7.54 .loc fileno lineno [ column ] [ options ]

When emitting DWARF2 line number information, the .loc directive will add a row to the .debug_line line number matrix corresponding to the immediately following assembly instruction. The fileno , lineno , and optional column arguments will be applied to the .debug_line state machine before the row is added.

The options are a sequence of the following tokens in any order:

basic_block
This option will set the basic_block register in the .debug_line state machine to true .
prologue_end
This option will set the prologue_end register in the .debug_line state machine to true .
epilogue_begin
This option will set the epilogue_begin register in the .debug_line state machine to true .
is_stmt value
This option will set the is_stmt register in the .debug_line state machine to value , which must be either 0 or 1.
isa value
This directive will set the isa register in the .debug_line state machine to value , which must be an unsigned integer.
discriminator value
This directive will set the discriminator register in the .debug_line state machine to value , which must be an unsigned integer.