feat: opts builder

const.go

@@ -1,5 +1,9 @@
 package main
 
+const (
+	gobin = "go"
+)
+
 const (
 	flagNameRace                      = "race"
 	flagNameMSAN                      = "msan"

constraints.go

@@ -0,0 +1,97 @@
+package main
+
+import "github.com/hashicorp/go-version"
+
+var (
+	flagConstraints       map[string]version.Constraints
+	platformConstraints   []PlatformConstraint
+	experimentConstraints map[string]version.Constraints
+)
+
+// Parse all of the constraints as efficiently as possible.
+func init() {
+	var (
+		ok         bool
+		constraint version.Constraints
+		err        error
+	)
+
+	parsed := map[string]version.Constraints{}
+
+	flagConstraints = map[string]version.Constraints{}
+
+	flagConstraintsInputs := []struct {
+		name       string
+		constraint string
+	}{
+		{"C", ">= 1.20"},
+		{flagNameASAN, ">= 1.18"},
+		{flagNameCover, ">= 1.20"},
+		{flagNameCoverPKG, ">= 1.20"},
+		{flagNameBuildVCS, ">= 1.18"},
+		{flagNameModCacheRW, ">= 1.14"},
+		{flagNameMod, ">= 1.11"},
+		{flagNameModFile, ">= 1.14"},
+		{flagNameOverlay, ">= 1.16"},
+		{flagNameProfileGuidedOptimization, ">= 1.20"},
+		{flagNameTrimPath, ">= 1.13"},
+	}
+
+	for _, input := range flagConstraintsInputs {
+		if constraint, ok = parsed[input.constraint]; ok {
+			flagConstraints[input.name] = constraint
+
+			continue
+		}
+
+		if constraint, err = version.NewConstraint(input.constraint); err != nil {
+			panic(err)
+		}
+
+		flagConstraints[input.name] = constraint
+		parsed[input.constraint] = constraint
+	}
+
+	platformConstraintsInputs := []struct {
+		constraint string
+		platforms  []Platform
+	}{
+		{"<= 1.0", Platforms_1_0},
+		{">= 1.1, < 1.3", Platforms_1_1},
+		{">= 1.3, < 1.4", Platforms_1_3},
+		{">= 1.4, < 1.5", Platforms_1_4},
+		{">= 1.5, < 1.6", Platforms_1_5},
+		{">= 1.6, < 1.7", Platforms_1_6},
+		{">= 1.7, < 1.8", Platforms_1_7},
+		{">= 1.8, < 1.9", Platforms_1_8},
+		{">= 1.9, < 1.10", Platforms_1_9},
+		{">= 1.10, < 1.11", Platforms_1_10},
+		{">= 1.11, < 1.12", Platforms_1_11},
+		{">= 1.12, < 1.13", Platforms_1_12},
+		{">= 1.13, < 1.14", Platforms_1_13},
+		{">= 1.14, < 1.15", Platforms_1_14},
+		{">= 1.15, < 1.16", Platforms_1_15},
+		{">= 1.16, < 1.17", Platforms_1_16},
+		{">= 1.17, < 1.18", Platforms_1_17},
+		{">= 1.18, < 1.19", Platforms_1_18},
+		{">= 1.19, < 1.20", Platforms_1_19},
+		{">= 1.20, < 1.21", Platforms_1_20},
+	}
+
+	platformConstraints = make([]PlatformConstraint, len(platformConstraintsInputs))
+
+	for i, input := range platformConstraintsInputs {
+		if constraint, ok = parsed[input.constraint]; ok {
+			platformConstraints[i] = PlatformConstraint{Constraints: constraint, Platforms: input.platforms}
+
+			continue
+		}
+
+		if constraint, err = version.NewConstraint(input.constraint); err != nil {
+			panic(err)
+		}
+
+		platformConstraints[i] = PlatformConstraint{Constraints: constraint, Platforms: input.platforms}
+		parsed[input.constraint] = constraint
+	}
+}

go.go

@@ -21,31 +21,13 @@ type OutputTemplateData struct {
 
 // GoCrossCompile
 func GoCrossCompile(opts *CompileOpts) error {
-	env := append(os.Environ(),
-		"GOOS="+opts.Platform.OS,
-		"GOARCH="+opts.Platform.Arch)
-
-	if opts.Cc != "" {
-		env = append(env, "CC="+opts.Cc)
-	}
-	if opts.Cxx != "" {
-		env = append(env, "CXX="+opts.Cxx)
-	}
-
 	// If we're building for our own platform, then enable cgo always. We
 	// respect the CGO_ENABLED flag if that is explicitly set on the platform.
 	if !opts.Cgo && os.Getenv("CGO_ENABLED") != "0" {
 		opts.Cgo = runtime.GOOS == opts.Platform.OS &&
 			runtime.GOARCH == opts.Platform.Arch
 	}
 
-	// If cgo is enabled then set that env var
-	if opts.Cgo {
-		env = append(env, "CGO_ENABLED=1")
-	} else {
-		env = append(env, "CGO_ENABLED=0")
-	}
-
 	var outputPath bytes.Buffer
 	tpl, err := template.New("output").Parse(opts.OutputTpl)
 	if err != nil {
@@ -98,75 +80,15 @@ func GoCrossCompile(opts *CompileOpts) error {
 		opts.PackagePath = ""
 	}
 
-	args := []string{"build"}
-
-	if opts.Rebuild {
-		args = append(args, "-a")
-	}
-
-	if opts.TrimPath {
-		args = append(args, "-trimpath")
-	}
-
-	if opts.ModMode != "" {
-		args = append(args, fmtFlag("mod", opts.ModMode))
-	}
-
-	if opts.BuildMode != "" {
-		args = append(args, fmtFlag("buildmode", opts.BuildMode))
-	}
-
-	if opts.BuildVCS != "" {
-		args = append(args, fmtFlag("buildvcs", opts.BuildVCS))
-	}
-
-	if opts.Compiler != "" {
-		args = append(args, fmtFlag("-compiler", opts.Compiler))
-	}
-
-	if opts.Race {
-		args = append(args, "-race")
-	}
-
-	if opts.GcFlags != "" {
-		args = append(args, fmtFlagSpaceSeparated("gcflags", opts.GcFlags))
-	}
-
-	if opts.GcCGOFlags != "" {
-		args = append(args, fmtFlagSpaceSeparated("gccgoflags", opts.GcCGOFlags))
-	}
-
-	if opts.LDFlags != "" {
-		args = append(args, fmtFlagSpaceSeparated("ldflags", opts.LDFlags))
-	}
-
-	if opts.ASMFlags != "" {
-		args = append(args, fmtFlagSpaceSeparated("asmflags", opts.ASMFlags))
-	}
-
-	if opts.Tags != "" {
-		args = append(args, fmt.Sprintf("-tags=%s", opts.Tags))
-	}
+	args := append([]string{"build"}, opts.Arguments()...)
 
 	args = append(args, "-o", outputPathReal, opts.PackagePath)
 
-	_, err = execGo(opts.GoCmd, env, chdir, args...)
+	_, err = execGo(opts.GoCmd, opts.Env(), chdir, args...)
 
 	return err
 }
 
-func fmtFlag(name, value string) string {
-	return fmt.Sprintf(`-%s=%s`, name, value)
-}
-
-func fmtFlagSpaceSeparated(name, value string) string {
-	if strings.Contains(value, " ") && value[0] != '"' {
-		return fmt.Sprintf(`-%s="%s"`, name, value)
-	}
-
-	return fmt.Sprintf(`-%s=%s`, name, value)
-}
-
 // GoMainDirs returns the file paths to the packages that are "main"
 // packages, from the list of packages given. The list of packages can
 // include relative paths, the special "..." Go keyword, etc.
@@ -202,7 +124,7 @@ func GoMainDirs(packages []string, GoCmd string) ([]string, error) {
 
 // GoRoot returns the GOROOT value for the compiled `go` binary.
 func GoRoot() (string, error) {
-	output, err := execGo("go", nil, "", "env", "GOROOT")
+	output, err := execGo(gobin, nil, "", "env", "GOROOT")
 	if err != nil {
 		return "", err
 	}
@@ -231,7 +153,7 @@ func GoVersion() (string, error) {
 	}
 
 	// Execute and read the version, which will be the only thing on stdout.
-	version, err := execGo("go", nil, "", "run", sourcePath)
+	version, err := execGo(gobin, nil, "", "run", sourcePath)
 
 	fmt.Printf("Detected Go Version: %s\n", version)
 

go.mod

@@ -5,4 +5,11 @@ go 1.20
 require (
 	github.com/hashicorp/go-version v1.6.0
 	github.com/mitchellh/iochan v1.0.0
+	github.com/stretchr/testify v1.8.2
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,4 +1,21 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/hashicorp/go-version v1.6.0 h1:feTTfFNnjP967rlCxM/I9g701jU+RN74YKx2mOkIeek=
 github.com/hashicorp/go-version v1.6.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
 github.com/mitchellh/iochan v1.0.0 h1:C+X3KsSTLFVBr/tK1eYN/vs4rJcvsiLU338UhYPJWeY=
 github.com/mitchellh/iochan v1.0.0/go.mod h1:JwYml1nuB7xOzsp52dPpHFffvOCDupsG0QubkSMEySY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -41,7 +41,7 @@ func realMain() int {
 	flags.StringVar(&flagOutput, "output", "{{.Dir}}_{{.OS}}_{{.Arch}}", "")
 	flags.IntVar(&flagParallel, "parallel", -1, "")
 	flags.BoolVar(&flagVerbose, "verbose", false, "")
-	flags.StringVar(&flagGoCmd, "gocmd", "go", "")
+	flags.StringVar(&flagGoCmd, "gocmd", gobin, "")
 
 	// Misc.
 	flags.Var(flagPlatform.ArchFlagValue(), "arch", "")
@@ -111,7 +111,7 @@ func realMain() int {
 	var v *version.Version
 
 	// Use latest if we get an unexpected version string
-	if strings.HasPrefix(versionStr, "go") {
+	if strings.HasPrefix(versionStr, gobin) {
 		if v, err = version.NewVersion(versionStr[2:]); err != nil {
 			log.Printf("Unable to parse current go version: %s\n%s", versionStr, err.Error())
 		}
@@ -154,19 +154,6 @@ func realMain() int {
 		return 1
 	}
 
-	// Assume -mod is supported when no version prefix is found
-	if flagMod != "" {
-		constraint, err := version.NewConstraint(">= 1.11")
-		if err != nil {
-			panic(err)
-		}
-
-		if !constraint.Check(v) {
-			fmt.Printf("Go compiler version %s does not support the -mod flag\n", versionStr)
-			flagMod = ""
-		}
-	}
-
 	// Build in parallel!
 	fmt.Printf("Number of parallel builds: %d\n\n", flagParallel)
 
@@ -211,7 +198,7 @@ func realMain() int {
 					InstallSuffix:             flagInstallSuffix,
 					LDFlags:                   flagLDFlags,
 					LinkShared:                flagLinkShared,
-					ModMode:                   flagMod,
+					Mod:                       flagMod,
 					ModCacheRW:                flagModCacheRW,
 					ModFile:                   flagModFile,
 					Overlay:                   flagOverlay,