cmd: go get golang.org/x/mod@fc83a8f

cd src/cmd
go get golang.org/x/mod@fc83a8f  # CL 497400
go mod vendor
go mod tidy

For #57001.

Change-Id: I46b8584e493934883cc4148a16e287f667dcab7d
Reviewed-on: https://go-review.googlesource.com/c/go/+/497295
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/cmd/go.mod

@@ -5,7 +5,7 @@ go 1.21
 require (
 	github.com/google/pprof v0.0.0-20221118152302-e6195bd50e26
 	golang.org/x/arch v0.2.1-0.20230208145055-40c19ba4a7c5
-	golang.org/x/mod v0.10.1-0.20230517154618-e7bea8f1d64f
+	golang.org/x/mod v0.10.1-0.20230523205221-fc83a8faf993
 	golang.org/x/sync v0.2.0
 	golang.org/x/sys v0.8.0
 	golang.org/x/term v0.5.0

src/cmd/go.sum

@@ -4,8 +4,8 @@ github.com/ianlancetaylor/demangle v0.0.0-20220319035150-800ac71e25c2 h1:rcanfLh
 github.com/ianlancetaylor/demangle v0.0.0-20220319035150-800ac71e25c2/go.mod h1:aYm2/VgdVmcIU8iMfdMvDMsRAQjcfZSKFby6HOFvi/w=
 golang.org/x/arch v0.2.1-0.20230208145055-40c19ba4a7c5 h1:UFbINK7+lzLJEIqCXPlzx05ivYhLQeXCkxW3SSH3f8Q=
 golang.org/x/arch v0.2.1-0.20230208145055-40c19ba4a7c5/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
-golang.org/x/mod v0.10.1-0.20230517154618-e7bea8f1d64f h1:ghNt+qaUoQ453QdEj40jEN5kYz71m4aDEkk767JfeR0=
-golang.org/x/mod v0.10.1-0.20230517154618-e7bea8f1d64f/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/mod v0.10.1-0.20230523205221-fc83a8faf993 h1:hr4tBhz2ITxV3Dj4xUzXUVtuRnMSzdWcTF8JYcrbdGs=
+golang.org/x/mod v0.10.1-0.20230523205221-fc83a8faf993/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
 golang.org/x/sync v0.2.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=

src/cmd/go/testdata/script/mod_sum_issue56222.txt

@@ -76,7 +76,7 @@ import _ "example.com/m2/q"
 -- m2/go.mod --
 module example.com/m2
 
-go 1.21
+go 1.19
 
 require example.com/generics v1.0.0
 -- m2/q/q.go --

src/cmd/vendor/golang.org/x/mod/modfile/print.go

@@ -16,7 +16,13 @@ import (
 func Format(f *FileSyntax) []byte {
 	pr := &printer{}
 	pr.file(f)
-	return pr.Bytes()
+
+	// remove trailing blank lines
+	b := pr.Bytes()
+	for len(b) > 0 && b[len(b)-1] == '\n' && (len(b) == 1 || b[len(b)-2] == '\n') {
+		b = b[:len(b)-1]
+	}
+	return b
 }
 
 // A printer collects the state during printing of a file or expression.
@@ -59,7 +65,11 @@ func (p *printer) newline() {
 	}
 
 	p.trim()
-	p.printf("\n")
+	if b := p.Bytes(); len(b) == 0 || (len(b) >= 2 && b[len(b)-1] == '\n' && b[len(b)-2] == '\n') {
+		// skip the blank line at top of file or after a blank line
+	} else {
+		p.printf("\n")
+	}
 	for i := 0; i < p.margin; i++ {
 		p.printf("\t")
 	}

src/cmd/vendor/golang.org/x/mod/modfile/rule.go

@@ -35,12 +35,13 @@ import (
 
 // A File is the parsed, interpreted form of a go.mod file.
 type File struct {
-	Module  *Module
-	Go      *Go
-	Require []*Require
-	Exclude []*Exclude
-	Replace []*Replace
-	Retract []*Retract
+	Module    *Module
+	Go        *Go
+	Toolchain *Toolchain
+	Require   []*Require
+	Exclude   []*Exclude
+	Replace   []*Replace
+	Retract   []*Retract
 
 	Syntax *FileSyntax
 }
@@ -58,6 +59,12 @@ type Go struct {
 	Syntax  *Line
 }
 
+// A Toolchain is the toolchain statement.
+type Toolchain struct {
+	Name   string // "go1.21rc1"
+	Syntax *Line
+}
+
 // An Exclude is a single exclude statement.
 type Exclude struct {
 	Mod    module.Version
@@ -296,9 +303,13 @@ func parseToFile(file string, data []byte, fix VersionFixer, strict bool) (parse
 	return f, nil
 }
 
-var GoVersionRE = lazyregexp.New(`^([1-9][0-9]*)\.(0|[1-9][0-9]*)$`)
+var GoVersionRE = lazyregexp.New(`^([1-9][0-9]*)\.(0|[1-9][0-9]*)(\.(0|[1-9][0-9]*))?([a-z]+[0-9]+)?$`)
 var laxGoVersionRE = lazyregexp.New(`^v?(([1-9][0-9]*)\.(0|[1-9][0-9]*))([^0-9].*)$`)
 
+// Toolchains must be named beginning with `go1` or containing `-go1` as a substring,
+// like "go1.20.3" or "gccgo-go1.20.3". As a special case, "local" is also permitted.
+var ToolchainRE = lazyregexp.New(`^local$|(^|-)go1`)
+
 func (f *File) add(errs *ErrorList, block *LineBlock, line *Line, verb string, args []string, fix VersionFixer, strict bool) {
 	// If strict is false, this module is a dependency.
 	// We ignore all unknown directives as well as main-module-only
@@ -364,6 +375,21 @@ func (f *File) add(errs *ErrorList, block *LineBlock, line *Line, verb string, a
 		f.Go = &Go{Syntax: line}
 		f.Go.Version = args[0]
 
+	case "toolchain":
+		if f.Toolchain != nil {
+			errorf("repeated toolchain statement")
+			return
+		}
+		if len(args) != 1 {
+			errorf("toolchain directive expects exactly one argument")
+			return
+		} else if strict && !ToolchainRE.MatchString(args[0]) {
+			errorf("invalid toolchain version '%s': must match format go1.23 or local", args[0])
+			return
+		}
+		f.Toolchain = &Toolchain{Syntax: line}
+		f.Toolchain.Name = args[0]
+
 	case "module":
 		if f.Module != nil {
 			errorf("repeated module statement")
@@ -612,6 +638,22 @@ func (f *WorkFile) add(errs *ErrorList, line *Line, verb string, args []string,
 		f.Go = &Go{Syntax: line}
 		f.Go.Version = args[0]
 
+	case "toolchain":
+		if f.Toolchain != nil {
+			errorf("repeated toolchain statement")
+			return
+		}
+		if len(args) != 1 {
+			errorf("toolchain directive expects exactly one argument")
+			return
+		} else if !ToolchainRE.MatchString(args[0]) {
+			errorf("invalid toolchain version '%s': must match format go1.23 or local", args[0])
+			return
+		}
+
+		f.Toolchain = &Toolchain{Syntax: line}
+		f.Toolchain.Name = args[0]
+
 	case "use":
 		if len(args) != 1 {
 			errorf("usage: %s local/dir", verb)
@@ -926,7 +968,7 @@ func (f *File) Cleanup() {
 
 func (f *File) AddGoStmt(version string) error {
 	if !GoVersionRE.MatchString(version) {
-		return fmt.Errorf("invalid language version string %q", version)
+		return fmt.Errorf("invalid language version %q", version)
 	}
 	if f.Go == nil {
 		var hint Expr
@@ -944,6 +986,44 @@ func (f *File) AddGoStmt(version string) error {
 	return nil
 }
 
+// DropGoStmt deletes the go statement from the file.
+func (f *File) DropGoStmt() {
+	if f.Go != nil {
+		f.Go.Syntax.markRemoved()
+		f.Go = nil
+	}
+}
+
+// DropToolchainStmt deletes the toolchain statement from the file.
+func (f *File) DropToolchainStmt() {
+	if f.Toolchain != nil {
+		f.Toolchain.Syntax.markRemoved()
+		f.Toolchain = nil
+	}
+}
+
+func (f *File) AddToolchainStmt(name string) error {
+	if !ToolchainRE.MatchString(name) {
+		return fmt.Errorf("invalid toolchain name %q", name)
+	}
+	if f.Toolchain == nil {
+		var hint Expr
+		if f.Go != nil && f.Go.Syntax != nil {
+			hint = f.Go.Syntax
+		} else if f.Module != nil && f.Module.Syntax != nil {
+			hint = f.Module.Syntax
+		}
+		f.Toolchain = &Toolchain{
+			Name:   name,
+			Syntax: f.Syntax.addLine(hint, "toolchain", name),
+		}
+	} else {
+		f.Toolchain.Name = name
+		f.Syntax.updateLine(f.Toolchain.Syntax, "toolchain", name)
+	}
+	return nil
+}
+
 // AddRequire sets the first require line for path to version vers,
 // preserving any existing comments for that line and removing all
 // other lines for path.

src/cmd/vendor/golang.org/x/mod/modfile/work.go

@@ -12,9 +12,10 @@ import (
 
 // A WorkFile is the parsed, interpreted form of a go.work file.
 type WorkFile struct {
-	Go      *Go
-	Use     []*Use
-	Replace []*Replace
+	Go        *Go
+	Toolchain *Toolchain
+	Use       []*Use
+	Replace   []*Replace
 
 	Syntax *FileSyntax
 }
@@ -109,7 +110,7 @@ func (f *WorkFile) Cleanup() {
 
 func (f *WorkFile) AddGoStmt(version string) error {
 	if !GoVersionRE.MatchString(version) {
-		return fmt.Errorf("invalid language version string %q", version)
+		return fmt.Errorf("invalid language version %q", version)
 	}
 	if f.Go == nil {
 		stmt := &Line{Token: []string{"go", version}}
@@ -117,7 +118,7 @@ func (f *WorkFile) AddGoStmt(version string) error {
 			Version: version,
 			Syntax:  stmt,
 		}
-		// Find the first non-comment-only block that's and add
+		// Find the first non-comment-only block and add
 		// the go statement before it. That will keep file comments at the top.
 		i := 0
 		for i = 0; i < len(f.Syntax.Stmt); i++ {
@@ -133,6 +134,56 @@ func (f *WorkFile) AddGoStmt(version string) error {
 	return nil
 }
 
+func (f *WorkFile) AddToolchainStmt(name string) error {
+	if !ToolchainRE.MatchString(name) {
+		return fmt.Errorf("invalid toolchain name %q", name)
+	}
+	if f.Toolchain == nil {
+		stmt := &Line{Token: []string{"toolchain", name}}
+		f.Toolchain = &Toolchain{
+			Name:   name,
+			Syntax: stmt,
+		}
+		// Find the go line and add the toolchain line after it.
+		// Or else find the first non-comment-only block and add
+		// the toolchain line before it. That will keep file comments at the top.
+		i := 0
+		for i = 0; i < len(f.Syntax.Stmt); i++ {
+			if line, ok := f.Syntax.Stmt[i].(*Line); ok && len(line.Token) > 0 && line.Token[0] == "go" {
+				i++
+				goto Found
+			}
+		}
+		for i = 0; i < len(f.Syntax.Stmt); i++ {
+			if _, ok := f.Syntax.Stmt[i].(*CommentBlock); !ok {
+				break
+			}
+		}
+	Found:
+		f.Syntax.Stmt = append(append(f.Syntax.Stmt[:i:i], stmt), f.Syntax.Stmt[i:]...)
+	} else {
+		f.Toolchain.Name = name
+		f.Syntax.updateLine(f.Toolchain.Syntax, "toolchain", name)
+	}
+	return nil
+}
+
+// DropGoStmt deletes the go statement from the file.
+func (f *WorkFile) DropGoStmt() {
+	if f.Go != nil {
+		f.Go.Syntax.markRemoved()
+		f.Go = nil
+	}
+}
+
+// DropToolchainStmt deletes the toolchain statement from the file.
+func (f *WorkFile) DropToolchainStmt() {
+	if f.Toolchain != nil {
+		f.Toolchain.Syntax.markRemoved()
+		f.Toolchain = nil
+	}
+}
+
 func (f *WorkFile) AddUse(diskPath, modulePath string) error {
 	need := true
 	for _, d := range f.Use {

src/cmd/vendor/modules.txt

@@ -23,7 +23,7 @@ golang.org/x/arch/arm/armasm
 golang.org/x/arch/arm64/arm64asm
 golang.org/x/arch/ppc64/ppc64asm
 golang.org/x/arch/x86/x86asm
-# golang.org/x/mod v0.10.1-0.20230517154618-e7bea8f1d64f
+# golang.org/x/mod v0.10.1-0.20230523205221-fc83a8faf993
 ## explicit; go 1.17
 golang.org/x/mod/internal/lazyregexp
 golang.org/x/mod/modfile