From: Matthew Dempsky <mdempsky@google.com>
Date: Thu, 3 Dec 2020 22:00:19 +0000 (-0800)
Subject: [dev.regabi] cmd/compile: silence errors about missing blank methods
X-Git-Tag: go1.17beta1~1539^2~361
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=d90b199e9c;p=gostls13.git

[dev.regabi] cmd/compile: silence errors about missing blank methods

If an interface contains a blank method, that's already an error. No
need for useless follow-up error messages about not implementing them.

Fixes #42964.

Change-Id: I5bf53a8f27d75d4c86c61588c5e2e3e95563d320
Reviewed-on: https://go-review.googlesource.com/c/go/+/275294
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
---

diff --git a/src/cmd/compile/internal/gc/dcl.go b/src/cmd/compile/internal/gc/dcl.go
index 5936aeb950..a77c1aed45 100644
--- a/src/cmd/compile/internal/gc/dcl.go
+++ b/src/cmd/compile/internal/gc/dcl.go
@@ -317,18 +317,6 @@ func colasdefn(left []ir.Node, defn ir.Node) {
 	}
 }
 
-// declare the arguments in an
-// interface field declaration.
-func ifacedcl(n *ir.Field) {
-	if n.Sym == nil {
-		base.Fatalf("ifacedcl")
-	}
-
-	if n.Sym.IsBlank() {
-		base.Errorf("methods must have a unique non-blank name")
-	}
-}
-
 // declare the function proper
 // and declare the arguments.
 // called in extern-declaration context
diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go
index 61320123a8..1cd8375677 100644
--- a/src/cmd/compile/internal/gc/noder.go
+++ b/src/cmd/compile/internal/gc/noder.go
@@ -899,10 +899,13 @@ func (p *noder) interfaceType(expr *syntax.InterfaceType) ir.Node {
 			n = ir.NewField(p.pos(method), nil, importName(p.packname(method.Type)).(ir.Ntype), nil)
 		} else {
 			mname := p.name(method.Name)
+			if mname.IsBlank() {
+				base.Errorf("methods must have a unique non-blank name")
+				continue
+			}
 			sig := p.typeExpr(method.Type).(*ir.FuncType)
 			sig.Recv = fakeRecv()
 			n = ir.NewField(p.pos(method), mname, sig, nil)
-			ifacedcl(n)
 		}
 		l = append(l, n)
 	}
diff --git a/test/interface/explicit.go b/test/interface/explicit.go
index 3f9451e8d2..b705b97676 100644
--- a/test/interface/explicit.go
+++ b/test/interface/explicit.go
@@ -100,6 +100,7 @@ type T2 struct{}
 func (t *T2) M() {}
 func (t *T2) _() {}
 
-// Check that nothing satisfies an interface with blank methods.
-var b1 B1 = &T2{} // ERROR "incompatible|missing _ method"
-var b2 B2 = &T2{} // ERROR "incompatible|missing _ method"
+// Already reported about the invalid blank interface method above;
+// no need to report about not implementing it.
+var b1 B1 = &T2{}
+var b2 B2 = &T2{}