@itemx --gen-debug
Generate debugging information for each assembler source line using whichever
debug format is preferred by the target. This currently means either STABS,
-ECOFF or DWARF2.
+ECOFF or DWARF2. When the debug format is DWARF then a @code{.debug_info} and
+@code{.debug_line} section is only emitted when the assembly file doesn't
+generate one itself.
@item --gstabs
Generate stabs debugging information for each assembler line. This
number matrix corresponding to the immediately following assembly
instruction. The @var{fileno}, @var{lineno}, and optional @var{column}
arguments will be applied to the @code{.debug_line} state machine before
-the row is added.
+the row is added. It is an error for the input assembly file to generate
+a non-empty @code{.debug_line} and also use @code{loc} directives.
The @var{options} are a sequence of the following tokens in any order: