From bd2f9227435cc968b387e0b56498e5759718c56f Mon Sep 17 00:00:00 2001 From: Andrew Kelley <andrew@ziglang.org> Date: Mon, 31 Jul 2023 18:25:27 -0700 Subject: [PATCH] add behavior test for sub-aligned field access The workaround in std.zig.Server remains because the C backend is not passing the new test. see #14904 --- test/behavior/align.zig | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/test/behavior/align.zig b/test/behavior/align.zig index a5e0369ae7b8..ee6033ede443 100644 --- a/test/behavior/align.zig +++ b/test/behavior/align.zig @@ -593,3 +593,25 @@ test "alignment of slice element" { const a: []align(1024) const u8 = undefined; try expect(@TypeOf(&a[0]) == *align(1024) const u8); } + +test "sub-aligned pointer field access" { + if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; + if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; + if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; + if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; + if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; + + // Originally reported at https://github.com/ziglang/zig/issues/14904 + + const Header = extern struct { + tag: u32, + bytes_len: u32, + }; + var buf: [9]u8 align(4) = .{ 1, 2, 3, 4, 5, 6, 7, 8, 9 }; + const ptr: *align(1) Header = @ptrCast(buf[1..][0..8]); + const x = ptr.bytes_len; + switch (builtin.cpu.arch.endian()) { + .Big => try expect(x == 0x06070809), + .Little => try expect(x == 0x09080706), + } +}