From: Roman Kiryanov <r...@google.com>
to use the QEMU headers with a C++ compiler.
Signed-off-by: Felix Wu <f...@google.com>
Signed-off-by: Roman Kiryanov <r...@google.com>
---
include/qemu/atomic.h | 8 ++++++++
include/qemu/atomic.hpp | 38 ++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+)
create mode 100644 include/qemu/atomic.hpp
diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index 99110abefb..aeaecc440a 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -20,6 +20,13 @@
/* Compiler barrier */
#define barrier() ({ asm volatile("" ::: "memory"); (void)0; })
+#ifdef __cplusplus
+
+#ifndef typeof_strip_qual
+#error Use the typeof_strip_qual(expr) definition from atomic.hpp on C++
builds.
+#endif
+
+#else /* __cpluplus */
/* The variable that receives the old value of an atomically-accessed
* variable must be non-qualified, because atomic builtins return values
* through a pointer-type argument as in __atomic_load(&var, &old, MODEL).
@@ -61,6 +68,7 @@
__builtin_types_compatible_p(typeof(expr), const volatile unsigned
short), \
(unsigned short)1,
\
(expr)+0))))))
+#endif /* __cpluplus */
#ifndef __ATOMIC_RELAXED
#error "Expecting C11 atomic ops"
diff --git a/include/qemu/atomic.hpp b/include/qemu/atomic.hpp
new file mode 100644
index 0000000000..5844e3d427
--- /dev/null
+++ b/include/qemu/atomic.hpp
@@ -0,0 +1,38 @@
+/*
+ * The C++ definition for typeof_strip_qual used in atomic.h.
+ *
+ * Copyright (C) 2024 Google, Inc.
+ *
+ * Author: Roman Kiryanov <r...@google.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ * See docs/devel/atomics.rst for discussion about the guarantees each
+ * atomic primitive is meant to provide.
+ */
+
+#ifndef QEMU_ATOMIC_HPP
+#define QEMU_ATOMIC_HPP
+
+#include <type_traits>
+
+/* Match the integer promotion behavior of typeof_strip_qual, see atomic.h */
+template <class T> struct typeof_strip_qual_cpp { using result =
decltype(+T(0)); };
+
+template <> struct typeof_strip_qual_cpp<bool> { using result = bool; };
+template <> struct typeof_strip_qual_cpp<signed char> { using result = signed
char; };
+template <> struct typeof_strip_qual_cpp<unsigned char> { using result =
unsigned char; };
+template <> struct typeof_strip_qual_cpp<signed short> { using result = signed
short; };
+template <> struct typeof_strip_qual_cpp<unsigned short> { using result =
unsigned short; };
+
+#define typeof_strip_qual(expr) \
+ typeof_strip_qual_cpp< \
+ std::remove_cv< \
+ std::remove_reference< \
+ decltype(expr) \
+ >::type \
+ >::type \
+ >::result
+
+#endif /* QEMU_ATOMIC_HPP */
--
2.45.2.741.gdbec12cfda-goog
