go-pulse/internal/build/gotool.go
Felix Lange effaf18523
build: improve cross compilation setup (#22804)
This PR cleans up the CI build system and fixes a couple of issues.

- The go tool launcher code has been moved to internal/build. With the new
  toolchain functions, the environment of the host Go (i.e. the one that built
  ci.go) and the target Go (i.e. the toolchain downloaded by -dlgo) are isolated
  more strictly. This is important to make cross compilation and -dlgo work
  correctly in more cases.
- The -dlgo option now skips the download and uses the host Go if the running Go
  version matches dlgoVersion exactly.
- The 'test' command now supports -dlgo, -cc and -arch. Running unit tests with
  foreign GOARCH is occasionally useful. For example, it can be used to run
  32-bit tests on Windows. It can also be used to run darwin/amd64 tests on
  darwin/arm64 using Rosetta 2.
- The 'aar', 'xcode' and 'xgo' commands now use a slightly different method to
  install external tools. They previously used `go get`, but this comes with the
  annoying side effect of modifying go.mod. They now use `go install` instead,
  which is the recommended way of installing tools without modifying the local
  module.
- The old build warning about outdated Go version has been removed because we're
  much better at keeping backwards compatibility now.
2021-05-04 13:01:20 +02:00

150 lines
4.7 KiB
Go

// Copyright 2021 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package build
import (
"fmt"
"log"
"os"
"os/exec"
"path/filepath"
"runtime"
"strings"
)
type GoToolchain struct {
Root string // GOROOT
// Cross-compilation variables. These are set when running the go tool.
GOARCH string
GOOS string
CC string
}
// Go creates an invocation of the go command.
func (g *GoToolchain) Go(command string, args ...string) *exec.Cmd {
tool := g.goTool(command, args...)
// Configure environment for cross build.
if g.GOARCH != "" && g.GOARCH != runtime.GOARCH {
tool.Env = append(tool.Env, "CGO_ENABLED=1")
tool.Env = append(tool.Env, "GOARCH="+g.GOARCH)
}
if g.GOOS != "" && g.GOOS != runtime.GOOS {
tool.Env = append(tool.Env, "GOOS="+g.GOOS)
}
// Configure C compiler.
if g.CC != "" {
tool.Env = append(tool.Env, "CC="+g.CC)
} else if os.Getenv("CC") != "" {
tool.Env = append(tool.Env, "CC="+os.Getenv("CC"))
}
return tool
}
// Install creates an invocation of 'go install'. The command is configured to output
// executables to the given 'gobin' directory.
//
// This can be used to install auxiliary build tools without modifying the local go.mod and
// go.sum files. To install tools which are not required by go.mod, ensure that all module
// paths in 'args' contain a module version suffix (e.g. "...@latest").
func (g *GoToolchain) Install(gobin string, args ...string) *exec.Cmd {
if !filepath.IsAbs(gobin) {
panic("GOBIN must be an absolute path")
}
tool := g.goTool("install")
tool.Env = append(tool.Env, "GOBIN="+gobin)
tool.Args = append(tool.Args, "-mod=readonly")
tool.Args = append(tool.Args, args...)
// Ensure GOPATH is set because go install seems to absolutely require it. This uses
// 'go env' because it resolves the default value when GOPATH is not set in the
// environment. Ignore errors running go env and leave any complaining about GOPATH to
// the install command.
pathTool := g.goTool("env", "GOPATH")
output, _ := pathTool.Output()
tool.Env = append(tool.Env, "GOPATH="+string(output))
return tool
}
func (g *GoToolchain) goTool(command string, args ...string) *exec.Cmd {
if g.Root == "" {
g.Root = runtime.GOROOT()
}
tool := exec.Command(filepath.Join(g.Root, "bin", "go"), command)
tool.Args = append(tool.Args, args...)
tool.Env = append(tool.Env, "GOROOT="+g.Root)
// Forward environment variables to the tool, but skip compiler target settings.
// TODO: what about GOARM?
skip := map[string]struct{}{"GOROOT": {}, "GOARCH": {}, "GOOS": {}, "GOBIN": {}, "CC": {}}
for _, e := range os.Environ() {
if i := strings.IndexByte(e, '='); i >= 0 {
if _, ok := skip[e[:i]]; ok {
continue
}
}
tool.Env = append(tool.Env, e)
}
return tool
}
// DownloadGo downloads the Go binary distribution and unpacks it into a temporary
// directory. It returns the GOROOT of the unpacked toolchain.
func DownloadGo(csdb *ChecksumDB, version string) string {
// Shortcut: if the Go version that runs this script matches the
// requested version exactly, there is no need to download anything.
activeGo := strings.TrimPrefix(runtime.Version(), "go")
if activeGo == version {
log.Printf("-dlgo version matches active Go version %s, skipping download.", activeGo)
return runtime.GOROOT()
}
ucache, err := os.UserCacheDir()
if err != nil {
log.Fatal(err)
}
// For Arm architecture, GOARCH includes ISA version.
os := runtime.GOOS
arch := runtime.GOARCH
if arch == "arm" {
arch = "armv6l"
}
file := fmt.Sprintf("go%s.%s-%s", version, os, arch)
if os == "windows" {
file += ".zip"
} else {
file += ".tar.gz"
}
url := "https://golang.org/dl/" + file
dst := filepath.Join(ucache, file)
if err := csdb.DownloadFile(url, dst); err != nil {
log.Fatal(err)
}
godir := filepath.Join(ucache, fmt.Sprintf("geth-go-%s-%s-%s", version, os, arch))
if err := ExtractArchive(dst, godir); err != nil {
log.Fatal(err)
}
goroot, err := filepath.Abs(filepath.Join(godir, "go"))
if err != nil {
log.Fatal(err)
}
return goroot
}