diff --git a/src/analyze.cpp b/src/analyze.cpp index 95b2c77129..41ae69f803 100644 --- a/src/analyze.cpp +++ b/src/analyze.cpp @@ -1131,18 +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) || - type_val->data.x_type->id == ZigTypeIdPointer) + + // 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; } diff --git a/test/stage1/behavior/sizeof_and_typeof.zig b/test/stage1/behavior/sizeof_and_typeof.zig index a738dbbbf9..322c5fbbad 100644 --- a/test/stage1/behavior/sizeof_and_typeof.zig +++ b/test/stage1/behavior/sizeof_and_typeof.zig @@ -1,5 +1,7 @@ -const builtin = @import("builtin"); -const expect = @import("std").testing.expect; +const std = @import("std"); +const builtin = std.builtin; +const expect = std.testing.expect; +const expectEqual = std.testing.expectEqual; test "@sizeOf and @TypeOf" { const y: @TypeOf(x) = 120; @@ -135,3 +137,53 @@ test "@bitSizeOf" { a: u2 }) == 2); } + +test "@sizeOf comparison against zero" { + const S0 = struct { + f: *@This(), + }; + 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); + } + }; + // Zero-sized type + S.doTheTest(u0, false); + S.doTheTest(*u0, false); + // Non byte-sized type + S.doTheTest(u1, true); + S.doTheTest(*u1, true); + // Regular type + S.doTheTest(u8, true); + S.doTheTest(*u8, true); + S.doTheTest(f32, true); + S.doTheTest(*f32, true); + // Container with ptr pointing to themselves + S.doTheTest(S0, true); + S.doTheTest(U0, true); + S.doTheTest(S1, true); + S.doTheTest(U1, true); +}