Add bit_set type

core/fmt/fmt.odin

@@ -70,7 +70,7 @@ write_rune :: proc(buf: ^String_Buffer, r: rune) {
 
 write_i64 :: proc(buf: ^String_Buffer, i: i64, base: int) {
 	b: [129]byte;
-	s := strconv.append_bits(b[:], u64(i), base, true, 64, strconv.digits, 0);
+	s := strconv.append_bits(b[:], u64(i), base, true, 64, strconv.digits, nil);
 	write_string(buf, s);
 }
 
@@ -312,6 +312,11 @@ write_type :: proc(buf: ^String_Buffer, ti: ^runtime.Type_Info) {
 			write_i64(buf, i64(info.bits[i]), 10);
 		}
 		write_string(buf, "}");
+
+	case runtime.Type_Info_Bit_Set:
+		write_string(buf, "bit_set[");
+		write_type(buf, info.base);
+		write_string(buf, "]");
 	}
 }
 
@@ -714,6 +719,82 @@ fmt_enum :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 }
 
 
+
+enum_value_to_u64 :: proc(ev: runtime.Type_Info_Enum_Value) -> u64 {
+	switch i in ev {
+	case rune:    return u64(i);
+	case i8:      return u64(i);
+	case i16:     return u64(i);
+	case i32:     return u64(i);
+	case i64:     return u64(i);
+	case int:     return u64(i);
+	case u8:      return u64(i);
+	case u16:     return u64(i);
+	case u32:     return u64(i);
+	case u64:     return u64(i);
+	case uint:    return u64(i);
+	case uintptr: return u64(i);
+	case f32:     return u64(i);
+	case f64:     return u64(i);
+	}
+	return 0;
+}
+
+fmt_bit_set :: proc(fi: ^Fmt_Info, v: any, name: string = "") {
+	type_info := type_info_of(v.typeid);
+	switch info in type_info.variant {
+	case runtime.Type_Info_Named:
+		val := v;
+		val.typeid = info.base.id;
+		fmt_bit_set(fi, val, info.name);
+
+	case runtime.Type_Info_Bit_Set:
+		bits: u64;
+		bit_size := u64(8*type_info.size);
+		verb := 'b';
+
+		switch bit_size {
+		case  0: bits = 0;
+		case  8: bits = u64( (^u8)(v.data)^);
+		case 16: bits = u64((^u16)(v.data)^);
+		case 32: bits = u64((^u32)(v.data)^);
+		case 64: bits = u64((^u64)(v.data)^);
+		case: panic("unknown bit_size size");
+		}
+
+		et := runtime.type_info_base(info.base);
+		e := et.variant.(runtime.Type_Info_Enum);
+
+		if name != "" {
+			write_string(fi.buf, name);
+		} else {
+			write_type(fi.buf, type_info);
+		}
+		write_byte(fi.buf, '{');
+		defer write_byte(fi.buf, '}');
+
+		commas := 0;
+		loop: for i in 0 .. bit_size-1 {
+			if bits & (1<<i) == 0 {
+				continue loop;
+			}
+
+			if commas > 0 do write_string(fi.buf, ", ");
+
+			defer commas += 1;
+
+			for ev, evi in e.values {
+				v := enum_value_to_u64(ev);
+				if v == i {
+					write_string(fi.buf, e.names[evi]);
+					continue loop;
+				}
+			}
+			write_i64(fi.buf, i64(i), 10);
+		}
+	}
+}
+
 fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 	if v.data == nil || v.typeid == nil {
 		write_string(fi.buf, "<nil>");
@@ -765,6 +846,8 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 			if hash do for in 0..indent-1 do write_byte(fi.buf, '\t');
 			write_byte(fi.buf, '}');
 
+		case runtime.Type_Info_Bit_Set:
+			fmt_bit_set(fi, v);
 		case:
 			fmt_value(fi, any{v.data, typeid_of(info.base)}, verb);
 		}
@@ -929,6 +1012,9 @@ fmt_value :: proc(fi: ^Fmt_Info, v: any, verb: rune) {
 	case runtime.Type_Info_Type_Id:
 		id := (^typeid)(v.data)^;
 		write_typeid(fi.buf, id);
+
+	case runtime.Type_Info_Bit_Set:
+		fmt_bit_set(fi, v);
 	}
 }
 

core/runtime/core.odin

@@ -99,7 +99,9 @@ Type_Info_Bit_Field :: struct {
 	bits:    []i32,
 	offsets: []i32,
 };
-
+Type_Info_Bit_Set :: struct {
+	base: ^Type_Info,
+};
 
 Type_Info :: struct {
 	size:  int,
@@ -127,6 +129,7 @@ Type_Info :: struct {
 		Type_Info_Enum,
 		Type_Info_Map,
 		Type_Info_Bit_Field,
+		Type_Info_Bit_Set,
 	},
 }
 

core/runtime/procs_windows_amd64.odin

@@ -0,0 +1,50 @@
+package runtime
+
+foreign import kernel32 "system:Kernel32.lib"
+
+@(link_name="memcpy")
+memcpy :: proc "c" (dst, src: rawptr, len: int) -> rawptr {
+	foreign kernel32 {
+		RtlCopyMemory :: proc "c" (dst, src: rawptr, len: int) ---
+	}
+	RtlCopyMemory(dst, src, len);
+	return dst;
+}
+
+@(link_name="memmove")
+memmove :: proc "c" (dst, src: rawptr, len: int) -> rawptr {
+	foreign kernel32 {
+		RtlMoveMemory :: proc "c" (dst, src: rawptr, len: int) ---
+	}
+	RtlMoveMemory(dst, src, len);
+	return dst;
+}
+
+@(link_name="memset")
+memset :: proc "c" (ptr: rawptr, val: i32, len: int) -> rawptr {
+	foreign kernel32 {
+		RtlFillMemory :: proc "c" (dst: rawptr, len: int, fill: byte) ---
+	}
+	RtlFillMemory(ptr, len, byte(val));
+	return ptr;
+}
+
+// @(link_name="memcmp")
+// memcmp :: proc "c" (dst, src: rawptr, len: int) -> i32 {
+// 	if dst == nil || src == nil {
+// 		return 0;
+// 	}
+// 	if dst == src {
+// 		return 0;
+// 	}
+// 	d, s := uintptr(dst), uintptr(src);
+// 	n := uintptr(len);
+
+// 	for i := uintptr(0); i < n; i += 1 {
+// 		x, y := (^byte)(d+i)^, (^byte)(s+i)^;
+// 		if x != y {
+// 			return x < y ? -1 : +1;
+// 		}
+// 	}
+// 	return 0;
+// }

core/strconv/strconv.odin

@@ -198,10 +198,10 @@ append_bool :: proc(buf: []byte, b: bool) -> string {
 }
 
 append_uint :: proc(buf: []byte, u: u64, base: int) -> string {
-	return append_bits(buf, u64(u), base, false, 8*size_of(uint), digits, 0);
+	return append_bits(buf, u64(u), base, false, 8*size_of(uint), digits, nil);
 }
 append_int :: proc(buf: []byte, i: i64, base: int) -> string {
-	return append_bits(buf, u64(i), base, true, 8*size_of(int), digits, 0);
+	return append_bits(buf, u64(i), base, true, 8*size_of(int), digits, nil);
 }
 itoa :: proc(buf: []byte, i: int) -> string do return append_int(buf, i64(i), 10);
 
@@ -474,7 +474,7 @@ append_bits :: proc(buf: []byte, u: u64, base: int, is_signed: bool, bit_size: i
 	}
 	i-=1; a[i] = digits[u % b];
 
-	if flags&Int_Flag.Prefix != 0 {
+	if flags&Int_Flag.Prefix != nil {
 		ok := true;
 		switch base {
 		case  2: i-=1; a[i] = 'b';
@@ -492,9 +492,9 @@ append_bits :: proc(buf: []byte, u: u64, base: int, is_signed: bool, bit_size: i
 	switch {
 	case neg:
 		i-=1; a[i] = '-';
-	case flags&Int_Flag.Plus != 0:
+	case flags&Int_Flag.Plus != nil:
 		i-=1; a[i] = '+';
-	case flags&Int_Flag.Space != 0:
+	case flags&Int_Flag.Space != nil:
 		i-=1; a[i] = ' ';
 	}
 

examples/demo/demo.odin

@@ -712,6 +712,25 @@ deprecated_attribute :: proc() {
 	// foo_v1(1);
 }
 
+bit_set_type :: proc() {
+	using Day :: enum {
+		Sunday,
+		Monday,
+		Tuesday,
+		Wednesday,
+		Thursday,
+		Friday,
+		Saturday,
+	}
+
+	Days :: distinct bit_set[Day];
+	d: Days;
+	d = Days{Sunday};
+	x := Tuesday;
+	d |= Days{Saturday, x};
+	fmt.println(d);
+}
+
 main :: proc() {
 	when true {
 		general_stuff();
@@ -725,5 +744,6 @@ main :: proc() {
 		complete_switch();
 		cstring_example();
 		deprecated_attribute();
+		bit_set_type();
 	}
 }

src/check_expr.cpp

@@ -841,6 +841,9 @@ bool is_polymorphic_type_assignable(CheckerContext *c, Type *poly, Type *source,
 	case Type_Enum:
 		return false;
 
+	case Type_BitSet:
+		return false;
+
 	case Type_Union:
 		if (source->kind == Type_Union) {
 			TypeUnion *x = &poly->Union;
@@ -1115,8 +1118,8 @@ bool check_unary_op(CheckerContext *c, Operand *o, Token op) {
 		break;
 
 	case Token_Xor:
-		if (!is_type_integer(type) && !is_type_boolean(type)) {
+		if (!is_type_integer(type) && !is_type_boolean(type) && !is_type_bit_set(type)) {
-			error(op, "Operator '%.*s' is only allowed with integers or booleans", LIT(op.string));
+			error(op, "Operator '%.*s' is only allowed with integers, booleans, or bit sets", LIT(op.string));
 		}
 		break;
 
@@ -1142,33 +1145,17 @@ bool check_binary_op(CheckerContext *c, Operand *o, Token op) {
 	switch (op.kind) {
 	case Token_Sub:
 	case Token_SubEq:
-		if (!is_type_numeric(type) && !is_type_pointer(type)) {
+		if (!is_type_numeric(type)) {
-			error(op, "Operator '%.*s' is only allowed with numeric or pointer expressions", LIT(op.string));
+			error(op, "Operator '%.*s' is only allowed with numeric expressions", LIT(op.string));
-			return false;
-		}
-#if defined(NO_POINTER_ARITHMETIC)
-		if (is_type_pointer(type)) {
-			error(o->expr, "Pointer arithmetic is not supported");
-			return false;
-		}
-#else
-		if (is_type_pointer(type)) {
-			o->type = t_int;
-		}
-		if (base_type(type) == t_rawptr) {
-			gbString str = type_to_string(type);
-			error(o->expr, "Invalid pointer type for pointer arithmetic: '%s'", str);
-			gb_string_free(str);
 			return false;
 		}
 		break;
-#endif
 
 	case Token_Mul:
 	case Token_Quo:
-	case Token_AddEq:
 	case Token_MulEq:
 	case Token_QuoEq:
+	case Token_AddEq:
 		if (!is_type_numeric(type)) {
 			error(op, "Operator '%.*s' is only allowed with numeric expressions", LIT(op.string));
 			return false;
@@ -1194,24 +1181,30 @@ bool check_binary_op(CheckerContext *c, Operand *o, Token op) {
 	case Token_OrEq:
 	case Token_Xor:
 	case Token_XorEq:
-		if (!is_type_integer(type) && !is_type_boolean(type)) {
+		if (!is_type_integer(type) && !is_type_boolean(type) && !is_type_bit_set(type)) {
-			error(op, "Operator '%.*s' is only allowed with integers or booleans", LIT(op.string));
+			error(op, "Operator '%.*s' is only allowed with integers, booleans, or bit sets", LIT(op.string));
 			return false;
 		}
 		break;
 
 	case Token_Mod:
 	case Token_ModMod:
-	case Token_AndNot:
 	case Token_ModEq:
 	case Token_ModModEq:
-	case Token_AndNotEq:
 		if (!is_type_integer(type)) {
 			error(op, "Operator '%.*s' is only allowed with integers", LIT(op.string));
 			return false;
 		}
 		break;
 
+	case Token_AndNot:
+	case Token_AndNotEq:
+		if (!is_type_integer(type) && !is_type_bit_set(type)) {
+			error(op, "Operator '%.*s' is only allowed with integers and bit sets", LIT(op.string));
+			return false;
+		}
+		break;
+
 	case Token_CmpAnd:
 	case Token_CmpOr:
 	case Token_CmpAndEq:
@@ -2329,7 +2322,11 @@ void convert_to_typed(CheckerContext *c, Operand *operand, Type *target_type) {
 		return;
 	}
 
-	Type *t = core_type(target_type);
+	Type *t = base_type(target_type);
+	if (c->in_enum_type) {
+		t = core_type(target_type);
+	}
+
 	switch (t->kind) {
 	case Type_Basic:
 		if (operand->mode == Addressing_Constant) {
@@ -4264,6 +4261,12 @@ CallArgumentData check_call_arguments(CheckerContext *c, Operand *operand, Type
 					} else {
 						pt = type_to_string(t);
 					}
+					String prefix = {};
+					String prefix_sep = {};
+					if (proc->pkg) {
+						prefix = proc->pkg->name;
+						prefix_sep = str_lit(".");
+					}
 					String name = proc->token.string;
 
 					char const *sep = "::";
@@ -4271,7 +4274,7 @@ CallArgumentData check_call_arguments(CheckerContext *c, Operand *operand, Type
 						sep = ":=";
 					}
 					// gb_printf_err("\t%.*s %s %s at %.*s(%td:%td) with score %lld\n", LIT(name), sep, pt, LIT(pos.file), pos.line, pos.column, cast(long long)valids[i].score);
-					gb_printf_err("\t%.*s %s %s at %.*s(%td:%td)\n", LIT(name), sep, pt, LIT(pos.file), pos.line, pos.column);
+					gb_printf_err("\t%.*s%.*s%.*s %s %s at %.*s(%td:%td)\n", LIT(prefix), LIT(prefix_sep), LIT(name), sep, pt, LIT(pos.file), pos.line, pos.column);
 				}
 				if (procs.count > 0) {
 					gb_printf_err("\n");
@@ -5096,9 +5099,6 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 
 		switch (t->kind) {
 		case Type_Struct: {
-			if (is_type_union(t)) {
-				is_constant = false;
-			}
 			if (cl->elems.count == 0) {
 				break; // NOTE(bill): No need to init
 			}
@@ -5111,7 +5111,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 				break;
 			}
 
-			{ // Checker values
+			if (is_type_struct(t)) { // Checker values
 				isize field_count = t->Struct.fields.count;
 				isize min_field_count = t->Struct.fields.count;
 				for (isize i = min_field_count-1; i >= 0; i--) {
@@ -5220,6 +5220,7 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 					}
 				}
 			}
+
 			break;
 		}
 
@@ -5409,6 +5410,39 @@ ExprKind check_expr_base_internal(CheckerContext *c, Operand *o, Ast *node, Type
 			break;
 		}
 
+		case Type_BitSet: {
+			if (cl->elems.count == 0) {
+				break; // NOTE(bill): No need to init
+			}
+			Type *et = base_type(t->BitSet.base_type);
+			isize field_count = 0;
+			if (et->kind == Type_Enum) {
+				field_count = et->Enum.fields.count;
+			}
+
+			if (cl->elems[0]->kind == Ast_FieldValue) {
+				error(cl->elems[0], "'field = value' in a bit_set a literal is not allowed");
+			} else {
+				for_array(index, cl->elems) {
+					Entity *field = nullptr;
+					Ast *elem = cl->elems[index];
+					if (elem->kind == Ast_FieldValue) {
+						error(elem, "'field = value' in a bit_set a literal is not allowed");
+						continue;
+					}
+
+					check_expr(c, o, elem);
+
+					if (is_constant) {
+						is_constant = o->mode == Addressing_Constant;
+					}
+
+					check_assignment(c, o, t->BitSet.base_type, str_lit("bit_set literal"));
+				}
+			}
+			break;
+		}
+
 		default: {
 			if (cl->elems.count == 0) {
 				break; // NOTE(bill): No need to init
@@ -6108,6 +6142,24 @@ gbString write_expr_to_string(gbString str, Ast *node) {
 		str = write_expr_to_string(str, at->elem);
 	case_end;
 
+	case_ast_node(bf, BitFieldType, node);
+		str = gb_string_appendc(str, "bit_field ");
+		if (bf->align) {
+			str = gb_string_appendc(str, "#align ");
+			str = write_expr_to_string(str, bf->align);
+		}
+		str = gb_string_appendc(str, "{");
+		str = write_struct_fields_to_string(str, bf->fields);
+		str = gb_string_appendc(str, "}");
+	case_end;
+
+	case_ast_node(bs, BitSetType, node);
+		str = gb_string_appendc(str, "bit_set[");
+		str = write_expr_to_string(str, bs->base_type);
+		str = gb_string_appendc(str, "]");
+	case_end;
+
+
 	case_ast_node(mt, MapType, node);
 		str = gb_string_appendc(str, "map[");
 		str = write_expr_to_string(str, mt->key);

src/check_type.cpp

@@ -681,6 +681,59 @@ void check_bit_field_type(CheckerContext *ctx, Type *bit_field_type, Ast *node)
 }
 
 
+void check_bit_set_type(CheckerContext *ctx, Type *type, Ast *node) {
+	ast_node(bs, BitSetType, node);
+	GB_ASSERT(type->kind == Type_BitSet);
+
+	Type *bt = check_type_expr(ctx, bs->base_type, nullptr);
+
+	type->BitSet.base_type = bt;
+	if (!is_type_enum(bt)) {
+		error(bs->base_type, "Expected an enum type for a bit_set");
+	} else {
+		Type *et = base_type(bt);
+		GB_ASSERT(et->kind == Type_Enum);
+		if (!is_type_integer(et->Enum.base_type)) {
+			error(bs->base_type, "Enum type for bit_set must be an integer");
+			return;
+		}
+		i64 min_value = 0;
+		i64 max_value = 0;
+		BigInt v64 = {}; big_int_from_i64(&v64, 64);
+
+		for_array(i, et->Enum.fields) {
+			Entity *e = et->Enum.fields[i];
+			if (e->kind != Entity_Constant) {
+				continue;
+			}
+			ExactValue value = exact_value_to_integer(e->Constant.value);
+			GB_ASSERT(value.kind == ExactValue_Integer);
+			BigInt v = value.value_integer;
+
+
+			if (big_int_cmp(&v, &BIG_INT_ZERO) < 0) {
+				error(bs->base_type, "Negative enum values are not allowed in a bit_set");
+				return;
+			}
+
+			if (big_int_cmp(&v, &v64) >= 0) {
+				error(bs->base_type, "Enum values overe 64 are not allowed in a bit_set");
+				return;
+			}
+
+			i64 x = big_int_to_i64(&v);
+			min_value = gb_min(min_value, x);
+			max_value = gb_max(max_value, x);
+		}
+
+
+		type->BitSet.min = min_value;
+		type->BitSet.max = max_value;
+	}
+
+}
+
+
 bool check_type_specialization_to(CheckerContext *ctx, Type *specialization, Type *type, bool compound, bool modify_type) {
 	if (type == nullptr ||
 	    type == t_invalid) {
@@ -1014,6 +1067,12 @@ Type *check_get_params(CheckerContext *ctx, Scope *scope, Ast *_params, bool *is
 						type = t_invalid;
 					}
 				}
+
+				if (p->flags&FieldFlag_auto_cast) {
+					error(name, "'auto_cast' can only be applied variable fields");
+					p->flags &= ~FieldFlag_auto_cast;
+				}
+
 				param = alloc_entity_type_name(scope, name->Ident.token, type, EntityState_Resolved);
 				param->TypeName.is_type_alias = true;
 			} else {
@@ -1885,18 +1944,28 @@ bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, Type *named_t
 		check_enum_type(ctx, *type, named_type, e);
 		check_close_scope(ctx);
 		(*type)->Enum.node = e;
+
+		ctx->in_enum_type = false;
 		return true;
 	case_end;
 
 	case_ast_node(et, BitFieldType, e);
 		*type = alloc_type_bit_field();
 		set_base_type(named_type, *type);
-		check_open_scope(ctx, e);
 		check_bit_field_type(ctx, *type, e);
+		return true;
+	case_end;
+
+	case_ast_node(bs, BitSetType, e);
+		*type = alloc_type_bit_set();
+		set_base_type(named_type, *type);
+		check_open_scope(ctx, e);
+		check_bit_set_type(ctx, *type, e);
 		check_close_scope(ctx);
 		return true;
 	case_end;
 
+
 	case_ast_node(pt, ProcType, e);
 		bool ips = ctx->in_polymorphic_specialization;
 		defer (ctx->in_polymorphic_specialization = ips);

src/checker.cpp

@@ -1043,6 +1043,10 @@ void add_type_info_type(CheckerContext *c, Type *t) {
 		add_type_info_type(c, bt->Enum.base_type);
 		break;
 
+	case Type_BitSet:
+		add_type_info_type(c, bt->BitSet.base_type);
+		break;
+
 	case Type_Union:
 		add_type_info_type(c, t_int);
 		add_type_info_type(c, t_type_info_ptr);
@@ -1600,6 +1604,7 @@ void init_core_type_info(Checker *c) {
 	t_type_info_enum          = find_core_type(c, str_lit("Type_Info_Enum"));
 	t_type_info_map           = find_core_type(c, str_lit("Type_Info_Map"));
 	t_type_info_bit_field     = find_core_type(c, str_lit("Type_Info_Bit_Field"));
+	t_type_info_bit_set       = find_core_type(c, str_lit("Type_Info_Bit_Set"));
 
 	t_type_info_named_ptr         = alloc_type_pointer(t_type_info_named);
 	t_type_info_integer_ptr       = alloc_type_pointer(t_type_info_integer);
@@ -1621,6 +1626,7 @@ void init_core_type_info(Checker *c) {
 	t_type_info_enum_ptr          = alloc_type_pointer(t_type_info_enum);
 	t_type_info_map_ptr           = alloc_type_pointer(t_type_info_map);
 	t_type_info_bit_field_ptr     = alloc_type_pointer(t_type_info_bit_field);
+	t_type_info_bit_set_ptr       = alloc_type_pointer(t_type_info_bit_set);
 }
 
 void init_mem_allocator(Checker *c) {

src/ir.cpp

@@ -3275,8 +3275,6 @@ irValue *ir_emit_conv(irProcedure *proc, irValue *value, Type *t) {
 
 	// boolean -> boolean/integer
 	if (is_type_boolean(src) && (is_type_boolean(dst) || is_type_integer(dst))) {
-		GB_ASSERT(src != t_llvm_bool);
-
 		irValue *b = ir_emit(proc, ir_instr_binary_op(proc, Token_NotEq, value, v_zero, t_llvm_bool));
 		return ir_emit(proc, ir_instr_conv(proc, irConv_zext, b, t_llvm_bool, t));
 	}
@@ -4247,7 +4245,7 @@ irValue *ir_find_global_variable(irProcedure *proc, String name) {
 }
 
 void ir_build_stmt_list(irProcedure *proc, Array<Ast *> stmts);
-
+void ir_build_assign_op(irProcedure *proc, irAddr const &lhs, irValue *value, TokenKind op);
 
 bool is_double_pointer(Type *t) {
 	if (!is_type_pointer(t)) {
@@ -5610,8 +5608,9 @@ irAddr ir_build_addr(irProcedure *proc, Ast *expr) {
 
 		Type *et = nullptr;
 		switch (bt->kind) {
-		case Type_Array:  et = bt->Array.elem;  break;
+		case Type_Array:  et = bt->Array.elem;       break;
-		case Type_Slice:  et = bt->Slice.elem;  break;
+		case Type_Slice:  et = bt->Slice.elem;       break;
+		case Type_BitSet: et = bt->BitSet.base_type; break;
 		}
 
 		String proc_name = {};
@@ -5821,7 +5820,42 @@ irAddr ir_build_addr(irProcedure *proc, Ast *expr) {
 					ir_emit_store(proc, gep, fv);
 				}
 			}
+
+			break;
 		}
+
+		case Type_BitSet: {
+
+			i64 sz = type_size_of(type);
+			if (cl->elems.count > 0 && sz > 0) {
+				ir_emit_store(proc, v, ir_add_module_constant(proc->module, type, exact_value_compound(expr)));
+
+				irValue *lower = ir_value_constant(t_int, exact_value_i64(bt->BitSet.min));
+				for_array(i, cl->elems) {
+					Ast *elem = cl->elems[i];
+					GB_ASSERT(elem->kind != Ast_FieldValue);
+
+					if (ir_is_elem_const(proc->module, elem, et)) {
+						continue;
+					}
+
+					irValue *expr = ir_build_expr(proc, elem);
+					GB_ASSERT(ir_type(expr)->kind != Type_Tuple);
+
+					Type *it = bit_set_to_int(bt);
+					irValue *e = ir_emit_conv(proc, expr, it);
+					e = ir_emit_arith(proc, Token_Sub, e, lower, it);
+					e = ir_emit_arith(proc, Token_Shl, v_one, e, it);
+
+					irValue *old_value = ir_emit_bitcast(proc, ir_emit_load(proc, v), it);
+					irValue *new_value = ir_emit_arith(proc, Token_Or, old_value, e, it);
+					new_value = ir_emit_bitcast(proc, new_value, type);
+					ir_emit_store(proc, v, new_value);
+				}
+			}
+			break;
+		}
+
 		}
 
 		return ir_addr(v);
@@ -8025,8 +8059,14 @@ void ir_setup_type_info_data(irProcedure *proc) { // NOTE(bill): Setup type_info
 			}
 			break;
 		}
-		}
 
+		case Type_BitSet:
+			ir_emit_comment(proc, str_lit("Type_Info_Bit_Set"));
+			tag = ir_emit_conv(proc, variant_ptr, t_type_info_bit_set_ptr);
+			ir_emit_store(proc, ir_emit_struct_ep(proc, tag, 0), ir_get_type_info_ptr(proc, t->BitSet.base_type));
+			break;
+
+		}
 
 		if (tag != nullptr) {
 			Type *tag_type = type_deref(ir_type(tag));

src/ir_print.cpp

@@ -65,6 +65,10 @@ void ir_write_i64(irFileBuffer *f, i64 i) {
 	String str = i64_to_string(i, f->buf, IR_FILE_BUFFER_BUF_LEN-1);
 	ir_write_string(f, str);
 }
+void ir_write_u64(irFileBuffer *f, u64 i) {
+	String str = u64_to_string(i, f->buf, IR_FILE_BUFFER_BUF_LEN-1);
+	ir_write_string(f, str);
+}
 void ir_write_big_int(irFileBuffer *f, BigInt const &x) {
 	i64 i = 0;
 	if (x.neg) {
@@ -502,6 +506,19 @@ void ir_print_type(irFileBuffer *f, irModule *m, Type *t, bool in_struct) {
 		ir_fprintf(f, "{[0 x <%lld x i8>], [%lld x i8]}", align, size);
 		break;
 	}
+
+	case Type_BitSet: {
+		i64 align = type_align_of(t);
+		i64 size  = type_size_of(t);
+		switch (size) {
+		case 0: ir_write_str_lit(f, "{}");  return;
+		case 1: ir_write_str_lit(f, "i8");  return;
+		case 2: ir_write_str_lit(f, "i16"); return;
+		case 4: ir_write_str_lit(f, "i32"); return;
+		case 8: ir_write_str_lit(f, "i64"); return;
+		default: GB_PANIC("Unknown bit_set size"); break;
+		}
+	}
 	}
 }
 
@@ -766,6 +783,34 @@ void ir_print_exact_value(irFileBuffer *f, irModule *m, ExactValue value, Type *
 
 			ir_write_byte(f, '}');
 			if (type->Struct.is_packed) ir_write_byte(f, '>');
+		} else if (is_type_bit_set(type)) {
+			ast_node(cl, CompoundLit, value.value_compound);
+			if (cl->elems.count == 0) {
+				ir_write_str_lit(f, "zeroinitializer");
+				break;
+			}
+
+			i64 sz = type_size_of(type);
+			if (sz == 0) {
+				ir_write_str_lit(f, "zeroinitializer");
+				break;
+			}
+
+			u64 bits = 0;
+			for_array(i, cl->elems) {
+				Ast *e = cl->elems[i];
+				GB_ASSERT(e->kind != Ast_FieldValue);
+
+				TypeAndValue tav = e->tav;
+				if (tav.mode != Addressing_Constant) {
+					continue;
+				}
+				GB_ASSERT(tav.value.kind == ExactValue_Integer);
+				i64 v = big_int_to_i64(&tav.value.value_integer);
+				i64 lower = type->BitSet.min;
+				bits |= 1ull<<cast(u64)(v-lower);
+			}
+			ir_write_u64(f, bits);
 		} else {
 			ir_write_str_lit(f, "zeroinitializer");
 		}

src/parser.cpp

@@ -89,6 +89,7 @@ Token ast_token(Ast *node) {
 	case Ast_UnionType:        return node->UnionType.token;
 	case Ast_EnumType:         return node->EnumType.token;
 	case Ast_BitFieldType:     return node->BitFieldType.token;
+	case Ast_BitSetType:       return node->BitSetType.token;
 	case Ast_MapType:          return node->MapType.token;
 	}
 
@@ -344,6 +345,10 @@ Ast *clone_ast(Ast *node) {
 	case Ast_BitFieldType:
 		n->BitFieldType.fields = clone_ast_array(n->BitFieldType.fields);
 		n->BitFieldType.align = clone_ast(n->BitFieldType.align);
+		break;
+	case Ast_BitSetType:
+		n->BitSetType.base_type = clone_ast(n->BitSetType.base_type);
+		break;
 	case Ast_MapType:
 		n->MapType.count = clone_ast(n->MapType.count);
 		n->MapType.key   = clone_ast(n->MapType.key);
@@ -922,6 +927,13 @@ Ast *ast_bit_field_type(AstFile *f, Token token, Array<Ast *> fields, Ast *align
 	return result;
 }
 
+Ast *ast_bit_set_type(AstFile *f, Token token, Ast *base_type) {
+	Ast *result = alloc_ast_node(f, Ast_BitSetType);
+	result->BitSetType.token = token;
+	result->BitSetType.base_type = base_type;
+	return result;
+}
+
 Ast *ast_map_type(AstFile *f, Token token, Ast *key, Ast *value) {
 	Ast *result = alloc_ast_node(f, Ast_MapType);
 	result->MapType.token = token;
@@ -1962,6 +1974,15 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 		return ast_bit_field_type(f, token, fields, align);
 	} break;
 
+	case Token_bit_set: {
+		Token token = expect_token(f, Token_bit_set);
+		Token open = expect_token(f, Token_OpenBracket);
+		Ast *base_type = parse_type(f);
+		Token close = expect_token(f, Token_CloseBracket);
+
+		return ast_bit_set_type(f, token, base_type);
+	}
+
 	default: {
 		#if 0
 		Ast *type = parse_type_or_ident(f);

src/parser.hpp

@@ -480,6 +480,10 @@ AST_KIND(_TypeBegin, "", bool) \
 		Array<Ast *> fields; /* FieldValue with : */ \
 		Ast *        align; \
 	}) \
+	AST_KIND(BitSetType, "bit set type", struct { \
+		Token token; \
+		Ast * base_type; \
+	}) \
 	AST_KIND(MapType, "map type", struct { \
 		Token token; \
 		Ast *count; \

src/tokenizer.cpp

@@ -105,6 +105,7 @@ TOKEN_KIND(Token__KeywordBegin, ""), \
 	TOKEN_KIND(Token_union,       "union"),       \
 	TOKEN_KIND(Token_enum,        "enum"),        \
 	TOKEN_KIND(Token_bit_field,   "bit_field"),   \
+	TOKEN_KIND(Token_bit_set,     "bit_set"),     \
 	TOKEN_KIND(Token_map,         "map"),         \
 	TOKEN_KIND(Token_static,      "static"),      \
 	TOKEN_KIND(Token_dynamic,     "dynamic"),     \

src/types.cpp

@@ -178,6 +178,11 @@ struct TypeStruct {
 		Scope *         scope;                            \
 		i64             custom_align;                     \
 	})                                                    \
+	TYPE_KIND(BitSet, struct {                            \
+		Type *base_type;                                  \
+		i64   min;                                        \
+		i64   max;                                        \
+	})                                                    \
 
 
 
@@ -376,6 +381,7 @@ gb_global Type *t_type_info_union             = nullptr;
 gb_global Type *t_type_info_enum              = nullptr;
 gb_global Type *t_type_info_map               = nullptr;
 gb_global Type *t_type_info_bit_field         = nullptr;
+gb_global Type *t_type_info_bit_set           = nullptr;
 
 gb_global Type *t_type_info_named_ptr         = nullptr;
 gb_global Type *t_type_info_integer_ptr       = nullptr;
@@ -398,6 +404,7 @@ gb_global Type *t_type_info_union_ptr         = nullptr;
 gb_global Type *t_type_info_enum_ptr          = nullptr;
 gb_global Type *t_type_info_map_ptr           = nullptr;
 gb_global Type *t_type_info_bit_field_ptr     = nullptr;
+gb_global Type *t_type_info_bit_set_ptr       = nullptr;
 
 gb_global Type *t_allocator                   = nullptr;
 gb_global Type *t_allocator_ptr               = nullptr;
@@ -607,6 +614,10 @@ Type *alloc_type_bit_field() {
 	Type *t = alloc_type(Type_BitField);
 	return t;
 }
+Type *alloc_type_bit_set() {
+	Type *t = alloc_type(Type_BitSet);
+	return t;
+}
 
 
 
@@ -903,6 +914,10 @@ bool is_type_bit_field_value(Type *t) {
 	t = base_type(t);
 	return (t->kind == Type_BitFieldValue);
 }
+bool is_type_bit_set(Type *t) {
+	t = base_type(t);
+	return (t->kind == Type_BitSet);
+}
 bool is_type_map(Type *t) {
 	t = base_type(t);
 	return t->kind == Type_Map;
@@ -963,6 +978,19 @@ bool is_type_valid_for_keys(Type *t) {
 	return false;
 }
 
+Type *bit_set_to_int(Type *t) {
+	GB_ASSERT(is_type_bit_set(t));
+	i64 sz = type_size_of(t);
+	switch (sz) {
+	case 1: return t_u8;
+	case 2: return t_u16;
+	case 4: return t_u32;
+	case 8: return t_u64;
+	}
+	GB_PANIC("Unknown bit_set size");
+	return nullptr;
+}
+
 
 bool is_type_indexable(Type *t) {
 	Type *bt = base_type(t);
@@ -1108,6 +1136,10 @@ bool type_has_nil(Type *t) {
 		}
 		return false;
 	} break;
+	case Type_Enum:
+	case Type_BitSet:
+	case Type_BitField:
+		return true;
 	case Type_Slice:
 	case Type_Proc:
 	case Type_Pointer:
@@ -1158,6 +1190,9 @@ bool is_type_comparable(Type *t) {
 		return is_type_comparable(t->Array.elem);
 	case Type_Proc:
 		return true;
+
+	case Type_BitSet:
+		return true;
 	}
 	return false;
 }
@@ -1237,6 +1272,12 @@ bool are_types_identical(Type *x, Type *y) {
 		}
 		break;
 
+	case Type_BitSet:
+		if (y->kind == Type_BitSet) {
+			return are_types_identical(x->BitSet.base_type, y->BitSet.base_type);
+		}
+		break;
+
 
 	case Type_Enum:
 		return x == y; // NOTE(bill): All enums are unique
@@ -2023,6 +2064,16 @@ i64 type_align_of_internal(Type *t, TypePath *path) {
 		}
 		return gb_clamp(next_pow2(align), 1, build_context.max_align);
 	} break;
+
+	case Type_BitSet: {
+		i64 bits = t->BitSet.max - t->BitSet.min + 1;
+		if (bits == 0)  return 0;
+		if (bits <= 8)  return 1;
+		if (bits <= 16) return 2;
+		if (bits <= 32) return 4;
+		if (bits <= 64) return 8;
+		GB_PANIC("unknown bit_set size");
+	}
 	}
 
 	// return gb_clamp(next_pow2(type_size_of(t)), 1, build_context.max_align);
@@ -2239,6 +2290,16 @@ i64 type_size_of_internal(Type *t, TypePath *path) {
 		GB_ASSERT((bits%8) == 0);
 		return bits/8;
 	} break;
+
+	case Type_BitSet: {
+		i64 bits = t->BitSet.max - t->BitSet.min + 1;
+		if (bits == 0)  return 0;
+		if (bits <= 8)  return 1;
+		if (bits <= 16) return 2;
+		if (bits <= 32) return 4;
+		if (bits <= 64) return 8;
+		GB_PANIC("unknown bit_set size");
+	}
 	}
 
 	// Catch all
@@ -2549,6 +2610,12 @@ gbString write_type_to_string(gbString str, Type *type) {
 	case Type_BitFieldValue:
 		str = gb_string_append_fmt(str, "(bit field value with %d bits)", cast(int)type->BitFieldValue.bits);
 		break;
+
+	case Type_BitSet:
+		str = gb_string_appendc(str, "bit_field[");
+		str = write_type_to_string(str, type->BitSet.base_type);
+		str = gb_string_appendc(str, "]");
+		break;
 	}
 
 	return str;