X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Furcu%2Flfstack.h;h=77af43bf18069df89619f85be6ac46178980de5c;hb=HEAD;hp=b994ea6b5385285d7357da5c0a3fb2fc74eea257;hpb=9298902cee251b178bafe4f66aed7e0e6665d316;p=urcu.git

diff --git a/include/urcu/lfstack.h b/include/urcu/lfstack.h
index b994ea6..2a3073d 100644
--- a/include/urcu/lfstack.h
+++ b/include/urcu/lfstack.h
@@ -1,26 +1,12 @@
+// SPDX-FileCopyrightText: 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
 #ifndef _URCU_LFSTACK_H
 #define _URCU_LFSTACK_H
 
 /*
- * lfstack.h
- *
  * Userspace RCU library - Lock-Free Stack
- *
- * Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifdef __cplusplus
@@ -29,7 +15,6 @@ extern "C" {
 
 #include <stdbool.h>
 #include <pthread.h>
-#include <urcu/compiler.h>
 
 /*
  * Lock-free stack.
@@ -87,11 +72,26 @@ struct cds_lfs_stack {
  *
  * In C++, implement static inline wrappers using function overloading
  * to obtain an API similar to C.
+ *
+ * Avoid complaints from clang++ not knowing the transparent union
+ * attribute.
  */
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wignored-attributes"
+#endif
 typedef union {
 	struct __cds_lfs_stack *_s;
 	struct cds_lfs_stack *s;
-} caa_c_transparent_union cds_lfs_stack_ptr_t;
+} __attribute__((__transparent_union__)) cds_lfs_stack_ptr_t;
+
+typedef union {
+	const struct __cds_lfs_stack *_s;
+	const struct cds_lfs_stack *s;
+} __attribute__((__transparent_union__)) cds_lfs_stack_const_ptr_t;
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
 
 #ifdef _LGPL_SOURCE
 
@@ -146,7 +146,7 @@ extern void __cds_lfs_init(struct __cds_lfs_stack *s);
  *
  * No memory barrier is issued. No mutual exclusion is required.
  */
-extern bool cds_lfs_empty(cds_lfs_stack_ptr_t s);
+extern bool cds_lfs_empty(cds_lfs_stack_const_ptr_t s);
 
 /*
  * cds_lfs_push: push a node into the stack.
@@ -281,9 +281,25 @@ static inline cds_lfs_stack_ptr_t cds_lfs_stack_cast(struct cds_lfs_stack *s)
 	return ret;
 }
 
+static inline cds_lfs_stack_const_ptr_t cds_lfs_stack_const_cast(const struct __cds_lfs_stack *s)
+{
+	cds_lfs_stack_const_ptr_t ret = {
+		._s = s,
+	};
+	return ret;
+}
+
+static inline cds_lfs_stack_const_ptr_t cds_lfs_stack_const_cast(const struct cds_lfs_stack *s)
+{
+	cds_lfs_stack_const_ptr_t ret = {
+		.s = s,
+	};
+	return ret;
+}
+
 template<typename T> static inline bool cds_lfs_empty(T s)
 {
-	return cds_lfs_empty(cds_lfs_stack_cast(s));
+	return cds_lfs_empty(cds_lfs_stack_const_cast(s));
 }
 
 template<typename T> static inline bool cds_lfs_push(T s,