On 18/07/2025 1:00 pm, Frediano Ziglio wrote: > On Fri, Jul 18, 2025 at 12:12 PM Andrew Cooper > <andrew.coop...@citrix.com> wrote: >> On 18/07/2025 10:41 am, Frediano Ziglio wrote: >>> PrintMessage function print a message string followed by a >>> new line. >>> Move the function from ARM specific code to common code. >>> Reuse it in EFI code. >>> No functional changes. >>> >>> Signed-off-by: Frediano Ziglio <frediano.zig...@cloud.com> >> Please no. >> >> Hiding \n (or \r\n) in strings is an antipattern and a source of >> confusion that we do not want in Xen. >> > I didn't realize it was not a Xen pattern.
We went through a phase where it was inconsistent and we kept on having problems on the console. Missing a newline causes the next message to be appended with <0> and it's very confusion to read. > I found the thing not that > coherent between x86 and arm and attempted to fix it. Sure, and making things consistent is very welcome. > >> Instead, delete PrintMessage() and convert ARM to use PrintStr(). That >> looks like it was premature anti-optimisation. You save 4 bytes per >> string, but it costs 12 byte minimum in .text to set up the function >> call, let alone the function call itself. >> > To be honest I didn't consider this aspect and I don't feel it matters much. > Looking at other languages printing an implicit newline is pretty > common, Pascal has "Wtite" and "WtiteLn", Ocaml has "print_string" and > "print_endline", Right, and in both cases these are clear from context (i.e. the function name) that there's a newline. PrintStr() and PrintMessage() do not have the same kind of clarity. > Python has an "end" parameter which by default is the > newline, Basic (if I remember) has the possibility of an implicit > empty field. In C is not so common although there's "puts" and some > functions (like "syslog") have some kind of implicit newline. > But obviously Xen is not any of them. > > As I said above however my main reason is coherency so I'll post your > suggestion. Thankyou. I'm sure ARM will be better off as a result. ~Andrew
