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stage1: Fix edge case in Union ZigValue generation

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Unions that passed the one_possible_value check were incorrectly
generated, none of their internal fields were initialized.

Fixes #6758
This commit is contained in:
LemonBoy 2020-10-21 15:35:40 +02:00 committed by Andrew Kelley
parent 52879b50d9
commit 44f8e6a534
2 changed files with 39 additions and 1 deletions
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16
src/stage1/analyze.cpp
View File

@ -5973,7 +5973,8 @@ ZigValue *get_the_one_possible_value(CodeGen *g, ZigType *type_entry) {
}
ZigType *field_type = resolve_struct_field_type(g, field);
assert(field_type != nullptr);
result->data.x_struct.fields[i] = get_the_one_possible_value(g, field_type);
copy_const_val(g, result->data.x_struct.fields[i],
get_the_one_possible_value(g, field_type));
}
} else if (result->type->id == ZigTypeIdArray) {
// The elements array cannot be left unpopulated
@ -5986,7 +5987,20 @@ ZigValue *get_the_one_possible_value(CodeGen *g, ZigType *type_entry) {
ZigValue *elem_val = &result->data.x_array.data.s_none.elements[i];
copy_const_val(g, elem_val, get_the_one_possible_value(g, elem_type));
}
} else if (result->type->id == ZigTypeIdUnion) {
// The payload/tag fields cannot be left unpopulated
ZigType *union_type = result->type;
assert(union_type->data.unionation.src_field_count == 1);
TypeUnionField *only_field = &union_type->data.unionation.fields[0];
ZigType *field_type = resolve_union_field_type(g, only_field);
assert(field_type);
bigint_init_unsigned(&result->data.x_union.tag, 0);
result->data.x_union.payload = g->pass1_arena->create<ZigValue>();
copy_const_val(g, result->data.x_union.payload,
get_the_one_possible_value(g, field_type));
} else if (result->type->id == ZigTypeIdPointer) {
// Make sure nobody can modify the constant value
result->data.x_ptr.mut = ConstPtrMutComptimeConst;
result->data.x_ptr.special = ConstPtrSpecialRef;
result->data.x_ptr.data.ref.pointee = get_the_one_possible_value(g, result->type->data.pointer.child_type);
}

24
test/stage1/behavior/union.zig
View File

@ -713,3 +713,27 @@ test "switching on non exhaustive union" {
S.doTheTest();
comptime S.doTheTest();
}
test "containers with single-field enums" {
const S = struct {
const A = union(enum) { f1 };
const B = union(enum) { f1: void };
const C = struct { a: A };
const D = struct { a: B };
fn doTheTest() void {
var array1 = [1]A{A{ .f1 = {} }};
var array2 = [1]B{B{ .f1 = {} }};
expect(array1[0] == .f1);
expect(array2[0] == .f1);
var struct1 = C{ .a = A{ .f1 = {} } };
var struct2 = D{ .a = B{ .f1 = {} } };
expect(struct1.a == .f1);
expect(struct2.a == .f1);
}
};
S.doTheTest();
comptime S.doTheTest();
}