[PATCH][GOLD] Fix build breakage on OSX due to unintended macro substitution.

[Doug Kwan (關振德)]

Hi,

    This is fixes one of the problems that break OSX build of gold.
The problem is caused by an implicit inclusion of assert.h in library
headers we use and a use of assert as an argument to the macro
DEFINE_var.

-Doug

2010-01-10  Doug Kwan  <dougkwan@google.com>

        * options.h (EMPTY_PARAMETER_LIST): New macro.
        (DEFINE_var): Use EMPTY_PARAMETER_LIST to avoid unintended subsequent
        macro substitutions.
-------------- next part --------------
Index: gold/options.h
===================================================================
RCS file: /cvs/src/src/gold/options.h,v
retrieving revision 1.136
diff -u -p -r1.136 options.h
--- gold/options.h	7 Jan 2010 18:31:30 -0000	1.136
+++ gold/options.h	11 Jan 2010 05:04:57 -0000
@@ -238,6 +238,13 @@ struct Struct_special : public Struct_va
 
 }  // End namespace options.
 
+// This is defined to avoid unintended macro substitutions in DEFINE_var below.
+// On Mac OSX, assert.h is included transitively by some other library headers
+// we use.   We need to use EMPTY_PARAMETER_LIST to avoid assert() being
+// substituted as a macro when the "assert" command line option is defined.
+// Note that this only deals with function-like macros.
+
+#define EMPTY_PARAMETER_LIST	()
 
 // These are helper macros use by DEFINE_uint64/etc below.
 // This macro is used inside the General_options_ class, so defines
@@ -249,7 +256,7 @@ struct Struct_special : public Struct_va
                    optional_arg__, type__, param_type__, parse_fn__)	     \
  public:                                                                     \
   param_type__                                                               \
-  varname__() const                                                          \
+  varname__ EMPTY_PARAMETER_LIST const                                       \
   { return this->varname__##_.value; }                                       \
                                                                              \
   bool                                                                       \