From: Russ Cox <rsc@golang.org>
Date: Wed, 24 May 2023 19:22:33 +0000 (-0400)
Subject: cmd/go: expand acceptable toolchains a bit
X-Git-Tag: go1.21rc1~229
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=e8c6003023b64b80bea6af8c4bb0b54d55f65dc0;p=gostls13.git

cmd/go: expand acceptable toolchains a bit

Allow both prefix-goVERSION and goVERSION-suffix for custom toolchains.
Also make sure that a tie in the toolchain and min version goes to the
toolchain line.

For #57001.

Change-Id: Ibeea5f47db7349cfdf36da188bb43e195e196f5b
Reviewed-on: https://go-review.googlesource.com/c/go/+/498076
Auto-Submit: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---

diff --git a/src/cmd/go/gotoolchain.go b/src/cmd/go/gotoolchain.go
index 03e2e95edd..ef56c23d32 100644
--- a/src/cmd/go/gotoolchain.go
+++ b/src/cmd/go/gotoolchain.go
@@ -126,7 +126,7 @@ func switchGoToolchain() {
 			} else if toolchain != "" {
 				// Accept toolchain only if it is >= our min.
 				toolVers := gover.ToolchainVersion(toolchain)
-				if gover.Compare(toolVers, minVers) > 0 {
+				if gover.Compare(toolVers, minVers) >= 0 {
 					gotoolchain = toolchain
 				}
 			} else {
diff --git a/src/cmd/go/internal/gover/latest.go b/src/cmd/go/internal/gover/latest.go
index 05ee4401b5..56d3f2d049 100644
--- a/src/cmd/go/internal/gover/latest.go
+++ b/src/cmd/go/internal/gover/latest.go
@@ -8,7 +8,6 @@ import (
 	"internal/goversion"
 	"runtime"
 	"strconv"
-	"strings"
 )
 
 // TestVersion is initialized in the go command test binary
@@ -22,16 +21,10 @@ func Local() string {
 	if TestVersion != "" {
 		v = TestVersion
 	}
-	if strings.HasPrefix(v, "go") {
-		v := strings.TrimPrefix(v, "go")
-		// Some builds use custom suffixes; strip them.
-		if i := strings.IndexAny(v, " \t+-"); i >= 0 {
-			v = v[:i]
-		}
-		if IsValid(v) {
-			return v
-		}
+	if v := ToolchainVersion(v); v != "" {
+		return v
 	}
+
 	// Development branch. Use "Dev" version with just 1.N, no rc1 or .0 suffix.
 	return "1." + strconv.Itoa(goversion.Version)
 }
diff --git a/src/cmd/go/internal/gover/toolchain.go b/src/cmd/go/internal/gover/toolchain.go
index 58a4d620f3..d3a2353550 100644
--- a/src/cmd/go/internal/gover/toolchain.go
+++ b/src/cmd/go/internal/gover/toolchain.go
@@ -14,18 +14,28 @@ import (
 // ToolchainVersion returns the Go version for the named toolchain,
 // derived from the name itself (not by running the toolchain).
 // A toolchain is named "goVERSION" or "anything-goVERSION".
+// A suffix after the VERSION introduced by a +, -, space, or tab is removed.
 // Examples:
 //
 //	ToolchainVersion("go1.2.3") == "1.2.3"
+//	ToolchainVersion("go1.2.3+bigcorp") == "1.2.3"
+//	ToolchainVersion("go1.2.3-bigcorp") == "1.2.3"
 //	ToolchainVersion("gccgo-go1.23rc4") == "1.23rc4"
 //	ToolchainVersion("invalid") == ""
 func ToolchainVersion(name string) string {
 	var v string
-	if strings.HasPrefix(name, "go") && IsValid(name[2:]) {
+	if strings.HasPrefix(name, "go") {
 		v = name[2:]
-	} else if i := strings.Index(name, "-go"); i >= 0 && IsValid(name[i+3:]) {
+	} else if i := strings.Index(name, "-go"); i >= 0 {
 		v = name[i+3:]
 	}
+	// Some builds use custom suffixes; strip them.
+	if i := strings.IndexAny(v, " \t+-"); i >= 0 {
+		v = v[:i]
+	}
+	if !IsValid(v) {
+		return ""
+	}
 	return v
 }
 
diff --git a/src/cmd/go/testdata/script/gotoolchain.txt b/src/cmd/go/testdata/script/gotoolchain.txt
index 406bbd7568..40a4b13c9d 100644
--- a/src/cmd/go/testdata/script/gotoolchain.txt
+++ b/src/cmd/go/testdata/script/gotoolchain.txt
@@ -21,6 +21,8 @@ mkdir $WORK/bin
 [!GOOS:plan9] env PATH=$WORK/bin${:}$PATH
 [GOOS:plan9] env path=$WORK/bin${:}$path
 go build -o $WORK/bin/ ./go1.999testpath.go  # adds .exe extension implicitly on Windows
+cp $WORK/bin/go1.999testpath$GOEXE $WORK/bin/custom-go1.999.0$GOEXE
+cp $WORK/bin/go1.999testpath$GOEXE $WORK/bin/go1.999.0-custom$GOEXE
 
 # GOTOOLCHAIN from PATH
 env GOTOOLCHAIN=go1.999testpath
@@ -49,6 +51,25 @@ cp go119toolchain1999 go.mod
 go version
 stdout go1.999
 
+# custom toolchain line in go.mod
+env TESTGO_VERSION=go1.999
+go version
+stdout testpath # go1.999 < go1.999testpath
+
+env TESTGO_VERSION=go1.999.0
+go version
+! stdout testpath # go1.999testpath < go1.999.0
+
+cp go119customtoolchain1999 go.mod
+go version
+stdout go1.999testpath # custom-go1.999.0 >= go1.999.0
+
+cp go119customtoolchain1999b go.mod
+go version
+stdout go1.999testpath # go1.999.0-custom >= go1.999.0
+
+env TESTGO_VERSION=go1.100
+
 # toolchain local in go.mod
 cp go1999toolchainlocal go.mod
 ! go build
@@ -258,6 +279,14 @@ go 1.19
 go 1.19
 toolchain go1.999testpath
 
+-- go119customtoolchain1999 --
+go 1.19
+toolchain custom-go1.999.0
+
+-- go119customtoolchain1999b --
+go 1.19
+toolchain go1.999.0-custom
+
 -- go1999toolchainlocal --
 go 1.999
 toolchain local