allocator interface (first pass)

compiler/parser/parser.odin

@@ -113,7 +113,8 @@ is_type_token :: proc(kind: token.Kind) -> bool {
 	     .Keyword_C_Short, .Keyword_C_Ushort, .Keyword_C_Int, .Keyword_C_Uint,
 	     .Keyword_C_Long, .Keyword_C_Ulong, .Keyword_C_Longlong, .Keyword_C_Ulonglong,
 	     .Keyword_C_Float, .Keyword_C_Double, .Keyword_C_Longdouble,
-	     .Keyword_Void, .Keyword_Bool, .Keyword_Func, .Keyword_C_Func, .Identifier, .Question, .At, .Star, .Left_Bracket:
+	     .Keyword_Void, .Keyword_Anyopaque, .Keyword_Bool, .Keyword_Func, .Keyword_C_Func,
+	     .Identifier, .Question, .At, .Star, .Left_Bracket:
 		return true
 	}
 	return false
@@ -326,6 +327,9 @@ parse_type_atom :: proc(parser: ^Parser) -> ast.Type_Syntax {
 	case .Keyword_Void:
 		advance(parser)
 		return types.VOID
+	case .Keyword_Anyopaque:
+		advance(parser)
+		return types.ANYOPAQUE
 	case .Keyword_Bool:
 		advance(parser)
 		return types.BOOL
@@ -600,7 +604,7 @@ parse_integer_magnitude :: proc(text: string) -> (u64, bool) {
 parse_primary :: proc(parser: ^Parser, nesting: int) -> ast.Expr_Id {
 	tok := current(parser)
 	#partial switch tok.kind {
-	case .Keyword_Int, .Keyword_Float, .Keyword_Range, .Keyword_Void, .Keyword_Bool:
+	case .Keyword_Int, .Keyword_Float, .Keyword_Range, .Keyword_Void, .Keyword_Anyopaque, .Keyword_Bool:
 		start := tok
 		target := parse_type_atom(parser)
 		return add_expr(parser, ast.Expr{
@@ -2214,6 +2218,13 @@ parse_struct :: proc(parser: ^Parser, name: token.Token, c_layout: bool, is_unio
 	ended_by_newline := current(parser).kind == .Newline
 	skip_newlines(parser)
 	if current(parser).kind != .Left_Brace {
+		if c_layout {
+			source.add(parser.diagnostics, start.span, "c_struct declarations require a body; use 'opaque' for incomplete types")
+			if !ended_by_newline {
+				_ = finish_statement(parser)
+			}
+			return
+		}
 		if !c_layout {
 			source.add(
 				parser.diagnostics, start.span,
@@ -2242,6 +2253,18 @@ parse_struct :: proc(parser: ^Parser, name: token.Token, c_layout: bool, is_unio
 	_ = finish_statement(parser)
 }
 
+parse_opaque :: proc(parser: ^Parser, name: token.Token) {
+	start := advance(parser)
+	id := types.named(&parser.module.type_store, u32(parser.pkg), u32(name.symbol))
+	if !types.define_record(&parser.module.type_store, id, nil, false, true, false) {
+		source.addf(parser.diagnostics, name.span, "duplicate type declaration '%s'", token_text(parser, name))
+	}
+	if current(parser).kind == .Left_Brace {
+		source.add(parser.diagnostics, start.span, "opaque declarations do not have a body")
+	}
+	_ = finish_statement(parser)
+}
+
 // synthesize_union_tag builds the anonymous runtime discriminant enum for a tagged
 // union: one member per variant, valued by the program-global (name, payload-type)
 // ID. The declared tag enum, if any, remains only the validation surface.
@@ -2573,6 +2596,10 @@ parse_top_level :: proc(parser: ^Parser) {
 		parse_struct(parser, name, current(parser).kind == .Keyword_C_Struct)
 		return
 	}
+	if operator.kind == .Colon_Colon && current(parser).kind == .Keyword_Opaque {
+		parse_opaque(parser, name)
+		return
+	}
 	if operator.kind == .Colon_Colon && current(parser).kind == .Keyword_Union {
 		parse_struct(parser, name, false, is_union=true)
 		return