On 12/10/17 11:50 pm, Christian Mauderer wrote: > > OK. It felt a little bit like a hack to me (using an environment > variable during configure) but if you think it would be an improvement, > I wouldn't offend. >
Given the build system we have this seems to be the best of a poor set of options we have. It is preferable over asking users to edit config files. >> >>> If we want to offer something like that for all BSPs, it might would be >>> a better idea to split the flags up (what I haven't done here). >> >> Yes it might pay to split them up. >> >>> I think the -ffunction-sections -fdata-sections is allways necessary? >> >> I am not sure which archs can use the function and data sections. It is the >> `?=` >> I like. > > Like you noted, I'm not sure too. It just seems that every BSP sets > them. Joel let me know yesterday all bsps should support the options. > I'm also not sure why some BSPs have additional options and > whether they are necessary. That is just how the BSPs are. > So for me it would currently be only > possible to leave all other options untouched. Agreed. > >> >>> Some BSPs >>> have some other options too like an additional -fomit-frame-pointer in >>> rbtx4925 or a -mmultiple in mcp750. So if a user would want to use that >>> environment variable to change optimization, the value wouldn't be >>> consistent across BSPs. >> >> Ah ok. >> >>> >>> A consistent solution could be to split it up like in or1k: >>> >>> CFLAGS_OPTIMIZE_V ?= -O0 -g >>> CFLAGS_OPTIMIZE_V += -ffunction-sections -fdata-sections >>> >>> The general optimization could be overwritten with CFLAGS_OPTIMIZE_V and >>> the BSP-specific parts would be added in the second line. >>> >>> What do you think? >>> >> >> The or1k solution looks good. What if we did something like: >> >> CFLAGS_OPTIMIZE_V ?= -O0 >> CFLAGS_DEBUG_V ?= -g >> CFLAGS_OPTIMIZE_V += $(CFLAGS_DEBUG_V) -ffunction-sections -fdata-sections >> >> Is that too much? > > It would add two options instead of one. Maybe we should just put the -g > to the default options in every BSP. It only increases the size of the > binaries on the development host. I agree. I only split them because there is more than the `-g` option for debug info, there are other variants and some times debuggers need something different. > If it is necessary to have some very > small binaries, it is still possible to strip them. So I can't think of > a case where -g hurts someone. I agree. > So I would rather use a > > CFLAGS_OPTIMIZE_V ?= -O0 > CFLAGS_OPTIMIZE_V += -g -ffunction-sections -fdata-sections > >> >> It would make documenting what this does simpler. > > To be honest: I wouldn't be sure where the documentation should go. Do > we have some guide about how to configure and compile a BSP? > Is suppose the RTEMS User Manual. It could be part of the instructions on building. Chris _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
