On Wed, Nov 02, 2016 at 01:26:48PM +0000, Jiong Wang wrote:
> -/* A subroutine of dwarf2out_frame_debug, process a REG_CFA_EXPRESSION note.
> */
> +/* A subroutine of dwarf2out_frame_debug, process a REG_CFA_EXPRESSION note.
> */
Too long line.
> + /* RTL sequences inside PARALLEL are raw expression representation.
> +
> + mem_loc_descriptor can be used to build generic DWARF expressions for
> + DW_CFA_expression and DW_CFA_val_expression where the expression may
> can
> + not be represented using normal RTL sequences. In this case, group
> all
> + expression operations (DW_OP_*) inside a PARALLEL. For those DW_OP
> which
> + doesn't have RTL mapping, wrap it using UNSPEC. The logic for parsing
> + PARALLEL sequences is:
> +
> + foreach elem inside PARALLEL
> + if (elem is UNSPEC)
> + dw_op = XINT (elem, 1) (DWARF operation is kept as UNSPEC number)
> + oprnd1 = XVECEXP (elem, 0, 0)
> + oprnd2 = XVECEXP (elem, 0, 1)
> + else
> + call mem_loc_descriptor */
Not sure if it is a good idea to document in weirdly formatted
pseudo-language what the code actually does a few lines below. IMHO either
express it in words, or don't express it at all.
> + exp_result =
> + new_loc_descr ((enum dwarf_location_atom) dw_op, oprnd1,
> + oprnd2);
Wrong formatting, = should be on the next line.
> + }
> + else
> + exp_result =
> + mem_loc_descriptor (elem, mode, mem_mode,
> + VAR_INIT_STATUS_INITIALIZED);
Likewise.
Jakub
