Are there any C preprocessor variables?

Question

Is there anything like a preprocessor variable in C? It could simplify my definitions.

Currently I have something like this:

typedef struct mystruct {
  int val1;
  int val2;
  int val3;
  int val4;
} MYSTRUCT;

typedef struct mysuperstruct {
  MYSTRUCT *base;
  int val;
} MYSUPERSTRUCT;


#define MY_OBJECT_BEGIN(name, val1, val2, val3, val4) \
  MYSTRUCT name##Base = { val1, val2, val3, val4 }; \
  MYSUPERSTRUCT * name##Objs = {

#define MY_OBJECT_VALUE(name, val) \
  { &(name##Base), val },

#define MY_OBJECT_END() \
  NULL \
};

It is used this way:

MY_OBJECT_BEGIN(obj1, 1, 2, 3, 4)
MY_OBJECT_VALUE(obj1, 5)
MY_OBJECT_VALUE(obj1, 6)
MY_OBJECT_VALUE(obj1, 7)
MY_OBJECT_END()

Which generates something like this:

MYSTRUCT obj1Base = { 1, 2, 3, 4 };
MYSUPERSTRUCT * obj1Objs = {
  { &(obj1Base), 5 },
  { &(obj1Base), 6 },
  { &(obj1Base), 7 },
  NULL
}

It's obvious that repetitive use of the object name is redundant. I would like to store the name in the MY_OBJECT_BEGIN definition to some preprocessor variable so that I can use it the following way:

MY_OBJECT_BEGIN(obj1, 1, 2, 3, 4)
MY_OBJECT_VALUE(5)
MY_OBJECT_VALUE(6)
MY_OBJECT_VALUE(7)
MY_OBJECT_END()

Does standard C preprocessor provide a way to achieve this?

Answer 1

There are no standard C preprocessor variables. As Oli Charlesworth suggested, using X-Macros is probably your best bet if you want to keep it just with standard C. If there really is a lot of associated data that would touch several files, you'll want to use a code generator like GNU autogen.