48 lines
1.2 KiB
Zig
48 lines
1.2 KiB
Zig
const std = @import("std");
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// "Borrowed" from https://github.com/tupleapp/tuple-launch/blob/master/cmsghdr.zig
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pub fn cmsghdr(comptime T: type) type {
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const Header = extern struct {
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len: usize,
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level: c_int,
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type: c_int,
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};
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const data_align = @sizeOf(usize);
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const data_offset = std.mem.alignForward(usize, @sizeOf(Header), data_align);
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return extern struct {
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const Self = @This();
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bytes: [data_offset + @sizeOf(T)]u8 align(@alignOf(Header)),
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pub fn init(args: struct {
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level: c_int,
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type: c_int,
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data: T,
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}) Self {
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var self: Self = undefined;
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self.headerPtr().* = .{
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.len = data_offset + @sizeOf(T),
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.level = args.level,
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.type = args.type,
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};
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self.dataPtr().* = args.data;
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return self;
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}
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pub fn headerPtr(self: *Self) *Header {
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return @as(*Header, @ptrCast(self));
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}
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pub fn dataPtr(self: *Self) *T {
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return @as(*T, @alignCast(@ptrCast(self.bytes[data_offset..])));
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}
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};
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}
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test {
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std.testing.refAllDecls(cmsghdr([3]std.os.fd_t));
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}
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