go/types, types2: move Checker.langCompat from version.go to expr.go (cleanup)

This makes version.go holding core version checking code only.
No functional changes.

Change-Id: Ia88a48166cad2698765697dd7a8625b56ecc2226
Reviewed-on: https://go-review.googlesource.com/c/go/+/567536
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>

Author: griesemer

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

@@ -12,6 +12,7 @@ import (
 	"go/constant"
 	"go/token"
 	. "internal/types/errors"
+	"strings"
 )
 
 /*
@@ -1031,6 +1032,35 @@ func (check *Checker) nonGeneric(T *target, x *operand) {
 	}
 }
 
+// langCompat reports an error if the representation of a numeric
+// literal is not compatible with the current language version.
+func (check *Checker) langCompat(lit *syntax.BasicLit) {
+	s := lit.Value
+	if len(s) <= 2 || check.allowVersion(check.pkg, lit, go1_13) {
+		return
+	}
+	// len(s) > 2
+	if strings.Contains(s, "_") {
+		check.versionErrorf(lit, go1_13, "underscore in numeric literal")
+		return
+	}
+	if s[0] != '0' {
+		return
+	}
+	radix := s[1]
+	if radix == 'b' || radix == 'B' {
+		check.versionErrorf(lit, go1_13, "binary literal")
+		return
+	}
+	if radix == 'o' || radix == 'O' {
+		check.versionErrorf(lit, go1_13, "0o/0O-style octal literal")
+		return
+	}
+	if lit.Kind != syntax.IntLit && (radix == 'x' || radix == 'X') {
+		check.versionErrorf(lit, go1_13, "hexadecimal floating-point literal")
+	}
+}
+
 // exprInternal contains the core of type checking of expressions.
 // Must only be called by rawExpr.
 // (See rawExpr for an explanation of the parameters.)

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

@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"go/version"
 	"internal/goversion"
-	"strings"
 )
 
 // A goVersion is a Go language version string of the form "go1.%d"
@@ -50,35 +49,6 @@ var (
 	go_current = asGoVersion(fmt.Sprintf("go1.%d", goversion.Version))
 )
 
-// langCompat reports an error if the representation of a numeric
-// literal is not compatible with the current language version.
-func (check *Checker) langCompat(lit *syntax.BasicLit) {
-	s := lit.Value
-	if len(s) <= 2 || check.allowVersion(check.pkg, lit, go1_13) {
-		return
-	}
-	// len(s) > 2
-	if strings.Contains(s, "_") {
-		check.versionErrorf(lit, go1_13, "underscore in numeric literal")
-		return
-	}
-	if s[0] != '0' {
-		return
-	}
-	radix := s[1]
-	if radix == 'b' || radix == 'B' {
-		check.versionErrorf(lit, go1_13, "binary literal")
-		return
-	}
-	if radix == 'o' || radix == 'O' {
-		check.versionErrorf(lit, go1_13, "0o/0O-style octal literal")
-		return
-	}
-	if lit.Kind != syntax.IntLit && (radix == 'x' || radix == 'X') {
-		check.versionErrorf(lit, go1_13, "hexadecimal floating-point literal")
-	}
-}
-
 // allowVersion reports whether the given package is allowed to use version v.
 func (check *Checker) allowVersion(pkg *Package, at poser, v goVersion) bool {
 	// We assume that imported packages have all been checked,

src/go/types/expr.go

@@ -13,6 +13,7 @@ import (
 	"go/internal/typeparams"
 	"go/token"
 	. "internal/types/errors"
+	"strings"
 )
 
 /*
@@ -1016,6 +1017,35 @@ func (check *Checker) nonGeneric(T *target, x *operand) {
 	}
 }
 
+// langCompat reports an error if the representation of a numeric
+// literal is not compatible with the current language version.
+func (check *Checker) langCompat(lit *ast.BasicLit) {
+	s := lit.Value
+	if len(s) <= 2 || check.allowVersion(check.pkg, lit, go1_13) {
+		return
+	}
+	// len(s) > 2
+	if strings.Contains(s, "_") {
+		check.versionErrorf(lit, go1_13, "underscore in numeric literal")
+		return
+	}
+	if s[0] != '0' {
+		return
+	}
+	radix := s[1]
+	if radix == 'b' || radix == 'B' {
+		check.versionErrorf(lit, go1_13, "binary literal")
+		return
+	}
+	if radix == 'o' || radix == 'O' {
+		check.versionErrorf(lit, go1_13, "0o/0O-style octal literal")
+		return
+	}
+	if lit.Kind != token.INT && (radix == 'x' || radix == 'X') {
+		check.versionErrorf(lit, go1_13, "hexadecimal floating-point literal")
+	}
+}
+
 // exprInternal contains the core of type checking of expressions.
 // Must only be called by rawExpr.
 // (See rawExpr for an explanation of the parameters.)

src/go/types/version.go

@@ -10,7 +10,6 @@ import (
 	"go/token"
 	"go/version"
 	"internal/goversion"
-	"strings"
 )
 
 // A goVersion is a Go language version string of the form "go1.%d"
@@ -51,35 +50,6 @@ var (
 	go_current = asGoVersion(fmt.Sprintf("go1.%d", goversion.Version))
 )
 
-// langCompat reports an error if the representation of a numeric
-// literal is not compatible with the current language version.
-func (check *Checker) langCompat(lit *ast.BasicLit) {
-	s := lit.Value
-	if len(s) <= 2 || check.allowVersion(check.pkg, lit, go1_13) {
-		return
-	}
-	// len(s) > 2
-	if strings.Contains(s, "_") {
-		check.versionErrorf(lit, go1_13, "underscore in numeric literal")
-		return
-	}
-	if s[0] != '0' {
-		return
-	}
-	radix := s[1]
-	if radix == 'b' || radix == 'B' {
-		check.versionErrorf(lit, go1_13, "binary literal")
-		return
-	}
-	if radix == 'o' || radix == 'O' {
-		check.versionErrorf(lit, go1_13, "0o/0O-style octal literal")
-		return
-	}
-	if lit.Kind != token.INT && (radix == 'x' || radix == 'X') {
-		check.versionErrorf(lit, go1_13, "hexadecimal floating-point literal")
-	}
-}
-
 // allowVersion reports whether the given package is allowed to use version v.
 func (check *Checker) allowVersion(pkg *Package, at positioner, v goVersion) bool {
 	// We assume that imported packages have all been checked,