Zalloc

Replace malloc, calloc, realloc and free in a c module with a zig allocator. Usefull in order to use zigs debug allocator when interacting with C code to check for memory leaks, double frees and all its features. In Release modes it is probably just unnecessary if you pass it the gpa from juice main.

Usage

zig fetch --save git+https://github.com/D-Berg/zalloc.git

const zalloc = @import("zalloc");

pub fn build(b: *std.Build) !void {

    //...

    // add it as a dependency
    const zalloc_dep = b.dependency("zalloc", .{
        .optimize = optimize,
        .target = target,
    });

    // Example c lib, shoutout to md4c
    const md4c_mod = b.addModule("md4c", .{
        .target = target,
        .optimize = optimize,
        .link_libc = true,
    });

    // this overwrites malloc, calloc, realloc and free in 
    // all c source files in the c module and will only affect that module.
    zalloc.infect(md4c_mod);

    // import the and link zalloc to your exe
    exe_mod.addImport("zalloc", zalloc_dep.module("zalloc"));
    exe_mod.linkLibrary(zalloc_dep.artifact("zalloc"));
}

const zalloc = @import("zalloc");

pub fn main(init: std.Io.Init) !void {
    // Specify which allocator the c library will use
    // DO this before calling any of the c functions.
    // Forgetting this will lead to allocations returning null.
    zalloc.allocator = init.gpa;
    zalloc.io = init.io;

    // ...

    // now md4c will use zigs debug allocator.
    const rc = md4c.md_html(
        markdown.ptr,
        @intCast(markdown.len),
        processHtml,
        null,
        md4c.MD_FLAG_COLLAPSEWHITESPACE,
        0,
    );
    if (rc != 0) return error.FailedToParseMarkdown;
}