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stage2: fix onePossibleValue of empty unions and enums

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Closes #13402
This commit is contained in:
Veikka Tuominen 2022-11-04 18:38:42 +02:00
parent 42db468dcb
commit 51b1083d66
3 changed files with 42 additions and 20 deletions
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23
src/Sema.zig
View file

@ -10343,6 +10343,9 @@ fn zirSwitchBlock(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError
}
if (err_set) try sema.maybeErrorUnwrapComptime(&child_block, special.body, operand);
if (special.is_inline) child_block.inline_case_capture = operand;
if (empty_enum) {
return Air.Inst.Ref.void_value;
}
return sema.resolveBlockBody(block, src, &child_block, special.body, inst, merges);
}
@ -30479,23 +30482,23 @@ pub fn typeHasOnePossibleValue(
if (enum_obj.tag_ty.hasRuntimeBits()) {
return null;
}
if (enum_obj.fields.count() == 1) {
if (enum_obj.values.count() == 0) {
switch (enum_obj.fields.count()) {
0 => return Value.initTag(.unreachable_value),
1 => if (enum_obj.values.count() == 0) {
return Value.zero; // auto-numbered
} else {
return enum_obj.values.keys()[0];
}
} else {
return null;
},
else => return null,
}
},
.enum_simple => {
const resolved_ty = try sema.resolveTypeFields(block, src, ty);
const enum_simple = resolved_ty.castTag(.enum_simple).?.data;
if (enum_simple.fields.count() == 1) {
return Value.zero;
} else {
return null;
switch (enum_simple.fields.count()) {
0 => return Value.initTag(.unreachable_value),
1 => return Value.zero,
else => return null,
}
},
.enum_nonexhaustive => {
@ -30512,7 +30515,7 @@ pub fn typeHasOnePossibleValue(
const tag_val = (try sema.typeHasOnePossibleValue(block, src, union_obj.tag_ty)) orelse
return null;
const fields = union_obj.fields.values();
if (fields.len == 0) return Value.initTag(.empty_struct_value);
if (fields.len == 0) return Value.initTag(.unreachable_value);
const only_field = fields[0];
if (only_field.ty.eql(resolved_ty, sema.mod)) {
const msg = try Module.ErrorMsg.create(

21
src/type.zig
View file

@ -5015,22 +5015,22 @@ pub const Type = extern union {
if (enum_full.tag_ty.hasRuntimeBits()) {
return null;
}
if (enum_full.fields.count() == 1) {
if (enum_full.values.count() == 0) {
return Value.zero;
switch (enum_full.fields.count()) {
0 => return Value.initTag(.unreachable_value),
1 => if (enum_full.values.count() == 0) {
return Value.zero; // auto-numbered
} else {
return enum_full.values.keys()[0];
}
} else {
return null;
},
else => return null,
}
},
.enum_simple => {
const enum_simple = ty.castTag(.enum_simple).?.data;
if (enum_simple.fields.count() == 1) {
return Value.zero;
} else {
return null;
switch (enum_simple.fields.count()) {
0 => return Value.initTag(.unreachable_value),
1 => return Value.zero,
else => return null,
}
},
.enum_nonexhaustive => {
@ -5044,6 +5044,7 @@ pub const Type = extern union {
.@"union", .union_safety_tagged, .union_tagged => {
const union_obj = ty.cast(Payload.Union).?.data;
const tag_val = union_obj.tag_ty.onePossibleValue() orelse return null;
if (union_obj.fields.count() == 0) return Value.initTag(.unreachable_value);
const only_field = union_obj.fields.values()[0];
const val_val = only_field.ty.onePossibleValue() orelse return null;
_ = tag_val;

18
test/behavior/empty_union.zig
View file

@ -48,3 +48,21 @@ test "empty extern union" {
try expect(@sizeOf(U) == 0);
try expect(@alignOf(U) == 1);
}
test "empty union passed as argument" {
const U = union(enum) {
fn f(u: @This()) void {
switch (u) {}
}
};
U.f(@as(U, undefined));
}
test "empty enum passed as argument" {
const E = enum {
fn f(e: @This()) void {
switch (e) {}
}
};
E.f(@as(E, undefined));
}