version: Support single override and add git hash.

config.go

@@ -87,7 +87,7 @@ var (
 
 // config defines the configuration options for the pool.
 type config struct {
-	ShowVersion           bool          `long:"version" no-ini:"true" description:"Display version information and exit."`
+	ShowVersion           bool          `short:"V" long:"version" no-ini:"true" description:"Display version information and exit."`
 	HomeDir               string        `long:"appdata" ini-name:"appdata" description:"Path to application home directory."`
 	ConfigFile            string        `long:"configfile" ini-name:"configfile" description:"Path to configuration file."`
 	DataDir               string        `long:"datadir" ini-name:"datadir" description:"The data directory."`
@@ -396,7 +396,7 @@ func loadConfig(appName string) (*config, []string, error) {
 	// Show the version and exit if the version flag was specified.
 	if preCfg.ShowVersion {
 		fmt.Printf("%s version %s (Go version %s %s/%s)\n", appName,
-			version(), runtime.Version(), runtime.GOOS, runtime.GOARCH)
+			Version, runtime.Version(), runtime.GOOS, runtime.GOARCH)
 		os.Exit(0)
 	}
 

dcrpool.go

@@ -200,10 +200,10 @@ func realMain() error {
 		}()
 	}
 
-	mpLog.Infof("Version: %s", version())
-	mpLog.Infof("Runtime: Go version %s", runtime.Version())
+	mpLog.Infof("%s version %s (Go version %s %s/%s)", appName,
+		Version, runtime.Version(), runtime.GOOS, runtime.GOARCH)
 	mpLog.Infof("Home dir: %s", cfg.HomeDir)
-	mpLog.Infof("Started dcrpool.")
+	mpLog.Infof("Started dcrpool")
 
 	go func() {
 		select {

version.go

@@ -1,99 +1,148 @@
 // Copyright (c) 2013-2014 The btcsuite developers
-// Copyright (c) 2015-2021 The Decred developers
+// Copyright (c) 2015-2023 The Decred developers
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
 package main
 
 import (
-	"bytes"
 	"fmt"
+	"regexp"
+	"strconv"
 	"strings"
 )
 
 const (
-	// semanticAlphabet defines the allowed characters for the pre-release
-	// portion of a semantic version string.
-	semanticAlphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-"
-
-	// semanticBuildAlphabet defines the allowed characters for the build
-	// portion of a semantic version string.
-	semanticBuildAlphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-."
+	// semanticAlphabet defines the allowed characters for the pre-release and
+	// build metadata portions of a semantic version string.
+	semanticAlphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-."
 )
 
-// These constants define the application version and follow the semantic
-// versioning 2.0.0 spec (http://semver.org/).
-const (
-	appMajor uint = 1
-	appMinor uint = 2
-	appPatch uint = 0
-)
+// semverRE is a regular expression used to parse a semantic version string into
+// its constituent parts.
+var semverRE = regexp.MustCompile(`^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)` +
+	`(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*` +
+	`[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$`)
 
+// These variables define the application version and follow the semantic
+// versioning 2.0.0 spec (https://semver.org/).
 var (
-	// appPreRelease is defined as a variable so it can be overridden during
-	// the build process with '-ldflags "-X main.appPreRelease=foo"' if
-	// needed.  It MUST only contain characters from semanticAlphabet per
-	// the semantic versioning spec.
-	appPreRelease = ""
-
-	// appBuild is defined as a variable so it can be overridden during the
-	// build process with '-ldflags "-X main.appBuild=foo"' if needed.  It
-	// MUST only contain characters from semanticBuildAlphabet per the
-	// semantic versioning spec.
-	appBuild = "dev"
-)
+	// Note for maintainers:
+	//
+	// The expected process for setting the version in releases is as follows:
+	// - Create a release branch of the form 'release-vMAJOR.MINOR'
+	// - Modify the Version variable below on that branch to:
+	//   - Remove the pre-release portion
+	//   - Set the build metadata to 'release.local'
+	// - Update the Version variable below on the master branch to the next
+	//   expected version while retaining a pre-release of 'pre'
+	//
+	// These steps ensure that building from source produces versions that are
+	// distinct from reproducible builds that override the Version via linker
+	// flags.
 
-// version returns the application version as a properly formed string per the
-// semantic versioning 2.0.0 spec (http://semver.org/).
-func version() string {
-	// Start with the major, minor, and patch versions.
-	version := fmt.Sprintf("%d.%d.%d", appMajor, appMinor, appPatch)
-
-	// Append pre-release version if there is one.  The hyphen called for
-	// by the semantic versioning spec is automatically appended and should
-	// not be contained in the pre-release string.  The pre-release version
-	// is not appended if it contains invalid characters.
-	preRelease := normalizePreRelString(appPreRelease)
-	if preRelease != "" {
-		version = fmt.Sprintf("%s-%s", version, preRelease)
-	}
+	// Version is the application version per the semantic versioning 2.0.0 spec
+	// (https://semver.org/).
+	//
+	// It is defined as a variable so it can be overridden during the build
+	// process with:
+	// '-ldflags "-X main.Version=fullsemver"'
+	// if needed.
+	//
+	// It MUST be a full semantic version per the semantic versioning spec or
+	// the app will panic at runtime.  Of particular note is the pre-release
+	// and build metadata portions MUST only contain characters from
+	// semanticAlphabet.
+	Version = "1.3.0-pre"
 
-	// Append build metadata if there is any.  The plus called for
-	// by the semantic versioning spec is automatically appended and should
-	// not be contained in the build metadata string.  The build metadata
-	// string is not appended if it contains invalid characters.
-	build := normalizeBuildString(appBuild)
-	if build != "" {
-		version = fmt.Sprintf("%s+%s", version, build)
-	}
+	// NOTE: The following values are set via init by parsing the above Version
+	// string.
 
-	return version
+	// These fields are the individual semantic version components that define
+	// the application version.
+	Major         uint32
+	Minor         uint32
+	Patch         uint32
+	PreRelease    string
+	BuildMetadata string
+)
+
+// parseUint32 converts the passed string to an unsigned integer or returns an
+// error if it is invalid.
+func parseUint32(s string, fieldName string) (uint32, error) {
+	val, err := strconv.ParseUint(s, 10, 32)
+	if err != nil {
+		return 0, fmt.Errorf("malformed semver %s: %w", fieldName, err)
+	}
+	return uint32(val), err
 }
 
-// normalizeSemString returns the passed string stripped of all characters
-// which are not valid according to the provided semantic versioning alphabet.
-func normalizeSemString(str, alphabet string) string {
-	var result bytes.Buffer
-	for _, r := range str {
-		if strings.ContainsRune(alphabet, r) {
-			result.WriteRune(r)
+// checkSemString returns an error if the passed string contains characters that
+// are not in the provided alphabet.
+func checkSemString(s, alphabet, fieldName string) error {
+	for _, r := range s {
+		if !strings.ContainsRune(alphabet, r) {
+			return fmt.Errorf("malformed semver %s: %q invalid", fieldName, r)
 		}
 	}
-	return result.String()
+	return nil
 }
 
-// normalizePreRelString returns the passed string stripped of all characters
-// which are not valid according to the semantic versioning guidelines for
-// pre-release strings.  In particular they MUST only contain characters in
-// semanticAlphabet.
-func normalizePreRelString(str string) string {
-	return normalizeSemString(str, semanticAlphabet)
+// parseSemVer parses various semver components from the provided string.
+func parseSemVer(s string) (uint32, uint32, uint32, string, string, error) {
+	// Parse the various semver component from the version string via a regular
+	// expression.
+	m := semverRE.FindStringSubmatch(s)
+	if m == nil {
+		err := fmt.Errorf("malformed version string %q: does not conform to "+
+			"semver specification", s)
+		return 0, 0, 0, "", "", err
+	}
+
+	major, err := parseUint32(m[1], "major")
+	if err != nil {
+		return 0, 0, 0, "", "", err
+	}
+
+	minor, err := parseUint32(m[2], "minor")
+	if err != nil {
+		return 0, 0, 0, "", "", err
+	}
+
+	patch, err := parseUint32(m[3], "patch")
+	if err != nil {
+		return 0, 0, 0, "", "", err
+	}
+
+	preRel := m[4]
+	err = checkSemString(preRel, semanticAlphabet, "pre-release")
+	if err != nil {
+		return 0, 0, 0, "", "", err
+	}
+
+	build := m[5]
+	err = checkSemString(build, semanticAlphabet, "buildmetadata")
+	if err != nil {
+		return 0, 0, 0, "", "", err
+	}
+
+	return major, minor, patch, preRel, build, nil
 }
 
-// normalizeBuildString returns the passed string stripped of all characters
-// which are not valid according to the semantic versioning guidelines for build
-// metadata strings.  In particular they MUST only contain characters in
-// semanticBuildAlphabet.
-func normalizeBuildString(str string) string {
-	return normalizeSemString(str, semanticBuildAlphabet)
+func init() {
+	var err error
+	Major, Minor, Patch, PreRelease, BuildMetadata, err = parseSemVer(Version)
+	if err != nil {
+		panic(err)
+	}
+	if BuildMetadata == "" {
+		BuildMetadata = vcsCommitID()
+		if BuildMetadata != "" {
+			Version = fmt.Sprintf("%d.%d.%d", Major, Minor, Patch)
+			if PreRelease != "" {
+				Version += "-" + PreRelease
+			}
+			Version += "+" + BuildMetadata
+		}
+	}
 }

version_buildinfo.go

@@ -0,0 +1,35 @@
+// Copyright (c) 2021-2022 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+//go:build go1.18
+// +build go1.18
+
+package main
+
+import "runtime/debug"
+
+// vcsCommitID attempts to return the version control system short commit hash
+// that was used to build the binary.  It currently only detects git commits.
+func vcsCommitID() string {
+	bi, ok := debug.ReadBuildInfo()
+	if !ok {
+		return ""
+	}
+	var vcs, revision string
+	for _, bs := range bi.Settings {
+		switch bs.Key {
+		case "vcs":
+			vcs = bs.Value
+		case "vcs.revision":
+			revision = bs.Value
+		}
+	}
+	if vcs == "" {
+		return ""
+	}
+	if vcs == "git" && len(revision) > 9 {
+		revision = revision[:9]
+	}
+	return revision
+}

version_nobuildinfo.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2021-2022 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+//go:build !go1.18
+// +build !go1.18
+
+package main
+
+// vcsCommitID returns an empty string for all Go versions prior to 1.18 since
+// the information is not available in binaries prior to that version.
+func vcsCommitID() string {
+	return ""
+}