cmd/compile/internal/noder: decode generic methods and pipe receivers

Change-Id: I7a66fba400a743f4ef2fb989cd8e74e955e22b0f
Reviewed-on: https://go-review.googlesource.com/c/go/+/762020
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Mark Freeman <markfreeman@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>

1 files changed, 30 insertions, 8 deletions

diff --git a/src/cmd/compile/internal/noder/reader.go b/src/cmd/compile/internal/noder/reader.go
index ebb5043a05..e0545a86db 100644
--- a/src/cmd/compile/internal/noder/reader.go
+++ b/src/cmd/compile/internal/noder/reader.go
@@ -784,14 +784,22 @@ func (pr *pkgReader) objIdxMayFail(idx index, implicits, explicits []*types.Type
 		return name, nil
 
 	case pkgbits.ObjFunc:
-		if sym.Name == "init" {
-			sym = Renameinit()
-		}
-
 		npos := r.pos()
 		setBasePos(npos)
+
+		var sel *types.Sym
+		var recv *types.Field
+		if r.Version().Has(pkgbits.GenericMethods) && r.Bool() {
+			sel = r.selector()
+			r.recvTypeParamNames()
+			recv = r.param()
+		} else {
+			if sym.Name == "init" {
+				sym = Renameinit()
+			}
+		}
 		r.typeParamNames()
-		typ := r.signature(nil)
+		typ := r.signature(recv)
 		fpos := r.pos()
 
 		fn := ir.NewFunc(fpos, npos, sym, typ)
@@ -819,7 +827,7 @@ func (pr *pkgReader) objIdxMayFail(idx index, implicits, explicits []*types.Type
 			}
 		}
 
-		rext.funcExt(name, nil)
+		rext.funcExt(name, sel)
 		return name, nil
 
 	case pkgbits.ObjType:
@@ -1021,7 +1029,11 @@ func (pr *pkgReader) objDictIdx(sym *types.Sym, idx index, implicits, explicits
 	}
 
 	nimplicits := r.Len()
-	nexplicits := r.Len()
+	nreceivers := 0
+	if r.Version().Has(pkgbits.GenericMethods) {
+		nreceivers = r.Len()
+	}
+	nexplicits := r.Len() + nreceivers
 
 	if nimplicits > len(implicits) || nexplicits != len(explicits) {
 		return nil, fmt.Errorf("%v has %v+%v params, but instantiated with %v+%v args", sym, nimplicits, nexplicits, len(implicits), len(explicits))
@@ -1029,6 +1041,7 @@ func (pr *pkgReader) objDictIdx(sym *types.Sym, idx index, implicits, explicits
 
 	dict.targs = append(implicits[:nimplicits:nimplicits], explicits...)
 	dict.implicits = nimplicits
+	dict.receivers = nreceivers
 
 	// Within the compiler, we can just skip over the type parameters.
 	for range dict.targs[dict.implicits:] {
@@ -1095,10 +1108,19 @@ func (pr *pkgReader) objDictIdx(sym *types.Sym, idx index, implicits, explicits
 	return &dict, nil
 }
 
+func (r *reader) recvTypeParamNames() {
+	r.Sync(pkgbits.SyncTypeParamNames)
+
+	for range r.dict.targs[r.dict.implicits : r.dict.implicits+r.dict.receivers] {
+		r.pos()
+		r.localIdent()
+	}
+}
+
 func (r *reader) typeParamNames() {
 	r.Sync(pkgbits.SyncTypeParamNames)
 
-	for range r.dict.targs[r.dict.implicits:] {
+	for range r.dict.targs[r.dict.implicits+r.dict.receivers:] {
 		r.pos()
 		r.localIdent()
 	}