init

binfo.go

@@ -0,0 +1,197 @@
+package binfo
+
+import (
+	"fmt"
+	"runtime/debug"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/hashicorp/go-multierror"
+)
+
+type Binfo struct {
+	// Module information.
+	Module struct {
+		// The module path, e.g. "golang.org/x/tools/cmd/stringer".
+		Path string
+
+		// The version of this module.
+		Version string
+
+		// The checksum of this module.
+		Sum string
+	}
+
+	// Information about the build process and target.
+	Build struct {
+		// The version of the Go toolchain used to build the binary, e.g. "go1.19.2".
+		GoVersion string
+
+		// The buildmode flag value, e.g. "exe".
+		Mode string
+
+		// The compiler toolchain, e.g. "gc" or "gccgo".
+		Compiler string
+
+		// The architecture target, e.g. "amd64".
+		Arch string
+
+		// The operating system target, e.g. "linux".
+		OS string
+	}
+
+	// Information about CGO.
+	CGO struct {
+		Enabled bool
+
+		Flags struct {
+			C   string
+			CPP string
+			CXX string
+			LD  string
+		}
+	}
+
+	// Information about version control at the time of building.
+	VCS struct {
+		// The name of the version control system, e.g. "git".
+		Name string
+
+		// The current revision, e.g. "6cb6d5fa113f26aa2bc139539eab8939632f0693".
+		Revision string
+
+		// The modification time for the current revision.
+		Time time.Time
+
+		// Whether or not the source tree had local modifications.
+		Modified bool
+	}
+
+	// The original data source for build information.
+	Orig *debug.BuildInfo
+}
+
+func Get() (Binfo, error) {
+	var merr *multierror.Error
+
+	b := Binfo{}
+
+	if o, ok := debug.ReadBuildInfo(); ok {
+		b.Orig = o
+
+		b.Module.Version = o.Main.Version
+		b.Module.Path = o.Main.Path
+		b.Module.Sum = o.Main.Sum
+
+		for _, setting := range o.Settings {
+			switch setting.Key {
+			case "-buildmode":
+				b.Build.Mode = setting.Value
+			case "-compiler":
+				b.Build.Compiler = setting.Value
+			case "GOARCH":
+				b.Build.Arch = setting.Value
+			case "GOOS":
+				b.Build.OS = setting.Value
+
+			case "CGO_ENABLED":
+				switch setting.Value {
+				case "1":
+					b.CGO.Enabled = true
+				case "0":
+					b.CGO.Enabled = false
+				default:
+					merr = multierror.Append(merr, fmt.Errorf("failed to parse %s", setting.Key))
+				}
+			case "CGO_CFLAGS":
+				b.CGO.Flags.C = setting.Value
+			case "CGO_CPPFLAGS":
+				b.CGO.Flags.CPP = setting.Value
+			case "CGO_CXXFLAGS":
+				b.CGO.Flags.CXX = setting.Value
+			case "CGO_LDFLAGS":
+				b.CGO.Flags.LD = setting.Value
+
+			case "vcs":
+				b.VCS.Name = setting.Value
+			case "vcs.revision":
+				b.VCS.Revision = setting.Value
+			case "vcs.time":
+				v, err := time.Parse(time.RFC3339, setting.Value)
+				if err != nil {
+					merr = multierror.Append(merr, fmt.Errorf("unable to parse VCS time: %w", err))
+				}
+				b.VCS.Time = v
+			case "vcs.modified":
+				v, err := strconv.ParseBool(setting.Value)
+				if err != nil {
+					merr = multierror.Append(merr, fmt.Errorf("unable to parse VCS modified: %w", err))
+				}
+				b.VCS.Modified = v
+			}
+		}
+	}
+
+	return b, merr.ErrorOrNil()
+}
+
+type SummaryMode uint
+
+const (
+	ModeModule SummaryMode = 1 << iota
+	ModeBuild
+	ModeCGO
+	ModeVCS
+	ModeMultiline
+)
+
+func (b Binfo) Summarize(program string, mode SummaryMode) string {
+	wants := func(test SummaryMode) bool {
+		return mode&test == test
+	}
+
+	sep := ", "
+	if wants(ModeMultiline) {
+		sep = "\n"
+	}
+
+	parts := make([]string, 4)
+
+	if wants(ModeModule) {
+		parts = append(
+			parts,
+			fmt.Sprintf("module %s (%s) (sum %s)", b.Module.Path, b.Module.Version, b.Module.Sum),
+		)
+	}
+
+	if wants(ModeBuild) {
+		parts = append(
+			parts,
+			fmt.Sprintf("built with %s (%s) (mode %s)", b.Build.Compiler, b.Build.GoVersion, b.Build.Mode),
+		)
+	}
+
+	if wants(ModeCGO) {
+		if b.CGO.Enabled {
+			parts = append(
+				parts,
+				fmt.Sprintf("with cgo (c %q) (cpp %q) (cxx %q) (ld %q)", b.CGO.Flags.C, b.CGO.Flags.CPP, b.CGO.Flags.CXX, b.CGO.Flags.LD),
+			)
+		} else {
+			parts = append(
+				parts,
+				"without cgo",
+			)
+		}
+	}
+
+	if wants(ModeVCS) {
+		parts = append(
+			parts,
+			fmt.Sprintf("via %s (rev %s) (at %s)", b.VCS.Name, b.VCS.Revision, b.VCS.Time.Format("2006-01-02 15:04:05")),
+		)
+	}
+
+	return fmt.Sprintf("%s:%s%s", program, sep, strings.Join(parts, sep))
+}