Thread: Help for the c error

I am having an annoy problem with errors:

processor.c:22: called object is not a function
processor.c:24: called object is not a function
processor.c:26: called object is not a function
processor.c:28: called object is not a function
processor.c:30: called object is not a function
processor.c:32: called object is not a function
processor.c:34: called object is not a function
processor.c:36: called object is not a function
processor.c:38: called object is not a function
processor.c:40: called object is not a function
processor.c:42: called object is not a function
processor.c:44: called object is not a function

The processor.c 's source code is like this:


#include <stdio.h>
#include "memory.h"
#include "processor.h"
#include "Instructions.h"

void execute(void)
{
int instructionRegister = 0;
int instruction = 0;
int operand = 0;
accumulator = 0;
instructionCounter = 0;
while(instructionCounter<size)
{
instructionRegister = readMemory(instructionCounter);
++instructionCounter;
instruction = instructionRegister/100;
operand = instructionRegister%100;
switch(instruction)
{
case read: read(operand);
break;
case write: write(operand);
break;
case load: load(operand);
break;
case store: store(operand);
break;
case add: add(operand);
break;
case substract: substract(operand);
break;
case divide: divide(operand);
break;
case multiply: multiply(operand);
break;
case branch: branch(operand);
break;
case branchNeg: branchNeg(operand);
break;
case branchZero: branchZero(operand);
break;
case halt: halt();
break;
}
}
}

All those "read", "write", "load" , ... functions are declared in the header file "Instructions.h". The Instruction.h is like following:

#define read 10
#define write 11
#define load 20
#define store 21
#define add 30
#define substract 31
#define divide 32
#define multiply 33
#define branch 40
#define branchNeg 41
#define branchZero 42
#define halt 43

void read(int);
void write(int);
void load(int);
void store(int);
void add(int);
void substract(int);
void divide(int);
void multiply(int);
void branch(int);
void branchNeg(int);
void branchZero(int);
void halt(void);

I really can't see why the compiler can't recognise all the functions in the Instruction.h header file???

The preprocessor performs textual replacement before anything else is done with the source code. That means all occurances of read, write, etc. will be replaced with integer literals. As an example, the following

Code:

case read: read(operand);

becomes

Code:

case 10: 10(operand);

That's why macros typically use all uppercase letters for their names. Repeat that explanation for everywhere the macros are defined and you shouldn't have trouble finding your errors.

thanks for the help. I have changed all te define in the Instruction header file, after the compilation, the new error messages come up like this:

snow:Cproject$ gcc processor.c
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crt1.o(.text+0x18): In function `_start':
../sysdeps/i386/elf/start.S:77: undefined reference to `main'
/tmp/ccko1gwi.o(.text+0x47): In function `execute':
: undefined reference to `readMemory'
/tmp/ccko1gwi.o(.text+0xe6): In function `execute':
: undefined reference to `load'
/tmp/ccko1gwi.o(.text+0xf9): In function `execute':
: undefined reference to `store'
/tmp/ccko1gwi.o(.text+0x10c): In function `execute':
: undefined reference to `add'
/tmp/ccko1gwi.o(.text+0x11f): In function `execute':
: undefined reference to `substract'
/tmp/ccko1gwi.o(.text+0x132): In function `execute':
: undefined reference to `divide'
/tmp/ccko1gwi.o(.text+0x145): In function `execute':
: undefined reference to `multiply'
/tmp/ccko1gwi.o(.text+0x158): In function `execute':
: undefined reference to `branch'
/tmp/ccko1gwi.o(.text+0x16b): In function `execute':
: undefined reference to `branchNeg'
/tmp/ccko1gwi.o(.text+0x17e): In function `execute':
: undefined reference to `branchZero'
/tmp/ccko1gwi.o(.text+0x18b): In function `execute':
: undefined reference to `halt'
collect2: ld returned 1 exit status

The "readMemory" function is declared in the "memory.h" header file which has been included in the "processor.c" file. The "memroy.h" file is like this:

#define size 100
int memory[size];
int readMemory(int);
void writeMemory(int, int);


For the rest of the functions are all declared in the "Instructions.h" header file which is also included in the "processor.c". The header file is like this now:

#define READ 10
#define WRITE 11
#define LOAD 20
#define STORE 21
#define ADD 30
#define SUBSTRUCT 31
#define DIVIDE 32
#define MULTIPLY 33
#define BRANCH 40
#define BRANCHNEG 41
#define BRANCHZERO 42
#define HALT 43

void read(int);
void write(int);
void load(int);
void store(int);
void add(int);
void substract(int);
void divide(int);
void multiply(int);
void branch(int);
void branchNeg(int);
void branchZero(int);
void halt(void);

The "processor.c" file is like this now:

#include <stdio.h>
//#include "Instructions.c"
#include "memory.h"
#include "processor.h"
#include "Instructions.h"

void execute(void)
{
int instructionRegister = 0;
int instruction = 0;
int operand = 0;
accumulator = 0;
instructionCounter = 0;
while(instructionCounter<size)
{
instructionRegister = readMemory(instructionCounter);
++instructionCounter;
instruction = instructionRegister/100;
operand = instructionRegister%100;
switch(instruction)
{
case READ: read(operand);
break;
case WRITE: write(operand);
break;
case LOAD: load(operand);
break;
case STORE: store(operand);
break;
case ADD: add(operand);
break;
case SUBSTRUCT: substract(operand);
break;
case DIVIDE: divide(operand);
break;
case MULTIPLY: multiply(operand);
break;
case BRANCH: branch(operand);
break;
case BRANCHNEG: branchNeg(operand);
break;
case BRANCHZERO: branchZero(operand);
break;
case HALT: halt();
break;
}
}
}

Can you see why the compiler still can't recognise the functions????

Have you actually written these functions or just prototyped them?