This file defines errno and constants to match the darwin libsystem ABI. +// Values have been determined experimentally by compiling some C code on macOS +// with Clang and looking at the resulting LLVM IR. + +// This function returns the error location in the darwin ABI. +// Discovered by compiling the following code using Clang: +// +// #include +// int getErrno() { +// return errno; +// } +// +//go:export __error +func libc___error() *int32 + +// getErrno returns the current C errno. It may not have been caused by the last +// call, so it should only be relied upon when the last call indicates an error +// (for example, by returning -1). +func getErrno() Errno { + errptr := libc___error() + return Errno(uintptr(*errptr)) +} + +const ( + ENOENT Errno = 2 + EINTR Errno = 4 + EMFILE Errno = 24 + EAGAIN Errno = 35 + ETIMEDOUT Errno = 60 + ENOSYS Errno = 78 + EWOULDBLOCK Errno = EAGAIN +) + +type Signal int + +const ( + SIGCHLD Signal = 20 + SIGINT Signal = 2 + SIGKILL Signal = 9 + SIGTRAP Signal = 5 + SIGQUIT Signal = 3 + SIGTERM Signal = 15 +) + +const ( + O_RDONLY = 0 + O_WRONLY = 1 + O_RDWR = 2 +) diff --git a/src/syscall/syscall_libc.go b/src/syscall/syscall_libc.go new file mode 100644 index 0000000000..c5fc4b28d6 --- /dev/null +++ b/src/syscall/syscall_libc.go @@ -0,0 +1,57 @@ +// +build darwin + +package syscall + +import ( + "unsafe" +) + +func Close(fd int) (err error) { + return ENOSYS // TODO +} + +func Write(fd int, p []byte) (n int, err error) { + buf, count := splitSlice(p) + n = libc_write(int32(fd), buf, uint(count)) + if n < 0 { + err = getErrno() + } + return +} + +func Read(fd int, p []byte) (n int, err error) { + return 0, ENOSYS // TODO +} + +func Seek(fd int, offset int64, whence int) (off int64, err error) { + return 0, ENOSYS // TODO +} + +func Open(path string, mode int, perm uint32) (fd int, err error) { + return 0, ENOSYS // TODO +} + +func Kill(pid int, sig Signal) (err error) { + return ENOSYS // TODO +} + +func Getpid() (pid int) { + panic("unimplemented: getpid") // TODO +} + +func Getenv(key string) (value string, found bool) { + return "", false // TODO +} + +func splitSlice(p []byte) (buf *byte, len uintptr) { + slice := (*struct { + buf *byte + len uintptr + cap uintptr + })(unsafe.Pointer(&p)) + return slice.buf, slice.len +} + +// ssize_t write(int fd, const void *buf, size_t count) +//go:export write +func libc_write(fd int32, buf *byte, count uint) int diff --git a/src/syscall/tables_baremetal.go b/src/syscall/tables_baremetal.go index 38b099f9fc..c10799c0dc 100644 --- a/src/syscall/tables_baremetal.go +++ b/src/syscall/tables_baremetal.go @@ -6,8 +6,6 @@ package syscall -import "runtime" - // TODO: generate with runtime/mknacl.sh, allow override with IRT. const ( sys_null = 1 @@ -223,123 +221,6 @@ const ( EWOULDBLOCK Errno = EAGAIN /* Operation would block */ ) -// TODO: Auto-generate some day. (Hard-coded in binaries so not likely to change.) -var errorstr = [...]string{ - EPERM: "Operation not permitted", - ENOENT: "No such file or directory", - ESRCH: "No such process", - EINTR: "Interrupted system call", - EIO: "I/O error", - ENXIO: "No such device or address", - E2BIG: "Argument list too long", - ENOEXEC: "Exec format error", - EBADF: "Bad file number", - ECHILD: "No child processes", - EAGAIN: "Try again", - ENOMEM: "Out of memory", - EACCES: "Permission denied", - EFAULT: "Bad address", - EBUSY: "Device or resource busy", - EEXIST: "File exists", - EXDEV: "Cross-device link", - ENODEV: "No such device", - ENOTDIR: "Not a directory", - EISDIR: "Is a directory", - EINVAL: "Invalid argument", - ENFILE: "File table overflow", - EMFILE: "Too many open files", - ENOTTY: "Not a typewriter", - EFBIG: "File too large", - ENOSPC: "No space left on device", - ESPIPE: "Illegal seek", - EROFS: "Read-only file system", - EMLINK: "Too many links", - EPIPE: "Broken pipe", - ENAMETOOLONG: "File name too long", - ENOSYS: "not implemented on " + runtime.GOOS, - EDQUOT: "Quota exceeded", - EDOM: "Math arg out of domain of func", - ERANGE: "Math result not representable", - EDEADLK: "Deadlock condition", - ENOLCK: "No record locks available", - ENOTEMPTY: "Directory not empty", - ELOOP: "Too many symbolic links", - ENOMSG: "No message of desired type", - EIDRM: "Identifier removed", - ECHRNG: "Channel number out of range", - EL2NSYNC: "Level 2 not synchronized", - EL3HLT: "Level 3 halted", - EL3RST: "Level 3 reset", - ELNRNG: "Link number out of range", - EUNATCH: "Protocol driver not attached", - ENOCSI: "No CSI structure available", - EL2HLT: "Level 2 halted", - EBADE: "Invalid exchange", - EBADR: "Invalid request descriptor", - EXFULL: "Exchange full", - ENOANO: "No anode", - EBADRQC: "Invalid request code", - EBADSLT: "Invalid slot", - EBFONT: "Bad font file fmt", - ENOSTR: "Device not a stream", - ENODATA: "No data (for no delay io)", - ETIME: "Timer expired", - ENOSR: "Out of streams resources", - ENONET: "Machine is not on the network", - ENOPKG: "Package not installed", - EREMOTE: "The object is remote", - ENOLINK: "The link has been severed", - EADV: "Advertise error", - ESRMNT: "Srmount error", - ECOMM: "Communication error on send", - EPROTO: "Protocol error", - EMULTIHOP: "Multihop attempted", - EDOTDOT: "Cross mount point (not really error)", - EBADMSG: "Trying to read unreadable message", - EOVERFLOW: "Value too large for defined data type", - ENOTUNIQ: "Given log. name not unique", - EBADFD: "f.d. invalid for this operation", - EREMCHG: "Remote address changed", - ELIBACC: "Can't access a needed shared lib", - ELIBBAD: "Accessing a corrupted shared lib", - ELIBSCN: ".lib section in a.out corrupted", - ELIBMAX: "Attempting to link in too many libs", - ELIBEXEC: "Attempting to exec a shared library", - ENOTSOCK: "Socket operation on non-socket", - EDESTADDRREQ: "Destination address required", - EMSGSIZE: "Message too long", - EPROTOTYPE: "Protocol wrong type for socket", - ENOPROTOOPT: "Protocol not available", - EPROTONOSUPPORT: "Unknown protocol", - ESOCKTNOSUPPORT: "Socket type not supported", - EOPNOTSUPP: "Operation not supported on transport endpoint", - EPFNOSUPPORT: "Protocol family not supported", - EAFNOSUPPORT: "Address family not supported by protocol family", - EADDRINUSE: "Address already in use", - EADDRNOTAVAIL: "Address not available", - ENETDOWN: "Network interface is not configured", - ENETUNREACH: "Network is unreachable", - ECONNABORTED: "Connection aborted", - ECONNRESET: "Connection reset by peer", - ENOBUFS: "No buffer space available", - EISCONN: "Socket is already connected", - ENOTCONN: "Socket is not connected", - ESHUTDOWN: "Can't send after socket shutdown", - ETIMEDOUT: "Connection timed out", - ECONNREFUSED: "Connection refused", - EHOSTDOWN: "Host is down", - EHOSTUNREACH: "Host is unreachable", - EALREADY: "Socket already connected", - EINPROGRESS: "Connection already in progress", - ENOMEDIUM: "No medium (in tape drive)", - ECANCELED: "Operation canceled.", - ELBIN: "Inode is remote (not really error)", - EFTYPE: "Inappropriate file type or format", - ENMFILE: "No more files", - ENOSHARE: "No such host or network path", - ECASECLASH: "Filename exists with different case", -} - // Do the interface allocations only once for common // Errno values. var (