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ir: Fix regression with self-referencing containers

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This commit is contained in:
LemonBoy 2020-02-26 10:05:04 +01:00
parent b46efcde82
commit d2535c003c
2 changed files with 36 additions and 5 deletions
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19
src/analyze.cpp
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@ -1131,17 +1131,26 @@ Error type_val_resolve_zero_bits(CodeGen *g, ZigValue *type_val, ZigType *parent
Error err;
if (type_val->special != ConstValSpecialLazy) {
assert(type_val->special == ConstValSpecialStatic);
if ((type_val->data.x_type->id == ZigTypeIdStruct &&
type_val->data.x_type->data.structure.resolve_loop_flag_zero_bits) ||
(type_val->data.x_type->id == ZigTypeIdUnion &&
type_val->data.x_type->data.unionation.resolve_loop_flag_zero_bits))
// Self-referencing types via pointers are allowed and have non-zero size
ZigType *ty = type_val->data.x_type;
while (ty->id == ZigTypeIdPointer &&
!ty->data.unionation.resolve_loop_flag_zero_bits)
{
ty = ty->data.pointer.child_type;
}
if ((ty->id == ZigTypeIdStruct && ty->data.structure.resolve_loop_flag_zero_bits) ||
(ty->id == ZigTypeIdUnion && ty->data.unionation.resolve_loop_flag_zero_bits) ||
(ty->id == ZigTypeIdPointer && ty->data.pointer.resolve_loop_flag_zero_bits))
{
// Does a struct/union which contains a pointer field to itself have bits? Yes.
*is_zero_bits = false;
return ErrorNone;
}
if ((err = type_resolve(g, type_val->data.x_type, ResolveStatusZeroBitsKnown)))
return err;
*is_zero_bits = (type_val->data.x_type->abi_size == 0);
return ErrorNone;
}

22
test/stage1/behavior/sizeof_and_typeof.zig
View File

@ -145,6 +145,26 @@ test "@sizeOf comparison against zero" {
const U0 = union {
f: *@This(),
};
const S1 = struct {
fn H(comptime T: type) type {
return struct {
x: T,
};
}
f0: H(*@This()),
f1: H(**@This()),
f2: H(***@This()),
};
const U1 = union {
fn H(comptime T: type) type {
return struct {
x: T,
};
}
f0: H(*@This()),
f1: H(**@This()),
f2: H(***@This()),
};
const S = struct {
fn doTheTest(comptime T: type, comptime result: bool) void {
expectEqual(result, @sizeOf(T) > 0);
@ -164,4 +184,6 @@ test "@sizeOf comparison against zero" {
// Container with ptr pointing to themselves
S.doTheTest(S0, true);
S.doTheTest(U0, true);
S.doTheTest(S1, true);
S.doTheTest(U1, true);
}