Strange Malloc Problem

[Zetr0]

Greetings fellow z88dk'ers

Going through tidying up code and ( attempting ) to make it more modular I decided to use memory allocation ( stdlib.h ) function "malloc" to assert structures and sizes as opposed to direct declaration of vectors / structures

Imagine my surprise when I was met with errors - it must be a Saturday

Host System:

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System : Linux / Ubuntu x86 64
z88dk version : z88dk Cross-C Compiler - v22110-51889e5300-20231219

Code : malloctest.c

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/*
        Malloc Test
*/

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

int main( void )
{
    char *ptr;

    ptr = ( char* ) malloc( 400 * sizeof( char ) );  // allocated 

    if( ptr == NULL )
    {
        printf("Error : ptr == NULL ");
    }
    else
    {
        printf("Success : ptr != NULL ");
    }

    free( ptr );

    return 0;

}

// EOF

Compile Line: ( executable shell script ) "make.sh"

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#!/bin/bash
z88dk.zcc +zx -lp3 -DPLUS3 -lm -create-app malloctest.c > build.txt

Compile Error:

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alloc/malloc-classic/free.asm:25: error: undefined symbol: _heap
  ^---- _heap
alloc/malloc-classic/malloc.asm:27: error: undefined symbol: _heap
  ^---- _heap

I am unsure what is going on as an error but I suspect I have to link these in another way or include another header descriptor for the symbol: _heap

I would appreciate any clues on how I messed up

Thanks for reading

[dom]

I would appreciate any clues on how I messed up

Try here: https://github.com/z88dk/z88dk/wiki/Cla ... ry-malloch

Note that some of those initialisation methods have been added in the past week or so. For the version you're on -DAMALLOC is the answer.

[Zetr0]

@dom
A huge thanks sir, I do so appreciate the heads up.

from my perspective, instead of adding <stdlib.h> to my build and then additionally configuring a pragma - I might as well declare a large 6-8k byte array ( since that's what I am working with ) and store all the graphical data in there.

Then using a structure ( like this )

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struct BITMAP
{
    ubyte *imgdata;
    uword byte_size;
    ubyte byte_width;
    ubyte byte_height;
};

ubyte gfx_data[8000];

struct BITMAP cave_wall[5];

I can then assign to cave_wall[ n ].imgdata the location of the gfx_data[ n ];

unless there is a limit of array size? ( I was keeping in mind the 8k page size )

[dom]

No worries.

There's no limit to the size of the array apart from how much memory you've got available.

[Zetr0]

@dom

No worries.

There's no limit to the size of the array apart from how much memory you've got available.

Would this mean I could do something quite crazy like declaring -

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ubyte wadfile[64000];
ubyte music[32000];

and then use pointers indexing these arrays without impunity on a 128k Spectrum +3 ( +3e ) ?

[dom]

If you want that much, then have a read of the __far thread: viewtopic.php?f=16&t=11937

You can allocate up to 65534 bytes in one block with that.