gc: line number + type checking nits

Fixes #1910.
Fixes #1979.
Fixes #1990.
Fixes #1993.
Fixes #2089.

R=ken2
CC=golang-dev
https://golang.org/cl/4828046

src/cmd/gc/go.y

@@ -1249,7 +1249,10 @@ fnliteral:
 		$$ = closurebody($3);
 		fixlbrace($2);
 	}
-
+|	fnlitdcl error
+	{
+		$$ = closurebody(nil);
+	}
 
 /*
  * lists of things

src/cmd/gc/lex.c

@@ -254,7 +254,7 @@ main(int argc, char *argv[])
 	resumetypecopy();
 	resumecheckwidth();
 
-	for(l=xtop; l; l=l->next)
+	for(l=xtop; l; l=l->next) {
 		if(l->n->op == ODCLFUNC || l->n->op == OCLOSURE) {
 			curfn = l->n;
 			saveerrors();
@@ -262,7 +262,12 @@ main(int argc, char *argv[])
 			if(nerrors != 0)
 				l->n->nbody = nil;  // type errors; do not compile
 		}
+	}
+
 	curfn = nil;
+	
+	if(nsavederrors+nerrors)
+		errorexit();
 
 	for(l=xtop; l; l=l->next)
 		if(l->n->op == ODCLFUNC)

src/cmd/gc/typecheck.c

@@ -146,17 +146,18 @@ typecheck(Node **np, int top)
 		case OPACK:
 			break;
 		default:
+			lineno = lno;
 			return n;
 		}
 	}
 
 	if(n->typecheck == 2) {
 		yyerror("typechecking loop");
+		lineno = lno;
 		return n;
 	}
 	n->typecheck = 2;
 
-	lno = setlineno(n);
 	if(n->sym) {
 		if(n->op == ONAME && n->etype != 0 && !(top & Ecall)) {
 			yyerror("use of builtin %S not in function call", n->sym);

test/fixedbugs/bug274.go

@@ -25,6 +25,7 @@ func main() {
 		L1:  // ERROR "statement"
 	default:
 		     // correct since no semicolon is required before a '}'
-		L2:  // ERROR "not used"
+		goto L2
+		L2:
 	}
 }

test/fixedbugs/bug298.go

@@ -7,5 +7,5 @@
 package ddd
 
 func Sum() int
-	for i := range []int{} { return i }  // ERROR "return outside function|expected"
+	for i := range []int{} { return i }  // ERROR "statement outside function|expected"
 

test/fixedbugs/bug353.go

+// errchk $G $D/$F.go
+
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// issue 2089 - internal compiler error
+
+package main
+
+import (
+	"io"
+	"os"
+)
+
+func echo(fd io.ReadWriterCloser) { // ERROR "undefined: io.ReadWriterCloser"
+	var buf [1024]byte
+	for {
+		n, err := fd.Read(buf)
+		if err != nil {
+			break
+		}
+		fd.Write(buf[0:n])
+	}
+}
+
+func main() {
+	fd, _ := os.Open("a.txt")
+	echo(fd)
+}

test/fixedbugs/bug357.go

+// errchk $G $D/$F.go
+
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// issue 1993.
+// error used to have last line number in file
+
+package main
+
+func bla1() bool {
+	return false
+}
+
+func bla5() bool {
+	_ = 1
+	false  // ERROR "false not used"
+	_ = 2
+}
+
+func main() {
+	x := bla1()
+	_ = x
+}

test/fixedbugs/bug358.go

+// errchk $G $D/$F.go
+
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// issue 1979
+// used to get internal compiler error too
+
+package main
+
+import (
+	"http"
+	"io/ioutil"
+	"os"
+)
+
+func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request)  // ERROR "syntax error"
+}
+
+type Page struct {
+	Title string
+	Body []byte
+}
+

test/fixedbugs/bug359.go

+// errchk $G $D/$F.go
+
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// issue 1910
+// error on wrong line
+
+package main
+
+import "container/list"
+
+type Painting struct {
+	fragments list.List // private
+}
+
+func (p Painting) Foo() {
+	for e := p.fragments; e.Front() != nil; e = e.Next() {  // ERROR "unexported field"
+	}
+}
+
+// from comment 4 of issue 1910
+type Foo interface {
+	Run(a int) (a int)  // ERROR "a redeclared"
+}