Integer Enumerations

5 files changed, 204 insertions, 19 deletions

diff --git a/src/checker/expr.cpp b/src/checker/expr.cpp
index 415bbe545..128d9e6e0 100644
--- a/src/checker/expr.cpp
+++ b/src/checker/expr.cpp
@@ -57,6 +57,73 @@ void check_struct_type(Checker *c, Type *struct_type, AstNode *node) {
 	struct_type->structure.is_packed = st->is_packed;
 }
 
+void check_enum_type(Checker *c, Type *enum_type, AstNode *node) {
+	GB_ASSERT(node->kind == AstNode_EnumType);
+	GB_ASSERT(enum_type->kind == Type_Enumeration);
+	ast_node(et, EnumType, node);
+
+	Map<Entity *> entity_map = {};
+	map_init(&entity_map, gb_heap_allocator());
+	defer (map_destroy(&entity_map));
+
+	Type *base_type = t_int;
+	if (et->base_type != NULL) {
+		base_type = check_type(c, et->base_type);
+	}
+
+	if (base_type == NULL || !is_type_integer(base_type)) {
+		error(&c->error_collector, et->token, "Base type for enumeration must be an integer");
+		return;
+	} else
+	if (base_type == NULL) {
+		base_type = t_int;
+	}
+	enum_type->enumeration.base = base_type;
+
+	Entity **fields = gb_alloc_array(c->allocator, Entity *, et->field_count);
+	isize field_index = 0;
+	ExactValue iota = make_exact_value_integer(-1);
+	for (AstNode *field = et->field_list; field != NULL; field = field->next) {
+		ast_node(f, FieldValue, field);
+		Token name_token = f->field->Ident.token;
+
+		Operand o = {};
+		if (f->value != NULL) {
+			check_expr(c, &o, f->value);
+			if (o.mode != Addressing_Constant) {
+				error(&c->error_collector, ast_node_token(f->value), "Enumeration value must be a constant integer");
+				o.mode = Addressing_Invalid;
+			}
+			if (o.mode != Addressing_Invalid) {
+				check_assignment(c, &o, base_type, make_string("enumeration"));
+			}
+			if (o.mode != Addressing_Invalid) {
+				iota = o.value;
+			} else {
+				Token add_token = {Token_Add};
+				iota = exact_binary_operator_value(add_token, iota, make_exact_value_integer(1));
+			}
+		} else {
+			Token add_token = {Token_Add};
+			iota = exact_binary_operator_value(add_token, iota, make_exact_value_integer(1));
+		}
+
+		Entity *e = make_entity_constant(c->allocator, c->context.scope, name_token, enum_type, iota);
+
+		HashKey key = hash_string(name_token.string);
+		if (map_get(&entity_map, key)) {
+			// TODO(bill): Scope checking already checks the declaration
+			error(&c->error_collector, name_token, "`%.*s` is already declared in this enumeration", LIT(name_token.string));
+		} else {
+			map_set(&entity_map, key, e);
+			fields[field_index++] = e;
+		}
+		add_entity_use(&c->info, f->field, e);
+	}
+	enum_type->enumeration.fields = fields;
+	enum_type->enumeration.field_count = et->field_count;
+}
+
 Type *check_get_params(Checker *c, Scope *scope, AstNode *field_list, isize field_count) {
 	if (field_list == NULL || field_count == 0)
 		return NULL;
@@ -399,6 +466,13 @@ Type *check_type(Checker *c, AstNode *e, Type *named_type) {
 		goto end;
 	case_end;
 
+	case_ast_node(et, EnumType, e);
+		type = make_type_enumeration(c->allocator);
+		set_base_type(named_type, type);
+		check_enum_type(c, type, e);
+		goto end;
+	case_end;
+
 	case_ast_node(pt, PointerType, e);
 		type = make_type_pointer(c->allocator, check_type(c, pt->type));
 		set_base_type(named_type, type);
@@ -584,6 +658,7 @@ b32 check_value_is_expressible(Checker *c, ExactValue in_value, Type *type, Exac
 		if (out_value) *out_value = in_value;
 	}
 
+
 	return false;
 }
 
@@ -821,8 +896,8 @@ b32 check_castable_to(Checker *c, Operand *operand, Type *y) {
 		return true;
 
 	Type *x = operand->type;
-	Type *xb = get_base_type(x);
-	Type *yb = get_base_type(y);
+	Type *xb = get_enum_base_type(get_base_type(x));
+	Type *yb = get_enum_base_type(get_base_type(y));
 	if (are_types_identical(xb, yb))
 		return true;
 
@@ -870,13 +945,12 @@ b32 check_castable_to(Checker *c, Operand *operand, Type *y) {
 	}
 
 	// proc <-> proc
-	if (is_type_proc(xb), is_type_proc(yb)) {
+	if (is_type_proc(xb) && is_type_proc(yb)) {
 		return true;
 	}
 
-
 	// proc -> rawptr
-	if (is_type_proc(xb), is_type_rawptr(yb)) {
+	if (is_type_proc(xb) && is_type_rawptr(yb)) {
 		return true;
 	}
 
@@ -903,6 +977,7 @@ void check_binary_expr(Checker *c, Operand *x, AstNode *node) {
 
 		Type *base_type = get_base_type(type);
 		if (is_const_expr && is_type_constant_type(base_type)) {
+
 			if (base_type->kind == Type_Basic) {
 				if (check_value_is_expressible(c, x->value, base_type, &x->value)) {
 					can_convert = true;
@@ -1167,7 +1242,7 @@ void convert_to_typed(Checker *c, Operand *operand, Type *target_type) {
 		return;
 	}
 
-	Type *t = get_base_type(target_type);
+	Type *t = get_enum_base_type(get_base_type(target_type));
 	switch (t->kind) {
 	case Type_Basic:
 		if (operand->mode == Addressing_Constant) {
@@ -1239,7 +1314,7 @@ b32 check_index_value(Checker *c, AstNode *index_value, i64 max_count, i64 *valu
 		return false;
 	}
 
-	if (!is_type_integer(operand.type)) {
+	if (!is_type_integer(get_enum_base_type(operand.type))) {
 		gbString expr_str = expr_to_string(operand.expr);
 		error(&c->error_collector, ast_node_token(operand.expr),
 		            "Index `%s` must be an integer", expr_str);
@@ -1300,6 +1375,18 @@ Entity *lookup_field(Type *type, AstNode *field_node, isize *index = NULL) {
 			}
 		}
 		break;
+	case Type_Enumeration:
+		for (isize i = 0; i < type->enumeration.field_count; i++) {
+			Entity *f = type->enumeration.fields[i];
+			GB_ASSERT(f->kind == Entity_Constant);
+			String str = f->token.string;
+			if (are_strings_equal(field_str, str)) {
+				if (index) *index = i;
+				return f;
+			}
+		}
+		break;
+		break;
 	// TODO(bill): Other types and extra "hidden" fields (e.g. introspection stuff)
 	// TODO(bill): Allow for access of field through index? e.g. `x.3` will get member of index 3
 	// Or is this only suitable if tuples are first-class?
@@ -1328,10 +1415,17 @@ void check_selector(Checker *c, Operand *operand, AstNode *node) {
 		}
 		add_entity_use(&c->info, selector, entity);
 
-		operand->type = entity->type;
-		operand->expr = node;
-		if (operand->mode != Addressing_Variable)
-			operand->mode = Addressing_Value;
+		if (is_type_enum(operand->type)) {
+			operand->type = entity->type;
+			operand->expr = node;
+			operand->mode = Addressing_Constant;
+			operand->value = entity->Constant.value;
+		} else {
+			operand->type = entity->type;
+			operand->expr = node;
+			if (operand->mode != Addressing_Variable)
+				operand->mode = Addressing_Value;
+		}
 	} else {
 		operand->mode = Addressing_Invalid;
 		operand->expr = node;
@@ -2046,7 +2140,7 @@ ExpressionKind check__expr_base(Checker *c, Operand *o, AstNode *node, Type *typ
 		} break;
 
 		default: {
-			gbString str = type_to_string(t);
+			gbString str = type_to_string(type);
 			error(&c->error_collector, ast_node_token(node), "Invalid compound literal type `%s`", str);
 			gb_string_free(str);
 			goto error;
diff --git a/src/checker/type.cpp b/src/checker/type.cpp
index 6613228e6..ed8130d1e 100644
--- a/src/checker/type.cpp
+++ b/src/checker/type.cpp
@@ -62,6 +62,7 @@ struct BasicType {
 	TYPE_KIND(Vector), \
 	TYPE_KIND(Slice), \
 	TYPE_KIND(Structure), \
+	TYPE_KIND(Enumeration), \
 	TYPE_KIND(Pointer), \
 	TYPE_KIND(Named), \
 	TYPE_KIND(Tuple), \
@@ -126,6 +127,11 @@ struct Type {
 			isize  param_count;
 			isize  result_count;
 		} proc;
+		struct {
+			Type *   base; // Default is `int`
+			Entity **fields; // Entity_Constant
+			isize    field_count;
+		} enumeration;
 	};
 };
 
@@ -181,6 +187,11 @@ Type *make_type_structure(gbAllocator a) {
 	return t;
 }
 
+Type *make_type_enumeration(gbAllocator a) {
+	Type *t = alloc_type(a, Type_Enumeration);
+	return t;
+}
+
 Type *make_type_pointer(gbAllocator a, Type *elem) {
 	Type *t = alloc_type(a, Type_Pointer);
 	t->pointer.elem = elem;
@@ -396,6 +407,17 @@ Type *base_vector_type(Type *t) {
 	}
 	return t;
 }
+b32 is_type_enum(Type *t) {
+	t = get_base_type(t);
+	return t->kind == Type_Enumeration;
+}
+Type *get_enum_base_type(Type *t) {
+	Type *bt = get_base_type(t);
+	if (is_type_enum(bt)) {
+		return bt->enumeration.base;
+	}
+	return t;
+}
 
 
 
@@ -417,6 +439,8 @@ b32 is_type_comparable(Type *t) {
 		return is_type_comparable(t->array.elem);
 	case Type_Vector:
 		return is_type_comparable(t->vector.elem);
+	case Type_Enumeration:
+		return is_type_comparable(t->enumeration.base);
 	case Type_Proc:
 		return true;
 	}
@@ -581,6 +605,9 @@ i64 type_align_of(BaseTypeSizes s, gbAllocator allocator, Type *t) {
 			return max;
 		}
 	} break;
+
+	case Type_Enumeration:
+		return type_align_of(s, allocator, t->enumeration.base);
 	}
 
 	return gb_clamp(next_pow2(type_size_of(s, allocator, t)), 1, s.max_align);
@@ -671,6 +698,9 @@ i64 type_size_of(BaseTypeSizes s, gbAllocator allocator, Type *t) {
 		type_set_offsets(s, allocator, t);
 		return t->structure.offsets[count-1] + type_size_of(s, allocator, t->structure.fields[count-1]->type);
 	} break;
+
+	case Type_Enumeration:
+		return type_size_of(s, allocator, t->enumeration.base);
 	}
 
 	// Catch all
@@ -727,6 +757,11 @@ gbString write_type_to_string(gbString str, Type *type) {
 		str = gb_string_appendc(str, "}");
 	} break;
 
+	case Type_Enumeration: {
+		str = gb_string_appendc(str, "enum ");
+		str = write_type_to_string(str, type->enumeration.base);
+	} break;
+
 	case Type_Pointer:
 		str = gb_string_appendc(str, "^");
 		str = write_type_to_string(str, type->pointer.elem);
diff --git a/src/codegen/print_llvm.cpp b/src/codegen/print_llvm.cpp
index 6a983d09d..cb2e1e3ad 100644
--- a/src/codegen/print_llvm.cpp
+++ b/src/codegen/print_llvm.cpp
@@ -157,6 +157,9 @@ void ssa_print_type(gbFile *f, BaseTypeSizes s, Type *t) {
 		}
 
 		break;
+	case Type_Enumeration:
+		ssa_print_type(f, s, t->enumeration.base);
+		break;
 	case Type_Pointer:
 		ssa_print_type(f, s, t->pointer.elem);
 		ssa_fprintf(f, "*");
diff --git a/src/codegen/ssa.cpp b/src/codegen/ssa.cpp
index 0d9780e74..ad5e997ed 100644
--- a/src/codegen/ssa.cpp
+++ b/src/codegen/ssa.cpp
@@ -1237,10 +1237,11 @@ ssaValue *ssa_emit_conv(ssaProcedure *proc, ssaValue *value, Type *t) {
 	}
 
 
-	Type *src = get_base_type(src_type);
-	Type *dst = get_base_type(t);
-	if (are_types_identical(t, src_type))
+	Type *src = get_enum_base_type(get_base_type(src_type));
+	Type *dst = get_enum_base_type(get_base_type(t));
+	if (are_types_identical(src, dst)) {
 		return value;
+	}
 
 	if (value->kind == ssaValue_Constant) {
 		if (dst->kind == Type_Basic) {
@@ -1383,7 +1384,6 @@ ssaValue *ssa_emit_conv(ssaProcedure *proc, ssaValue *value, Type *t) {
 		return v;
 	}
 
-
 	gb_printf_err("Not Identical %s != %s\n", type_to_string(src_type), type_to_string(t));
 	gb_printf_err("Not Identical %s != %s\n", type_to_string(src), type_to_string(dst));
 
diff --git a/src/parser.cpp b/src/parser.cpp
index a0d6084a7..beb0eb49f 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -218,6 +218,12 @@ AST_NODE_KIND(_TypeBegin, struct{}) \
 		isize field_count; \
 		b32 is_packed; \
 	}) \
+	AST_NODE_KIND(EnumType, struct { \
+		Token token; \
+		AstNode *base_type; \
+		AstNode *field_list; \
+		isize field_count; \
+	}) \
 AST_NODE_KIND(_TypeEnd, struct{}) \
 	AST_NODE_KIND(Count, struct{})
 
@@ -361,6 +367,8 @@ Token ast_node_token(AstNode *node) {
 		return node->VectorType.token;
 	case AstNode_StructType:
 		return node->StructType.token;
+	case AstNode_EnumType:
+		return node->EnumType.token;
 	}
 
 	return empty_token;
@@ -763,6 +771,16 @@ gb_inline AstNode *make_struct_type(AstFile *f, Token token, AstNode *field_list
 	return result;
 }
 
+
+gb_inline AstNode *make_enum_type(AstFile *f, Token token, AstNode *base_type, AstNode *field_list, isize field_count) {
+	AstNode *result = make_node(f, AstNode_EnumType);
+	result->EnumType.token = token;
+	result->EnumType.base_type = base_type;
+	result->EnumType.field_list = field_list;
+	result->EnumType.field_count = field_count;
+	return result;
+}
+
 gb_inline AstNode *make_type_decl(AstFile *f, Token token, AstNode *name, AstNode *type) {
 	AstNode *result = make_node(f, AstNode_TypeDecl);
 	result->TypeDecl.token = token;
@@ -1616,6 +1634,43 @@ AstNode *parse_identifier_or_type(AstFile *f) {
 		return make_struct_type(f, token, params, param_count, is_packed);
 	}
 
+	case Token_enum: {
+		Token token = expect_token(f, Token_enum);
+		AstNode *base_type = NULL;
+		Token open, close;
+		
+		if (f->cursor[0].kind != Token_OpenBrace) {
+			base_type = parse_type(f);
+		}
+
+		AstNode *root = NULL;
+		AstNode *curr = NULL;
+		isize field_count = 0;
+
+		open  = expect_token(f, Token_OpenBrace);
+
+		while (f->cursor[0].kind != Token_CloseBrace &&
+		       f->cursor[0].kind != Token_EOF) {
+			AstNode *name = parse_identifier(f);
+			AstNode *value = NULL;
+			Token eq = empty_token;
+			if (f->cursor[0].kind == Token_Eq) {
+				eq = expect_token(f, Token_Eq);
+				value = parse_value(f);
+			}
+			AstNode *field = make_field_value(f, name, value, eq);
+			DLIST_APPEND(root, curr, field);
+			field_count++;
+			if (f->cursor[0].kind != Token_Comma)
+				break;
+			next_token(f);
+		}
+
+		close = expect_token(f, Token_CloseBrace);
+
+		return make_enum_type(f, token, base_type, root, field_count);
+	}	
+
 	case Token_proc:
 		return parse_proc_type(f, NULL);
 
@@ -1763,9 +1818,6 @@ AstNode *parse_decl(AstFile *f, AstNode *name_list, isize name_count) {
 			}
 
 			AstNode *type = parse_type(f);
-			// if (type->kind != AstNode_StructType) {
-				// expect_token(f, Token_Semicolon);
-			// }
 			return make_type_decl(f, token, name_list, type);
 		} else if (f->cursor[0].kind == Token_proc &&
 		    declaration_kind == Declaration_Immutable) {
@@ -1980,6 +2032,7 @@ AstNode *parse_stmt(AstFile *f) {
 		if (s->kind != AstNode_ProcDecl &&
 		    (s->kind == AstNode_TypeDecl &&
 		     s->TypeDecl.type->kind != AstNode_StructType &&
+		     s->TypeDecl.type->kind != AstNode_EnumType &&
 		     s->TypeDecl.type->kind != AstNode_ProcType) &&
 		    !allow_token(f, Token_Semicolon)) {
 			// CLEANUP(bill): Semicolon handling in parser