diff options
Diffstat (limited to 'vendor/golang.org/x/tools/internal/versions/gover.go')
| -rw-r--r-- | vendor/golang.org/x/tools/internal/versions/gover.go | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/internal/versions/gover.go b/vendor/golang.org/x/tools/internal/versions/gover.go new file mode 100644 index 0000000..bbabcd2 --- /dev/null +++ b/vendor/golang.org/x/tools/internal/versions/gover.go @@ -0,0 +1,172 @@ +// Copyright 2023 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This is a fork of internal/gover for use by x/tools until +// go1.21 and earlier are no longer supported by x/tools. + +package versions + +import "strings" + +// A gover is a parsed Go gover: major[.Minor[.Patch]][kind[pre]] +// The numbers are the original decimal strings to avoid integer overflows +// and since there is very little actual math. (Probably overflow doesn't matter in practice, +// but at the time this code was written, there was an existing test that used +// go1.99999999999, which does not fit in an int on 32-bit platforms. +// The "big decimal" representation avoids the problem entirely.) +type gover struct { + major string // decimal + minor string // decimal or "" + patch string // decimal or "" + kind string // "", "alpha", "beta", "rc" + pre string // decimal or "" +} + +// compare returns -1, 0, or +1 depending on whether +// x < y, x == y, or x > y, interpreted as toolchain versions. +// The versions x and y must not begin with a "go" prefix: just "1.21" not "go1.21". +// Malformed versions compare less than well-formed versions and equal to each other. +// The language version "1.21" compares less than the release candidate and eventual releases "1.21rc1" and "1.21.0". +func compare(x, y string) int { + vx := parse(x) + vy := parse(y) + + if c := cmpInt(vx.major, vy.major); c != 0 { + return c + } + if c := cmpInt(vx.minor, vy.minor); c != 0 { + return c + } + if c := cmpInt(vx.patch, vy.patch); c != 0 { + return c + } + if c := strings.Compare(vx.kind, vy.kind); c != 0 { // "" < alpha < beta < rc + return c + } + if c := cmpInt(vx.pre, vy.pre); c != 0 { + return c + } + return 0 +} + +// lang returns the Go language version. For example, lang("1.2.3") == "1.2". +func lang(x string) string { + v := parse(x) + if v.minor == "" || v.major == "1" && v.minor == "0" { + return v.major + } + return v.major + "." + v.minor +} + +// isValid reports whether the version x is valid. +func isValid(x string) bool { + return parse(x) != gover{} +} + +// parse parses the Go version string x into a version. +// It returns the zero version if x is malformed. +func parse(x string) gover { + var v gover + + // Parse major version. + var ok bool + v.major, x, ok = cutInt(x) + if !ok { + return gover{} + } + if x == "" { + // Interpret "1" as "1.0.0". + v.minor = "0" + v.patch = "0" + return v + } + + // Parse . before minor version. + if x[0] != '.' { + return gover{} + } + + // Parse minor version. + v.minor, x, ok = cutInt(x[1:]) + if !ok { + return gover{} + } + if x == "" { + // Patch missing is same as "0" for older versions. + // Starting in Go 1.21, patch missing is different from explicit .0. + if cmpInt(v.minor, "21") < 0 { + v.patch = "0" + } + return v + } + + // Parse patch if present. + if x[0] == '.' { + v.patch, x, ok = cutInt(x[1:]) + if !ok || x != "" { + // Note that we are disallowing prereleases (alpha, beta, rc) for patch releases here (x != ""). + // Allowing them would be a bit confusing because we already have: + // 1.21 < 1.21rc1 + // But a prerelease of a patch would have the opposite effect: + // 1.21.3rc1 < 1.21.3 + // We've never needed them before, so let's not start now. + return gover{} + } + return v + } + + // Parse prerelease. + i := 0 + for i < len(x) && (x[i] < '0' || '9' < x[i]) { + if x[i] < 'a' || 'z' < x[i] { + return gover{} + } + i++ + } + if i == 0 { + return gover{} + } + v.kind, x = x[:i], x[i:] + if x == "" { + return v + } + v.pre, x, ok = cutInt(x) + if !ok || x != "" { + return gover{} + } + + return v +} + +// cutInt scans the leading decimal number at the start of x to an integer +// and returns that value and the rest of the string. +func cutInt(x string) (n, rest string, ok bool) { + i := 0 + for i < len(x) && '0' <= x[i] && x[i] <= '9' { + i++ + } + if i == 0 || x[0] == '0' && i != 1 { // no digits or unnecessary leading zero + return "", "", false + } + return x[:i], x[i:], true +} + +// cmpInt returns cmp.Compare(x, y) interpreting x and y as decimal numbers. +// (Copied from golang.org/x/mod/semver's compareInt.) +func cmpInt(x, y string) int { + if x == y { + return 0 + } + if len(x) < len(y) { + return -1 + } + if len(x) > len(y) { + return +1 + } + if x < y { + return -1 + } else { + return +1 + } +} |