Fixed handling of preprocessor defines and comments in metadata for anonymous structs (#101)

Author: ShironekoBen

dear_bindings.py

@@ -1,4 +1,4 @@
-# Dear Bindings Version v0.16
+# Dear Bindings Version v0.16 WIP
 # Generates C-language headers for Dear ImGui
 # Developed by Ben Carter (e-mail: ben AT shironekolabs.com, github: @ShironekoBen)
 

docs/Changelog.txt

@@ -1,3 +1,12 @@
+--- v0.16 WIP
+
+* Fixed the JSON metadata generator where preprocessor declarations on anonymous structs were getting applied to the
+  fields in the structure but not the implicit field where that structure was used. (#101)
+* Made implicit fields generated by anonymous structs in the metadata inherit the comments from their original
+  structure declarations. This produces duplicate comments in some cases (one at the point where the anonymous struct
+  is declared and another where it is used), but this seems preferable to potentially losing the comment entirely in
+  some usage scenarios. (#101)
+
 --- v0.15
 
 * Fixed the DX11 backend header including forward-declarations for some DirectX types that conflict with the actual

src/generators/gen_metadata.py

@@ -358,6 +358,16 @@ def emit_struct_field_list(container, fields_root):
                     dummy_field.is_array = [False]
                     dummy_field.width_specifiers = [None]
                     dummy_field.is_anonymous = child.is_anonymous  # Technically wrong, but see above
+                    # We need to pretend this is in the same place in the tree, otherwise preprocessor defines don't
+                    # propagate correctly to it
+                    dummy_field.parent = child
+                    # If the struct had comments, temporarily attach them to the dummy field
+                    # This will result in the comments getting duplicated as they will also appear on the struct
+                    # declaration, but that's probably acceptable
+                    if child.pre_comments:
+                        dummy_field.pre_comments = child.pre_comments
+                    if child.attached_comment:
+                        dummy_field.attached_comment = child.attached_comment
                     dummy_type = utils.create_type(child.name)
                     dummy_field.field_type = dummy_type
                     emit_field(fields_root, dummy_field)