complain when trying to put T into an interface

if T has pointer methods.  this is just a heuristic
but it catches the problem robert ran into and
lets me put the larger interface issues aside for
now.  found one bug in pretty.

R=ken
OCL=26141
CL=26141

src/cmd/gc/subr.c

@@ -2805,12 +2805,23 @@ ifacelookdot(Sym *s, Type *t)
 // check whether non-interface type t
 // satisifes inteface type iface.
 int
-ifaceokT2I(Type *t, Type *iface, Type **m)
+ifaceokT2I(Type *t0, Type *iface, Type **m)
 {
-	Type *im, *tm;
+	Type *t, *im, *tm;
 	int imhash;
 
-	t = methtype(t);
+	t = methtype(t0);
+
+	// stopgap: check for
+	// non-pointer type in T2I, methods want pointers.
+	// supposed to do something better eventually
+	// but this will catch errors while we decide the
+	// details of the "better" solution.
+	if(t == t0 && t->methptr == 2) {
+		yyerror("probably wanted *%T not %T", t, t);
+		*m = iface->type;
+		return 0;
+	}
 
 	// if this is too slow,
 	// could sort these first

test/golden.out

@@ -64,10 +64,6 @@ Faulting address: 0x0
 pc: xxx
 
 
-=========== ./interface6.go
-failure in f4 i
-BUG interface6
-
 =========== ./peano.go
 0! = 1
 1! = 1

test/interface4.go

@@ -35,11 +35,11 @@ func ptrs() {
 	var smallptr SmallPtr = SmallPtr{ 12345 };
 	var intptr IntPtr = 12345;
 
-	test("bigptr", bigptr);
+//	test("bigptr", bigptr);
 	test("&bigptr", &bigptr);
-	test("smallptr", smallptr);
+//	test("smallptr", smallptr);
 	test("&smallptr", &smallptr);
-	test("intptr", intptr);
+//	test("intptr", intptr);
 	test("&intptr", &intptr);
 }
 

test/interface6.go

@@ -49,13 +49,13 @@ type S2 struct { i int }
 func (p *S2) Get() int { return p.i }
 func (p *S2) Put(i int) { p.i = i }
 
-func f4() {
-  s := S2{1};
-  var i I1 = s;
-  i.Put(2);
-  check(i.Get() == 2, "f4 i");
-  check(s.i == 1, "f4 s");
-}
+// func f4() {
+//   s := S2{1};
+//   var i I1 = s;
+//   i.Put(2);
+//   check(i.Get() == 2, "f4 i");
+//   check(s.i == 1, "f4 s");
+// }
 
 func f5() {
   s := S2{1};
@@ -107,13 +107,13 @@ type S4 struct { i, j, k, l int64 }
 func (p *S4) Get() int64 { return p.l }
 func (p *S4) Put(i int64) { p.l = i }
 
-func f10() {
-  s := S4{1, 2, 3, 4};
-  var i I2 = s;
-  i.Put(5);
-  check(i.Get() == 5, "f10 i");
-  check(s.l == 4, "f10 s");
-}
+// func f10() {
+//   s := S4{1, 2, 3, 4};
+//   var i I2 = s;
+//   i.Put(5);
+//   check(i.Get() == 5, "f10 i");
+//   check(s.l == 4, "f10 s");
+// }
 
 func f11() {
   s := S4{1, 2, 3, 4};
@@ -135,13 +135,13 @@ func main() {
   f1();
   f2();
   f3();
-  f4();
+//  f4();
   f5();
   f6();
   f7();
   f8();
   f9();
-  f10();
+//  f10();
   f11();
   f12();
   if fail > 0 {

usr/gri/pretty/parser.go

@@ -363,7 +363,7 @@ func (P *Parser) parseParameterDecl(ellipsis_ok bool) (*vector.Vector, ast.Expr)
 
 	// if we had a list of identifiers, it must be followed by a type
 	typ := P.tryParameterType();
-	
+
 	return list, typ;
 }
 
@@ -383,7 +383,7 @@ func (P *Parser) parseParameterList(ellipsis_ok bool) []*ast.Field {
 		}
 		list.Init(0);
 		list.Push(&ast.Field{idents, typ, nil});
-		
+
 		for P.tok == token.COMMA {
 			P.next();
 			idents := P.parseIdentList2(nil);
@@ -473,7 +473,7 @@ func (P *Parser) parseFunctionType() *ast.FunctionType {
 	loc := P.loc;
 	P.expect(token.FUNC);
 	sig := P.parseSignature();
-	
+
 	return &ast.FunctionType{loc, sig};
 }
 
@@ -494,7 +494,7 @@ func (P *Parser) parseMethodSpec() *ast.Field {
 		// embedded interface
 		typ = x;
 	}
-	
+
 	return &ast.Field{idents, typ, nil};
 }
 
@@ -523,7 +523,7 @@ func (P *Parser) parseInterfaceType() *ast.InterfaceType {
 		end = P.loc;
 		P.expect(token.RBRACE);
 		P.opt_semi = true;
-		
+
 		// convert vector
 		methods = make([]*ast.Field, list.Len());
 		for i := list.Len() - 1; i >= 0; i-- {
@@ -600,7 +600,7 @@ func (P *Parser) parseFieldDecl() *ast.Field {
 			P.error(P.loc, "anonymous field expected");
 		}
 	}
-	
+
 	return &ast.Field{idents, typ, tag};
 }
 
@@ -613,7 +613,7 @@ func (P *Parser) parseStructType() ast.Expr {
 	loc := P.loc;
 	var end scanner.Location;
 	var fields []*ast.Field;
-	
+
 	P.expect(token.STRUCT);
 	if P.tok == token.LBRACE {
 		P.next();
@@ -642,7 +642,7 @@ func (P *Parser) parseStructType() ast.Expr {
 		}
 	}
 
-	return ast.StructType{loc, fields, end};
+	return &ast.StructType{loc, fields, end};
 }
 
 
@@ -722,7 +722,7 @@ func (P *Parser) parseBlock(tok int) *ast.Block {
 	P.expect(tok);
 
 	P.parseStatementList(b.List);
-	
+
 	if tok == token.LBRACE {
 		b.End = P.loc;
 		P.expect(token.RBRACE);
@@ -781,7 +781,7 @@ func (P *Parser) parseStringLit() ast.Expr {
 
 	var x ast.Expr = &ast.BasicLit{P.loc, P.tok, P.val};
 	P.expect(token.STRING);  // always satisfied
-	
+
 	for P.tok == token.STRING {
 		y := &ast.BasicLit{P.loc, P.tok, P.val};
 		P.next();
@@ -805,7 +805,7 @@ func (P *Parser) parseOperand() ast.Expr {
 		x := &ast.BasicLit{P.loc, P.tok, P.val};
 		P.next();
 		return x;
-		
+
 	case token.STRING:
 		return P.parseStringLit();
 
@@ -1150,7 +1150,7 @@ func (P *Parser) parseControlClause(isForStat bool) (init ast.Stat, expr ast.Exp
 
 	if P.tok != token.LBRACE {
 		prev_lev := P.expr_lev;
-		P.expr_lev = -1;	
+		P.expr_lev = -1;
 		if P.tok != token.SEMICOLON {
 			init = P.parseSimpleStat(isForStat);
 			// TODO check for range clause and exit if found
@@ -1372,7 +1372,7 @@ func (P *Parser) parseImportSpec(loc scanner.Location) *ast.ImportDecl {
 	} else {
 		P.expect(token.STRING);  // use expect() error handling
 	}
-	
+
 	return &ast.ImportDecl{loc, ident, path};
 }
 
@@ -1389,7 +1389,7 @@ func (P *Parser) parseConstSpec(loc scanner.Location) *ast.ConstDecl {
 		P.next();
 		vals = P.parseExpressionList();
 	}
-	
+
 	return &ast.ConstDecl{loc, idents, typ, vals};
 }
 
@@ -1401,7 +1401,7 @@ func (P *Parser) parseTypeSpec(loc scanner.Location) *ast.TypeDecl {
 
 	ident := P.parseIdent();
 	typ := P.parseType();
-	
+
 	return &ast.TypeDecl{loc, ident, typ};
 }
 
@@ -1424,7 +1424,7 @@ func (P *Parser) parseVarSpec(loc scanner.Location) *ast.VarDecl {
 			vals = P.parseExpressionList();
 		}
 	}
-	
+
 	return &ast.VarDecl{loc, idents, typ, vals};
 }
 
@@ -1436,7 +1436,7 @@ func (P *Parser) parseSpec(loc scanner.Location, keyword int) ast.Decl {
 	case token.TYPE: return P.parseTypeSpec(loc);
 	case token.VAR: return P.parseVarSpec(loc);
 	}
-	
+
 	unreachable();
 	return nil;
 }
@@ -1463,13 +1463,13 @@ func (P *Parser) parseDecl(keyword int) ast.Decl {
 		end := P.loc;
 		P.expect(token.RPAREN);
 		P.opt_semi = true;
-		
+
 		// convert vector
 		decls := make([]ast.Decl, list.Len());
 		for i := 0; i < list.Len(); i++ {
 			decls[i] = list.At(i).(ast.Decl);
 		}
-		
+
 		return &ast.DeclList{loc, keyword, decls, end};
 	}
 
@@ -1528,7 +1528,7 @@ func (P *Parser) parseDeclaration() ast.Decl {
 	case token.FUNC:
 		return P.parseFunctionDecl();
 	}
-	
+
 	loc := P.loc;
 	P.error(loc, "declaration expected");
 	P.next();  // make progress
@@ -1588,7 +1588,7 @@ func (P *Parser) ParseImportDecls() []ast.Decl {
 	for i := 0; i < list.Len(); i++ {
 		imports[i] = list.At(i).(ast.Decl);
 	}
-	
+
 	return imports;
 }