From 32fd31934c32f55a2e42f56172ad1cb8e2c5e148 Mon Sep 17 00:00:00 2001
From: Philippe Pittoli <karchnu@karchnu.fr>
Date: Fri, 13 Jan 2023 02:05:17 +0100
Subject: [PATCH] Example code: first steps towards C bindings.

---
 zig-impl/drop/build.zig    |  2 ++
 zig-impl/drop/src/main.zig | 18 ++++++++++++++++--
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/zig-impl/drop/build.zig b/zig-impl/drop/build.zig
index 7e83769..bf66010 100644
--- a/zig-impl/drop/build.zig
+++ b/zig-impl/drop/build.zig
@@ -7,11 +7,13 @@ pub fn build(b: *std.build.Builder) void {
 
     const lib = b.addStaticLibrary("ipc", "src/main.zig");
     lib.setOutputDir("build");
+    lib.linkLibC();
     lib.setBuildMode(mode);
     lib.install();
 
     const solib = b.addSharedLibrary("ipc", "src/main.zig", b.version(0, 0, 1));
     solib.setOutputDir("build");
+    solib.linkLibC();
     solib.setBuildMode(mode);
     solib.install();
 
diff --git a/zig-impl/drop/src/main.zig b/zig-impl/drop/src/main.zig
index 7c98d29..9cf93f3 100644
--- a/zig-impl/drop/src/main.zig
+++ b/zig-impl/drop/src/main.zig
@@ -1,6 +1,8 @@
 const std = @import("std");
 const testing = std.testing;
 
+const print = std.debug.print;
+
 const SOMESTRUCT = packed struct {
     somevalue: i32,
     const Self = @This();
@@ -11,8 +13,20 @@ const SOMESTRUCT = packed struct {
     }
 };
 
-export fn some_struct_bidouillage_init() callconv(.C) SOMESTRUCT {
-    return SOMESTRUCT {.somevalue = 2};
+export fn some_struct_bidouillage_init(ptr: *anyopaque) callconv(.C) void {
+    var pointer = @ptrCast(*SOMESTRUCT, @alignCast(@alignOf(SOMESTRUCT),ptr));
+    var somestruct = std.heap.c_allocator.create(SOMESTRUCT) catch null;
+
+    print ("hello we just did something\n", .{});
+    if (somestruct) |s| {
+        s.somevalue = 2;
+        print ("just changed a value\n", .{});
+        pointer.* = s.*;
+    }
+    print ("hello again\n", .{});
+//    else {
+//        pointer.* = null;
+//    }
 }
 
 export fn some_struct_bidouillage_update(s: *SOMESTRUCT) callconv(.C) i32 {