go/types, types2: use "invalid operation: x rel y (cause)" for comparison error messages

griesemer · gopherbot · commit dbe56ff6c7a0 · 2022-09-28T10:36:02.000Z
Matches compiler behavior and is consistent with what we do with other binary operations. While at it, also use parentheses rather than a colon for a couple of errors caused by not having a core type. For #55326. Change-Id: I0a5cec1a31ffda98d363e5528791965a1ccb5842 Reviewed-on: https://go-review.googlesource.com/c/go/+/435618 Reviewed-by: Robert Griesemer <gri@google.com> Reviewed-by: Robert Findley <rfindley@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Robert Griesemer <gri@google.com> Run-TryBot: Robert Griesemer <gri@google.com>
diff --git a/src/cmd/compile/internal/types2/expr.go b/src/cmd/compile/internal/types2/expr.go
@@ -193,7 +193,7 @@ func (check *Checker) unary(x *operand, e *syntax.Operation) {
 	case syntax.Recv:
 		u := coreType(x.typ)
 		if u == nil {
-			check.errorf(x, _InvalidReceive, invalidOp+"cannot receive from %s: no core type", x)
+			check.errorf(x, _InvalidReceive, invalidOp+"cannot receive from %s (no core type)", x)
 			x.mode = invalid
 			return
 		}
@@ -875,11 +875,7 @@ Error:
 	if switchCase {
 		check.errorf(x, code, "invalid case %s in switch on %s (%s)", x.expr, y.expr, cause) // error position always at 1st operand
 	} else {
-		if check.conf.CompilerErrorMessages {
-			check.errorf(errOp, code, invalidOp+"%s %s %s (%s)", x.expr, op, y.expr, cause)
-		} else {
-			check.errorf(errOp, code, invalidOp+"cannot compare %s %s %s (%s)", x.expr, op, y.expr, cause)
-		}
+		check.errorf(errOp, code, invalidOp+"%s %s %s (%s)", x.expr, op, y.expr, cause)
 	}
 	x.mode = invalid
 }
@@ -1372,7 +1368,7 @@ func (check *Checker) exprInternal(x *operand, e syntax.Expr, hint Type) exprKin
 			typ = hint
 			base, _ = deref(coreType(typ)) // *T implies &T{}
 			if base == nil {
-				check.errorf(e, _InvalidLit, "invalid composite literal element type %s: no core type", typ)
+				check.errorf(e, _InvalidLit, "invalid composite literal element type %s (no core type)", typ)
 				goto Error
 			}
 
diff --git a/src/go/types/expr.go b/src/go/types/expr.go
@@ -179,7 +179,7 @@ func (check *Checker) unary(x *operand, e *ast.UnaryExpr) {
 	case token.ARROW:
 		u := coreType(x.typ)
 		if u == nil {
-			check.invalidOp(x, _InvalidReceive, "cannot receive from %s: no core type", x)
+			check.invalidOp(x, _InvalidReceive, "cannot receive from %s (no core type)", x)
 			x.mode = invalid
 			return
 		}
@@ -852,11 +852,7 @@ Error:
 	if switchCase {
 		check.errorf(x, code, "invalid case %s in switch on %s (%s)", x.expr, y.expr, cause) // error position always at 1st operand
 	} else {
-		if compilerErrorMessages {
-			check.invalidOp(errOp, code, "%s %s %s (%s)", x.expr, op, y.expr, cause)
-		} else {
-			check.invalidOp(errOp, code, "cannot compare %s %s %s (%s)", x.expr, op, y.expr, cause)
-		}
+		check.invalidOp(errOp, code, "%s %s %s (%s)", x.expr, op, y.expr, cause)
 	}
 	x.mode = invalid
 }
@@ -1351,7 +1347,7 @@ func (check *Checker) exprInternal(x *operand, e ast.Expr, hint Type) exprKind {
 			typ = hint
 			base, _ = deref(coreType(typ)) // *T implies &T{}
 			if base == nil {
-				check.errorf(e, _InvalidLit, "invalid composite literal element type %s: no core type", typ)
+				check.errorf(e, _InvalidLit, "invalid composite literal element type %s (no core type)", typ)
 				goto Error
 			}
 
diff --git a/src/internal/types/testdata/check/expr2.go b/src/internal/types/testdata/check/expr2.go
@@ -9,7 +9,7 @@ package expr2
 func _bool() {
 	const t = true == true
 	const f = true == false
-	_ = t /* ERROR cannot compare */ < f
+	_ = t /* ERROR operator .* not defined */ < f
 	_ = 0 == t /* ERROR mismatched types untyped int and untyped bool */
 	var b bool
 	var x, y float32
@@ -29,7 +29,7 @@ func arrays() {
 	_ = a == b
 	_ = a != b
 	_ = a /* ERROR < not defined */ < b
-	_ = a == nil /* ERROR cannot compare.*mismatched types */
+	_ = a == nil /* ERROR mismatched types */
 
 	type C [10]int
 	var c C
@@ -53,7 +53,7 @@ func structs() {
 	_ = s == t
 	_ = s != t
 	_ = s /* ERROR < not defined */ < t
-	_ = s == nil /* ERROR cannot compare.*mismatched types */
+	_ = s == nil /* ERROR mismatched types */
 
 	type S struct {
 		x int
@@ -74,7 +74,7 @@ func structs() {
 		x int
 		a [10]map[string]int
 	}
-	_ = u /* ERROR cannot compare */ == u
+	_ = u /* ERROR cannot be compared */ == u
 }
 
 func pointers() {
diff --git a/src/internal/types/testdata/check/typeparams.go b/src/internal/types/testdata/check/typeparams.go
@@ -58,10 +58,10 @@ func min[T interface{ ~int }](x, y T) T {
 }
 
 func _[T interface{~int | ~float32}](x, y T) bool { return x < y }
-func _[T any](x, y T) bool { return x /* ERROR cannot compare */ < y }
-func _[T interface{~int | ~float32 | ~bool}](x, y T) bool { return x /* ERROR cannot compare */ < y }
+func _[T any](x, y T) bool { return x /* ERROR type parameter T is not comparable */ < y }
+func _[T interface{~int | ~float32 | ~bool}](x, y T) bool { return x /* ERROR type parameter T is not comparable */ < y }
 
-func _[T C1[T]](x, y T) bool { return x /* ERROR cannot compare */ < y }
+func _[T C1[T]](x, y T) bool { return x /* ERROR type parameter T is not comparable */ < y }
 func _[T C2[T]](x, y T) bool { return x < y }
 
 type C1[T any] interface{}
diff --git a/src/internal/types/testdata/fixedbugs/issue43671.go b/src/internal/types/testdata/fixedbugs/issue43671.go
@@ -12,7 +12,7 @@ type C4 interface{ chan int | chan<- int }
 type C5[T any] interface{ ~chan T | <-chan T }
 
 func _[T any](ch T) {
-	<-ch // ERROR cannot receive from ch .* no core type
+	<-ch // ERROR cannot receive from ch .* \(no core type\)
 }
 
 func _[T C0](ch T) {
@@ -28,7 +28,7 @@ func _[T C2](ch T) {
 }
 
 func _[T C3](ch T) {
-	<-ch // ERROR cannot receive from ch .* no core type
+	<-ch // ERROR cannot receive from ch .* \(no core type\)
 }
 
 func _[T C4](ch T) {
diff --git a/src/internal/types/testdata/fixedbugs/issue51335.go b/src/internal/types/testdata/fixedbugs/issue51335.go
@@ -8,9 +8,9 @@ type S1 struct{}
 type S2 struct{}
 
 func _[P *S1|*S2]() {
-	_= []P{{ /* ERROR invalid composite literal element type P: no core type */ }}
+	_= []P{{ /* ERROR invalid composite literal element type P \(no core type\) */ }}
 }
 
 func _[P *S1|S1]() {
-	_= []P{{ /* ERROR invalid composite literal element type P: no core type */ }}
+	_= []P{{ /* ERROR invalid composite literal element type P \(no core type\) */ }}
 }
diff --git a/src/internal/types/testdata/fixedbugs/issue51472.go b/src/internal/types/testdata/fixedbugs/issue51472.go
@@ -21,25 +21,25 @@ func _[T interface{comparable; ~int}](x T) {
 }
 
 func _[T interface{comparable; ~[]byte}](x T) {
-        _ = x /* ERROR cannot compare */ == x
+        _ = x /* ERROR empty type set */ == x
 }
 
 // TODO(gri) The error message here should be better. See issue #51525.
 func _[T interface{comparable; ~int; ~string}](x T) {
-        _ = x /* ERROR cannot compare */ == x
+        _ = x /* ERROR empty type set */ == x
 }
 
 // TODO(gri) The error message here should be better. See issue #51525.
 func _[T interface{~int; ~string}](x T) {
-        _ = x /* ERROR cannot compare */ == x
+        _ = x /* ERROR empty type set */ == x
 }
 
 func _[T interface{comparable; interface{~int}; interface{int|float64}}](x T) {
         _ = x == x
 }
 
 func _[T interface{interface{comparable; ~int}; interface{~float64; comparable; m()}}](x T) {
-        _ = x /* ERROR cannot compare */ == x
+        _ = x /* ERROR empty type set */ == x
 }
 
 // test case from issue

Original file line number	Diff line number	Diff line change
`@@ -12,7 +12,7 @@ type C4 interface{ chan int \| chan<- int }`
`12`	`12`	`type C5[T any] interface{ ~chan T \| <-chan T }`
`13`	`13`
`14`	`14`	`func _[T any](ch T) {`
`15`		`- <-ch // ERROR cannot receive from ch .* no core type`
	`15`	`+ <-ch // ERROR cannot receive from ch .* \(no core type\)`
`16`	`16`	`}`
`17`	`17`
`18`	`18`	`func _[T C0](ch T) {`
`@@ -28,7 +28,7 @@ func _[T C2](ch T) {`
`28`	`28`	`}`
`29`	`29`
`30`	`30`	`func _[T C3](ch T) {`
`31`		`- <-ch // ERROR cannot receive from ch .* no core type`
	`31`	`+ <-ch // ERROR cannot receive from ch .* \(no core type\)`
`32`	`32`	`}`
`33`	`33`
`34`	`34`	`func _[T C4](ch T) {`
Original file line number	Diff line number	Diff line change
`@@ -8,9 +8,9 @@ type S1 struct{}`
`8`	`8`	`type S2 struct{}`
`9`	`9`
`10`	`10`	`func _[P S1\|S2]() {`
`11`		`- _= []P{{ /* ERROR invalid composite literal element type P: no core type */ }}`
	`11`	`+ _= []P{{ /* ERROR invalid composite literal element type P \(no core type\) */ }}`
`12`	`12`	`}`
`13`	`13`
`14`	`14`	`func _[P *S1\|S1]() {`
`15`		`- _= []P{{ /* ERROR invalid composite literal element type P: no core type */ }}`
	`15`	`+ _= []P{{ /* ERROR invalid composite literal element type P \(no core type\) */ }}`
`16`	`16`	`}`
Original file line number	Diff line number	Diff line change
`@@ -21,25 +21,25 @@ func _[T interface{comparable; ~int}](x T) {`
`21`	`21`	`}`
`22`	`22`
`23`	`23`	`func _[T interface{comparable; ~[]byte}](x T) {`
`24`		`- _ = x /* ERROR cannot compare */ == x`
	`24`	`+ _ = x /* ERROR empty type set */ == x`
`25`	`25`	`}`
`26`	`26`
`27`	`27`	`// TODO(gri) The error message here should be better. See issue #51525.`
`28`	`28`	`func _[T interface{comparable; ~int; ~string}](x T) {`
`29`		`- _ = x /* ERROR cannot compare */ == x`
	`29`	`+ _ = x /* ERROR empty type set */ == x`
`30`	`30`	`}`
`31`	`31`
`32`	`32`	`// TODO(gri) The error message here should be better. See issue #51525.`
`33`	`33`	`func _[T interface{~int; ~string}](x T) {`
`34`		`- _ = x /* ERROR cannot compare */ == x`
	`34`	`+ _ = x /* ERROR empty type set */ == x`
`35`	`35`	`}`
`36`	`36`
`37`	`37`	`func _[T interface{comparable; interface{~int}; interface{int\|float64}}](x T) {`
`38`	`38`	`_ = x == x`
`39`	`39`	`}`
`40`	`40`
`41`	`41`	`func _[T interface{interface{comparable; ~int}; interface{~float64; comparable; m()}}](x T) {`
`42`		`- _ = x /* ERROR cannot compare */ == x`
	`42`	`+ _ = x /* ERROR empty type set */ == x`
`43`	`43`	`}`
`44`	`44`
`45`	`45`	`// test case from issue`