authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2016-08-25 20:52:35-07:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2016-08-29 22:14:10-07:00
log6e6d138c2f50f95fe9c6b4acbc16ffa17475a4a5
treef89b50b2a9f57c9149b555240e2e9a2fc760c6b8
parent651dc31247c2f637925ed6a6e92c8bc1a19efd5c

add ability to explicitly cast enum with no payload to int

5 files changed, 44 insertions(+), 1 deletions(-)

src/all_types.hpp+1
......@@ -404,6 +404,7 @@ enum CastOp {
404404 CastOpBoolToInt,
405405 CastOpResizeSlice,
406406 CastOpIntToEnum,
407 CastOpEnumToInt,
407408 CastOpBytesToSlice,
408409};
409410
src/analyze.cpp+14-1
......@@ -2641,7 +2641,12 @@ static TypeTableEntry *analyze_container_init_expr(CodeGen *g, ImportTableEntry
26412641 codegen->type_entry = fixed_size_array_type;
26422642 codegen->source_node = node;
26432643 if (!const_val->ok) {
2644 context->fn_entry->struct_val_expr_alloca_list.append(codegen);
2644 if (!context->fn_entry) {
2645 add_node_error(g, node,
2646 buf_sprintf("unable to evaluate constant expression"));
2647 } else {
2648 context->fn_entry->struct_val_expr_alloca_list.append(codegen);
2649 }
26452650 }
26462651
26472652 return fixed_size_array_type;
......@@ -4601,6 +4606,14 @@ static TypeTableEntry *analyze_cast_expr(CodeGen *g, ImportTableEntry *import, B
46014606 return resolve_cast(g, context, node, expr_node, wanted_type, CastOpIntToEnum, false);
46024607 }
46034608
4609 // explicit cast from enum type with no payload to integer
4610 if (wanted_type->id == TypeTableEntryIdInt &&
4611 actual_type->id == TypeTableEntryIdEnum &&
4612 actual_type->data.enumeration.gen_field_count == 0)
4613 {
4614 return resolve_cast(g, context, node, expr_node, wanted_type, CastOpEnumToInt, false);
4615 }
4616
46044617 add_node_error(g, node,
46054618 buf_sprintf("invalid cast from type '%s' to '%s'",
46064619 buf_ptr(&actual_type->name),
src/codegen.cpp+2
......@@ -1062,6 +1062,8 @@ static LLVMValueRef gen_cast_expr(CodeGen *g, AstNode *node) {
10621062
10631063 case CastOpIntToEnum:
10641064 return gen_widen_or_shorten(g, node, actual_type, wanted_type->data.enumeration.tag_type, expr_val);
1065 case CastOpEnumToInt:
1066 return gen_widen_or_shorten(g, node, actual_type->data.enumeration.tag_type, wanted_type, expr_val);
10651067 }
10661068 zig_unreachable();
10671069}
src/eval.cpp+3
......@@ -694,6 +694,9 @@ void eval_const_expr_implicit_cast(CastOp cast_op,
694694 const_val->ok = true;
695695 break;
696696 }
697 case CastOpEnumToInt:
698 bignum_init_unsigned(&const_val->data.x_bignum, other_val->data.x_enum.tag);
699 const_val->ok = true;
697700 }
698701}
699702
test/cases/enum_to_int.zig created+24
......@@ -0,0 +1,24 @@
1const assert = @import("std").debug.assert;
2
3enum Number {
4 Zero,
5 One,
6 Two,
7 Three,
8 Four,
9}
10
11#attribute("test")
12fn enumToInt() {
13 shouldEqual(Number.Zero, 0);
14 shouldEqual(Number.One, 1);
15 shouldEqual(Number.Two, 2);
16 shouldEqual(Number.Three, 3);
17 shouldEqual(Number.Four, 4);
18}
19
20// TODO add test with this disabled
21#static_eval_enable(false)
22fn shouldEqual(n: Number, expected: usize) {
23 assert(usize(n) == expected);
24}