go/types, types2: consistently use _UnsupportedFeature error code

Change-Id: Ie880871bb855e1c1f6e543508bdc7dd415451ba3
Reviewed-on: https://go-review.googlesource.com/c/go/+/429735
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Run-TryBot: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>

src/cmd/compile/internal/types2/errorcodes.go

@@ -279,7 +279,7 @@ const (
 
 	// _InvalidIfaceEmbed occurs when a non-interface type is embedded in an
 	// interface (for go 1.17 or earlier).
-	_InvalidIfaceEmbed
+	_ // not used anymore
 
 	// _InvalidPtrEmbed occurs when an embedded field is of the pointer form *T,
 	// and T itself is itself a pointer, an unsafe.Pointer, or an interface.
@@ -1419,5 +1419,5 @@ const (
 
 	// _InvalidUnsafeStringData occurs if it is used in a package
 	// compiled for a language version before go1.20.
-	_InvalidUnsafeStringData
+	_ // not used anymore
 )

src/cmd/compile/internal/types2/expr.go

@@ -978,7 +978,7 @@ func (check *Checker) shift(x, y *operand, e syntax.Expr, op syntax.Operator) {
 		switch {
 		case allInteger(y.typ):
 			if !allUnsigned(y.typ) && !check.allowVersion(check.pkg, 1, 13) {
-				check.errorf(y, _InvalidShiftCount, invalidOp+"signed shift count %s requires go1.13 or later", y)
+				check.versionErrorf(y, "go1.13", invalidOp+"signed shift count %s", y)
 				x.mode = invalid
 				return
 			}

src/go/types/builtins.go

@@ -604,7 +604,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	case _Add:
 		// unsafe.Add(ptr unsafe.Pointer, len IntegerType) unsafe.Pointer
 		if !check.allowVersion(check.pkg, 1, 17) {
-			check.errorf(call.Fun, _InvalidUnsafeAdd, "unsafe.Add requires go1.17 or later")
+			check.errorf(call.Fun, _UnsupportedFeature, "unsafe.Add requires go1.17 or later")
 			return
 		}
 
@@ -730,7 +730,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	case _Slice:
 		// unsafe.Slice(ptr *T, len IntegerType) []T
 		if !check.allowVersion(check.pkg, 1, 17) {
-			check.errorf(call.Fun, _InvalidUnsafeSlice, "unsafe.Slice requires go1.17 or later")
+			check.errorf(call.Fun, _UnsupportedFeature, "unsafe.Slice requires go1.17 or later")
 			return
 		}
 
@@ -755,7 +755,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	case _SliceData:
 		// unsafe.SliceData(slice []T) *T
 		if !check.allowVersion(check.pkg, 1, 20) {
-			check.errorf(call.Fun, _InvalidUnsafeSliceData, "unsafe.SliceData requires go1.20 or later")
+			check.errorf(call.Fun, _UnsupportedFeature, "unsafe.SliceData requires go1.20 or later")
 			return
 		}
 
@@ -774,7 +774,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	case _String:
 		// unsafe.String(ptr *byte, len IntegerType) string
 		if !check.allowVersion(check.pkg, 1, 20) {
-			check.errorf(call.Fun, _InvalidUnsafeString, "unsafe.String requires go1.20 or later")
+			check.errorf(call.Fun, _UnsupportedFeature, "unsafe.String requires go1.20 or later")
 			return
 		}
 
@@ -798,7 +798,7 @@ func (check *Checker) builtin(x *operand, call *ast.CallExpr, id builtinId) (_ b
 	case _StringData:
 		// unsafe.StringData(str string) *byte
 		if !check.allowVersion(check.pkg, 1, 20) {
-			check.errorf(call.Fun, _InvalidUnsafeStringData, "unsafe.StringData requires go1.20 or later")
+			check.errorf(call.Fun, _UnsupportedFeature, "unsafe.StringData requires go1.20 or later")
 			return
 		}
 

src/go/types/decl.go

@@ -569,7 +569,7 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *ast.TypeSpec, def *Named) {
 	// alias declaration
 	if alias {
 		if !check.allowVersion(check.pkg, 1, 9) {
-			check.errorf(atPos(tdecl.Assign), _BadDecl, "type aliases requires go1.9 or later")
+			check.errorf(atPos(tdecl.Assign), _UnsupportedFeature, "type aliases requires go1.9 or later")
 		}
 
 		check.brokenAlias(obj)

src/go/types/errorcodes.go

@@ -279,7 +279,7 @@ const (
 
 	// _InvalidIfaceEmbed occurs when a non-interface type is embedded in an
 	// interface (for go 1.17 or earlier).
-	_InvalidIfaceEmbed
+	_ // not used anymore
 
 	// _InvalidPtrEmbed occurs when an embedded field is of the pointer form *T,
 	// and T itself is itself a pointer, an unsafe.Pointer, or an interface.
@@ -1419,5 +1419,5 @@ const (
 
 	// _InvalidUnsafeStringData occurs if it is used in a package
 	// compiled for a language version before go1.20.
-	_InvalidUnsafeStringData
+	_ // not used anymore
 )

src/go/types/expr.go

@@ -955,7 +955,7 @@ func (check *Checker) shift(x, y *operand, e ast.Expr, op token.Token) {
 		switch {
 		case allInteger(y.typ):
 			if !allUnsigned(y.typ) && !check.allowVersion(check.pkg, 1, 13) {
-				check.invalidOp(y, _InvalidShiftCount, "signed shift count %s requires go1.13 or later", y)
+				check.invalidOp(y, _UnsupportedFeature, "signed shift count %s requires go1.13 or later", y)
 				x.mode = invalid
 				return
 			}

src/go/types/typeset.go

@@ -286,7 +286,7 @@ func computeInterfaceTypeSet(check *Checker, pos token.Pos, ityp *Interface) *_T
 			terms = tset.terms
 		case *Union:
 			if check != nil && !check.allowVersion(check.pkg, 1, 18) {
-				check.errorf(atPos(pos), _InvalidIfaceEmbed, "embedding interface element %s requires go1.18 or later", u)
+				check.errorf(atPos(pos), _UnsupportedFeature, "embedding interface element %s requires go1.18 or later", u)
 				continue
 			}
 			tset := computeUnionTypeSet(check, unionSets, pos, u)
@@ -301,7 +301,7 @@ func computeInterfaceTypeSet(check *Checker, pos token.Pos, ityp *Interface) *_T
 				continue
 			}
 			if check != nil && !check.allowVersion(check.pkg, 1, 18) {
-				check.errorf(atPos(pos), _InvalidIfaceEmbed, "embedding non-interface type %s requires go1.18 or later", typ)
+				check.errorf(atPos(pos), _UnsupportedFeature, "embedding non-interface type %s requires go1.18 or later", typ)
 				continue
 			}
 			terms = termlist{{false, typ}}

src/go/types/version.go

@@ -22,7 +22,7 @@ func (check *Checker) langCompat(lit *ast.BasicLit) {
 	}
 	// len(s) > 2
 	if strings.Contains(s, "_") {
-		check.errorf(lit, _InvalidLit, "underscores in numeric literals requires go1.13 or later")
+		check.errorf(lit, _UnsupportedFeature, "underscores in numeric literals requires go1.13 or later")
 		return
 	}
 	if s[0] != '0' {
@@ -30,15 +30,15 @@ func (check *Checker) langCompat(lit *ast.BasicLit) {
 	}
 	radix := s[1]
 	if radix == 'b' || radix == 'B' {
-		check.errorf(lit, _InvalidLit, "binary literals requires go1.13 or later")
+		check.errorf(lit, _UnsupportedFeature, "binary literals requires go1.13 or later")
 		return
 	}
 	if radix == 'o' || radix == 'O' {
-		check.errorf(lit, _InvalidLit, "0o/0O-style octal literals requires go1.13 or later")
+		check.errorf(lit, _UnsupportedFeature, "0o/0O-style octal literals requires go1.13 or later")
 		return
 	}
 	if lit.Kind != token.INT && (radix == 'x' || radix == 'X') {
-		check.errorf(lit, _InvalidLit, "hexadecimal floating-point literals requires go1.13 or later")
+		check.errorf(lit, _UnsupportedFeature, "hexadecimal floating-point literals requires go1.13 or later")
 	}
 }