`.line LINE-NUMBER'
===================

   Tell `as' to change the logical line number.  LINE-NUMBER must be an
absolute expression.  The next line will have that logical line number.
So any other statements on the current line (after a statement
separator character) will be reported as on logical line number
LINE-NUMBER - 1.  One day this directive will be unsupported: it is
used only for compatibility with existing assembler programs.

   *Warning:* In the AMD29K configuration of as, this command is only
available with the name `.ln', rather than as either `.line' or `.ln'.

   Even though this is a directive associated with the `a.out' or
`b.out' object-code formats, `as' will still recognize it when
producing COFF output, and will treat `.line' as though it were the
COFF `.ln' *if* it is found outside a `.def'/`.endef' pair.

   Inside a `.def', `.line' is, instead, one of the directives used by
compilers to generate auxiliary symbol information for debugging.