cmd/go: convert semver.IsValid to gover.ModIsValid

Change-Id: Id584c4bd6d1c12fd085414188bc7e7ca08164c04
Reviewed-on: https://go-review.googlesource.com/c/go/+/497416
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>

src/cmd/go/internal/gover/mod.go

@@ -88,3 +88,25 @@ func untoolchain(x string) string {
 	}
 	return x
 }
+
+// ModIsPrefix reports whether v is a valid version syntax prefix for the module with the given path.
+// The caller is assumed to have checked that ModIsValid(path, vers) is true.
+func ModIsPrefix(path, vers string) bool {
+	if IsToolchain(path) {
+		return IsLang(vers)
+	}
+	// Semver
+	dots := 0
+	for i := 0; i < len(vers); i++ {
+		switch vers[i] {
+		case '-', '+':
+			return false
+		case '.':
+			dots++
+			if dots >= 2 {
+				return false
+			}
+		}
+	}
+	return true
+}

src/cmd/go/internal/load/pkg.go

@@ -3231,9 +3231,10 @@ func PackagesAndErrorsOutsideModule(ctx context.Context, opts PackageOpts, args
 
 	// Check that the arguments satisfy syntactic constraints.
 	var version string
+	var firstPath string
 	for _, arg := range args {
 		if i := strings.Index(arg, "@"); i >= 0 {
-			version = arg[i+1:]
+			firstPath, version = arg[:i], arg[i+1:]
 			if version == "" {
 				return nil, fmt.Errorf("%s: version must not be empty", arg)
 			}
@@ -3271,7 +3272,7 @@ func PackagesAndErrorsOutsideModule(ctx context.Context, opts PackageOpts, args
 	// later arguments, and other modules would. Let's not try to be too
 	// magical though.
 	allowed := modload.CheckAllowed
-	if modload.IsRevisionQuery(version) {
+	if modload.IsRevisionQuery(firstPath, version) {
 		// Don't check for retractions if a specific revision is requested.
 		allowed = nil
 	}

src/cmd/go/internal/modfetch/cache.go

@@ -50,7 +50,7 @@ func CachePath(ctx context.Context, m module.Version, suffix string) (string, er
 	if err != nil {
 		return "", err
 	}
-	if !semver.IsValid(m.Version) {
+	if !gover.ModIsValid(m.Path, m.Version) {
 		return "", fmt.Errorf("non-semver module version %q", m.Version)
 	}
 	if module.CanonicalVersion(m.Version) != m.Version {
@@ -79,7 +79,7 @@ func DownloadDir(ctx context.Context, m module.Version) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	if !semver.IsValid(m.Version) {
+	if !gover.ModIsValid(m.Path, m.Version) {
 		return "", fmt.Errorf("non-semver module version %q", m.Version)
 	}
 	if module.CanonicalVersion(m.Version) != m.Version {
@@ -334,7 +334,7 @@ func (r *cachingRepo) Zip(ctx context.Context, dst io.Writer, version string) er
 // InfoFile is like Lookup(ctx, path).Stat(version) but also returns the name of the file
 // containing the cached information.
 func InfoFile(ctx context.Context, path, version string) (*RevInfo, string, error) {
-	if !semver.IsValid(version) {
+	if !gover.ModIsValid(path, version) {
 		return nil, "", fmt.Errorf("invalid version %q", version)
 	}
 
@@ -374,7 +374,7 @@ func InfoFile(ctx context.Context, path, version string) (*RevInfo, string, erro
 func GoMod(ctx context.Context, path, rev string) ([]byte, error) {
 	// Convert commit hash to pseudo-version
 	// to increase cache hit rate.
-	if !semver.IsValid(rev) {
+	if !gover.ModIsValid(path, rev) {
 		if _, info, err := readDiskStat(ctx, path, rev); err == nil {
 			rev = info.Version
 		} else {
@@ -409,7 +409,7 @@ func GoMod(ctx context.Context, path, rev string) ([]byte, error) {
 // GoModFile is like GoMod but returns the name of the file containing
 // the cached information.
 func GoModFile(ctx context.Context, path, version string) (string, error) {
-	if !semver.IsValid(version) {
+	if !gover.ModIsValid(path, version) {
 		return "", fmt.Errorf("invalid version %q", version)
 	}
 	if _, err := GoMod(ctx, path, version); err != nil {
@@ -426,7 +426,7 @@ func GoModFile(ctx context.Context, path, version string) (string, error) {
 // GoModSum returns the go.sum entry for the module version's go.mod file.
 // (That is, it returns the entry listed in go.sum as "path version/go.mod".)
 func GoModSum(ctx context.Context, path, version string) (string, error) {
-	if !semver.IsValid(version) {
+	if !gover.ModIsValid(path, version) {
 		return "", fmt.Errorf("invalid version %q", version)
 	}
 	data, err := GoMod(ctx, path, version)

src/cmd/go/internal/modload/list.go

@@ -183,7 +183,7 @@ func listModules(ctx context.Context, rs *Requirements, args []string, mode List
 			}
 
 			allowed := CheckAllowed
-			if IsRevisionQuery(vers) || mode&ListRetracted != 0 {
+			if IsRevisionQuery(path, vers) || mode&ListRetracted != 0 {
 				// Allow excluded and retracted versions if the user asked for a
 				// specific revision or used 'go list -retracted'.
 				allowed = nil

src/cmd/go/internal/modload/modfile.go

@@ -25,7 +25,6 @@ import (
 
 	"golang.org/x/mod/modfile"
 	"golang.org/x/mod/module"
-	"golang.org/x/mod/semver"
 )
 
 const (
@@ -762,7 +761,7 @@ func rawGoModData(m module.Version) (name string, data []byte, err error) {
 			return "", nil, module.VersionError(m, fmt.Errorf("reading %s: %v", base.ShortPath(name), err))
 		}
 	} else {
-		if !semver.IsValid(m.Version) {
+		if !gover.ModIsValid(m.Path, m.Version) {
 			// Disallow the broader queries supported by fetch.Lookup.
 			base.Fatalf("go: internal error: %s@%s: unexpected invalid semantic version", m.Path, m.Version)
 		}

src/cmd/go/internal/modload/mvs.go

@@ -60,7 +60,7 @@ func (r *mvsReqs) Required(mod module.Version) ([]module.Version, error) {
 	return summary.require, nil
 }
 
-// Max returns the maximum of v1 and v2 according to semver.Compare.
+// Max returns the maximum of v1 and v2 according to gover.ModCompare.
 //
 // As a special case, the version "" is considered higher than all other
 // versions. The main module (also known as the target) has no version and must

src/cmd/go/internal/modload/query.go

@@ -324,36 +324,18 @@ func queryProxy(ctx context.Context, proxy, path, query, current string, allowed
 // a particular version or revision in a repository like "v1.0.0", "master",
 // or "0123abcd". IsRevisionQuery returns false if vers is a query that
 // chooses from among available versions like "latest" or ">v1.0.0".
-func IsRevisionQuery(vers string) bool {
+func IsRevisionQuery(path, vers string) bool {
 	if vers == "latest" ||
 		vers == "upgrade" ||
 		vers == "patch" ||
 		strings.HasPrefix(vers, "<") ||
 		strings.HasPrefix(vers, ">") ||
-		(semver.IsValid(vers) && isSemverPrefix(vers)) {
+		(gover.ModIsValid(path, vers) && gover.ModIsPrefix(path, vers)) {
 		return false
 	}
 	return true
 }
 
-// isSemverPrefix reports whether v is a semantic version prefix: v1 or v1.2 (not v1.2.3).
-// The caller is assumed to have checked that semver.IsValid(v) is true.
-func isSemverPrefix(v string) bool {
-	dots := 0
-	for i := 0; i < len(v); i++ {
-		switch v[i] {
-		case '-', '+':
-			return false
-		case '.':
-			dots++
-			if dots >= 2 {
-				return false
-			}
-		}
-	}
-	return true
-}
-
 type queryMatcher struct {
 	path               string
 	prefix             string
@@ -417,10 +399,10 @@ func newQueryMatcher(path string, query, current string, allowed AllowedFunc) (*
 
 	case strings.HasPrefix(query, "<="):
 		v := query[len("<="):]
-		if !semver.IsValid(v) {
+		if !gover.ModIsValid(path, v) {
 			return badVersion(v)
 		}
-		if isSemverPrefix(v) {
+		if gover.ModIsPrefix(path, v) {
 			// Refuse to say whether <=v1.2 allows v1.2.3 (remember, @v1.2 might mean v1.2.3).
 			return nil, fmt.Errorf("ambiguous semantic version %q in range %q", v, query)
 		}
@@ -431,7 +413,7 @@ func newQueryMatcher(path string, query, current string, allowed AllowedFunc) (*
 
 	case strings.HasPrefix(query, "<"):
 		v := query[len("<"):]
-		if !semver.IsValid(v) {
+		if !gover.ModIsValid(path, v) {
 			return badVersion(v)
 		}
 		qm.filter = func(mv string) bool { return gover.ModCompare(qm.path, mv, v) < 0 }
@@ -441,7 +423,7 @@ func newQueryMatcher(path string, query, current string, allowed AllowedFunc) (*
 
 	case strings.HasPrefix(query, ">="):
 		v := query[len(">="):]
-		if !semver.IsValid(v) {
+		if !gover.ModIsValid(path, v) {
 			return badVersion(v)
 		}
 		qm.filter = func(mv string) bool { return gover.ModCompare(qm.path, mv, v) >= 0 }
@@ -452,10 +434,10 @@ func newQueryMatcher(path string, query, current string, allowed AllowedFunc) (*
 
 	case strings.HasPrefix(query, ">"):
 		v := query[len(">"):]
-		if !semver.IsValid(v) {
+		if !gover.ModIsValid(path, v) {
 			return badVersion(v)
 		}
-		if isSemverPrefix(v) {
+		if gover.ModIsPrefix(path, v) {
 			// Refuse to say whether >v1.2 allows v1.2.3 (remember, @v1.2 might mean v1.2.3).
 			return nil, fmt.Errorf("ambiguous semantic version %q in range %q", v, query)
 		}
@@ -465,8 +447,8 @@ func newQueryMatcher(path string, query, current string, allowed AllowedFunc) (*
 			qm.preferIncompatible = true
 		}
 
-	case semver.IsValid(query):
-		if isSemverPrefix(query) {
+	case gover.ModIsValid(path, query):
+		if gover.ModIsPrefix(path, query) {
 			qm.prefix = query + "."
 			// Do not allow the query "v1.2" to match versions lower than "v1.2.0",
 			// such as prereleases for that version. (https://golang.org/issue/31972)