Error during using enum in C

Question

I try to make enum for assembly instructions,

 typedef enum opcode {load, loada, store, mov, add, sub, mul, div, mod, cmp,   b, blt, ble, bne, beq, bge, bgt, read, write}OP_CODE;

but I get this error because, I think, some of the instruction is already define in C.

DEF.h:13:62: error: ‘div’ redeclared as different kind of symbol
 typedef enum opcode {load, loada, store, mov, add, sub, mul, div, mod, cmp, b, 

Does anyone know how to solve this problem. I cannot change the words or the case letters. Thanks

Answer 1

Since you are in C, cannot rename the words and cannot change the case, and you don't want also to mess with the libraries... no much choice.

You could create a struct

typedef struct {int load, loada, store, mov, add, sub, mul, div, mod, cmp, b,
                blt, ble, bne, beq, bge, bgt, read, write;
} OP_CODE;

Assign member values

OP_CODE op;
op.load  = 1;
op.loada = 2;
...

and use op.opcode wherever necessary.

---

Use #define

The other workaround which will do exactly what you want is not very clean

• the #define have to be declared after the headers includes
• you cannot use the definitions that you define from the libraries anymore

for instance

#include <stdlib.h>
...
#define load  1
#define loada 2
....

Then you can use the names as is

if (opcode == div) { 
    // do div stuff
}

Not recommended but if you have to use the names as they are in C, that's the solution (note that a few defines are used a lot in C, like read and write to name two, to read and write files).

Answer 2

div is a library function, so you should not use the same name. So you should "change the words or the case letters" (or change the compiler to C++ and use namespace to isolate your enumeration).

You can rename all members of your enum, e.g.

 typedef enum opcode {LOAD, LOADA, STORE, MOV, ADD, SUB, MUL, DIV, MOD, CMP, B, BLT, BLE, BNE, BEQ, BGE, BGT, READ, WRITE} OP_CODE;

or

 typedef enum opcode {op_load, op_loada, op_store, op_mov, op_add, op_sub, op_mul, op_div, op_mod, op_cmp, op_b, op_blt, op_ble, op_bne, op_beq, op_bge, op_bgt, op_read, op_write} OP_CODE;

I prefer the last option (with prefix added to names of all values of opcode)