refactor crate loading

std/std.mod.nil

@@ -0,0 +1,123 @@
+function printlnI32(x: I32) = (
+    printI32(x);
+    print("\n");
+);
+
+function printlnInt(x: Int) = (
+  printInt(x);
+  print("\n");
+);
+
+function printI32(x: I32) = printInt(i32ToInt(x));
+
+function printInt(x: Int) = (
+  let mag = log10(x);
+
+  loop (
+    if mag == 0 then break;
+    let base = pow(10, mag);
+
+    let digit = x / base;
+    print(stringForDigit(digit));
+
+    x = x % base;
+    mag = mag - 1;
+  );
+
+  print(stringForDigit(x % 10));
+);
+
+function stringForDigit(x: Int): String = 
+  if x == 0 then "0"
+  else if x == 1 then "1"
+  else if x == 2 then "2"
+  else if x == 3 then "3"
+  else if x == 4 then "4"
+  else if x == 5 then "5"
+  else if x == 6 then "6"
+  else if x == 7 then "7"
+  else if x == 8 then "8"
+  else if x == 9 then "9"
+  else trap();
+
+function log10(x: Int): Int = (
+  let i = 0;
+  loop (
+    if x < 10 then break;
+    i = i + 1;
+    x = x / 10;
+  );
+  i
+);
+
+function pow(base: Int, exp: Int): Int = (
+  let acc = 1;
+  loop (
+    if exp == 0 then break;
+    acc = acc * base;
+    exp = exp - 1;
+  );
+  acc
+);
+
+function println(s: String) = (
+  print(s);
+  print("\n");
+);
+
+mod rt (
+    // Start the heap at 1024. In practice this could probably be as low as we want.
+    global BASE_PTR: I32 = 1024_I32;
+    global HEAD_PTR: I32 = 1024_I32;
+
+    /*
+    Every struct has a header of an I32 as a refcount.
+    */
+
+    // Allocate a new item. We do not deallocate anything yet.
+    // lol.
+    function allocateItem(objSize: I32, align: I32): I32 = (
+        if align < 4_I32 then std.abort("invalid alignment");
+
+        // Include the refcount header.
+        let actualSize = 4_I32 + objSize;
+
+        // Let's see whether we can fit the refcount into the align bits.
+        // I happen to know that everything will always be at least 4 bytes aligned.
+        let alignedPtr = std.alignUp(HEAD_PTR, align);
+        let actualObjPtr = if (alignedPtr - HEAD_PTR) > align then (
+            alignedPtr - 4_I32
+        ) else (
+            // Take up the next spot.
+            alignedPtr + align - 4_I32
+        );
+
+        let newHeadPtr = actualObjPtr + actualSize;
+
+        if newHeadPtr > __memory_size() then (
+            // 16 pages, very arbitrary.
+            let result = __memory_grow(16_I32);
+            // If allocation failed we get -1. We don't have negative numbers yet, lol.
+            if result > 4294967295_I32 then (
+                std.abort("failed to grow memory");
+            );
+        );
+
+        actualObjPtr
+    );
+);
+
+function alignUp(x: I32, align: I32): I32 = (x + (align - 1_I32)) & !(align - 1_I32);
+
+function i32ToInt(x: I32): Int = __i32_extend_to_i64_u(x);
+
+function abort(message: String) = (
+    print("fatal error: ");
+    print(message);
+    println(".. aborting");
+    trap();
+);
+
+function main() = (
+    std.rt.allocateItem(100000000_I32, 8_I32);
+);