re PR go/65755 (incorrect reflection of struct fields with gccgo)

	PR go/65755
compiler, runtime, reflect: Use reflection string for type comparisons.

Change the runtime and reflect libraries to always use only
the type reflection string to determine whether two types are
equal.  It previously used the PkgPath and Name values for a
type name, but that required a PkgPath that did not match the
gc compiler.

Change the compiler to use the same PkgPath value as the gc
compiler in all cases.

Change the compiler to put the receiver type in the reflection
string for a type defined inside a method.

From-SVN: r222194

gcc/go/gofrontend/types.cc

@@ -2253,22 +2253,7 @@ Type::uncommon_type_constructor(Gogo* gogo, Type* uncommon_type,
 	  const std::string& pkgpath(package == NULL
 				     ? gogo->pkgpath()
 				     : package->pkgpath());
-	  n.assign(pkgpath);
-	  unsigned int index;
-	  const Named_object* in_function = name->in_function(&index);
-	  if (in_function != NULL)
-	    {
-	      n.append(1, '.');
-	      n.append(Gogo::unpack_hidden_name(in_function->name()));
-	      if (index > 0)
-		{
-		  char buf[30];
-		  snprintf(buf, sizeof buf, "%u", index);
-		  n.append(1, '.');
-		  n.append(buf);
-		}
-	    }
-	  s = Expression::make_string(n, bloc);
+	  s = Expression::make_string(pkgpath, bloc);
 	  vals->push_back(Expression::make_unary(OPERATOR_AND, s, bloc));
 	}
     }
@@ -9102,22 +9087,17 @@ Named_type::do_reflection(Gogo* gogo, std::string* ret) const
     }
   if (!this->is_builtin())
     {
-      // We handle -fgo-prefix and -fgo-pkgpath differently here for
-      // compatibility with how the compiler worked before
-      // -fgo-pkgpath was introduced.  When -fgo-pkgpath is specified,
-      // we use it to make a unique reflection string, so that the
-      // type canonicalization in the reflect package will work.  In
-      // order to be compatible with the gc compiler, we put tabs into
-      // the package path, so that the reflect methods can discard it.
+      // When -fgo-pkgpath or -fgo-prefix is specified, we use it to
+      // make a unique reflection string, so that the type
+      // canonicalization in the reflect package will work.  In order
+      // to be compatible with the gc compiler, we put tabs into the
+      // package path, so that the reflect methods can discard it.
       const Package* package = this->named_object_->package();
-      if (gogo->pkgpath_from_option())
-	{
-	  ret->push_back('\t');
-	  ret->append(package != NULL
-		      ? package->pkgpath_symbol()
-		      : gogo->pkgpath_symbol());
-	  ret->push_back('\t');
-	}
+      ret->push_back('\t');
+      ret->append(package != NULL
+		  ? package->pkgpath_symbol()
+		  : gogo->pkgpath_symbol());
+      ret->push_back('\t');
       ret->append(package != NULL
 		  ? package->package_name()
 		  : gogo->package_name());
@@ -9126,6 +9106,14 @@ Named_type::do_reflection(Gogo* gogo, std::string* ret) const
   if (this->in_function_ != NULL)
     {
       ret->push_back('\t');
+      const Typed_identifier* rcvr =
+	this->in_function_->func_value()->type()->receiver();
+      if (rcvr != NULL)
+	{
+	  Named_type* rcvr_type = rcvr->type()->deref()->named_type();
+	  ret->append(Gogo::unpack_hidden_name(rcvr_type->name()));
+	  ret->push_back('.');
+	}
       ret->append(Gogo::unpack_hidden_name(this->in_function_->name()));
       ret->push_back('$');
       if (this->in_function_index_ > 0)

libgo/go/reflect/type.go

@@ -1940,13 +1940,7 @@ func canonicalize(t Type) Type {
 	if t == nil {
 		return nil
 	}
-	u := t.uncommon()
-	var s string
-	if u == nil || u.PkgPath() == "" {
-		s = t.rawString()
-	} else {
-		s = u.PkgPath() + "." + u.Name()
-	}
+	s := t.rawString()
 	canonicalTypeLock.RLock()
 	if r, ok := canonicalType[s]; ok {
 		canonicalTypeLock.RUnlock()

libgo/runtime/go-typedesc-equal.c

@@ -24,16 +24,5 @@ __go_type_descriptors_equal (const struct __go_type_descriptor *td1,
     return 0;
   if (td1->__code != td2->__code || td1->__hash != td2->__hash)
     return 0;
-  if (td1->__uncommon != NULL && td1->__uncommon->__name != NULL)
-    {
-      if (td2->__uncommon == NULL || td2->__uncommon->__name == NULL)
-	return 0;
-      return (__go_ptr_strings_equal (td1->__uncommon->__name,
-				      td2->__uncommon->__name)
-	      && __go_ptr_strings_equal (td1->__uncommon->__pkg_path,
-					 td2->__uncommon->__pkg_path));
-    }
-  if (td2->__uncommon != NULL && td2->__uncommon->__name != NULL)
-    return 0;
   return __go_ptr_strings_equal (td1->__reflection, td2->__reflection);
 }