Clang version 3.4.2 does not know the -Wpragmas option yet and bails out with an error when we try to disable it in linux-user/qemu.h. Fortunately, clang has a __has_warning() macro which allows us to add an explicit check for this option to fix this issue.
Fixes: 850d5e330a9c68cc998cecc02caf8a3c8d1ee8a3 Signed-off-by: Thomas Huth <th...@redhat.com> --- Today, I noticed that building the linux-user targets is currently also not working with Clang 3.4 anymore ... so in case we will roll out 3.1-rc4, I think this patch should be considered, too. Otherwise, this certainly does not justify another rc, so it can also be added later via stable. include/qemu/compiler.h | 4 ++++ linux-user/qemu.h | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 6b92710..ca9bc85 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -119,6 +119,10 @@ #define GCC_FMT_ATTR(n, m) #endif +#ifndef __has_warning +#define __has_warning(x) 0 /* compatibility with non-clang compilers */ +#endif + #ifndef __has_feature #define __has_feature(x) 0 /* compatibility with non-clang compilers */ #endif diff --git a/linux-user/qemu.h b/linux-user/qemu.h index dd5771c..c7b3c37 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -481,7 +481,7 @@ static inline int access_ok(int type, abi_ulong addr, abi_ulong size) * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only * include the warning-suppression pragmas for clang */ -#ifdef __clang__ +#if defined(__clang__) && __has_warning("-Wpragmas") #define PRAGMA_DISABLE_PACKED_WARNING \ _Pragma("GCC diagnostic push"); \ _Pragma("GCC diagnostic ignored \"-Wpragmas\""); \ -- 1.8.3.1
