Boolean (or int) returned by a function that allocates memory on the heap

[serge-hulne]

So that lack of de-allocation can be inferred automatically at compile time (without impact on runtime performance)... and optionally displayed in the code editor.

[nalgeon]

If you're talking about detecting "alloc-without-free" situations at compile time, that's not possible.

As for allocation functions, there's mem.TryAlloc, which returns an error if the allocation fails.

[serge-hulne]

I understand. What about, instead, returning an additional integer, holding the value of the amount of memory allocated by a function when it is called, so that, it would be possible to calculate (optionally) the total amount of memory in use at any time, and in particular make sure that all memory is released before the program exists. C3, Odin and Zig have allocators which check for memory leaks (in debug mode).

[nalgeon]

That would be a poor man's version of AddressSanitizer, which can check for such leaks and many other problems. I suggest you simply enable it by adding -fsanitize=address to the CFLAGS environment variable if you are using GCC.

For example, if you have this leaky program:

package main

import "solod.dev/so/mem"

type Point struct {
	X int
	Y int
}

func main() {
	p := mem.Alloc[Point](nil)
	p.X = 10
	p.Y = 20
	println(p.X, p.Y)
}

And you run it with the address sanitizer enabled:

CFLAGS="-O1 -g -fsanitize=address" so run .

You'll immediately see the problem:

=================================================================
==1==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0xffffa13ffc0c in calloc (/usr/local/lib64/libasan.so.8+0xcfc0c)
    #1 0x0000004030ec in mem_SystemAllocator_Alloc generated/so/mem/mem.c:144
    #2 0x000000403e40 in main generated/main.c:6
    #3 0xffffa10e2218  (/lib/aarch64-linux-gnu/libc.so.6+0x22218) (BuildId: 94ff8ab28d4939c80a3e048c763805a37e51edc5)
    #4 0xffffa10e22f8 in __libc_start_main (/lib/aarch64-linux-gnu/libc.so.6+0x222f8) (BuildId: 94ff8ab28d4939c80a3e048c763805a37e51edc5)
    #5 0x0000004019ac in _start (/src/main+0x4019ac)

SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).

[serge-hulne]

That seems to be a much better solution indeed. Thanks!
What about adding these flags into So's command-line, something like:
so --debug
(or something of that sort)?

[nalgeon]

I like CFLAGS — it's a more flexible approach.

[serge-hulne]

Sure, it's available and pragmatic, but it would be nice from the use's point of view to have it available out-of-the-box, C3, Odin, Zig have variants of a 'debug allocator' as a standard feature.