[PATCH 4/5] add three macros for empty dummy functions that do nothing

[Jens Gustedt <Jens.Gustedt@inria.fr>]

these are functions that receive arguments according to three different
interfaces, void, void* or int.

31	0	src/internal/libc.h

diff --git a/src/internal/libc.h b/src/internal/libc.h
index a097a66..1f15f4d 100644
--- a/src/internal/libc.h
+++ b/src/internal/libc.h
@@ -73,6 +73,37 @@ extern char **__environ;
 #define weak_alias(old, new) \
 	extern __typeof(old) new __attribute__((weak, alias(#old)))
 
+/* provide a weak function symbol for a function that receives no
+   arguments */
+#define WEAK_PROVIDE_VOID                       \
+_Weak                                           \
+void __weak_dummy_void(void) {                  \
+  /* empty */                                   \
+}                                               \
+/* syntax sugar */                              \
+_Weak void __weak_dummy_void(void)
+
+/* provide a weak function symbol for a function that receives a void
+   pointer argument */
+#define WEAK_PROVIDE_VOIDP                      \
+_Weak                                           \
+void __weak_dummy_voidp(void* _ign) {           \
+  /* empty */                                   \
+}                                               \
+/* syntax sugar */                              \
+_Weak void __weak_dummy_voidp(void*)
+
+/* provide a weak function symbol for a function that receives an int
+   argument */
+#define WEAK_PROVIDE_INT                        \
+_Weak                                           \
+void __weak_dummy_int(int _ign) {               \
+  /* empty */                                   \
+}                                               \
+/* syntax sugar */                              \
+_Weak void __weak_dummy_int(int _ign)
+
+
 #undef LFS64_2
 #define LFS64_2(x, y) weak_alias(x, y)
 
-- 
1.7.9.5