gc: correct handling of unexported method names in embedded interfaces

go/types: update for export data format change
reflect: require package qualifiers to match during interface check
runtime: require package qualifiers to match during interface check
test: fixed bug324, adapt to be silent

Fixes #1550.
Issue 1536 remains open.

R=gri, ken2, r
CC=golang-dev
https://golang.org/cl/4442071

src/cmd/gc/go.h

@@ -315,6 +315,7 @@ struct	Pkg
 {
 	char*	name;
 	Strlit*	path;
+	Sym*	pathsym;
 	char*	prefix;
 	Pkg*	link;
 	char	exported;	// import line written in export data

src/cmd/gc/go.y

@@ -1853,6 +1853,10 @@ hidden_interfacedcl:
 	{
 		$$ = nod(ODCLFIELD, newname($1), typenod(functype(fakethis(), $3, $5)));
 	}
+|	hidden_importsym '(' ohidden_funarg_list ')' ohidden_funres
+	{
+		$$ = nod(ODCLFIELD, newname($1), typenod(functype(fakethis(), $3, $5)));
+	}
 
 ohidden_funres:
 	{

src/cmd/gc/reflect.c

@@ -182,6 +182,11 @@ methods(Type *t)
 		a = b;
 
 		a->name = method->name;
+		if(!exportname(method->name)) {
+			if(method->pkg == nil)
+				fatal("methods: missing package");
+			a->pkg = method->pkg;
+		}
 		a->isym = methodsym(method, it, 1);
 		a->tsym = methodsym(method, t, 0);
 		a->type = methodfunc(f->type, t);
@@ -253,8 +258,11 @@ imethods(Type *t)
 		method = f->sym;
 		a = mal(sizeof(*a));
 		a->name = method->name;
-		if(!exportname(method->name))
+		if(!exportname(method->name)) {
+			if(method->pkg == nil)
+				fatal("imethods: missing package");
 			a->pkg = method->pkg;
+		}
 		a->mtype = f->type;
 		a->offset = 0;
 		a->type = methodfunc(f->type, nil);
@@ -297,26 +305,6 @@ imethods(Type *t)
 	return all;
 }
 
-static int
-dgopkgpath(Sym *s, int ot, Pkg *pkg)
-{
-	if(pkg == nil)
-		return dgostringptr(s, ot, nil);
-
-	// Emit reference to go.importpath.""., which 6l will
-	// rewrite using the correct import path.  Every package
-	// that imports this one directly defines the symbol.
-	if(pkg == localpkg) {
-		static Sym *ns;
-		
-		if(ns == nil)
-			ns = pkglookup("importpath.\"\".", mkpkg(strlit("go")));
-		return dsymptr(s, ot, ns, 0);
-	}
-
-	return dgostringptr(s, ot, pkg->name);
-}
-
 static void
 dimportpath(Pkg *p)
 {
@@ -324,6 +312,9 @@ dimportpath(Pkg *p)
 	char *nam;
 	Node *n;
 	
+	if(p->pathsym != S)
+		return;
+
 	if(gopkg == nil) {
 		gopkg = mkpkg(strlit("go"));
 		gopkg->name = "go";
@@ -335,11 +326,33 @@ dimportpath(Pkg *p)
 	free(nam);
 	n->class = PEXTERN;
 	n->xoffset = 0;
+	p->pathsym = n->sym;
 	
 	gdatastring(n, p->path);
 	ggloblsym(n->sym, types[TSTRING]->width, 1);
 }
 
+static int
+dgopkgpath(Sym *s, int ot, Pkg *pkg)
+{
+	if(pkg == nil)
+		return dgostringptr(s, ot, nil);
+
+	// Emit reference to go.importpath.""., which 6l will
+	// rewrite using the correct import path.  Every package
+	// that imports this one directly defines the symbol.
+	if(pkg == localpkg) {
+		static Sym *ns;
+		
+		if(ns == nil)
+			ns = pkglookup("importpath.\"\".", mkpkg(strlit("go")));
+		return dsymptr(s, ot, ns, 0);
+	}
+
+	dimportpath(pkg);
+	return dsymptr(s, ot, pkg->pathsym, 0);
+}
+
 /*
  * uncommonType
  * ../../pkg/runtime/type.go:/uncommonType

src/cmd/gc/subr.c

@@ -1264,7 +1264,12 @@ Tpretty(Fmt *fp, Type *t)
 	case TINTER:
 		fmtprint(fp, "interface {");
 		for(t1=t->type; t1!=T; t1=t1->down) {
-			fmtprint(fp, " %hS%hhT", t1->sym, t1->type);
+			fmtprint(fp, " ");
+			if(exportname(t1->sym->name))
+				fmtprint(fp, "%hS", t1->sym);
+			else
+				fmtprint(fp, "%S", t1->sym);
+			fmtprint(fp, "%hhT", t1->type);
 			if(t1->down)
 				fmtprint(fp, ";");
 		}

src/pkg/go/types/gcimporter.go

@@ -461,7 +461,13 @@ func (p *gcParser) parseFuncType() Type {
 // MethodSpec = identifier Signature .
 //
 func (p *gcParser) parseMethodSpec(scope *ast.Scope) {
-	p.expect(scanner.Ident)
+	if p.tok == scanner.Ident {
+		p.expect(scanner.Ident)
+	} else {
+		p.parsePkgId()
+		p.expect('.')
+		p.parseDotIdent()
+	}
 	isVariadic := false
 	p.parseSignature(scope, &isVariadic)
 }

src/pkg/reflect/all_test.go

@@ -152,7 +152,7 @@ var typeTests = []pair{
 			b()
 		})
 	}{},
-		"interface { a(func(func(int) int) func(func(int)) int); b() }",
+		"interface { reflect_test.a(func(func(int) int) func(func(int)) int); reflect_test.b() }",
 	},
 }
 
@@ -1300,40 +1300,40 @@ func TestNestedMethods(t *testing.T) {
 	}
 }
 
-type innerInt struct {
-	x int
+type InnerInt struct {
+	X int
 }
 
-type outerInt struct {
-	y int
-	innerInt
+type OuterInt struct {
+	Y int
+	InnerInt
 }
 
-func (i *innerInt) m() int {
-	return i.x
+func (i *InnerInt) M() int {
+	return i.X
 }
 
 func TestEmbeddedMethods(t *testing.T) {
-	typ := Typeof((*outerInt)(nil))
-	if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != NewValue((*outerInt).m).Pointer() {
-		t.Errorf("Wrong method table for outerInt: (m=%p)", (*outerInt).m)
+	typ := Typeof((*OuterInt)(nil))
+	if typ.NumMethod() != 1 || typ.Method(0).Func.Pointer() != NewValue((*OuterInt).M).Pointer() {
+		t.Errorf("Wrong method table for OuterInt: (m=%p)", (*OuterInt).M)
 		for i := 0; i < typ.NumMethod(); i++ {
 			m := typ.Method(i)
 			t.Errorf("\t%d: %s %#x\n", i, m.Name, m.Func.Pointer())
 		}
 	}
 
-	i := &innerInt{3}
+	i := &InnerInt{3}
 	if v := NewValue(i).Method(0).Call(nil)[0].Int(); v != 3 {
-		t.Errorf("i.m() = %d, want 3", v)
+		t.Errorf("i.M() = %d, want 3", v)
 	}
 
-	o := &outerInt{1, innerInt{2}}
+	o := &OuterInt{1, InnerInt{2}}
 	if v := NewValue(o).Method(0).Call(nil)[0].Int(); v != 2 {
-		t.Errorf("i.m() = %d, want 2", v)
+		t.Errorf("i.M() = %d, want 2", v)
 	}
 
-	f := (*outerInt).m
+	f := (*OuterInt).M
 	if v := f(o); v != 2 {
 		t.Errorf("f(o) = %d, want 2", v)
 	}

src/pkg/reflect/type.go

@@ -941,9 +941,7 @@ func implements(T, V *commonType) bool {
 		for j := 0; j < len(v.methods); j++ {
 			tm := &t.methods[i]
 			vm := &v.methods[j]
-			// TODO(rsc):  && vm.pkgPath == tm.pkgPath should be here
-			// but it breaks the *ast.Ident vs ast.Expr test.
-			if vm.name == tm.name && vm.typ == tm.typ {
+			if vm.name == tm.name && vm.pkgPath == tm.pkgPath && vm.typ == tm.typ {
 				if i++; i >= len(t.methods) {
 					return true
 				}
@@ -960,9 +958,7 @@ func implements(T, V *commonType) bool {
 	for j := 0; j < len(v.methods); j++ {
 		tm := &t.methods[i]
 		vm := &v.methods[j]
-		// TODO(rsc):  && vm.pkgPath == tm.pkgPath should be here
-		// but it breaks the *ast.Ident vs ast.Expr test.
-		if vm.name == tm.name && vm.mtyp == tm.typ {
+		if vm.name == tm.name && vm.pkgPath == tm.pkgPath && vm.mtyp == tm.typ {
 			if i++; i >= len(t.methods) {
 				return true
 			}

src/pkg/runtime/iface.c

@@ -50,7 +50,7 @@ itab(InterfaceType *inter, Type *type, int32 canfail)
 	Method *t, *et;
 	IMethod *i, *ei;
 	uint32 h;
-	String *iname;
+	String *iname, *ipkgPath;
 	Itab *m;
 	UncommonType *x;
 	Type *itype;
@@ -120,6 +120,7 @@ search:
 	for(; i < ei; i++) {
 		itype = i->type;
 		iname = i->name;
+		ipkgPath = i->pkgPath;
 		for(;; t++) {
 			if(t >= et) {
 				if(!canfail) {
@@ -136,7 +137,7 @@ search:
 				m->bad = 1;
 				goto out;
 			}
-			if(t->mtyp == itype && t->name == iname)
+			if(t->mtyp == itype && t->name == iname && t->pkgPath == ipkgPath)
 				break;
 		}
 		if(m)

test/bugs/bug324.dir/main.go → test/fixedbugs/bug324.dir/main.go

@@ -14,7 +14,7 @@ type Exported interface {
 
 type Implementation struct{}
 
-func (p *Implementation) private() { println("main.Implementation.private()") }
+func (p *Implementation) private() {}
 
 
 func main() {
@@ -40,7 +40,12 @@ func main() {
 	// x = px
 
 	// this assignment unexpectedly compiles and then executes
+	defer func() {
+		recover()
+	}()
 	x = px.(Exported)
+	
+	println("should not get this far")
 
 	// this is a legitimate call, but because of the previous assignment,
 	// it invokes the method private in p!

test/bugs/bug324.go → test/fixedbugs/bug324.go

-// $G $D/$F.dir/p.go && $G $D/$F.dir/main.go && $L main.$A && ! ./$A.out || echo BUG: should fail
+// $G $D/$F.dir/p.go && $G $D/$F.dir/main.go && $L main.$A && ./$A.out
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

test/golden.out

@@ -166,8 +166,3 @@ panic: interface conversion: interface is main.T, not main.T
 bugs/bug322.dir/main.go:19: implicit assignment of unexported field 'x' of lib.T in method receiver
 bugs/bug322.dir/main.go:32: implicit assignment of unexported field 'x' of lib.T in method receiver
 BUG: fails incorrectly
-
-=========== bugs/bug324.go
-main.Implementation.private()
-p.Implementation.private()
-BUG: should fail