mirror of
https://github.com/ziglang/zig.git
synced 2024-11-27 07:32:44 +00:00
261fec8036
- unwrap_errunion_err for registers - unwrap_errunion_payload for registers - ptr_slice_len_ptr for all MCValues - ptr_slice_ptr_ptr for all MCValues
418 lines
14 KiB
Zig
418 lines
14 KiB
Zig
const builtin = @import("builtin");
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const endian = builtin.cpu.arch.endian();
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const testing = @import("std").testing;
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const ptr_size = @sizeOf(usize);
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test "type pun signed and unsigned as single pointer" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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comptime {
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var x: u32 = 0;
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const y = @ptrCast(*i32, &x);
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y.* = -1;
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try testing.expectEqual(@as(u32, 0xFFFFFFFF), x);
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}
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}
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test "type pun signed and unsigned as many pointer" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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comptime {
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var x: u32 = 0;
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const y = @ptrCast([*]i32, &x);
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y[0] = -1;
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try testing.expectEqual(@as(u32, 0xFFFFFFFF), x);
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}
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}
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test "type pun signed and unsigned as array pointer" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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comptime {
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var x: u32 = 0;
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const y = @ptrCast(*[1]i32, &x);
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y[0] = -1;
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try testing.expectEqual(@as(u32, 0xFFFFFFFF), x);
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}
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}
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test "type pun signed and unsigned as offset many pointer" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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var x: u32 = 0;
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var y = @ptrCast([*]i32, &x);
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y -= 10;
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y[10] = -1;
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try testing.expectEqual(@as(u32, 0xFFFFFFFF), x);
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}
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}
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test "type pun signed and unsigned as array pointer" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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var x: u32 = 0;
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const y = @ptrCast([*]i32, &x) - 10;
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const z: *[15]i32 = y[0..15];
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z[10] = -1;
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try testing.expectEqual(@as(u32, 0xFFFFFFFF), x);
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}
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}
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test "type pun value and struct" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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comptime {
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const StructOfU32 = extern struct { x: u32 };
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var inst: StructOfU32 = .{ .x = 0 };
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@ptrCast(*i32, &inst.x).* = -1;
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try testing.expectEqual(@as(u32, 0xFFFFFFFF), inst.x);
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@ptrCast(*i32, &inst).* = -2;
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try testing.expectEqual(@as(u32, 0xFFFFFFFE), inst.x);
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}
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}
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fn bigToNativeEndian(comptime T: type, v: T) T {
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return if (endian == .Big) v else @byteSwap(v);
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}
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test "type pun endianness" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
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comptime {
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const StructOfBytes = extern struct { x: [4]u8 };
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var inst: StructOfBytes = .{ .x = [4]u8{ 0, 0, 0, 0 } };
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const structPtr = @ptrCast(*align(1) u32, &inst);
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const arrayPtr = @ptrCast(*align(1) u32, &inst.x);
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inst.x[0] = 0xFE;
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inst.x[2] = 0xBE;
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try testing.expectEqual(bigToNativeEndian(u32, 0xFE00BE00), structPtr.*);
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try testing.expectEqual(bigToNativeEndian(u32, 0xFE00BE00), arrayPtr.*);
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structPtr.* = bigToNativeEndian(u32, 0xDEADF00D);
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try testing.expectEqual(bigToNativeEndian(u32, 0xDEADF00D), structPtr.*);
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try testing.expectEqual(bigToNativeEndian(u32, 0xDEADF00D), arrayPtr.*);
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try testing.expectEqual(@as(u8, 0xDE), inst.x[0]);
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try testing.expectEqual(@as(u8, 0xAD), inst.x[1]);
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try testing.expectEqual(@as(u8, 0xF0), inst.x[2]);
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try testing.expectEqual(@as(u8, 0x0D), inst.x[3]);
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}
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}
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const Bits = packed struct {
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// Note: This struct has only single byte words so it
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// doesn't need to be byte swapped.
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p0: u1,
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p1: u4,
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p2: u3,
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p3: u2,
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p4: u6,
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p5: u8,
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p6: u7,
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p7: u1,
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};
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const ShuffledBits = packed struct {
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p1: u4,
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p3: u2,
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p7: u1,
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p0: u1,
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p5: u8,
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p2: u3,
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p6: u7,
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p4: u6,
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};
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fn shuffle(ptr: usize, comptime From: type, comptime To: type) usize {
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if (@sizeOf(From) != @sizeOf(To))
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@compileError("Mismatched sizes! " ++ @typeName(From) ++ " and " ++ @typeName(To) ++ " must have the same size!");
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const array_len = @divExact(ptr_size, @sizeOf(From));
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var result: usize = 0;
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const pSource = @ptrCast(*align(1) const [array_len]From, &ptr);
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const pResult = @ptrCast(*align(1) [array_len]To, &result);
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var i: usize = 0;
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while (i < array_len) : (i += 1) {
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inline for (@typeInfo(To).Struct.fields) |f| {
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@field(pResult[i], f.name) = @field(pSource[i], f.name);
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}
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}
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return result;
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}
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fn doTypePunBitsTest(as_bits: *Bits) !void {
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const as_u32 = @ptrCast(*align(1) u32, as_bits);
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const as_bytes = @ptrCast(*[4]u8, as_bits);
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as_u32.* = bigToNativeEndian(u32, 0xB0A7DEED);
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try testing.expectEqual(@as(u1, 0x00), as_bits.p0);
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try testing.expectEqual(@as(u4, 0x08), as_bits.p1);
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try testing.expectEqual(@as(u3, 0x05), as_bits.p2);
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try testing.expectEqual(@as(u2, 0x03), as_bits.p3);
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try testing.expectEqual(@as(u6, 0x29), as_bits.p4);
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try testing.expectEqual(@as(u8, 0xDE), as_bits.p5);
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try testing.expectEqual(@as(u7, 0x6D), as_bits.p6);
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try testing.expectEqual(@as(u1, 0x01), as_bits.p7);
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as_bits.p6 = 0x2D;
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as_bits.p1 = 0x0F;
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try testing.expectEqual(bigToNativeEndian(u32, 0xBEA7DEAD), as_u32.*);
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// clobbering one bit doesn't clobber the word
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as_bits.p7 = undefined;
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try testing.expectEqual(@as(u7, 0x2D), as_bits.p6);
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// even when read as a whole
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const u = as_u32.*;
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_ = u; // u is undefined
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try testing.expectEqual(@as(u7, 0x2D), as_bits.p6);
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// or if a field which shares the byte is modified
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as_bits.p6 = 0x6D;
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try testing.expectEqual(@as(u7, 0x6D), as_bits.p6);
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// but overwriting the undefined will clear it
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as_bytes[3] = 0xAF;
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try testing.expectEqual(bigToNativeEndian(u32, 0xBEA7DEAF), as_u32.*);
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}
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test "type pun bits" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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var v: u32 = undefined;
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try doTypePunBitsTest(@ptrCast(*Bits, &v));
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}
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}
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const imports = struct {
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var global_u32: u32 = 0;
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};
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// Make sure lazy values work on their own, before getting into more complex tests
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test "basic pointer preservation" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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const lazy_address = @ptrToInt(&imports.global_u32);
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try testing.expectEqual(@ptrToInt(&imports.global_u32), lazy_address);
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try testing.expectEqual(&imports.global_u32, @intToPtr(*u32, lazy_address));
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}
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}
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test "byte copy preserves linker value" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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const ct_value = comptime blk: {
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const lazy = &imports.global_u32;
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var result: *u32 = undefined;
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const pSource = @ptrCast(*const [ptr_size]u8, &lazy);
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const pResult = @ptrCast(*[ptr_size]u8, &result);
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var i: usize = 0;
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while (i < ptr_size) : (i += 1) {
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pResult[i] = pSource[i];
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try testing.expectEqual(pSource[i], pResult[i]);
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}
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try testing.expectEqual(&imports.global_u32, result);
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break :blk result;
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};
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try testing.expectEqual(&imports.global_u32, ct_value);
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}
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test "unordered byte copy preserves linker value" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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const ct_value = comptime blk: {
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const lazy = &imports.global_u32;
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var result: *u32 = undefined;
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const pSource = @ptrCast(*const [ptr_size]u8, &lazy);
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const pResult = @ptrCast(*[ptr_size]u8, &result);
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if (ptr_size > 8) @compileError("This array needs to be expanded for platform with very big pointers");
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const shuffled_indices = [_]usize{ 4, 5, 2, 6, 1, 3, 0, 7 };
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for (shuffled_indices) |i| {
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pResult[i] = pSource[i];
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try testing.expectEqual(pSource[i], pResult[i]);
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}
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try testing.expectEqual(&imports.global_u32, result);
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break :blk result;
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};
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try testing.expectEqual(&imports.global_u32, ct_value);
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}
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test "shuffle chunks of linker value" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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const lazy_address = @ptrToInt(&imports.global_u32);
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const shuffled1_rt = shuffle(lazy_address, Bits, ShuffledBits);
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const unshuffled1_rt = shuffle(shuffled1_rt, ShuffledBits, Bits);
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try testing.expectEqual(lazy_address, unshuffled1_rt);
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const shuffled1_ct = comptime shuffle(lazy_address, Bits, ShuffledBits);
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const shuffled1_ct_2 = comptime shuffle(lazy_address, Bits, ShuffledBits);
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comptime try testing.expectEqual(shuffled1_ct, shuffled1_ct_2);
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const unshuffled1_ct = comptime shuffle(shuffled1_ct, ShuffledBits, Bits);
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comptime try testing.expectEqual(lazy_address, unshuffled1_ct);
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try testing.expectEqual(shuffled1_ct, shuffled1_rt);
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}
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test "dance on linker values" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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var arr: [2]usize = undefined;
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arr[0] = @ptrToInt(&imports.global_u32);
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arr[1] = @ptrToInt(&imports.global_u32);
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const weird_ptr = @ptrCast([*]Bits, @ptrCast([*]u8, &arr) + @sizeOf(usize) - 3);
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try doTypePunBitsTest(&weird_ptr[0]);
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if (ptr_size > @sizeOf(Bits))
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try doTypePunBitsTest(&weird_ptr[1]);
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var arr_bytes = @ptrCast(*[2][ptr_size]u8, &arr);
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var rebuilt_bytes: [ptr_size]u8 = undefined;
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var i: usize = 0;
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while (i < ptr_size - 3) : (i += 1) {
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rebuilt_bytes[i] = arr_bytes[0][i];
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}
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while (i < ptr_size) : (i += 1) {
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rebuilt_bytes[i] = arr_bytes[1][i];
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}
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try testing.expectEqual(&imports.global_u32, @intToPtr(*u32, @bitCast(usize, rebuilt_bytes)));
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}
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}
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test "offset array ptr by element size" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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const VirtualStruct = struct { x: u32 };
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var arr: [4]VirtualStruct = .{
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.{ .x = bigToNativeEndian(u32, 0x0004080c) },
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.{ .x = bigToNativeEndian(u32, 0x0105090d) },
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.{ .x = bigToNativeEndian(u32, 0x02060a0e) },
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.{ .x = bigToNativeEndian(u32, 0x03070b0f) },
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};
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const address = @ptrToInt(&arr);
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try testing.expectEqual(@ptrToInt(&arr[0]), address);
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try testing.expectEqual(@ptrToInt(&arr[0]) + 10, address + 10);
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try testing.expectEqual(@ptrToInt(&arr[1]), address + @sizeOf(VirtualStruct));
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try testing.expectEqual(@ptrToInt(&arr[2]), address + 2 * @sizeOf(VirtualStruct));
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try testing.expectEqual(@ptrToInt(&arr[3]), address + @sizeOf(VirtualStruct) * 3);
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const secondElement = @intToPtr(*VirtualStruct, @ptrToInt(&arr[0]) + 2 * @sizeOf(VirtualStruct));
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try testing.expectEqual(bigToNativeEndian(u32, 0x02060a0e), secondElement.x);
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}
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}
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test "offset instance by field size" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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const VirtualStruct = struct { x: u32, y: u32, z: u32, w: u32 };
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var inst = VirtualStruct{ .x = 0, .y = 1, .z = 2, .w = 3 };
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var ptr = @ptrToInt(&inst);
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ptr -= 4;
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ptr += @offsetOf(VirtualStruct, "x");
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try testing.expectEqual(@as(u32, 0), @intToPtr([*]u32, ptr)[1]);
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ptr -= @offsetOf(VirtualStruct, "x");
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ptr += @offsetOf(VirtualStruct, "y");
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try testing.expectEqual(@as(u32, 1), @intToPtr([*]u32, ptr)[1]);
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ptr = ptr - @offsetOf(VirtualStruct, "y") + @offsetOf(VirtualStruct, "z");
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try testing.expectEqual(@as(u32, 2), @intToPtr([*]u32, ptr)[1]);
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ptr = @ptrToInt(&inst.z) - 4 - @offsetOf(VirtualStruct, "z");
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ptr += @offsetOf(VirtualStruct, "w");
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try testing.expectEqual(@as(u32, 3), @intToPtr(*u32, ptr + 4).*);
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}
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}
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test "offset field ptr by enclosing array element size" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend != .stage1) {
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// TODO https://github.com/ziglang/zig/issues/9646
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return error.SkipZigTest;
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}
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comptime {
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const VirtualStruct = struct { x: u32 };
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var arr: [4]VirtualStruct = .{
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.{ .x = bigToNativeEndian(u32, 0x0004080c) },
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.{ .x = bigToNativeEndian(u32, 0x0105090d) },
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.{ .x = bigToNativeEndian(u32, 0x02060a0e) },
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.{ .x = bigToNativeEndian(u32, 0x03070b0f) },
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};
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var i: usize = 0;
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while (i < 4) : (i += 1) {
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var ptr: [*]u8 = @ptrCast([*]u8, &arr[0]);
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ptr += i;
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ptr += @offsetOf(VirtualStruct, "x");
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var j: usize = 0;
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while (j < 4) : (j += 1) {
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const base = ptr + j * @sizeOf(VirtualStruct);
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try testing.expectEqual(@intCast(u8, i * 4 + j), base[0]);
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}
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}
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}
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}
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test "accessing reinterpreted memory of parent object" {
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if (builtin.zig_backend == .stage1) return error.SkipZigTest;
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if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
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const S = extern struct {
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a: f32,
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b: [4]u8,
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c: f32,
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};
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const expected = if (endian == .Little) 102 else 38;
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comptime {
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const x = S{
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.a = 1.5,
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.b = [_]u8{ 1, 2, 3, 4 },
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.c = 2.6,
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};
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const ptr = &x.b[0];
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const b = @ptrCast([*c]const u8, ptr)[5];
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try testing.expect(b == expected);
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}
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}
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