gc: fix handling of return values named _

Fixes #1586.

R=ken2
CC=golang-dev
https://golang.org/cl/4244057

diff --git a/src/cmd/gc/dcl.c b/src/cmd/gc/dcl.c
index 2aa1bc817017296778901fbc02088e6db01cf9da..cbcdcbf8c706729e01e11d6f6f14564eba89b730 100644 (file)
--- a/src/cmd/gc/dcl.c
+++ b/src/cmd/gc/dcl.c
@@ -693,13 +693,13 @@ ok:
  * turn a parsed struct into a type
  */
 static Type**
-stotype(NodeList *l, int et, Type **t)
+stotype(NodeList *l, int et, Type **t, int funarg)
 {
        Type *f, *t1, *t2, **t0;
        Strlit *note;
        int lno;
        NodeList *init;
-       Node *n;
+       Node *n, *left;
        char *what;
 
        t0 = t;
@@ -716,15 +716,18 @@ stotype(NodeList *l, int et, Type **t)
 
                if(n->op != ODCLFIELD)
                        fatal("stotype: oops %N\n", n);
+               left = n->left;
+               if(funarg && isblank(left))
+                       left = N;
                if(n->right != N) {
-                       if(et == TINTER && n->left != N) {
+                       if(et == TINTER && left != N) {
                                // queue resolution of method type for later.
                                // right now all we need is the name list.
                                // avoids cycles for recursive interface types.
                                n->type = typ(TINTERMETH);
                                n->type->nname = n->right;
                                n->right = N;
-                               n->left->type = n->type;
+                               left->type = n->type;
                                queuemethod(n);
                        } else {
                                typecheck(&n->right, Etype);
@@ -733,8 +736,8 @@ stotype(NodeList *l, int et, Type **t)
                                        *t0 = T;
                                        return t0;
                                }
-                               if(n->left != N)
-                                       n->left->type = n->type;
+                               if(left != N)
+                                       left->type = n->type;
                                n->right = N;
                                if(n->embedded && n->type != T) {
                                        t1 = n->type;
@@ -772,7 +775,7 @@ stotype(NodeList *l, int et, Type **t)
                        break;
                }
 
-               if(et == TINTER && n->left == N) {
+               if(et == TINTER && left == N) {
                        // embedded interface - inline the methods
                        if(n->type->etype != TINTER) {
                                if(n->type->etype == TFORW)
@@ -805,8 +808,8 @@ stotype(NodeList *l, int et, Type **t)
                f->width = BADWIDTH;
                f->isddd = n->isddd;
 
-               if(n->left != N && n->left->op == ONAME) {
-                       f->nname = n->left;
+               if(left != N && left->op == ONAME) {
+                       f->nname = left;
                        f->embedded = n->embedded;
                        f->sym = f->nname->sym;
                        if(importpkg && !exportname(f->sym->name))
@@ -848,7 +851,7 @@ dostruct(NodeList *l, int et)
        }
        t = typ(et);
        t->funarg = funarg;
-       stotype(l, et, &t->type);
+       stotype(l, et, &t->type, funarg);
        if(t->type == T && l != nil) {
                t->broke = 1;
                return t;
@@ -942,8 +945,6 @@ checkarglist(NodeList *all, int input)
                        t = n;
                        n = N;
                }
-               if(isblank(n))
-                       n = N;
                if(n != N && n->sym == S) {
                        t = n;
                        n = N;
@@ -1160,9 +1161,9 @@ addmethod(Sym *sf, Type *t, int local)
        }
 
        if(d == T)
-               stotype(list1(n), 0, &pa->method);
+               stotype(list1(n), 0, &pa->method, 0);
        else
-               stotype(list1(n), 0, &d->down);
+               stotype(list1(n), 0, &d->down, 0);
        return;
 }
 

diff --git a/test/fixedbugs/bug326.go b/test/fixedbugs/bug326.go
new file mode 100644 (file)
index 0000000..efdd0ef
--- /dev/null
+++ b/test/fixedbugs/bug326.go
@@ -0,0 +1,41 @@
+// 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.
+
+package p
+
+import "os"
+
+func f() (_ int, err os.Error) {
+       return
+}
+
+func g() (x int, _ os.Error) {
+       return
+}
+
+func h() (_ int, _ os.Error) {
+       return
+}
+
+func i() (int, os.Error) {
+       return  // ERROR "not enough arguments to return"
+}
+
+func f1() (_ int, err os.Error) {
+       return 1, nil
+}
+
+func g1() (x int, _ os.Error) {
+       return 1, nil
+}
+
+func h1() (_ int, _ os.Error) {
+       return 1, nil
+}
+
+func ii() (int, os.Error) {
+       return 1, nil
+}