Trying to use vector with custom memory allocator

[leonsal]

Hi,

I am trying to use a vector with a custom memory allocator and I followed the example Per container-instance customization. I am probably doing something wrong because the compiler complains (see below). Is there something missing in the allocator definition ? Regards.

Errors from: clang -I stc/include -fsanitize=address,leak main.c my_alloc.c -o vec

stc/include/stc/cvec.h:311:36: error: too many arguments provided to function-like macro invocation
        _cx_value* d = (_cx_value*)i_realloc(self->data, cap*c_sizeof(i_key));
                                   ^
stc/include/stc/priv/template.h:51:21: note: expanded from macro 'i_realloc'
  #define i_realloc c_JOIN(i_allocator, _realloc)
                    ^
stc/include/stc/ccommon.h:50:22: note: expanded from macro 'c_JOIN'
#define c_JOIN(a, b) c_JOIN0(a, b)
                     ^
stc/include/stc/ccommon.h:49:23: note: expanded from macro 'c_JOIN0'
#define c_JOIN0(a, b) a ## b
                      ^
<scratch space>:32:1: note: expanded from here
alloc_realloc
^
./my_alloc.h:12:53: note: expanded from macro 'alloc_realloc'
#define alloc_realloc(p, sz)    my_realloc(c_extend(self)->ctx, p, sz)
                                                    ^
stc/include/stc/extend.h:59:9: note: macro 'c_extend' defined here
#define c_extend() c_container_of(self, _cx_MEMB(_ext), get)
        ^
In file included from main.c:13:
In file included from ./my_alloc.h:18:
In file included from stc/include/stc/extend.h:66:
stc/include/stc/cvec.h:311:36: error: use of undeclared identifier 'c_extend'
        _cx_value* d = (_cx_value*)i_realloc(self->data, cap*c_sizeof(i_key)

my_alloc.c

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

void* my_malloc(void* ctx, size_t sz) {
    printf("my_malloc(%p, %lu)\n", ctx, sz);
    return malloc(sz);
}

void* my_calloc(void* ctx, size_t n, size_t sz) {
    printf("my_calloc(%p, %lu, %lu)\n", ctx, n, sz);
    return calloc(n, sz);
}

void* my_realloc(void* ctx, void* p, size_t sz) {
    printf("my_realloc(%p, %p, %lu)\n", ctx, p, sz);
    return realloc(p, sz);
}

void my_free(void* ctx, void* p) {
    printf("my_free(%p, %p)\n", ctx, p);
    free(p);
}

my_alloc.h

#ifndef MY_ALLOC_H
#define MY_ALLOC_H
#include <stdlib.h>

void* my_malloc(void* ctx, size_t sz);
void* my_calloc(void* ctx, size_t n, size_t sz);
void* my_realloc(void* ctx, void* p, size_t sz);
void  my_free(void* ctx, void* p);

#define alloc_malloc(sz)        my_alloc(c_extend(self)->ctx, sz)
#define alloc_calloc(n, sz)     my_calloc(c_extend(self)->ctx, n, sz)
#define alloc_realloc(p, sz)    my_realloc(c_extend(self)->ctx, p, sz)
#define alloc_free(p)           my_free(c_extend(self)->ctx, p)

#define i_allocator     alloc
#define i_no_clone
#define i_extend        void* ctx;
#include "stc/extend.h"

#endif

main.c

#include <stdlib.h>
#include <stdint.h>

// Vector using standard allocator
#define i_type vi32
#define i_key  int32_t
#include "stc/cvec.h"

// Vector using "my allocator"
#define i_type vu32
#define i_base cvec
#define i_key  uint32_t
#include "my_alloc.h"

int main(int argc, char* argv[]) {

    vi32 v1;
    vi32_push(&v1, 1);
    vi32_drop(&v1);

    vu32_ext v2 = {.ctx = NULL};
    vu32_push(&v2.get, 1);
    vu32_drop(&v2.get);
    return 0;
}

[tylov]

Hi. Yes there is a bug in the docs, will fix it (point 1.).

1. c_extend() does not take any arguments (self is used internally).
2. You forgot to init v1 to {0};
3. STC uses purely signed integers for sizes and indices, i.e. also for the allocator functions - consider to change from size_t to intptr_t (or ptrdiff_t if you prefer) to avoid warning with -Wconversion, and cast to size_t in the calls to std alloc functions.

Otherwise, this works as expected.