fixes

examples/issue-0017.sx

@@ -0,0 +1,53 @@
+// issue-0017: Investigate data corruption in callconv(.c) callbacks
+//             when accessing struct methods on global pointers.
+
+#import "modules/std.sx";
+
+Pipe :: struct {
+    pw: s32;
+    ph: s32;
+    frame: s32;
+
+    resize :: (self: *Pipe, nw: s32, nh: s32) {
+        self.pw = nw;
+        self.ph = nh;
+    }
+
+    tick :: (self: *Pipe) {
+        self.frame = self.frame + 1;
+    }
+}
+
+g_pipe : *Pipe = ---;
+g_width  : s32 = 800;
+g_height : s32 = 600;
+
+do_render :: () {
+    g_pipe.resize(g_width, g_height);
+    g_pipe.tick();
+    print("wrapper: pw={}, ph={}, frame={}\n", g_pipe.pw, g_pipe.ph, g_pipe.frame);
+}
+
+callback_inline :: (userdata: *void, code: s64) -> bool callconv(.c) {
+    g_width = xx code;
+    g_height = xx (code + 1);
+    g_pipe.resize(xx g_width, xx g_height);
+    g_pipe.tick();
+    print("inline:  pw={}, ph={}, frame={}\n", g_pipe.pw, g_pipe.ph, g_pipe.frame);
+    true;
+}
+
+callback_wrapper :: (userdata: *void, code: s64) -> bool callconv(.c) {
+    g_width = xx code;
+    g_height = xx (code + 1);
+    do_render();
+    true;
+}
+
+main :: () {
+    pipe := Pipe.{ pw = 0, ph = 0, frame = 0 };
+    g_pipe = @pipe;
+
+    callback_inline(xx 0, 320);
+    callback_wrapper(xx 0, 640);
+}