C99 inline functions are useful whenever a function provide an
abstraction that is generally expected to be inlined away, but
yet a function pointer might be needed. One such case is function
passed to GCC's cleanup attribute.
Unfortunately, C99 inline functions clash a bit with -Wredundant-decls.
Provide a helper macro to hide the ugliness.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
include/qemu/compiler.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 340e5fdc09..e02b73b9e2 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -94,6 +94,21 @@
#define QEMU_BUILD_BUG_ON_ZERO(x) (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)))
+/* Provide an extern declaration for a C99 inline function. This can
+ * be simply placed in a C file but, unfortunately, this means the
+ * declaration comes after the inline definition, and GCC thus
+ * stubbornly raises a -Wredundant-decls warning.
+ *
+ * Putting the declaration before the header would be uglier (it couldn't
+ * just use typeof) and not always possible if the function requires types
+ * that are defined in the header. Therefore, we just shut up the warning.
+ */
+#define QEMU_EXTERN_INLINE(func) \
+ _Pragma("GCC diagnostic push"); \
+ _Pragma("GCC diagnostic ignored \"-Wredundant-decls\""); \
+ extern typeof(func) func; \
+ _Pragma("GCC diagnostic pop") \
+
#if defined __GNUC__
# if !QEMU_GNUC_PREREQ(4, 4)
/* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
--
2.14.3
