CODEWITHSUNDEEP
csyntaxmacros
Kac
Kac

Reputation: 21

(Macro Creation) Syntax Error in C

I've already created the macros for the assignment, but cannot find the syntax error I get when running the program. Any ideas would be greatly appreciated, thanks.

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define ODD(X) ((X) & 01)
#define BITON(X,N) (((X) >> N) & 01)
#define ALLON(X,S,E) (((X) & ((((int) pow(2,(E-S))-1) << (E-S))) ^ (((int) pow(2,E-S)-1) << (E-S)))
//-----------------------------------------------------------------------------                                          
int main(void) {

  unsigned int U1,BitNumber,Start,End;

  printf("Enter an integer : ");
  scanf("%ud",&U1);
  printf("%u is %s\n",U1,ODD(U1)?"odd":"even");

  printf("Enter an integer and a bit number : ");
  scanf("%u %d",&U1,&BitNumber);
  printf("%u has bit %d %s\n",U1,BitNumber,BITON(U1,BitNumber)?"on":"off");

  printf("Enter an integer, start and end bit numbers : ");
  scanf("%u %u %u",&U1,&Start,&End);
  printf("%u has %s those bits on\n",U1,ALLON(U1,Start,End)?"all":"not all");

  return(EXIT_SUCCESS);
}

//-----------------------------------------------------------------------------

Error: 

BitOps.c: In function ‘main’:
BitOps.c:23:77: error: expected ‘)’ before ‘;’ token
   printf("%u has %s those bits on\n",U1,ALLON(U1,Start,End)?"all":"not all");
                                                                             ^
BitOps.c:26:1: error: expected ‘;’ before ‘}’ token
 }

Upvotes: 0

Views: 102

Answers (2)

zwol
zwol

Reputation: 140609

The macro definition of ALLON has an extra open parenthesis in it. The compiler can't be sure that it's wrong until it reaches the semicolon at the end of the line where ALLON is used, so the error message complains about that line (which is fine) rather than the definition of ALLON, but the definition of ALLON is where the problem is.

Upvotes: 1

Achal
Achal

Reputation: 11921

Enable -Wall flags and compile the code, its very informative, don't ignore it. There are few bugs in your code as

  • Better 01 replace with 0x1 that serve actual purpose.
  • Read the warning, BitNumber is declared as unsigned but %d format specifier is used. Compile your code with -Wall flag.
  • ALLON() macro expansion is not correct, which I correctly added below.

Here is expected one

#define ODD(X) ((X) & 0x1)
#define BITON(X,N) (((X) >> N) & 0x1)
#define ALLON(X,S,E) (((X) & ( ((((int) pow(2,(E-S))-1) << (E-S))) ^ (((int) pow(2,E-S)-1) << (E-S)))) )

int main(void) {

  unsigned int U1,BitNumber,Start,End;

  printf("Enter an integer : ");
  scanf("%u",&U1);
  printf("%u is %s\n",U1,ODD(U1)?"odd":"even");

  printf("Enter an integer and a bit number : ");
  scanf("%u %u",&U1,&BitNumber);
  printf("%u has bit %d %s\n",U1,BitNumber,BITON(U1,BitNumber)?"on":"off");

  printf("Enter an integer, start and end bit numbers : ");
  scanf("%u %u %u",&U1,&Start,&End);
  printf("%u has %s those bits on\n",U1,ALLON(U1,Start,End) ?"all":"not all");

  return(EXIT_SUCCESS);
}

Upvotes: 0

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