CODEWITHSUNDEEP
cmacros
michaelAdam
michaelAdam

Reputation: 1137

error: expected statement before ‘)’ token in C macro

#define ALIGNMENT 8

#define CHUNK_SIZE (1<<12) //Extend heap by this amount (bytes)
#define WSIZE 4
#define DSIZE 8
#define MIN_BLOCK_SIZE (4*WSIZE) //Should it require at least 1 word of payload?

#define MAX(x,y) ((x) > (y) ? (x) : (y))

//Pack a size and allocated bit into a word
//#define PACK(size, alloc) ((size << 1 ) | (alloc))

//Read and write a word at address p
#define GET(p) (*(unsigned int*)(p))
#define PUT(p,val) (*(unsigned int *)(p) = (val))

//Read the size and allocated fields from address p
#define GET_SIZE(hp) (GET(hp)) //alli has doubts
//#define GET_ALLOC(hp) (GET(hp) & 0x1) 
//Get next and prev block pointers from a block
#define GET_NEXT(hp) ((char*)(hp)+2*WSIZE)
#define GET_PREV(hp) ((char*)(hp)+1*WSIZE)

//Given block ptr bp, compute address of its header and footer
//Should we ever reference a block ptr in an explicit list?
#define HDRP(bp) ((char*)(bp) - 3 * WSIZE))
#define FTRP(bp) ((char*)(bp) + GET_SIZE(HDRP(bp)))
#define BP(hp) ((char*)(hp) + (3 * WSIZE))

/* rounds up to the nearest multiple of ALIGNMENT */
#define ALIGN(size) (((size) + (ALIGNMENT-1)) & ~0x7)


#define SIZE_T_SIZE (ALIGN(sizeof(size_t)))

I am getting

error: expected statement before ‘)’ token in C macro

One place where I use PUT is:

static int extend_heap(size_t words) {
char* hp;
size_t size;

//This returns a ptr to the HEADER of the list allocatable block
void* last_block = find_end_of_free_list();
void* tail = GET_NEXT(last_block);



 //Only allocate an even number of words to maintain alignment
  size = (words % 2) ? (words+1) * WSIZE : words * WSIZE;
  if((long)(hp = mem_sbrk(size)) == -1)
    return -1;

  //Maybe we should make a function (create header/create footer when given an address)
  PUT(hp, size); //Free block header
  PUT(FTRP(BP(hp)), size); //Free block footer

  PUT(GET_PREV(hp), last_block); //Make prev of new block point to end of old list
  PUT(GET_NEXT(hp), tail); //Make next of new block point to tail

  PUT(GET_NEXT(last_block), hp); // Make next of old list point to new list
  return 0;
}

I am getting the error on PUT.
In extend_heap I get another error:

mm.c:121:3: note: in expansion of macro ‘PUT’ PUT(FTRP(BP(hp)), size); //Free block footer ^ mm.c:53:49: error: expected statement before ‘)’ token #define PUT(p,val) (*(unsigned int *)(p) = (val))

I included the code above PUT because I thought the error might be due to syntax of something above it.

Upvotes: 0

Views: 9989

Answers (1)

Gopi
Gopi

Reputation: 19864

The bug is in line:

#define HDRP(bp) ((char*)(bp) - 3 * WSIZE))

This has a extra ) at the end.Which should be removed. Since in PUT you are using FTRP() macro and before this macro is HDRP() we see this error. Removing the extra ) will solve your problem.

Upvotes: 1

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