Refactor: Generate all struct bindings within the codegen.

PiperOrigin-RevId: 828973537
Change-Id: I3f371d2f88e1cd9b1bb5c0a9c6a5ace7a21673fb

wasm/codegen/generators/structs.py

@@ -65,14 +65,7 @@ class Generator:
         autogenned_struct_source.append(
             struct_data.wrapped_source + "\n"
         )
-      if struct_data.bindings:
+      autogenned_struct_bindings.append(struct_data.bindings)
-        autogenned_struct_bindings.append(struct_data.bindings)
-      else:
-        # Bindings with markers
-        markers_and_content.append((
-            f"// INSERT-GENERATED-{struct_data.wrap_name}-BINDINGS",
-            [l.binding for l in struct_data.wrapped_fields],
-        ))
 
     markers_and_content.append((
         "// {{ AUTOGENNED_STRUCTS_SOURCE }}",

wasm/codegen/helpers/code_builder.py

@@ -47,13 +47,15 @@ class CodeBuilder:
   class IndentBlock:
     """Helper class to manage indentation within a `with` statement."""
 
-    def __init__(self, builder: "CodeBuilder", header_line=""):
+    def __init__(self, builder: "CodeBuilder", header_line="", braces=True):
       self._builder = builder
       self._header_line = header_line
+      self._braces = braces
 
     def __enter__(self):
       line = self._header_line
-      line += " {" if line else "{"
+      if self._braces:
+        line += " {" if line else "{"
       self._builder.line(line)
       self._builder._indent_level += 1
       self._line_count_enter = len(self._builder._lines)
@@ -65,20 +67,22 @@ class CodeBuilder:
       if self._line_count_enter == len(self._builder._lines):
         self._builder._lines[-1] += "}"
       else:
-        self._builder.line("}")
+        if self._braces:
+          self._builder.line("}")
 
-  def block(self, header_line="") -> IndentBlock:
+  def block(self, header_line="", braces=True) -> IndentBlock:
     """Creates a block including braces and an optional header before the opening brace.
 
     Use via a `with` statement.
 
     Args:
         header_line: Optional header line to add before the opening brace.
+        braces: Whether to include opening and closing braces.
 
     Returns:
         An IndentBlock instance that manages the indentation.
     """
-    return self.IndentBlock(self, header_line)
+    return self.IndentBlock(self, header_line, braces)
 
   def function(self, signature="") -> IndentBlock:
     """Creates a function."""

wasm/codegen/helpers/structs.py

@@ -668,33 +668,38 @@ def _build_struct_bindings(
     wrapped_fields: List[WrappedFieldData],
 ):
   """Builds the C++ bindings for a struct."""
-  # These structs require specific constructors
-  # which, for now, are hardcoded in the template file.
-  if struct_name in [
-      "mjData",
-      "mjModel",
-      "mjvScene",
-      "mjSpec",
-  ]:
-    return ""
-
   w = common.uppercase_first_letter(struct_name)
-  spc = "    "
   builder = code_builder.CodeBuilder()
-  builder.line(f"emscripten::class_<{w}>(\"{w}\")")
+  with builder.block(
+      header_line=f'emscripten::class_<{w}>("{w}")', braces=False
+  ):
+    if w == "MjData":
+      builder.line(".constructor<MjModel *>()")
+      builder.line(".constructor<const MjModel &, const MjData &>()")
+    elif w == "MjModel":
+      builder.line(
+          '.class_function("loadFromXML", &loadFromXML, take_ownership())'
+      )
+      builder.line(".constructor<const MjModel &>()")
+    elif w == "MjSpec":
+      builder.line(".constructor<const MjSpec &>()")
+    elif w == "MjvScene":
+      builder.line(".constructor<MjModel *, int>()")
 
-  is_mjs = w.startswith("Mjs")
+    is_mjs = w.startswith("Mjs")
-  if not is_mjs:
+    if not is_mjs and w not in ["MjData", "MjModel", "MjSpec"]:
-    builder.line(f"{spc}.constructor<>()")
+      builder.line(".constructor<>()")
 
-  shallow_copy = use_shallow_copy(wrapped_fields)
+    shallow_copy = use_shallow_copy(wrapped_fields)
-  if shallow_copy and not is_mjs:
+    if shallow_copy and not is_mjs:
-    builder.line(f"{spc}.function(\"copy\", &{w}::copy, take_ownership())")
+      builder.line(f'.function("copy", &{w}::copy, take_ownership())')
+
+    for field in wrapped_fields[:-1]:
+      if field.binding:
+        builder.line(field.binding)
+    if wrapped_fields:
+      builder.line(f"{wrapped_fields[-1].binding};")
 
-  for field in wrapped_fields:
-    if field.binding:
-      builder.line(f"{spc}{field.binding}")
-  builder.line(f"{spc};")
   return builder.to_string()
 
 

wasm/codegen/templates/bindings.cc

@@ -597,26 +597,6 @@ std::unique_ptr<MjSpec> parseXMLString(const std::string &xml) {
 
 EMSCRIPTEN_BINDINGS(mujoco_bindings) {
   function("parseXMLString", &parseXMLString, take_ownership());
-
-  emscripten::class_<MjModel>("MjModel")
-      .class_function("loadFromXML", &loadFromXML, take_ownership())
-      .constructor<const MjModel &>()
-      // INSERT-GENERATED-MjModel-BINDINGS
-      ;
-  emscripten::class_<MjData>("MjData")
-      .constructor<MjModel *>()
-      .constructor<const MjModel &, const MjData &>()
-      // INSERT-GENERATED-MjData-BINDINGS
-      ;
-  emscripten::class_<MjvScene>("MjvScene")
-      .constructor<>()
-      .constructor<MjModel *, int>()
-      // INSERT-GENERATED-MjvScene-BINDINGS
-      ;
-  emscripten::class_<MjSpec>("MjSpec")
-      .constructor<const MjSpec &>()
-      // INSERT-GENERATED-MjSpec-BINDINGS
-      ;
   // {{ AUTOGENNED_STRUCTS_BINDINGS }}
 
   // TODO: should be generated in future CLs -- //