[U-Boot] a couple questions about CONFIG_SYS_LONGHELP

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Robert,

On Sat, 26 Jan 2013 07:37:45 -0500 (EST), "Robert P. J. Day"
<rpjday@crashcourse.ca> wrote:

> On Sat, 26 Jan 2013, Albert ARIBAUD wrote:
> 
> > Hi Robert,
> >
> > On Sat, 26 Jan 2013 07:11:18 -0500 (EST), "Robert P. J. Day"
> > <rpjday@crashcourse.ca> wrote:
> >
> > > On Sat, 26 Jan 2013, Albert ARIBAUD wrote:
> > >
> > > > Hi Robert,
> > > >
> > > > On Sat, 26 Jan 2013 06:38:51 -0500 (EST), "Robert P. J. Day"
> > > > <rpjday@crashcourse.ca> wrote:
> > >
> > > ... snip ...
> > >
> > > > >   and second, i'm not sure how to read this out of cmd_pci.c:
> > > > >
> > > > > ===== start
> > > > >
> > > > > #ifdef CONFIG_SYS_LONGHELP
> > > > > static char pci_help_text[] =
> > > > >         "[bus] [long]\n"
> > > > >         "    - short or long list of PCI devices on bus 'bus'\n"
> > > > > #ifdef CONFIG_CMD_PCI_ENUM
> > > > >         "pci enum\n"
> > > > >         "    - re-enumerate PCI buses\n"
> > > > > #endif
> > > > >         "pci header b.d.f\n"
> > > > >         "    - show header of PCI device 'bus.device.function'\n"
> > > > >         "pci display[.b, .w, .l] b.d.f [address] [# of objects]\n"
> > > > >         "    - display PCI configuration space (CFG)\n"
> > > > >         "pci next[.b, .w, .l] b.d.f address\n"
> > > > >         "    - modify, read and keep CFG address\n"
> > > > >         "pci modify[.b, .w, .l] b.d.f address\n"
> > > > >         "    -  modify, auto increment CFG address\n"
> > > > >         "pci write[.b, .w, .l] b.d.f address value\n"
> > > > >         "    - write to CFG address";
> > > > > #endif
> > > > >
> > > > > U_BOOT_CMD(
> > > > >         pci,    5,      1,      do_pci,
> > > > >         "list and access PCI Configuration Space", pci_help_text
> > > > > );
> > > > >
> > > > > ===== end
> > > > >
> > > > >   note how, if CONFIG_SYS_LONGHELP is defined, the symbol
> > > > > "pci_help_text" is created as the text, but its *usage* just below in
> > > > > the U_BOOT_CMD macro is *outside* of that preprocessor check.  how
> > > > > would that work if CONFIG_SYS_LONGHELP is undefined?  not at my dev
> > > > > host right this minute so i can't test, but it just looks ... weird.
> > > >
> > > > Probably would not work. Submit a fix. :)
> > >
> > >   there appears to be a number of common/cmd_*.c files that have that
> > > structure:
> > >
> > > $ grep "ifdef.*CONFIG_SYS_LONGHELP" cmd*.c
> > > cmd_bootm.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_bootm.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_fdt.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_help.c:#ifdef  CONFIG_SYS_LONGHELP
> > > cmd_i2c.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_mp.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_mtdparts.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_nand.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_nvedit.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_pci.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_source.c:#ifdef CONFIG_SYS_LONGHELP
> > > cmd_ximg.c:#ifdef CONFIG_SYS_LONGHELP
> > > $
> > >
> > >   so it's not just one file.
> >
> > The grep above just shows that there are files have conditionally
> > compiled code for CONFIG_SYS_LONGHELP; however it does not show per
> > se that these files wound not compile without it.
> 
>   i'm aware of that -- but i manually examined some of the files
> above, and all of the ones i looked at had the same "issue" as
> cmd_pci.c.  the grep command was not meant as proof, i just used it as
> a guide for which files i wanted to look at more closely, and i see
> the same problem with all of them.  so someone higher up the food
> chain than me can decide if this is something worth addressing.

Actually there is no such hierarchical decision process where decision
to fix would come from some 'upper layer' -- which simply does not
exist as such in U-Boot. Decision comes from whoever feels something has
to be changed, and these persons just submit a patch or patch-set which
embodies their change. At this point board maintainers or custodians,
or plain readers on the list too, may comment the submission and
request changes; and custodians and maintainers can NAK it if it is
wrong or had dead code or does not match the overall design or some
other technical reason ; but submitting in the first place requires no
authorization.

> rday

Amicalement,
-- 
Albert.