Fixes alignment

Author: Timmy Silesmo

crates/csharp/src/function.rs

@@ -882,15 +882,22 @@ impl Bindgen for FunctionBindgen<'_, '_> {
                 );
                 let ret_area = self.locals.tmp("retArea");
 
+                let array_size = if align > 1 { 
+                    // Add one additional element in case the starting address is not aligned
+                    format!("{array_size} * {list}.Count + 1")
+                } else {
+                    format!("{array_size} * {list}.Count")
+                };
+
                 match realloc {
                     None => {
                         self.needs_cleanup = true;
                         uwrite!(self.src,
                             "
                             void* {address};
                             if (({size} * {list}.Count) < 1024) {{
-                                var {ret_area} = stackalloc {element_type}[{array_size}*{list}.Count];
-                                {address} = (void*)((int){ret_area});
+                                var {ret_area} = stackalloc {element_type}[{array_size}];
+                                {address} = (void*)(((int){ret_area}) + ({align} - 1) & -{align});
                             }}
                             else
                             {{
@@ -1288,10 +1295,17 @@ impl Bindgen for FunctionBindgen<'_, '_> {
                 // to align the allocation via the stackalloc command, unlike with a fixed array where the pointer will be aligned.
                 // We get the final ptr to pass to the wasm runtime by shifting to the
                 // correctly aligned pointer (sometimes it can be already aligned).
+                let array_size = if self.import_return_pointer_area_align > 1 {
+                    // Add one additional element in case the starting address is not aligned
+                    array_size + 1
+                } else {
+                    array_size
+                };
+
                 uwrite!(
                     self.src,
                     "
-                    var {ret_area} = stackalloc {element_type}[{array_size}+1];
+                    var {ret_area} = stackalloc {element_type}[{array_size}];
                     var {ptr} = ((int){ret_area}) + ({align} - 1) & -{align};
                     ",
                     align = align.align_wasm32()

crates/csharp/src/world_generator.rs

@@ -797,13 +797,10 @@ enum Stubs<'a> {
 // We cant use "StructLayout.Pack" as dotnet will use the minimum of the type and the "Pack" field,
 // so for byte it would always use 1 regardless of the "Pack".
 pub fn dotnet_aligned_array(array_size: usize, required_alignment: usize) -> (usize, String) {
-    let num_elements = if array_size % required_alignment > 0 {
-        array_size / required_alignment + 1
-    } else {
-        array_size / required_alignment
-    };
+    let num_elements = array_size.div_ceil(required_alignment);
     match required_alignment {
         1 => (num_elements, "byte".to_owned()),
+        // Add one additional element in case the starting address is not aligned
         2 => (num_elements, "ushort".to_owned()),
         4 => (num_elements, "uint".to_owned()),
         8 => (num_elements, "ulong".to_owned()),