deftype and defmethod syntax major changes (#3094)

Major change to how `deftype` shows up in our code:
- the decompiler will no longer emit the `offset-assert`,
`method-count-assert`, `size-assert` and `flag-assert` parameters. There
are extremely few cases where having this in the decompiled code is
helpful, as the types there come from `all-types` which already has
those parameters. This also doesn't break type consistency because:
  - the asserts aren't compared.
- the first step of the test uses `all-types`, which has the asserts,
which will throw an error if they're bad.
- the decompiler won't emit the `heap-base` parameter unless necessary
now.
- the decompiler will try its hardest to turn a fixed-offset field into
an `overlay-at` field. It falls back to the old offset if all else
fails.
- `overlay-at` now supports field "dereferencing" to specify the offset
that's within a field that's a structure, e.g.:
```lisp
(deftype foobar (structure)
  ((vec    vector  :inline)
   (flags  int32   :overlay-at (-> vec w))
   )
  )
```
in this structure, the offset of `flags` will be 12 because that is the
final offset of `vec`'s `w` field within this structure.
- **removed ID from all method declarations.** IDs are only ever
automatically assigned now. Fixes #3068.
- added an `:overlay` parameter to method declarations, in order to
declare a new method that goes on top of a previously-defined method.
Syntax is `:overlay <method-name>`. Please do not ever use this.
- added `state-methods` list parameter. This lets you quickly specify a
list of states to be put in the method table. Same syntax as the
`states` list parameter. The decompiler will try to put as many states
in this as it can without messing with the method ID order.

Also changes `defmethod` to make the first type definition (before the
arguments) optional. The type can now be inferred from the first
argument. Fixes #3093.

---------

Co-authored-by: Hat Kid <[email protected]>

.vscode/settings.json

@@ -8,5 +8,98 @@
     "editor.wordBasedSuggestions": true,
     "editor.snippetSuggestions": "top"
   },
-  "python.formatting.provider": "black"
+  "python.formatting.provider": "black",
+  "files.associations": {
+    "optional": "cpp",
+    "algorithm": "cpp",
+    "any": "cpp",
+    "array": "cpp",
+    "atomic": "cpp",
+    "bit": "cpp",
+    "bitset": "cpp",
+    "cctype": "cpp",
+    "charconv": "cpp",
+    "chrono": "cpp",
+    "cinttypes": "cpp",
+    "clocale": "cpp",
+    "cmath": "cpp",
+    "codecvt": "cpp",
+    "compare": "cpp",
+    "concepts": "cpp",
+    "condition_variable": "cpp",
+    "cstdarg": "cpp",
+    "cstddef": "cpp",
+    "cstdint": "cpp",
+    "cstdio": "cpp",
+    "cstdlib": "cpp",
+    "cstring": "cpp",
+    "ctime": "cpp",
+    "cwchar": "cpp",
+    "cwctype": "cpp",
+    "deque": "cpp",
+    "exception": "cpp",
+    "filesystem": "cpp",
+    "format": "cpp",
+    "forward_list": "cpp",
+    "fstream": "cpp",
+    "functional": "cpp",
+    "future": "cpp",
+    "initializer_list": "cpp",
+    "iomanip": "cpp",
+    "ios": "cpp",
+    "iosfwd": "cpp",
+    "iostream": "cpp",
+    "istream": "cpp",
+    "iterator": "cpp",
+    "limits": "cpp",
+    "list": "cpp",
+    "locale": "cpp",
+    "map": "cpp",
+    "memory": "cpp",
+    "mutex": "cpp",
+    "new": "cpp",
+    "numeric": "cpp",
+    "ostream": "cpp",
+    "queue": "cpp",
+    "random": "cpp",
+    "ranges": "cpp",
+    "ratio": "cpp",
+    "regex": "cpp",
+    "set": "cpp",
+    "shared_mutex": "cpp",
+    "span": "cpp",
+    "sstream": "cpp",
+    "stack": "cpp",
+    "stdexcept": "cpp",
+    "stop_token": "cpp",
+    "streambuf": "cpp",
+    "string": "cpp",
+    "system_error": "cpp",
+    "thread": "cpp",
+    "tuple": "cpp",
+    "type_traits": "cpp",
+    "typeinfo": "cpp",
+    "unordered_map": "cpp",
+    "unordered_set": "cpp",
+    "utility": "cpp",
+    "valarray": "cpp",
+    "variant": "cpp",
+    "vector": "cpp",
+    "xfacet": "cpp",
+    "xhash": "cpp",
+    "xiosbase": "cpp",
+    "xlocale": "cpp",
+    "xlocbuf": "cpp",
+    "xlocinfo": "cpp",
+    "xlocmes": "cpp",
+    "xlocmon": "cpp",
+    "xlocnum": "cpp",
+    "xloctime": "cpp",
+    "xmemory": "cpp",
+    "xstddef": "cpp",
+    "xstring": "cpp",
+    "xtr1common": "cpp",
+    "xtree": "cpp",
+    "xutility": "cpp"
+  }
 }

common/goos/PrettyPrinter2.cpp

@@ -288,7 +288,11 @@ void break_list(Node* node) {
       node->sub_elt_indent += name.size();
     } else if (name == "defmethod") {
       // things with 4 things in the top line: (defmethod <method> <type> <args>
-      node->top_line_count = 4;
+      // or just 3 things in the top line: (defmethod <method> <args>
+      node->top_line_count = 3;
+      if (node->child_nodes.size() >= 4 && node->child_nodes[2].kind == Node::Kind::ATOM) {
+        node->top_line_count = 4;
+      }
     } else if (name == "until" || name == "while" || name == "dotimes" || name == "countdown" ||
                name == "when" || name == "behavior" || name == "lambda" || name == "defpart" ||
                name == "define") {

common/type_system/Type.cpp

@@ -421,10 +421,12 @@ int Type::get_num_methods() const {
  * Add a method defined specifically for this type.
  */
 const MethodInfo& Type::add_method(const MethodInfo& info) {
-  for (auto it = m_methods.rbegin(); it != m_methods.rend(); it++) {
-    if (!it->overrides_parent && !it->only_overrides_docstring) {
-      ASSERT(it->id + 1 == info.id);
-      break;
+  if (!info.overrides_parent) {
+    for (auto it = m_methods.rbegin(); it != m_methods.rend(); it++) {
+      if (!it->overrides_parent && !it->only_overrides_docstring) {
+        ASSERT(it->id + 1 == info.id);
+        break;
+      }
     }
   }
 

common/type_system/Type.h

@@ -32,6 +32,7 @@ struct MethodInfo {
   bool overrides_parent = false;
   bool only_overrides_docstring = false;
   std::optional<std::string> docstring;
+  std::optional<std::string> overlay_name;
 
   bool operator==(const MethodInfo& other) const;
   bool operator!=(const MethodInfo& other) const { return !((*this) == other); }