Assigning to $Type now works.

README.md

@@ -115,19 +115,19 @@ to C3 and compiled with the c3c compiler:
 - [x] CT only macros evaluating to constants
 - [x] range initializers e.g. `{ [1..2] = 2 }`
 - [x] Trailing body macros e.g. `@foo(1, 100; int a) { bar(a); };`
+- [x] Complex macros
 - [ ] Anonymous structs
 - [ ] Complete C ABI conformance *in progress*
 - [ ] Debug info *in progress*
 - [ ] Virtual type *in progress*
 - [ ] Enum associated data support  
-- [ ] Windows support
-- [ ] All attributes
+- [ ] Windows support *in progress*
+- [ ] All attributes *in progress*
 - [ ] Associative array literals
 - [ ] CT type constants
 - [ ] Reflection methods
 - [ ] LTO/ThinLTO setup
 - [ ] `global` / `shared` for globals 
-- [ ] Complex macros
 - [ ] Escape macros
 - [ ] Implicit capturing macros
 - [ ] Subarray initializers

src/compiler/ast.c

@@ -581,6 +581,9 @@ void fprint_expr_recursive(Context *context, FILE *file, Expr *expr, int indent)
 	if (!expr) return;
 	switch (expr->expr_kind)
 	{
+		case EXPR_NOP:
+			DUMP("(nop)");
+			return;
 		case EXPR_FLATPATH:
 			DUMP("(idents)");
 			return;

src/compiler/copying.c

@@ -75,6 +75,7 @@ Expr *copy_expr(Expr *source_expr)
 			UNREACHABLE
 		case EXPR_FLATPATH:
 		case EXPR_UNDEF:
+		case EXPR_NOP:
 			return expr;
 		case EXPR_CT_CALL:
 			MACRO_COPY_EXPR_LIST(expr->ct_call_expr.arguments);

src/compiler/enums.h

@@ -214,6 +214,7 @@ typedef enum
 	EXPR_UNARY,
 	EXPR_UNDEF,
 	EXPR_CT_CALL,
+	EXPR_NOP,
 } ExprKind;
 
 typedef enum

src/compiler/llvm_codegen_expr.c

@@ -3177,6 +3177,8 @@ void llvm_emit_expr(GenContext *c, BEValue *value, Expr *expr)
 		case EXPR_CATCH:
 			gencontext_emit_trycatch_expr(c, value, expr);
 			return;
+		case EXPR_NOP:
+			return;
 		case EXPR_ELSE:
 			gencontext_emit_else_expr(c, value, expr);
 			return;

src/compiler/sema_expr.c

@@ -3357,6 +3357,43 @@ static bool sema_expr_analyse_ct_identifier_assign(Context *context, Expr *expr,
 	return true;
 }
 
+static bool sema_expr_analyse_ct_type_identifier_assign(Context *context, Expr *expr, Expr *left, Expr *right)
+{
+	TypeInfo *info = left->type_expr;
+
+	if (info->kind != TYPE_INFO_IDENTIFIER || info->unresolved.path || TOKTYPE(info->unresolved.name_loc) != TOKEN_CT_TYPE_IDENT)
+	{
+		SEMA_ERROR(left, "A type cannot be assigned to.");
+		return false;
+	}
+
+	TokenId token = info->unresolved.name_loc;
+
+	if (!sema_analyse_expr_value(context, NULL, right)) return false;
+
+	if (right->expr_kind != EXPR_TYPEINFO)
+	{
+		SEMA_ERROR(right, "Expected a type here.");
+		return false;
+	}
+
+	Decl *decl = sema_resolve_normal_symbol(context, token, NULL, false);
+
+	if (!decl)
+	{
+		decl = decl_new(DECL_VAR, token, VISIBLE_LOCAL);
+		decl->var.kind = VARDECL_LOCAL_CT_TYPE;
+		if (!sema_add_local(context, decl)) return false;
+	}
+	decl = sema_resolve_normal_symbol(context, token, NULL, true);
+
+	decl->var.init_expr = right;
+
+	expr->expr_kind = EXPR_NOP;
+	expr->type = type_void;
+
+	return true;
+}
 
 /**
  * Analyse a = b
@@ -3372,6 +3409,11 @@ static bool sema_expr_analyse_assign(Context *context, Expr *expr, Expr *left, E
 	{
 		return sema_expr_analyse_ct_identifier_assign(context, expr, left, right);
 	}
+
+	if (left->expr_kind == EXPR_TYPEINFO)
+	{
+		return sema_expr_analyse_ct_type_identifier_assign(context, expr, left, right);
+	}
 	if (!sema_analyse_expr_value(context, NULL, left)) return false;
 
 	// 2. Check assignability
@@ -3442,6 +3484,7 @@ static bool sema_expr_analyse_common_assign(Context *context, Expr *expr, Expr *
 	{
 		return sema_expr_analyse_ct_common_assign(context, expr, left);
 	}
+
 	// 1. Analyse left side.
 	if (!sema_analyse_expr_value(context, NULL, left)) return false;
 
@@ -5690,6 +5733,7 @@ static inline bool sema_analyse_expr_dispatch(Context *context, Type *to, Expr *
 		case EXPR_DESIGNATOR:
 		case EXPR_MACRO_BODY_EXPANSION:
 		case EXPR_FLATPATH:
+		case EXPR_NOP:
 			UNREACHABLE
 		case EXPR_CT_CALL:
 			return sema_expr_analyse_ct_call(context, to, expr);

test/test_suite/expressions/assignability.c3

@@ -31,3 +31,8 @@ func void test21()
     int b = 2;
     a++ = b++;      // #error: Expression is not assignable
 }
+
+func void test22()
+{
+    $Type = int;
+}