### 7.56 `.linkonce [` type `]`

Mark the current section so that the linker only includes a single copy of it. This may be used to include the same section in several different object files, but ensure that the linker will only include it once in the final output file. The `.linkonce` pseudo-op must be used for each instance of the section. Duplicate sections are detected based on the section name, so it should be unique.

This directive is only supported by a few object file formats; as of this writing, the only object file format which supports it is the Portable Executable format used on Windows NT.

The type argument is optional. If specified, it must be one of the following strings. For example:

         .linkonce same_size

Not all types may be supported on all object file formats.

`discard`
  Silently discard duplicate sections. This is the default.
`one_only`
  Warn if there are duplicate sections, but still keep only one copy.
`same_size`
  Warn if any of the duplicates have different sizes.
`same_contents`
  Warn if any of the duplicates do not have exactly the same contents.