added panic, hello world and allocate

Author: Pyrolistical

allocate.py

@@ -0,0 +1,24 @@
+from cffi import FFI
+
+cffi = FFI()
+cffi.cdef(
+    """
+      char* allocByteArrayZ(long long size);
+      void printZ(char* messageZ);
+      void freeByteArrayZ(char* array);
+      bool detectLeaks();
+    """
+)
+
+import os
+
+allocate = cffi.dlopen(os.path.abspath("allocate.dll"))
+
+messageZ = allocate.allocByteArrayZ(5)
+messageZ[0:5] = b"hello"
+
+allocate.printZ(messageZ)
+
+allocate.freeByteArrayZ(messageZ)
+
+print("leaked: {leaked}".format(leaked=allocate.detectLeaks()))

allocate.zig

@@ -0,0 +1,20 @@
+const std = @import("std");
+var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+
+export fn allocByteArrayZ(size: u64) [*:0]u8 {
+    const arrayZ = gpa.allocator().allocSentinel(u8, size, 0) catch unreachable;
+    return arrayZ.ptr;
+}
+
+export fn printZ(message: [*:0]u8) callconv(.C) void {
+    std.debug.print("{s}\n", .{message});
+}
+
+export fn freeByteArrayZ(array: [*:0]u8) callconv(.C) void {
+    const len = std.mem.len(array);
+    gpa.allocator().free(array[0..len]);
+}
+
+export fn detectLeaks() bool {
+    return gpa.detectLeaks();
+}

hello-world.py

@@ -3,7 +3,7 @@
 cffi = FFI()
 cffi.cdef(
     """
-      void print(char* x);
+      void printZ(char* messageZ);
     """
 )
 
@@ -12,4 +12,4 @@
 helloWorld = cffi.dlopen(os.path.abspath("hello-world.dll"))
 
 # pass in null-terminated array
-helloWorld.print(b"Hello world\x00")
+helloWorld.printZ(b"Hello world\x00")

hello-world.zig

@@ -1,9 +1,9 @@
 const std = @import("std");
 
 // messageZ must be null-terminated
-export fn print(messageZ: [*]u8) void {
+export fn printZ(messageZ: [*]u8) void {
     // [*:0]u8 is not allowed by C ABI, cast to right type
     const message = @ptrCast([*:0]u8, messageZ);
 
-    std.debug.print("{s}", .{message});
+    std.debug.print("{s}\n", .{message});
 }

panic.py

@@ -0,0 +1,14 @@
+from cffi import FFI
+
+cffi = FFI()
+cffi.cdef(
+    """
+      void panic();
+    """
+)
+
+import os
+
+panic = cffi.dlopen(os.path.abspath("panic.dll"))
+
+print(panic.panic())

panic.zig

@@ -0,0 +1,3 @@
+export fn panic() void {
+    @panic("uh oh");
+}