DJGPP Compiler Warning...

[chrisa128]

warning: passing arg 1 of 'memcpy' discards qualifiers from pointer target type

Can anyone give me any ideas on fixing this?

[Tim]

You've probably done something like this:

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const char *str = "Hello ";
mempcy(str, "World", 6);

memcpy() is prototyped as:

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void *memcpy(void *dest, const void *src, size_t bytes);

...so by passing const char* as the first parameter, you're discarding the const qualifier.

[chrisa128]

My memcpy is as follows...

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void *memcpy(void *dst_ptr, const void *src_ptr, unsigned count)
{
   void *ret_val = dst_ptr;
   const char *src = (const char *)src_ptr;
   char *dst = (char *)dst_ptr;
   for(; count != 0; count--)
      *dst++ = *src++;
   return ret_val;
}

The code I am calling it from is

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static volatile virtual_stream virtual_sessions[10];

FILE *retval = kmalloc(sizeof(FILE));

memcpy(&virtual_sessions[totalvirt].substream, retval, sizeof(FILE));

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typedef struct
{
   char *truepath;
   int objid;
   FILE substream;
} virtual_stream;

typedef struct
{
   int type, id;
   int location;
   int mode;
} FILE;

[Tim]

OK, discarding 'volatile' isn't as bad as discarding 'const'. Cast the pointer, removing volatile, and you should be fine. It's generally not a good idea to shut the compiler up by inserting casts, but as long as you understand why, it's OK.