teb

pub fn teb() *TEB {
    if (builtin.zig_backend == .stage2_c) return @ptrCast(@alignCast(struct {
        /// This is a workaround for the C backend until zig has the ability to put
        /// C code in inline assembly.
        extern fn zig_windows_teb() callconv(.c) *anyopaque;
    }.zig_windows_teb()));
    switch (native_arch) {
        .thumb => return asm (
            \\ mrc p15, 0, %[ptr], c13, c0, 2
            : [ptr] "=r" (-> *TEB),
        ),
        .aarch64 => return asm (
            \\ mov %[ptr], x18
            : [ptr] "=r" (-> *TEB),
        ),
        .x86 => {
            comptime assert(
                @offsetOf(TEB, "NtTib") + @offsetOf(@FieldType(TEB, "NtTib"), "Self") == 0x18,
            );
            return asm (
                \\ movl %%fs:0x18, %[ptr]
                : [ptr] "=r" (-> *TEB),
            );
        },
        .x86_64 => {
            comptime assert(
                @offsetOf(TEB, "NtTib") + @offsetOf(@FieldType(TEB, "NtTib"), "Self") == 0x30,
            );
            return asm (
                \\ movq %%gs:0x30, %[ptr]
                : [ptr] "=r" (-> *TEB),
            );
        },
        else => @compileError("unsupported arch"),
    }
}