Fix fakegen.rb C header generator for M macro compatibility.

fakegen.rb

@@ -405,6 +405,11 @@ def include_guard
   putd "#endif /* FAKE_FUNCTIONS */"
 end
 
+def msvc_expand_macro_fix
+    putd "/* MSVC expand macro fix */"
+    putd "#define EXPAND(x) x"
+end
+
 def generate_arg_sequence(args, prefix, do_reverse, joinstr)
  fmap = (0..args).flat_map {|i| [prefix + i.to_s]}
  if do_reverse then fmap.reverse.join(joinstr) else fmap.join(", ") end
@@ -416,25 +421,26 @@ def counting_macro_instance(type, vararg = :non_vararg, prefix = "")
 
   <<-MACRO_COUNTING_INSTANCE
 #define #{prefix}FAKE_#{type.to_s}_FUNC#{appendix}(...) \
-    #{prefix}FUNC_#{type.to_s}#{appendix}_(PP_NARG_MINUS#{minus_count}(__VA_ARGS__), __VA_ARGS__)
+    EXPAND(#{prefix}FUNC_#{type.to_s}#{appendix}_(PP_NARG_MINUS#{minus_count}(__VA_ARGS__), __VA_ARGS__))
 
 #define #{prefix}FUNC_#{type.to_s}#{appendix}_(N,...) \
-    #{prefix}FUNC_#{type.to_s}#{appendix}_N(N,__VA_ARGS__)
+    EXPAND(#{prefix}FUNC_#{type.to_s}#{appendix}_N(N,__VA_ARGS__))
 
 #define #{prefix}FUNC_#{type.to_s}#{appendix}_N(N,...) \
-    #{prefix}FAKE_#{type.to_s}_FUNC ## N#{" ## _VARARG" if vararg == :vararg}(__VA_ARGS__)
+    EXPAND(#{prefix}FAKE_#{type.to_s}_FUNC ## N#{" ## _VARARG" if vararg == :vararg}(__VA_ARGS__))
 
   MACRO_COUNTING_INSTANCE
 end
 
 def output_macro_counting_shortcuts
+  msvc_expand_macro_fix
   putd <<-MACRO_COUNTING
 
 #define PP_NARG_MINUS2(...) \
-    PP_NARG_MINUS2_(__VA_ARGS__, PP_RSEQ_N_MINUS2())
+    EXPAND(PP_NARG_MINUS2_(__VA_ARGS__, PP_RSEQ_N_MINUS2()))
 
 #define PP_NARG_MINUS2_(...) \
-    PP_ARG_MINUS2_N(__VA_ARGS__)
+    EXPAND(PP_ARG_MINUS2_N(__VA_ARGS__))
 
 #define PP_ARG_MINUS2_N(returnVal, #{generate_arg_sequence($MAX_ARGS, '_', false, ", ")}, N, ...)   N
 
@@ -443,10 +449,10 @@ def output_macro_counting_shortcuts
 
 
 #define PP_NARG_MINUS1(...) \
-    PP_NARG_MINUS1_(__VA_ARGS__, PP_RSEQ_N_MINUS1())
+    EXPAND(PP_NARG_MINUS1_(__VA_ARGS__, PP_RSEQ_N_MINUS1()))
 
 #define PP_NARG_MINUS1_(...) \
-    PP_ARG_MINUS1_N(__VA_ARGS__)
+    EXPAND(PP_ARG_MINUS1_N(__VA_ARGS__))
 
 #define PP_ARG_MINUS1_N(#{generate_arg_sequence($MAX_ARGS, '_', false, ", ")}, N, ...)   N