Merge pull request #3200 from LemonBoy/eq-tagged-union

Allow comparison between union tag and enum literal
master
Andrew Kelley 2019-09-09 16:17:45 -04:00 committed by GitHub
commit a3993465fe
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2 changed files with 55 additions and 0 deletions

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@ -13228,6 +13228,46 @@ static IrInstruction *ir_analyze_bin_op_cmp(IrAnalyze *ira, IrInstructionBinOp *
ir_add_error_node(ira, source_node, buf_sprintf("comparison of '%s' with null",
buf_ptr(&non_null_type->name)));
return ira->codegen->invalid_instruction;
} else if (is_equality_cmp && (
(op1->value.type->id == ZigTypeIdEnumLiteral && op2->value.type->id == ZigTypeIdUnion) ||
(op2->value.type->id == ZigTypeIdEnumLiteral && op1->value.type->id == ZigTypeIdUnion)))
{
// Support equality comparison between a union's tag value and a enum literal
IrInstruction *union_val = op1->value.type->id == ZigTypeIdUnion ? op1 : op2;
IrInstruction *enum_val = op1->value.type->id == ZigTypeIdUnion ? op2 : op1;
ZigType *tag_type = union_val->value.type->data.unionation.tag_type;
assert(tag_type != nullptr);
IrInstruction *casted_union = ir_implicit_cast(ira, union_val, tag_type);
if (type_is_invalid(casted_union->value.type))
return ira->codegen->invalid_instruction;
IrInstruction *casted_val = ir_implicit_cast(ira, enum_val, tag_type);
if (type_is_invalid(casted_val->value.type))
return ira->codegen->invalid_instruction;
if (instr_is_comptime(casted_union)) {
ConstExprValue *const_union_val = ir_resolve_const(ira, casted_union, UndefBad);
if (!const_union_val)
return ira->codegen->invalid_instruction;
ConstExprValue *const_enum_val = ir_resolve_const(ira, casted_val, UndefBad);
if (!const_enum_val)
return ira->codegen->invalid_instruction;
Cmp cmp_result = bigint_cmp(&const_union_val->data.x_union.tag, &const_enum_val->data.x_enum_tag);
bool bool_result = (op_id == IrBinOpCmpEq) ? cmp_result == CmpEQ : cmp_result != CmpEQ;
return ir_const_bool(ira, &bin_op_instruction->base, bool_result);
}
IrInstruction *result = ir_build_bin_op(&ira->new_irb,
bin_op_instruction->base.scope, bin_op_instruction->base.source_node,
op_id, casted_union, casted_val, bin_op_instruction->safety_check_on);
result->value.type = ira->codegen->builtin_types.entry_bool;
return result;
}
if (op1->value.type->id == ZigTypeIdErrorSet && op2->value.type->id == ZigTypeIdErrorSet) {

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@ -467,3 +467,18 @@ test "union no tag with struct member" {
var u = Union{ .s = Struct{} };
u.foo();
}
fn testComparison() void {
var x = Payload{.A = 42};
expect(x == .A);
expect(x != .B);
expect(x != .C);
expect((x == .B) == false);
expect((x == .C) == false);
expect((x != .A) == false);
}
test "comparison between union and enum literal" {
testComparison();
comptime testComparison();
}