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const std = @import("std");
const builtin = @import("builtin");
const expect = std.testing.expect;
const native_endian = builtin.target.cpu.arch.endian();
test "reinterpret bytes as integer with nonzero offset" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
try testReinterpretBytesAsInteger();
try comptime testReinterpretBytesAsInteger();
}
fn testReinterpretBytesAsInteger() !void {
const bytes = "\x12\x34\x56\x78\xab";
const expected = switch (native_endian) {
.Little => 0xab785634,
.Big => 0x345678ab,
};
try expect(@as(*align(1) const u32, @ptrCast(bytes[1..5])).* == expected);
}
test "reinterpret an array over multiple elements, with no well-defined layout" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
try testReinterpretWithOffsetAndNoWellDefinedLayout();
try comptime testReinterpretWithOffsetAndNoWellDefinedLayout();
}
fn testReinterpretWithOffsetAndNoWellDefinedLayout() !void {
const bytes: ?[5]?u8 = [5]?u8{ 0x12, 0x34, 0x56, 0x78, 0x9a };
const ptr = &bytes.?[1];
const copy: [4]?u8 = @as(*const [4]?u8, @ptrCast(ptr)).*;
_ = copy;
//try expect(@ptrCast(*align(1)?u8, bytes[1..5]).* == );
}
test "reinterpret bytes inside auto-layout struct as integer with nonzero offset" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
try testReinterpretStructWrappedBytesAsInteger();
try comptime testReinterpretStructWrappedBytesAsInteger();
}
fn testReinterpretStructWrappedBytesAsInteger() !void {
const S = struct { bytes: [5:0]u8 };
const obj = S{ .bytes = "\x12\x34\x56\x78\xab".* };
const expected = switch (native_endian) {
.Little => 0xab785634,
.Big => 0x345678ab,
};
try expect(@as(*align(1) const u32, @ptrCast(obj.bytes[1..5])).* == expected);
}
test "reinterpret bytes of an array into an extern struct" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
try testReinterpretBytesAsExternStruct();
try comptime testReinterpretBytesAsExternStruct();
}
fn testReinterpretBytesAsExternStruct() !void {
var bytes align(2) = [_]u8{ 1, 2, 3, 4, 5, 6 };
const S = extern struct {
a: u8,
b: u16,
c: u8,
};
var ptr = @as(*const S, @ptrCast(&bytes));
var val = ptr.c;
try expect(val == 5);
}
test "reinterpret bytes of an extern struct (with under-aligned fields) into another" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
try testReinterpretExternStructAsExternStruct();
try comptime testReinterpretExternStructAsExternStruct();
}
fn testReinterpretExternStructAsExternStruct() !void {
const S1 = extern struct {
a: u8,
b: u16,
c: u8,
};
comptime var bytes align(2) = S1{ .a = 0, .b = 0, .c = 5 };
const S2 = extern struct {
a: u32 align(2),
c: u8,
};
var ptr = @as(*const S2, @ptrCast(&bytes));
var val = ptr.c;
try expect(val == 5);
}
test "reinterpret bytes of an extern struct into another" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
try testReinterpretOverAlignedExternStructAsExternStruct();
try comptime testReinterpretOverAlignedExternStructAsExternStruct();
}
fn testReinterpretOverAlignedExternStructAsExternStruct() !void {
const S1 = extern struct {
a: u32,
b: u32,
c: u8,
};
comptime var bytes: S1 = .{ .a = 0, .b = 0, .c = 5 };
const S2 = extern struct {
a0: u32,
a1: u16,
a2: u16,
c: u8,
};
var ptr = @as(*const S2, @ptrCast(&bytes));
var val = ptr.c;
try expect(val == 5);
}
test "lower reinterpreted comptime field ptr (with under-aligned fields)" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
// Test lowering a field ptr
comptime var bytes align(2) = [_]u8{ 1, 2, 3, 4, 5, 6 };
const S = extern struct {
a: u32 align(2),
c: u8,
};
comptime var ptr = @as(*const S, @ptrCast(&bytes));
var val = &ptr.c;
try expect(val.* == 5);
// Test lowering an elem ptr
comptime var src_value = S{ .a = 15, .c = 5 };
comptime var ptr2 = @as(*[@sizeOf(S)]u8, @ptrCast(&src_value));
var val2 = &ptr2[4];
try expect(val2.* == 5);
}
test "lower reinterpreted comptime field ptr" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
// Test lowering a field ptr
comptime var bytes align(4) = [_]u8{ 1, 2, 3, 4, 5, 6, 7, 8 };
const S = extern struct {
a: u32,
c: u8,
};
comptime var ptr = @as(*const S, @ptrCast(&bytes));
var val = &ptr.c;
try expect(val.* == 5);
// Test lowering an elem ptr
comptime var src_value = S{ .a = 15, .c = 5 };
comptime var ptr2 = @as(*[@sizeOf(S)]u8, @ptrCast(&src_value));
var val2 = &ptr2[4];
try expect(val2.* == 5);
}
test "reinterpret struct field at comptime" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
const numNative = comptime Bytes.init(0x12345678);
if (native_endian != .Little) {
try expect(std.mem.eql(u8, &[_]u8{ 0x12, 0x34, 0x56, 0x78 }, &numNative.bytes));
} else {
try expect(std.mem.eql(u8, &[_]u8{ 0x78, 0x56, 0x34, 0x12 }, &numNative.bytes));
}
}
const Bytes = struct {
bytes: [4]u8,
pub fn init(v: u32) Bytes {
var res: Bytes = undefined;
@as(*align(1) u32, @ptrCast(&res.bytes)).* = v;
return res;
}
};
test "ptrcast of const integer has the correct object size" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const is_value = ~@as(isize, @intCast(std.math.minInt(isize)));
const is_bytes = @as([*]const u8, @ptrCast(&is_value))[0..@sizeOf(isize)];
if (@sizeOf(isize) == 8) {
switch (native_endian) {
.Little => {
try expect(is_bytes[0] == 0xff);
try expect(is_bytes[1] == 0xff);
try expect(is_bytes[2] == 0xff);
try expect(is_bytes[3] == 0xff);
try expect(is_bytes[4] == 0xff);
try expect(is_bytes[5] == 0xff);
try expect(is_bytes[6] == 0xff);
try expect(is_bytes[7] == 0x7f);
},
.Big => {
try expect(is_bytes[0] == 0x7f);
try expect(is_bytes[1] == 0xff);
try expect(is_bytes[2] == 0xff);
try expect(is_bytes[3] == 0xff);
try expect(is_bytes[4] == 0xff);
try expect(is_bytes[5] == 0xff);
try expect(is_bytes[6] == 0xff);
try expect(is_bytes[7] == 0xff);
},
}
}
}
test "implicit optional pointer to optional anyopaque pointer" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
var buf: [4]u8 = "aoeu".*;
var x: ?[*]u8 = &buf;
var y: ?*anyopaque = x;
var z = @as(*[4]u8, @ptrCast(y));
try expect(std.mem.eql(u8, z, "aoeu"));
}
test "@ptrCast slice to slice" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
const S = struct {
fn foo(slice: []u32) []i32 {
return @as([]i32, @ptrCast(slice));
}
};
var buf: [4]u32 = .{ 0, 0, 0, 0 };
const alias = S.foo(&buf);
alias[1] = 42;
try expect(buf[1] == 42);
try expect(alias.len == 4);
}
test "comptime @ptrCast a subset of an array, then write through it" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
comptime {
var buff: [16]u8 align(4) = undefined;
const len_bytes = @as(*u32, @ptrCast(&buff));
len_bytes.* = 16;
std.mem.copy(u8, buff[4..], "abcdef");
}
}
test "@ptrCast undefined value at comptime" {
const S = struct {
fn transmute(comptime T: type, comptime U: type, value: T) U {
return @as(*const U, @ptrCast(&value)).*;
}
};
comptime {
var x = S.transmute([]u8, i32, undefined);
_ = x;
}
}
test "comptime @ptrCast with packed struct leaves value unmodified" {
const S = packed struct { three: u3 };
const st: S = .{ .three = 6 };
try expect(st.three == 6);
const p: *const [1]u3 = @ptrCast(&st);
try expect(p.*[0] == 6);
try expect(st.three == 6);
}
|
