Problem with typedef struct, cannot malloc(sizeof(struct element)); unless at the top

Danny · #1 10-Sep-2005, 23:45

Here is the .c, THIS will work

CPP / C++ / C Code:

//DDList.c
#include <stdio.h>
#include <malloc.h>
#include "DLList.h"
void main() 
{
      p_addy2 temp2 = malloc(sizeof(struct element));
      p_addy temp = malloc(sizeof(struct element));
//      temp->next = NULL; // LOOK HERE <--------------------
      p_addy3 temp3 = malloc(sizeof(struct element));
      temp->next = NULL; // AND LOOK HERE <----------------
      temp->num = 5;

      printf("%i", temp->num);

      free(temp);
      free(temp2);
      free(temp3);
}

and the .h:

CPP / C++ / C Code:

//DLList.h

typedef struct element *p_addy3;
typedef struct element *p_addy2;
typedef struct element *p_addy;

struct element
{
      int num;
      struct element *prev;
      struct element *next;
};

BUT, this one will not work:

CPP / C++ / C Code:

//DDList.c
#include <stdio.h>
#include <malloc.h>
#include "DLList.h"
void main() 
{
      p_addy2 temp2 = malloc(sizeof(struct element));
      p_addy temp = malloc(sizeof(struct element));
      temp->next = NULL; // LOOK HERE <---------- this line is un-commented
      p_addy3 temp3 = malloc(sizeof(struct element));
//      temp->next = NULL; // AND LOOK HERE <----------------
      temp->num = 5;        //  ^^^ This line is commented

      printf("%i", temp->num);

      free(temp);
      free(temp2);
      free(temp3);
}

and the .h is the same.

compiler error:

Quote:

c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : error C2275: 'p_addy3' : illegal use of this type as an expression
c:\home\programming\CTestPrograms\DLList\DLList.h( 4) : see declaration of 'p_addy3'
c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : error C2146: syntax error : missing ';' before identifier 'temp3'
c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : error C2144: syntax error : '<Unknown>' should be preceded by '<Unknown>'
c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : error C2144: syntax error : '<Unknown>' should be preceded by '<Unknown>'
c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : error C2143: syntax error : missing ';' before 'identifier'
c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : error C2065: 'temp3' : undeclared identifier
c:\home\programming\CTestPrograms\DLList\DLList.c( 15) : warning C4047: '=' : 'int' differs in levels of indirection from 'void *'
c:\home\programming\CTestPrograms\DLList\DLList.c( 27) : warning C4022: 'free' : pointer mismatch for actual parameter 1

Build log was saved at "file://c:\home\programming\CTestPrograms\DLList\Debug\Bui ldLog.htm"
DLList - 6 error(s), 2 warning(s)

Keep in mind that temp has allready been malloc'ed, SOOOOO why won't the second one work? Do I have to do ALL my malloc'ing at the beginning of the function? I don't get it, temp has nothing to do with temp3 OR even p_addy3! Or does it...

Dr. Evil · #2 11-Sep-2005, 00:46

Maybe your compile dosn't allow nested declarations.

EDIT: I get the same type of thing with Borland, so it probably is the fact that it's nested.

Danny · #3 11-Sep-2005, 01:56

Quote:

Originally Posted by Dr. Evil

Maybe your compile dosn't allow nested declarations.

EDIT: I get the same type of thing with Borland, so it probably is the fact that it's nested.

OMG, that's right, I'm writing in C! I think only cpp allows declerations "willy nilly". Thanks. BTW, I'm using VC++ 2003 .NET

Thanks.

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