From 21c794102c27d8474809cb54578941f8bbe63218 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= Date: Tue, 28 Feb 2012 11:22:11 +0100 Subject: [PATCH] Fix compiling C++ applications MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The compiler error is: /usr/include/bluetooth/bluetooth.h::131:9: error: invalid conversion from 'void*' to 'bt_get_le64(void*)::*' ... The reason is that C++, in contrast to C, does not allow conversion of void * to anything, and this code gets compiled as C++ when the app is written in C++. The macro with the assignment itself is older, but only recent Bluez starts to use it in inline functions, thus triggering the problem. This patch keeps the "struct __attribute__((packed))" magic and merely changes the typecast so that it works in C and C++. Like the existing macro this patch relies on support for typeof. The new variant of the code is in an ifdef and only used for C++ to avoid unexpected regressions in C applications. Signed-off-by: Patrick Ohly --- lib/bluetooth.h | 31 +++++++++++++++++++++++++++++++ 1 files changed, 31 insertions(+), 0 deletions(-) diff --git a/lib/bluetooth.h b/lib/bluetooth.h index 5bd4f03..3f1a177 100644 --- a/lib/bluetooth.h +++ b/lib/bluetooth.h @@ -109,6 +109,12 @@ enum { #endif /* Bluetooth unaligned access */ +#ifndef __cplusplus +/* + * traditional code, doesn't work in C++ because + * of the void * to struct pointer assignment + */ + #define bt_get_unaligned(ptr) \ ({ \ struct __attribute__((packed)) { \ @@ -125,6 +131,31 @@ do { \ __p->__v = (val); \ } while(0) +#else /* __cplusplus */ + +/* + * modified code with typeof typecast, for C++; + * the traditional code continues to be used for + * C to avoid unexpected regressions with this + * code here (it should work in C and C++, though) + */ +#define bt_get_unaligned(ptr) \ +({ \ + struct __attribute__((packed)) { \ + typeof(*(ptr)) __v; \ + } *__p = (typeof(__p)) (ptr); \ + __p->__v; \ +}) + +#define bt_put_unaligned(val, ptr) \ +do { \ + struct __attribute__((packed)) { \ + typeof(*(ptr)) __v; \ + } *__p = (typeof(__p)) (ptr); \ + __p->__v = (val); \ +} while(0) +#endif /* __cplusplus */ + #if __BYTE_ORDER == __LITTLE_ENDIAN static inline uint64_t bt_get_le64(void *ptr) { -- 1.7.7.6