Add "FFF_FUNCTION_ATTRIBUTES" definition that can be used to declare attributes for functions. More specifically, allow __weak__ attribute.

README.md

@@ -603,6 +603,18 @@ DEFINE_FAKE_VALUE_FUNC_VARARG(int, value_function_vargs, const char *, int, ...)
 DEFINE_FAKE_VOID_FUNC_VARARG(void_function_vargs, const char *, int, ...);
 
 ```
+## How simplify test linking
+
+You can define 
+```
+#define FFF_FUNCTION_ATTRIBUTES __attribute__((weak)) 
+#include "fff.h"
+```
+
+This will cause all of the fake functions to be declared with weak attribute. This causes that during link time a weak object (fake function) is replaced with non-weak (real function).
+
+You can use this so that you link all the fake objects into single fake-archive (compiled once) and then when a single real_implementation.c you can link with the fake-archive. During the link time the all other functions will be the fake ones, except the ones defined in real_implementation.c (that are non-weak).
+
 
 ## Find out more...
 

fakegen.rb

@@ -26,6 +26,13 @@ def output_constants
     putd "#define FFF_CALL_HISTORY_LEN (#{$MAX_CALL_HISTORY}u)"
   }
   putd "#endif"
+  # If user has defined functions to have some attributes, use those. If not, define as empty so it wont affect others.
+  putd "#ifndef FFF_FUNCTION_ATTRIBUTES"
+  indent {
+     putd "#define FFF_FUNCTION_ATTRIBUTES"
+  }
+  putd "#endif"
+  
 end
 
 
@@ -384,8 +391,8 @@ def function_signature(arg_count, has_varargs, has_calling_conventions, is_value
   return_type = is_value_function ? "RETURN_TYPE" : "void"
   varargs = has_varargs ? ", ..." : ""
   calling_conventions = has_calling_conventions ?
-    "#{return_type} CALLING_CONVENTION FUNCNAME(#{arg_val_list(arg_count)}#{varargs})" :
-    "#{return_type} FUNCNAME(#{arg_val_list(arg_count)}#{varargs})"
+    "#{return_type} FFF_FUNCTION_ATTRIBUTES CALLING_CONVENTION FUNCNAME(#{arg_val_list(arg_count)}#{varargs})" :
+    "#{return_type} FFF_FUNCTION_ATTRIBUTES FUNCNAME(#{arg_val_list(arg_count)}#{varargs})"
 end
 
 def output_function_body(arg_count, has_varargs, is_value_function)