7.50 .line line-number

Change the logical line number. line-number must be an absolute expression. The next line has that logical line number. Therefore any other statements on the current line (after a statement separator character) are reported as on logical line number line-number − 1. One day as will no longer support this directive: it is recognized only for compatibility with existing assembler programs.

Even though this is a directive associated with the a.out or b.out object-code formats, as still recognizes it when producing COFF output, and treats ‘.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.