Merge pull request #128 from mkeeler/go-mod-vendor

Allow -mod passthrough to the go compiler.

go.go

@@ -28,6 +28,7 @@ type CompileOpts struct {
 	Gcflags     string
 	Asmflags    string
 	Tags        string
+	ModMode     string
 	Cgo         bool
 	Rebuild     bool
 	GoCmd       string
@@ -107,6 +108,9 @@ func GoCrossCompile(opts *CompileOpts) error {
 	if opts.Rebuild {
 		args = append(args, "-a")
 	}
+	if opts.ModMode != "" {
+		args = append(args, "-mod", opts.ModMode)
+	}
 	args = append(args,
 		"-gcflags", opts.Gcflags,
 		"-ldflags", opts.Ldflags,

main.go

@@ -6,7 +6,10 @@ import (
 	"os"
 	"os/exec"
 	"runtime"
+	"strings"
 	"sync"
+
+	version "github.com/hashicorp/go-version"
 )
 
 func main() {
@@ -26,6 +29,7 @@ func realMain() int {
 	var flagGcflags, flagAsmflags string
 	var flagCgo, flagRebuild, flagListOSArch bool
 	var flagGoCmd string
+	var modMode string
 	flags := flag.NewFlagSet("gox", flag.ExitOnError)
 	flags.Usage = func() { printUsage() }
 	flags.Var(platformFlag.ArchFlagValue(), "arch", "arch to build for or skip")
@@ -43,6 +47,7 @@ func realMain() int {
 	flags.StringVar(&flagGcflags, "gcflags", "", "")
 	flags.StringVar(&flagAsmflags, "asmflags", "", "")
 	flags.StringVar(&flagGoCmd, "gocmd", "go", "")
+	flags.StringVar(&modMode, "mod", "", "")
 	if err := flags.Parse(os.Args[1:]); err != nil {
 		flags.Usage()
 		return 1
@@ -77,14 +82,14 @@ func realMain() int {
 		return 1
 	}
 
-	version, err := GoVersion()
+	versionStr, err := GoVersion()
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "error reading Go version: %s", err)
 		return 1
 	}
 
 	if flagListOSArch {
-		return mainListOSArch(version)
+		return mainListOSArch(versionStr)
 	}
 
 	// Determine the packages that we want to compile. Default to the
@@ -102,14 +107,34 @@ func realMain() int {
 	}
 
 	// Determine the platforms we're building for
-	platforms := platformFlag.Platforms(SupportedPlatforms(version))
+	platforms := platformFlag.Platforms(SupportedPlatforms(versionStr))
 	if len(platforms) == 0 {
 		fmt.Println("No valid platforms to build for. If you specified a value")
 		fmt.Println("for the 'os', 'arch', or 'osarch' flags, make sure you're")
 		fmt.Println("using a valid value.")
 		return 1
 	}
 
+	// Assume -mod is supported when no version prefix is found
+	if modMode != "" && strings.HasPrefix(versionStr, "go") {
+		// go-version only cares about version numbers
+		current, err := version.NewVersion(versionStr[2:])
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Unable to parse current go version: %s\n%s", versionStr, err.Error())
+			return 1
+		}
+
+		constraint, err := version.NewConstraint(">= 1.11")
+		if err != nil {
+			panic(err)
+		}
+
+		if !constraint.Check(current) {
+			fmt.Printf("Go compiler version %s does not support the -mod flag\n", versionStr)
+			modMode = ""
+		}
+	}
+
 	// Build in parallel!
 	fmt.Printf("Number of parallel builds: %d\n\n", parallel)
 	var errorLock sync.Mutex
@@ -133,6 +158,7 @@ func realMain() int {
 					Gcflags:     flagGcflags,
 					Asmflags:    flagAsmflags,
 					Tags:        tags,
+					ModMode:     modMode,
 					Cgo:         flagCgo,
 					Rebuild:     flagRebuild,
 					GoCmd:       flagGoCmd,
@@ -187,6 +213,7 @@ Options:
   -ldflags=""         Additional '-ldflags' value to pass to go build
   -asmflags=""        Additional '-asmflags' value to pass to go build
   -tags=""            Additional '-tags' value to pass to go build
+  -mod=""             Additional '-mod' value to pass to go build
   -os=""              Space-separated list of operating systems to build for
   -osarch=""          Space-separated list of os/arch pairs to build for
   -osarch-list        List supported os/arch pairs for your Go version