libgo: update to Go1.16rc1

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/287493

12 files changed, 108 insertions, 56 deletions

diff --git a/libgo/go/golang.org/x/mod/modfile/rule.go b/libgo/go/golang.org/x/mod/modfile/rule.go
index 83398dd..c6a189d 100644
--- a/libgo/go/golang.org/x/mod/modfile/rule.go
+++ b/libgo/go/golang.org/x/mod/modfile/rule.go
@@ -832,7 +832,16 @@ func (f *File) DropRequire(path string) error {
 	return nil
 }
 
+// AddExclude adds a exclude statement to the mod file. Errors if the provided
+// version is not a canonical version string
 func (f *File) AddExclude(path, vers string) error {
+	if !isCanonicalVersion(vers) {
+		return &module.InvalidVersionError{
+			Version: vers,
+			Err:     errors.New("must be of the form v1.2.3"),
+		}
+	}
+
 	var hint *Line
 	for _, x := range f.Exclude {
 		if x.Mod.Path == path && x.Mod.Version == vers {
@@ -904,7 +913,22 @@ func (f *File) DropReplace(oldPath, oldVers string) error {
 	return nil
 }
 
+// AddRetract adds a retract statement to the mod file. Errors if the provided
+// version interval does not consist of canonical version strings
 func (f *File) AddRetract(vi VersionInterval, rationale string) error {
+	if !isCanonicalVersion(vi.High) {
+		return &module.InvalidVersionError{
+			Version: vi.High,
+			Err:     errors.New("must be of the form v1.2.3"),
+		}
+	}
+	if !isCanonicalVersion(vi.Low) {
+		return &module.InvalidVersionError{
+			Version: vi.Low,
+			Err:     errors.New("must be of the form v1.2.3"),
+		}
+	}
+
 	r := &Retract{
 		VersionInterval: vi,
 	}
@@ -1061,3 +1085,9 @@ func lineRetractLess(li, lj *Line) bool {
 	}
 	return semver.Compare(vii.High, vij.High) > 0
 }
+
+// isCanonicalVersion tests if the provided version string represents a valid
+// canonical version.
+func isCanonicalVersion(vers string) bool {
+	return vers != "" && semver.Canonical(vers) == vers
+}
diff --git a/libgo/go/golang.org/x/tools/go/analysis/analysis.go b/libgo/go/golang.org/x/tools/go/analysis/analysis.go
index 8c3c2e7..d11505a 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/analysis.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/analysis.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package analysis
 
 import (
diff --git a/libgo/go/golang.org/x/tools/go/analysis/diagnostic.go b/libgo/go/golang.org/x/tools/go/analysis/diagnostic.go
index 57eaf6f..cd462a0 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/diagnostic.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/diagnostic.go
@@ -1,3 +1,7 @@
+// Copyright 2019 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.
+
 package analysis
 
 import "go/token"
diff --git a/libgo/go/golang.org/x/tools/go/analysis/doc.go b/libgo/go/golang.org/x/tools/go/analysis/doc.go
index 9fa3302..94a3bd5 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/doc.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/doc.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 /*
 
 Package analysis defines the interface between a modular static
diff --git a/libgo/go/golang.org/x/tools/go/analysis/internal/analysisflags/help.go b/libgo/go/golang.org/x/tools/go/analysis/internal/analysisflags/help.go
index c5a70f3..ce92892 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/internal/analysisflags/help.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/internal/analysisflags/help.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package analysisflags
 
 import (
diff --git a/libgo/go/golang.org/x/tools/go/analysis/passes/internal/analysisutil/util.go b/libgo/go/golang.org/x/tools/go/analysis/passes/internal/analysisutil/util.go
index 80c9476..ac37e47 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/passes/internal/analysisutil/util.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/passes/internal/analysisutil/util.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 // Package analysisutil defines various helper functions
 // used by two or more packages beneath go/analysis.
 package analysisutil
diff --git a/libgo/go/golang.org/x/tools/go/analysis/passes/printf/types.go b/libgo/go/golang.org/x/tools/go/analysis/passes/printf/types.go
index bd8a594..6a5fae4 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/passes/printf/types.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/passes/printf/types.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package printf
 
 import (
diff --git a/libgo/go/golang.org/x/tools/go/analysis/passes/structtag/structtag.go b/libgo/go/golang.org/x/tools/go/analysis/passes/structtag/structtag.go
index 0255564..f0b1505 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/passes/structtag/structtag.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/passes/structtag/structtag.go
@@ -207,12 +207,12 @@ var (
 )
 
 // validateStructTag parses the struct tag and returns an error if it is not
-// in the canonical format, as defined by reflect.StructTag.
+// in the canonical format, which is a space-separated list of key:"value"
+// settings. The value may contain spaces.
 func validateStructTag(tag string) error {
 	// This code is based on the StructTag.Get code in package reflect.
 
 	n := 0
-	var keys []string
 	for ; tag != ""; n++ {
 		if n > 0 && tag != "" && tag[0] != ' ' {
 			// More restrictive than reflect, but catches likely mistakes
@@ -240,27 +240,14 @@ func validateStructTag(tag string) error {
 		if i == 0 {
 			return errTagKeySyntax
 		}
-		if i+1 >= len(tag) || tag[i] < ' ' || tag[i] == 0x7f {
+		if i+1 >= len(tag) || tag[i] != ':' {
 			return errTagSyntax
 		}
-		key := tag[:i]
-		keys = append(keys, key)
-		tag = tag[i:]
-
-		// If we found a space char here - assume that we have a tag with
-		// multiple keys.
-		if tag[0] == ' ' {
-			continue
-		}
-
-		// Spaces were filtered above so we assume that here we have
-		// only valid tag value started with `:"`.
-		if tag[0] != ':' || tag[1] != '"' {
+		if tag[i+1] != '"' {
 			return errTagValueSyntax
 		}
-
-		// Remove the colon leaving tag at the start of the quoted string.
-		tag = tag[1:]
+		key := tag[:i]
+		tag = tag[i+1:]
 
 		// Scan quoted string to find value.
 		i = 1
@@ -276,56 +263,51 @@ func validateStructTag(tag string) error {
 		qvalue := tag[:i+1]
 		tag = tag[i+1:]
 
-		wholeValue, err := strconv.Unquote(qvalue)
+		value, err := strconv.Unquote(qvalue)
 		if err != nil {
 			return errTagValueSyntax
 		}
 
-		for _, key := range keys {
-			if !checkTagSpaces[key] {
-				continue
-			}
-
-			value := wholeValue
-			switch key {
-			case "xml":
-				// If the first or last character in the XML tag is a space, it is
-				// suspicious.
-				if strings.Trim(value, " ") != value {
-					return errTagValueSpace
-				}
+		if !checkTagSpaces[key] {
+			continue
+		}
 
-				// If there are multiple spaces, they are suspicious.
-				if strings.Count(value, " ") > 1 {
-					return errTagValueSpace
-				}
+		switch key {
+		case "xml":
+			// If the first or last character in the XML tag is a space, it is
+			// suspicious.
+			if strings.Trim(value, " ") != value {
+				return errTagValueSpace
+			}
 
-				// If there is no comma, skip the rest of the checks.
-				comma := strings.IndexRune(value, ',')
-				if comma < 0 {
-					continue
-				}
+			// If there are multiple spaces, they are suspicious.
+			if strings.Count(value, " ") > 1 {
+				return errTagValueSpace
+			}
 
-				// If the character before a comma is a space, this is suspicious.
-				if comma > 0 && value[comma-1] == ' ' {
-					return errTagValueSpace
-				}
-				value = value[comma+1:]
-			case "json":
-				// JSON allows using spaces in the name, so skip it.
-				comma := strings.IndexRune(value, ',')
-				if comma < 0 {
-					continue
-				}
-				value = value[comma+1:]
+			// If there is no comma, skip the rest of the checks.
+			comma := strings.IndexRune(value, ',')
+			if comma < 0 {
+				continue
 			}
 
-			if strings.IndexByte(value, ' ') >= 0 {
+			// If the character before a comma is a space, this is suspicious.
+			if comma > 0 && value[comma-1] == ' ' {
 				return errTagValueSpace
 			}
+			value = value[comma+1:]
+		case "json":
+			// JSON allows using spaces in the name, so skip it.
+			comma := strings.IndexRune(value, ',')
+			if comma < 0 {
+				continue
+			}
+			value = value[comma+1:]
 		}
 
-		keys = keys[:0]
+		if strings.IndexByte(value, ' ') >= 0 {
+			return errTagValueSpace
+		}
 	}
 	return nil
 }
diff --git a/libgo/go/golang.org/x/tools/go/analysis/unitchecker/unitchecker112.go b/libgo/go/golang.org/x/tools/go/analysis/unitchecker/unitchecker112.go
index 683b7e9..9051456 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/unitchecker/unitchecker112.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/unitchecker/unitchecker112.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 // +build go1.12
 
 package unitchecker
diff --git a/libgo/go/golang.org/x/tools/go/analysis/validate.go b/libgo/go/golang.org/x/tools/go/analysis/validate.go
index ad0e727..23e57bf 100644
--- a/libgo/go/golang.org/x/tools/go/analysis/validate.go
+++ b/libgo/go/golang.org/x/tools/go/analysis/validate.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package analysis
 
 import (
diff --git a/libgo/go/golang.org/x/tools/go/ast/astutil/util.go b/libgo/go/golang.org/x/tools/go/ast/astutil/util.go
index 7630629..919d530 100644
--- a/libgo/go/golang.org/x/tools/go/ast/astutil/util.go
+++ b/libgo/go/golang.org/x/tools/go/ast/astutil/util.go
@@ -1,3 +1,7 @@
+// Copyright 2015 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.
+
 package astutil
 
 import "go/ast"
diff --git a/libgo/go/golang.org/x/tools/go/ast/inspector/typeof.go b/libgo/go/golang.org/x/tools/go/ast/inspector/typeof.go
index d61301b..b6b00cf 100644
--- a/libgo/go/golang.org/x/tools/go/ast/inspector/typeof.go
+++ b/libgo/go/golang.org/x/tools/go/ast/inspector/typeof.go
@@ -1,3 +1,7 @@
+// Copyright 2018 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.
+
 package inspector
 
 // This file defines func typeOf(ast.Node) uint64.