From: Rob Findley <rfindley@google.com>
Date: Wed, 4 Aug 2021 01:39:53 +0000 (-0400)
Subject: [dev.typeparams] go/types: print constraint info for type param operands
X-Git-Tag: go1.18beta1~1818^2^2~46
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b01e775e9c05dd2e5fa19ea06ac09f9a12ae660e;p=gostls13.git

[dev.typeparams] go/types: print constraint info for type param operands

This is a clean port of CL 338309 to go/types.

Change-Id: Ie2c9e2ea51d6321af8bf149e43cd71b7ac282d13
Reviewed-on: https://go-review.googlesource.com/c/go/+/339676
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
---

diff --git a/src/go/types/operand.go b/src/go/types/operand.go
index c605cf781c..aea8bf5e7a 100644
--- a/src/go/types/operand.go
+++ b/src/go/types/operand.go
@@ -159,16 +159,20 @@ func operandString(x *operand, qf Qualifier) string {
 	if hasType {
 		if x.typ != Typ[Invalid] {
 			var intro string
-			switch {
-			case isGeneric(x.typ):
-				intro = " of generic type "
-			case asTypeParam(x.typ) != nil:
-				intro = " of type parameter type "
-			default:
+			var tpar *TypeParam
+			if isGeneric(x.typ) {
+				intro = " of parameterized type "
+			} else if tpar = asTypeParam(x.typ); tpar != nil {
+				intro = " of type parameter "
+			} else {
 				intro = " of type "
 			}
 			buf.WriteString(intro)
 			WriteType(&buf, x.typ, qf)
+			if tpar != nil {
+				buf.WriteString(" constrained by ")
+				WriteType(&buf, tpar.bound, qf) // do not compute interface type sets here
+			}
 		} else {
 			buf.WriteString(" with invalid type")
 		}