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remove @bytesToSlice, @sliceToBytes from tests, docs

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xackus 2020-02-23 18:03:50 +01:00
parent 783e8ad031
commit 7664c3bc11
14 changed files with 141 additions and 181 deletions
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61
doc/langref.html.in
View File

@ -2025,7 +2025,8 @@ test "volatile" {
conversions are not possible.
</p>
{#code_begin|test#}
const assert = @import("std").debug.assert;
const std = @import("std");
const assert = std.debug.assert;
test "pointer casting" {
const bytes align(@alignOf(u32)) = [_]u8{ 0x12, 0x12, 0x12, 0x12 };
@ -2034,7 +2035,7 @@ test "pointer casting" {
// Even this example is contrived - there are better ways to do the above than
// pointer casting. For example, using a slice narrowing cast:
const u32_value = @bytesToSlice(u32, bytes[0..])[0];
const u32_value = std.mem.bytesAsSlice(u32, bytes[0..])[0];
assert(u32_value == 0x12121212);
// And even another way, the most straightforward way to do it:
@ -2114,16 +2115,16 @@ test "function alignment" {
{#link|safety check|Incorrect Pointer Alignment#}:
</p>
{#code_begin|test_safety|incorrect alignment#}
const assert = @import("std").debug.assert;
const std = @import("std");
test "pointer alignment safety" {
var array align(4) = [_]u32{ 0x11111111, 0x11111111 };
const bytes = @sliceToBytes(array[0..]);
assert(foo(bytes) == 0x11111111);
const bytes = std.mem.sliceAsBytes(array[0..]);
std.debug.assert(foo(bytes) == 0x11111111);
}
fn foo(bytes: []u8) u32 {
const slice4 = bytes[1..5];
const int_slice = @bytesToSlice(u32, @alignCast(4, slice4));
const int_slice = std.mem.bytesAsSlice(u32, @alignCast(4, slice4));
return int_slice[0];
}
{#code_end#}
@ -2249,7 +2250,7 @@ test "slice widening" {
// Zig supports slice widening and slice narrowing. Cast a slice of u8
// to a slice of anything else, and Zig will perform the length conversion.
const array align(@alignOf(u32)) = [_]u8{ 0x12, 0x12, 0x12, 0x12, 0x13, 0x13, 0x13, 0x13 };
const slice = @bytesToSlice(u32, array[0..]);
const slice = mem.bytesAsSlice(u32, array[0..]);
assert(slice.len == 2);
assert(slice[0] == 0x12121212);
assert(slice[1] == 0x13131313);
@ -5186,7 +5187,6 @@ test "coercion of zero bit types" {
<li>{#link|@bitCast#} - change type but maintain bit representation</li>
<li>{#link|@alignCast#} - make a pointer have more alignment</li>
<li>{#link|@boolToInt#} - convert true to 1 and false to 0</li>
<li>{#link|@bytesToSlice#} - convert a slice of bytes to a slice of another type</li>
<li>{#link|@enumToInt#} - obtain the integer tag value of an enum or tagged union</li>
<li>{#link|@errSetCast#} - convert to a smaller error set</li>
<li>{#link|@errorToInt#} - obtain the integer value of an error code</li>
@ -5199,7 +5199,6 @@ test "coercion of zero bit types" {
<li>{#link|@intToPtr#} - convert an address to a pointer</li>
<li>{#link|@ptrCast#} - convert between pointer types</li>
<li>{#link|@ptrToInt#} - obtain the address of a pointer</li>
<li>{#link|@sliceToBytes#} - convert a slice of anything to a slice of bytes</li>
<li>{#link|@truncate#} - convert between integer types, chopping off bits</li>
</ul>
{#header_close#}
@ -6929,18 +6928,6 @@ async fn func(y: *i32) void {
{#see_also|@bitOffsetOf#}
{#header_close#}
{#header_open|@bytesToSlice#}
<pre>{#syntax#}@bytesToSlice(comptime Element: type, bytes: []u8) []Element{#endsyntax#}</pre>
<p>
Converts a slice of bytes or array of bytes into a slice of {#syntax#}Element{#endsyntax#}.
The resulting slice has the same {#link|pointer|Pointers#} properties as the parameter.
</p>
<p>
Attempting to convert a number of bytes with a length that does not evenly divide into a slice of
elements results in safety-protected {#link|Undefined Behavior#}.
</p>
{#header_close#}
{#header_open|@call#}
<pre>{#syntax#}@call(options: std.builtin.CallOptions, function: var, args: var) var{#endsyntax#}</pre>
<p>
@ -8101,14 +8088,6 @@ test "@setRuntimeSafety" {
{#see_also|@bitSizeOf|@typeInfo#}
{#header_close#}
{#header_open|@sliceToBytes#}
<pre>{#syntax#}@sliceToBytes(value: var) []u8{#endsyntax#}</pre>
<p>
Converts a slice or array to a slice of {#syntax#}u8{#endsyntax#}. The resulting slice has the same
{#link|pointer|Pointers#} properties as the parameter.
</p>
{#header_close#}
{#header_open|@splat#}
<pre>{#syntax#}@splat(comptime len: u32, scalar: var) @Vector(len, @TypeOf(scalar)){#endsyntax#}</pre>
<p>
@ -8919,25 +8898,6 @@ pub fn main() void {
var b: u32 = 3;
var c = @divExact(a, b);
std.debug.warn("value: {}\n", .{c});
}
{#code_end#}
{#header_close#}
{#header_open|Slice Widen Remainder#}
<p>At compile-time:</p>
{#code_begin|test_err|unable to convert#}
comptime {
var bytes = [5]u8{ 1, 2, 3, 4, 5 };
var slice = @bytesToSlice(u32, bytes[0..]);
}
{#code_end#}
<p>At runtime:</p>
{#code_begin|exe_err#}
const std = @import("std");
pub fn main() void {
var bytes = [5]u8{ 1, 2, 3, 4, 5 };
var slice = @bytesToSlice(u32, bytes[0..]);
std.debug.warn("value: {}\n", .{slice[0]});
}
{#code_end#}
{#header_close#}
@ -9119,14 +9079,15 @@ comptime {
{#code_end#}
<p>At runtime:</p>
{#code_begin|exe_err#}
const mem = @import("std").mem;
pub fn main() !void {
var array align(4) = [_]u32{ 0x11111111, 0x11111111 };
const bytes = @sliceToBytes(array[0..]);
const bytes = mem.sliceAsBytes(array[0..]);
if (foo(bytes) != 0x11111111) return error.Wrong;
}
fn foo(bytes: []u8) u32 {
const slice4 = bytes[1..5];
const int_slice = @bytesToSlice(u32, @alignCast(4, slice4));
const int_slice = mem.bytesAsSlice(u32, @alignCast(4, slice4));
return int_slice[0];
}
{#code_end#}

114
lib/std/mem.zig
View File

@ -1488,28 +1488,34 @@ test "bytesToValue" {
//TODO copy also is_volatile, etc. I tried to use @typeInfo, modify child type, use @Type, but ran into issues.
fn BytesAsSliceReturnType(comptime T: type, comptime bytesType: type) type {
if (comptime !trait.isSlice(bytesType) or comptime meta.Child(bytesType) != u8) {
@compileError("expected []u8, passed " ++ @typeName(bytesType));
if (!(trait.isSlice(bytesType) and meta.Child(bytesType) == u8) and !(trait.isPtrTo(.Array)(bytesType) and meta.Child(meta.Child(bytesType)) == u8)) {
@compileError("expected []u8 or *[_]u8, passed " ++ @typeName(bytesType));
}
const alignment = comptime meta.alignment(bytesType);
if (trait.isPtrTo(.Array)(bytesType) and @typeInfo(meta.Child(bytesType)).Array.len % @sizeOf(T) != 0) {
@compileError("number of bytes in " ++ @typeName(bytesType) ++ " is not divisible by size of " ++ @typeName(T));
}
return if (comptime trait.isConstPtr(bytesType)) []align(alignment) const T else []align(alignment) T;
const alignment = meta.alignment(bytesType);
return if (trait.isConstPtr(bytesType)) []align(alignment) const T else []align(alignment) T;
}
pub fn bytesAsSlice(comptime T: type, bytes: var) BytesAsSliceReturnType(T, @TypeOf(bytes)) {
const bytesSlice = if (comptime trait.isPtrTo(.Array)(@TypeOf(bytes))) bytes[0..] else bytes;
// let's not give an undefined pointer to @ptrCast
// it may be equal to zero and fail a null check
if (bytes.len == 0) {
if (bytesSlice.len == 0) {
return &[0]T{};
}
const bytesType = @TypeOf(bytes);
const bytesType = @TypeOf(bytesSlice);
const alignment = comptime meta.alignment(bytesType);
const castTarget = if (comptime trait.isConstPtr(bytesType)) [*]align(alignment) const T else [*]align(alignment) T;
return @ptrCast(castTarget, bytes.ptr)[0..@divExact(bytes.len, @sizeOf(T))];
return @ptrCast(castTarget, bytesSlice.ptr)[0..@divExact(bytes.len, @sizeOf(T))];
}
test "bytesAsSlice" {
@ -1520,30 +1526,59 @@ test "bytesAsSlice" {
testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
}
test "bytesAsSlice keeps pointer alignment" {
var bytes = [_]u8{ 0x01, 0x02, 0x03, 0x04 };
const numbers = bytesAsSlice(u32, bytes[0..]);
comptime testing.expect(@TypeOf(numbers) == []align(@alignOf(@TypeOf(bytes))) u32);
}
test "bytesAsSlice on a packed struct" {
const F = packed struct {
a: u8,
};
var b = [1]u8{9};
var f = bytesAsSlice(F, &b);
testing.expect(f[0].a == 9);
}
test "bytesAsSlice with specified alignment" {
var bytes align(4) = [_]u8{
0x33,
0x33,
0x33,
0x33,
};
const slice: []u32 = std.mem.bytesAsSlice(u32, bytes[0..]);
testing.expect(slice[0] == 0x33333333);
}
//TODO copy also is_volatile, etc. I tried to use @typeInfo, modify child type, use @Type, but ran into issues.
fn SliceAsBytesReturnType(comptime sliceType: type) type {
if (comptime !trait.isSlice(sliceType)) {
@compileError("expected []T, passed " ++ @typeName(sliceType));
if (!trait.isSlice(sliceType) and !trait.isPtrTo(.Array)(sliceType)) {
@compileError("expected []T or *[_]T, passed " ++ @typeName(sliceType));
}
const alignment = comptime meta.alignment(sliceType);
const alignment = meta.alignment(sliceType);
return if (comptime trait.isConstPtr(sliceType)) []align(alignment) const u8 else []align(alignment) u8;
return if (trait.isConstPtr(sliceType)) []align(alignment) const u8 else []align(alignment) u8;
}
pub fn sliceAsBytes(slice: var) SliceAsBytesReturnType(@TypeOf(slice)) {
const actualSlice = if (comptime trait.isPtrTo(.Array)(@TypeOf(slice))) slice[0..] else slice;
// let's not give an undefined pointer to @ptrCast
// it may be equal to zero and fail a null check
if (slice.len == 0) {
if (actualSlice.len == 0) {
return &[0]u8{};
}
const sliceType = @TypeOf(slice);
const sliceType = @TypeOf(actualSlice);
const alignment = comptime meta.alignment(sliceType);
const castTarget = if (comptime trait.isConstPtr(sliceType)) [*]align(alignment) const u8 else [*]align(alignment) u8;
return @ptrCast(castTarget, slice.ptr)[0 .. slice.len * @sizeOf(comptime meta.Child(sliceType))];
return @ptrCast(castTarget, actualSlice.ptr)[0 .. actualSlice.len * @sizeOf(comptime meta.Child(sliceType))];
}
test "sliceAsBytes" {
@ -1556,6 +1591,57 @@ test "sliceAsBytes" {
}));
}
test "sliceAsBytes packed struct at runtime and comptime" {
const Foo = packed struct {
a: u4,
b: u4,
};
const S = struct {
fn doTheTest() void {
var foo: Foo = undefined;
var slice = sliceAsBytes(@as(*[1]Foo, &foo)[0..1]);
slice[0] = 0x13;
switch (builtin.endian) {
.Big => {
testing.expect(foo.a == 0x1);
testing.expect(foo.b == 0x3);
},
.Little => {
testing.expect(foo.a == 0x3);
testing.expect(foo.b == 0x1);
},
}
}
};
S.doTheTest();
comptime S.doTheTest();
}
test "sliceAsBytes and bytesAsSlice back" {
testing.expect(@sizeOf(i32) == 4);
var big_thing_array = [_]i32{ 1, 2, 3, 4 };
const big_thing_slice: []i32 = big_thing_array[0..];
const bytes = sliceAsBytes(big_thing_slice);
testing.expect(bytes.len == 4 * 4);
bytes[4] = 0;
bytes[5] = 0;
bytes[6] = 0;
bytes[7] = 0;
testing.expect(big_thing_slice[1] == 0);
const big_thing_again = bytesAsSlice(i32, bytes);
testing.expect(big_thing_again[2] == 3);
big_thing_again[2] = -1;
testing.expect(bytes[8] == math.maxInt(u8));
testing.expect(bytes[9] == math.maxInt(u8));
testing.expect(bytes[10] == math.maxInt(u8));
testing.expect(bytes[11] == math.maxInt(u8));
}
fn SubArrayPtrReturnType(comptime T: type, comptime length: usize) type {
if (trait.isConstPtr(T))
return *const [length]meta.Child(meta.Child(T));

16
lib/std/meta/trait.zig
View File

@ -135,6 +135,22 @@ test "std.meta.trait.isPtrTo" {
testing.expect(!isPtrTo(.Struct)(**struct {}));
}
pub fn isSliceOf(comptime id: builtin.TypeId) TraitFn {
const Closure = struct {
pub fn trait(comptime T: type) bool {
if (!comptime isSlice(T)) return false;
return id == @typeId(meta.Child(T));
}
};
return Closure.trait;
}
test "std.meta.trait.isSliceOf" {
testing.expect(!isSliceOf(.Struct)(struct {}));
testing.expect(isSliceOf(.Struct)([]struct {}));
testing.expect(!isSliceOf(.Struct)([][]struct {}));
}
///////////Strait trait Fns
//@TODO:

10
test/compile_errors.zig
View File

@ -4747,16 +4747,6 @@ pub fn addCases(cases: *tests.CompileErrorContext) void {
"tmp.zig:1:15: error: comptime parameter not allowed in function with calling convention 'C'",
});
cases.add("convert fixed size array to slice with invalid size",
\\export fn f() void {
\\ var array: [5]u8 = undefined;
\\ var foo = @bytesToSlice(u32, &array)[0];
\\}
, &[_][]const u8{
"tmp.zig:3:15: error: unable to convert [5]u8 to []align(1) u32: size mismatch",
"tmp.zig:3:29: note: u32 has size 4; remaining bytes: 1",
});
cases.add("non-pure function returns type",
\\var a: u32 = 0;
\\pub fn List(comptime T: type) type {

16
test/runtime_safety.zig
View File

@ -553,15 +553,16 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
);
cases.addRuntimeSafety("cast []u8 to bigger slice of wrong size",
\\pub fn panic(message: []const u8, stack_trace: ?*@import("builtin").StackTrace) noreturn {
\\ @import("std").os.exit(126);
\\const std = @import("std");
\\pub fn panic(message: []const u8, stack_trace: ?*std.builtin.StackTrace) noreturn {
\\ std.os.exit(126);
\\}
\\pub fn main() !void {
\\ const x = widenSlice(&[_]u8{1, 2, 3, 4, 5});
\\ if (x.len == 0) return error.Whatever;
\\}
\\fn widenSlice(slice: []align(1) const u8) []align(1) const i32 {
\\ return @bytesToSlice(i32, slice);
\\ return std.mem.bytesAsSlice(i32, slice);
\\}
);
@ -656,17 +657,18 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
);
cases.addRuntimeSafety("@alignCast misaligned",
\\pub fn panic(message: []const u8, stack_trace: ?*@import("builtin").StackTrace) noreturn {
\\ @import("std").os.exit(126);
\\const std = @import("std");
\\pub fn panic(message: []const u8, stack_trace: ?*std.builtin.StackTrace) noreturn {
\\ std.os.exit(126);
\\}
\\pub fn main() !void {
\\ var array align(4) = [_]u32{0x11111111, 0x11111111};
\\ const bytes = @sliceToBytes(array[0..]);
\\ const bytes = std.mem.sliceAsBytes(array[0..]);
\\ if (foo(bytes) != 0x11111111) return error.Wrong;
\\}
\\fn foo(bytes: []u8) u32 {
\\ const slice4 = bytes[1..5];
\\ const int_slice = @bytesToSlice(u32, @alignCast(4, slice4));
\\ const int_slice = std.mem.bytesAsSlice(u32, @alignCast(4, slice4));
\\ return int_slice[0];
\\}
);

1
test/stage1/behavior.zig
View File

@ -92,7 +92,6 @@ comptime {
_ = @import("behavior/shuffle.zig");
_ = @import("behavior/sizeof_and_typeof.zig");
_ = @import("behavior/slice.zig");
_ = @import("behavior/slicetobytes.zig");
_ = @import("behavior/struct.zig");
_ = @import("behavior/struct_contains_null_ptr_itself.zig");
_ = @import("behavior/struct_contains_slice_of_itself.zig");

14
test/stage1/behavior/align.zig
View File

@ -81,20 +81,6 @@ fn testBytesAlign(b: u8) void {
expect(ptr.* == 0x33333333);
}
test "specifying alignment allows slice cast" {
testBytesAlignSlice(0x33);
}
fn testBytesAlignSlice(b: u8) void {
var bytes align(4) = [_]u8{
b,
b,
b,
b,
};
const slice: []u32 = @bytesToSlice(u32, bytes[0..]);
expect(slice[0] == 0x33333333);
}
test "@alignCast pointers" {
var x: u32 align(4) = 1;
expectsOnly1(&x);

4
test/stage1/behavior/async_fn.zig
View File

@ -334,7 +334,7 @@ test "async fn with inferred error set" {
var frame: [1]@Frame(middle) = undefined;
var fn_ptr = middle;
var result: @TypeOf(fn_ptr).ReturnType.ErrorSet!void = undefined;
_ = @asyncCall(@sliceToBytes(frame[0..]), &result, fn_ptr);
_ = @asyncCall(std.mem.sliceAsBytes(frame[0..]), &result, fn_ptr);
resume global_frame;
std.testing.expectError(error.Fail, result);
}
@ -954,7 +954,7 @@ test "@asyncCall with comptime-known function, but not awaited directly" {
fn doTheTest() void {
var frame: [1]@Frame(middle) = undefined;
var result: @TypeOf(middle).ReturnType.ErrorSet!void = undefined;
_ = @asyncCall(@sliceToBytes(frame[0..]), &result, middle);
_ = @asyncCall(std.mem.sliceAsBytes(frame[0..]), &result, middle);
resume global_frame;
std.testing.expectError(error.Fail, result);
}

2
test/stage1/behavior/bugs/1851.zig
View File

@ -13,7 +13,7 @@ test "allocation and looping over 3-byte integer" {
x[0] = 0xFFFFFF;
x[1] = 0xFFFFFF;
const bytes = @sliceToBytes(x);
const bytes = std.mem.sliceAsBytes(x);
expect(@TypeOf(bytes) == []align(4) u8);
expect(bytes.len == 8);

20
test/stage1/behavior/cast.zig
View File

@ -304,20 +304,6 @@ fn cast128Float(x: u128) f128 {
return @bitCast(f128, x);
}
test "const slice widen cast" {
const bytes align(4) = [_]u8{
0x12,
0x12,
0x12,
0x12,
};
const u32_value = @bytesToSlice(u32, bytes[0..])[0];
expect(u32_value == 0x12121212);
expect(@bitCast(u32, bytes) == 0x12121212);
}
test "single-item pointer of array to slice and to unknown length pointer" {
testCastPtrOfArrayToSliceAndPtr();
comptime testCastPtrOfArrayToSliceAndPtr();
@ -392,12 +378,6 @@ test "comptime_int @intToFloat" {
}
}
test "@bytesToSlice keeps pointer alignment" {
var bytes = [_]u8{ 0x01, 0x02, 0x03, 0x04 };
const numbers = @bytesToSlice(u32, bytes[0..]);
comptime expect(@TypeOf(numbers) == []align(@alignOf(@TypeOf(bytes))) u32);
}
test "@intCast i32 to u7" {
var x: u128 = maxInt(u128);
var y: i32 = 120;

10
test/stage1/behavior/eval.zig
View File

@ -711,16 +711,6 @@ test "bit shift a u1" {
expect(y == 1);
}
test "@bytesToslice on a packed struct" {
const F = packed struct {
a: u8,
};
var b = [1]u8{9};
var f = @bytesToSlice(F, &b);
expect(f[0].a == 9);
}
test "comptime pointer cast array and then slice" {
const array = [_]u8{ 1, 2, 3, 4, 5, 6, 7, 8 };

21
test/stage1/behavior/misc.zig
View File

@ -3,7 +3,6 @@ const expect = std.testing.expect;
const expectEqualSlices = std.testing.expectEqualSlices;
const mem = std.mem;
const builtin = @import("builtin");
const maxInt = std.math.maxInt;
// normal comment
@ -377,26 +376,6 @@ test "string concatenation" {
expect(b[len] == 0);
}
test "cast slice to u8 slice" {
expect(@sizeOf(i32) == 4);
var big_thing_array = [_]i32{ 1, 2, 3, 4 };
const big_thing_slice: []i32 = big_thing_array[0..];
const bytes = @sliceToBytes(big_thing_slice);
expect(bytes.len == 4 * 4);
bytes[4] = 0;
bytes[5] = 0;
bytes[6] = 0;
bytes[7] = 0;
expect(big_thing_slice[1] == 0);
const big_thing_again = @bytesToSlice(i32, bytes);
expect(big_thing_again[2] == 3);
big_thing_again[2] = -1;
expect(bytes[8] == maxInt(u8));
expect(bytes[9] == maxInt(u8));
expect(bytes[10] == maxInt(u8));
expect(bytes[11] == maxInt(u8));
}
test "pointer to void return type" {
testPointerToVoidReturnType() catch unreachable;
}

29
test/stage1/behavior/slicetobytes.zig
View File

@ -1,29 +0,0 @@
const std = @import("std");
const builtin = @import("builtin");
const expect = std.testing.expect;
test "@sliceToBytes packed struct at runtime and comptime" {
const Foo = packed struct {
a: u4,
b: u4,
};
const S = struct {
fn doTheTest() void {
var foo: Foo = undefined;
var slice = @sliceToBytes(@as(*[1]Foo, &foo)[0..1]);
slice[0] = 0x13;
switch (builtin.endian) {
builtin.Endian.Big => {
expect(foo.a == 0x1);
expect(foo.b == 0x3);
},
builtin.Endian.Little => {
expect(foo.a == 0x3);
expect(foo.b == 0x1);
},
}
}
};
S.doTheTest();
comptime S.doTheTest();
}

4
test/stage1/behavior/struct.zig
View File

@ -315,7 +315,7 @@ test "packed array 24bits" {
var bytes = [_]u8{0} ** (@sizeOf(FooArray24Bits) + 1);
bytes[bytes.len - 1] = 0xaa;
const ptr = &@bytesToSlice(FooArray24Bits, bytes[0 .. bytes.len - 1])[0];
const ptr = &std.mem.bytesAsSlice(FooArray24Bits, bytes[0 .. bytes.len - 1])[0];
expect(ptr.a == 0);
expect(ptr.b[0].field == 0);
expect(ptr.b[1].field == 0);
@ -364,7 +364,7 @@ test "aligned array of packed struct" {
}
var bytes = [_]u8{0xbb} ** @sizeOf(FooArrayOfAligned);
const ptr = &@bytesToSlice(FooArrayOfAligned, bytes[0..bytes.len])[0];
const ptr = &std.mem.bytesAsSlice(FooArrayOfAligned, bytes[0..])[0];
expect(ptr.a[0].a == 0xbb);
expect(ptr.a[0].b == 0xbb);