"fmt"
"go/ast"
"go/token"
+ "go/version"
+ "internal/goversion"
"strings"
)
-// A version represents a released Go version.
-type version struct {
- major, minor int
-}
-
-func (v version) String() string {
- return fmt.Sprintf("go%d.%d", v.major, v.minor)
-}
+// A goVersion is a Go language version string of the form "go1.%d"
+// where d is the minor version number. goVersion strings don't
+// contain release numbers ("go1.20.1" is not a valid goVersion).
+type goVersion string
-func (v version) equal(u version) bool {
- return v.major == u.major && v.minor == u.minor
+// asGoVersion returns v as a goVersion (e.g., "go1.20.1" becomes "go1.20").
+// If v is not a valid Go version, the result is the empty string.
+func asGoVersion(v string) goVersion {
+ return goVersion(version.Lang(v))
}
-func (v version) before(u version) bool {
- return v.major < u.major || v.major == u.major && v.minor < u.minor
+// isValid reports whether v is a valid Go version.
+func (v goVersion) isValid() bool {
+ return v != ""
}
-func (v version) after(u version) bool {
- return v.major > u.major || v.major == u.major && v.minor > u.minor
+// cmp returns -1, 0, or +1 depending on whether x < y, x == y, or x > y,
+// interpreted as Go versions.
+func (x goVersion) cmp(y goVersion) int {
+ return version.Compare(string(x), string(y))
}
-// Go versions that introduced language changes.
var (
- go0_0 = version{0, 0} // no version specified
- go1_9 = version{1, 9}
- go1_13 = version{1, 13}
- go1_14 = version{1, 14}
- go1_17 = version{1, 17}
- go1_18 = version{1, 18}
- go1_20 = version{1, 20}
- go1_21 = version{1, 21}
-)
+ // Go versions that introduced language changes
+ go1_9 = asGoVersion("go1.9")
+ go1_13 = asGoVersion("go1.13")
+ go1_14 = asGoVersion("go1.14")
+ go1_17 = asGoVersion("go1.17")
+ go1_18 = asGoVersion("go1.18")
+ go1_20 = asGoVersion("go1.20")
+ go1_21 = asGoVersion("go1.21")
-// parseGoVersion parses a Go version string (such as "go1.12")
-// and returns the version, or an error. If s is the empty
-// string, the version is 0.0.
-func parseGoVersion(s string) (v version, err error) {
- bad := func() (version, error) {
- return version{}, fmt.Errorf("invalid Go version syntax %q", s)
- }
- if s == "" {
- return
- }
- if !strings.HasPrefix(s, "go") {
- return bad()
- }
- s = s[len("go"):]
- i := 0
- for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
- if i >= 10 || i == 0 && s[i] == '0' {
- return bad()
- }
- v.major = 10*v.major + int(s[i]) - '0'
- }
- if i > 0 && i == len(s) {
- return
- }
- if i == 0 || s[i] != '.' {
- return bad()
- }
- s = s[i+1:]
- if s == "0" {
- // We really should not accept "go1.0",
- // but we didn't reject it from the start
- // and there are now programs that use it.
- // So accept it.
- return
- }
- i = 0
- for ; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
- if i >= 10 || i == 0 && s[i] == '0' {
- return bad()
- }
- v.minor = 10*v.minor + int(s[i]) - '0'
- }
- // Accept any suffix after the minor number.
- // We are only looking for the language version (major.minor)
- // but want to accept any valid Go version, like go1.21.0
- // and go1.21rc2.
- return
-}
+ // current (deployed) Go version
+ go_current = asGoVersion(fmt.Sprintf("go1.%d", goversion.Version))
+)
// langCompat reports an error if the representation of a numeric
// literal is not compatible with the current language version.
}
}
-// allowVersion reports whether the given package
-// is allowed to use version major.minor.
-func (check *Checker) allowVersion(pkg *Package, at positioner, v version) bool {
+// allowVersion reports whether the given package is allowed to use version v.
+func (check *Checker) allowVersion(pkg *Package, at positioner, v goVersion) bool {
// We assume that imported packages have all been checked,
// so we only have to check for the local package.
if pkg != check.pkg {
return true
}
- // If the source file declares its Go version and at references a valid
- // position, use that to decide.
- if pos := at.Pos(); pos.IsValid() && check.posVers != nil {
- fileStart := check.fset.File(pos).Pos(0)
- if src, ok := check.posVers[fileStart]; ok && src.major >= 1 {
- return !src.before(v)
- }
- }
-
- // Otherwise fall back to the version in the checker.
- return check.version.equal(go0_0) || !check.version.before(v)
+ // If no explicit file version is specified,
+ // fileVersion corresponds to the module version.
+ var fileVersion goVersion
+ if pos := at.Pos(); pos.IsValid() {
+ // We need version.Lang below because file versions
+ // can be (unaltered) Config.GoVersion strings that
+ // may contain dot-release information.
+ fileVersion = asGoVersion(check.versions[check.fileFor(pos)])
+ }
+ return !fileVersion.isValid() || fileVersion.cmp(v) >= 0
}
// verifyVersionf is like allowVersion but also accepts a format string and arguments
// which are used to report a version error if allowVersion returns false. It uses the
// current package.
-func (check *Checker) verifyVersionf(at positioner, v version, format string, args ...interface{}) bool {
+func (check *Checker) verifyVersionf(at positioner, v goVersion, format string, args ...interface{}) bool {
if !check.allowVersion(check.pkg, at, v) {
check.versionErrorf(at, v, format, args...)
return false
}
return true
}
+
+// TODO(gri) Consider a more direct (position-independent) mechanism
+// to identify which file we're in so that version checks
+// work correctly in the absence of correct position info.
+
+// fileFor returns the *ast.File which contains the position pos.
+// If there are no files, the result is nil.
+// The position must be valid.
+func (check *Checker) fileFor(pos token.Pos) *ast.File {
+ assert(pos.IsValid())
+ // Eval and CheckExpr tests may not have any source files.
+ if len(check.files) == 0 {
+ return nil
+ }
+ for _, file := range check.files {
+ if file.FileStart <= pos && pos < file.FileEnd {
+ return file
+ }
+ }
+ panic(check.sprintf("file not found for pos = %d (%s)", int(pos), check.fset.Position(pos)))
+}