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std.Io.Writer: fix writeSliceSwap

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tried to be too clever, wrote bad code
This commit is contained in:
Andrew Kelley
2025-07-19 21:53:48 -07:00
parent 741a66e03c
commit c40fb96ca3
7 changed files with 35 additions and 46 deletions
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2
lib/std/Build/Step/Run.zig
View File

@@ -1742,7 +1742,7 @@ fn sendMessage(file: std.fs.File, tag: std.zig.Client.Message.Tag) !void {
.tag = tag,
.bytes_len = 0,
};
try file.writeAll(std.mem.asBytes(&header));
try file.writeAll(@ptrCast(&header));
}
fn sendRunTestMessage(file: std.fs.File, tag: std.zig.Client.Message.Tag, index: u32) !void {

34
lib/std/Io/Reader.zig
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@@ -1108,9 +1108,9 @@ pub fn takeVarInt(r: *Reader, comptime Int: type, endian: std.builtin.Endian, n:
/// Asserts the buffer was initialized with a capacity at least `@sizeOf(T)`.
///
/// See also:
/// * `peekStructReference`
/// * `peekStructPointer`
/// * `takeStruct`
pub fn takeStructReference(r: *Reader, comptime T: type) Error!*align(1) T {
pub fn takeStructPointer(r: *Reader, comptime T: type) Error!*align(1) T {
// Only extern and packed structs have defined in-memory layout.
comptime assert(@typeInfo(T).@"struct".layout != .auto);
return @ptrCast(try r.takeArray(@sizeOf(T)));
@@ -1122,9 +1122,9 @@ pub fn takeStructReference(r: *Reader, comptime T: type) Error!*align(1) T {
/// Asserts the buffer was initialized with a capacity at least `@sizeOf(T)`.
///
/// See also:
/// * `takeStructReference`
/// * `takeStructPointer`
/// * `peekStruct`
pub fn peekStructReference(r: *Reader, comptime T: type) Error!*align(1) T {
pub fn peekStructPointer(r: *Reader, comptime T: type) Error!*align(1) T {
// Only extern and packed structs have defined in-memory layout.
comptime assert(@typeInfo(T).@"struct".layout != .auto);
return @ptrCast(try r.peekArray(@sizeOf(T)));
@@ -1136,14 +1136,14 @@ pub fn peekStructReference(r: *Reader, comptime T: type) Error!*align(1) T {
/// when `endian` is comptime-known and matches the host endianness.
///
/// See also:
/// * `takeStructReference`
/// * `takeStructPointer`
/// * `peekStruct`
pub inline fn takeStruct(r: *Reader, comptime T: type, endian: std.builtin.Endian) Error!T {
switch (@typeInfo(T)) {
.@"struct" => |info| switch (info.layout) {
.auto => @compileError("ill-defined memory layout"),
.@"extern" => {
var res = (try r.takeStructReference(T)).*;
var res = (try r.takeStructPointer(T)).*;
if (native_endian != endian) std.mem.byteSwapAllFields(T, &res);
return res;
},
@@ -1162,13 +1162,13 @@ pub inline fn takeStruct(r: *Reader, comptime T: type, endian: std.builtin.Endia
///
/// See also:
/// * `takeStruct`
/// * `peekStructReference`
/// * `peekStructPointer`
pub inline fn peekStruct(r: *Reader, comptime T: type, endian: std.builtin.Endian) Error!T {
switch (@typeInfo(T)) {
.@"struct" => |info| switch (info.layout) {
.auto => @compileError("ill-defined memory layout"),
.@"extern" => {
var res = (try r.peekStructReference(T)).*;
var res = (try r.peekStructPointer(T)).*;
if (native_endian != endian) std.mem.byteSwapAllFields(T, &res);
return res;
},
@@ -1557,27 +1557,27 @@ test takeVarInt {
try testing.expectError(error.EndOfStream, r.takeVarInt(u16, .little, 1));
}
test takeStructReference {
test takeStructPointer {
var r: Reader = .fixed(&.{ 0x12, 0x00, 0x34, 0x56 });
const S = extern struct { a: u8, b: u16 };
switch (native_endian) {
.little => try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x5634 }), (try r.takeStructReference(S)).*),
.big => try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x3456 }), (try r.takeStructReference(S)).*),
.little => try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x5634 }), (try r.takeStructPointer(S)).*),
.big => try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x3456 }), (try r.takeStructPointer(S)).*),
}
try testing.expectError(error.EndOfStream, r.takeStructReference(S));
try testing.expectError(error.EndOfStream, r.takeStructPointer(S));
}
test peekStructReference {
test peekStructPointer {
var r: Reader = .fixed(&.{ 0x12, 0x00, 0x34, 0x56 });
const S = extern struct { a: u8, b: u16 };
switch (native_endian) {
.little => {
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x5634 }), (try r.peekStructReference(S)).*);
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x5634 }), (try r.peekStructReference(S)).*);
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x5634 }), (try r.peekStructPointer(S)).*);
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x5634 }), (try r.peekStructPointer(S)).*);
},
.big => {
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x3456 }), (try r.peekStructReference(S)).*);
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x3456 }), (try r.peekStructReference(S)).*);
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x3456 }), (try r.peekStructPointer(S)).*);
try testing.expectEqual(@as(S, .{ .a = 0x12, .b = 0x3456 }), (try r.peekStructPointer(S)).*);
},
}
}

23
lib/std/Io/Writer.zig
View File

@@ -851,9 +851,6 @@ pub inline fn writeStruct(w: *Writer, value: anytype, endian: std.builtin.Endian
}
}
/// If, `endian` is not native,
/// * Asserts that the buffer storage capacity is at least enough to store `@sizeOf(Elem)`
/// * Asserts that the buffer is aligned enough for `@alignOf(Elem)`.
pub inline fn writeSliceEndian(
w: *Writer,
Elem: type,
@@ -867,18 +864,11 @@ pub inline fn writeSliceEndian(
}
}
/// Asserts that the buffer storage capacity is at least enough to store `@sizeOf(Elem)`
///
/// Asserts that the buffer is aligned enough for `@alignOf(Elem)`.
pub fn writeSliceSwap(w: *Writer, Elem: type, slice: []const Elem) Error!void {
var i: usize = 0;
while (i < slice.len) {
const dest_bytes = try w.writableSliceGreedy(@sizeOf(Elem));
const dest: []Elem = @alignCast(@ptrCast(dest_bytes[0 .. dest_bytes.len - dest_bytes.len % @sizeOf(Elem)]));
const copy_len = @min(dest.len, slice.len - i);
@memcpy(dest[0..copy_len], slice[i..][0..copy_len]);
i += copy_len;
std.mem.byteSwapAllElements(Elem, dest);
for (slice) |elem| {
var tmp = elem;
std.mem.byteSwapAllFields(Elem, &tmp);
try w.writeAll(@ptrCast(&tmp));
}
}
@@ -2650,9 +2640,10 @@ test writeStruct {
}
test writeSliceEndian {
var buffer: [4]u8 align(2) = undefined;
var buffer: [5]u8 align(2) = undefined;
var w: Writer = .fixed(&buffer);
try w.writeByte('x');
const array: [2]u16 = .{ 0x1234, 0x5678 };
try writeSliceEndian(&w, u16, &array, .big);
try testing.expectEqualSlices(u8, &.{ 0x12, 0x34, 0x56, 0x78 }, &buffer);
try testing.expectEqualSlices(u8, &.{ 'x', 0x12, 0x34, 0x56, 0x78 }, &buffer);
}

6
lib/std/zig/Server.zig
View File

@@ -118,8 +118,6 @@ pub fn init(options: Options) !Server {
.in = options.in,
.out = options.out,
};
assert(s.out.buffer.len >= 4);
std.debug.assertAligned(s.out.buffer.ptr, .@"4");
try s.serveStringMessage(.zig_version, options.zig_version);
return s;
}
@@ -203,8 +201,8 @@ pub const TestMetadata = struct {
pub fn serveTestMetadata(s: *Server, test_metadata: TestMetadata) !void {
const header: OutMessage.TestMetadata = .{
.tests_len = @as(u32, @intCast(test_metadata.names.len)),
.string_bytes_len = @as(u32, @intCast(test_metadata.string_bytes.len)),
.tests_len = @intCast(test_metadata.names.len),
.string_bytes_len = @intCast(test_metadata.string_bytes.len),
};
const trailing = 2;
const bytes_len = @sizeOf(OutMessage.TestMetadata) +