[M3devel] platform/build_dir is a big tuple?

[Olaf Wagner]

All this may be useful during development, but it is not really
useful for a software distribution to our users, I think.

Nobody will understand it :-( We need to keep things more simple.

We don't need to support everything out of the box. Instead, we should
offer some sensible default combinations of everyhing you describe.

First of all: we don't distribute cross compilers (at least until now).
This is a special topic reserved for adding new platforms.

Runtime and compilers used do not necessarily need to be distinguished
by target or build dir, in many cases different cm3.cfg may suffice.

Until now, threading models are also no choice that needs to be
visible at this level. There's one default model for every target,
and the user can change it by recompiling.

And if we should really agree that changing the target naming scheme
is a good idea, we should

  o use a systematic one with not more than 4 elements (better still,
    3 (e.g. <arch>-<os>-<variant>))
  o don't use cryptic abbreviations that will confuse most people

Just my 2 cents,

Olaf

Quoting Jay <jayk123 at hotmail.com>:
> I'm still torn over that any NT386 target could  have a choice of   
> three threading models (win32, pthread, vtalarm), two  windowing   
> libraries (ms, x), two (three) compilers (ms, mingwin, cygwin), two   
> (three) linkers (ms, mingwn, cygwin), various runtimes (msvc various  
>  versions, cygwin, mingwin (discouraged)) etc.
>
> Appending a short string of unreadable bits to BUILD_DIR is very   
> temptingin order to easily generate and test the combinatorial   
> possibilities.
>
> backend: 0 integrated, 1 gcc already a setting (with four values)
>
> ccompiler/linker: 0 ms, 1 gcc (these could be split, and could   
> allocate more bits...) maybe 00 ms, 01 cygwin, 10 ming  maybe define  
>  enum up front that allows for watcom, metrowerks, digitalmars, llvm  
>  etc.
>  maybe use a decimal digit for all these, and 0 is reserved, maybe.
>
> threading: 0 win32, 1 pthreads  drop vtalarm, or use two bits?
>
> windowing: 0 ms, 1 x
>
> cruntime: 0 ms, 1 cyg  There is also a ming runtime, discouraged    
> There also really N ms runtimes, ming offers several:   msvcrt.dll,   
> msvcr70.dll, msvcr71.dll, msvcr80.dll, msvcr90.dll...   but jmpbuf   
> presumbly doesn't change again could allocate multiple bits..
>
> cruntime I guess determines oSTYPE Win32 or Posix, thoughit loses   
> its meaning mostly, and X vs. not-X is usually decide the same...
>
> The three most common combinations:  00000 -- NT386  11111 --   
> NT386GNU  11000 -- NT386MINGNU
>
> but several others would work  11101 -- cygwin with native windowing  
>   11011 -- cygwin with native threads  11001 -- cygwin with native   
> threads and native windowing
>  BUILD_DIR would be NT386-$(config)as a special case perhaps, the   
> three commoncases could be translated to the above strings.
>
> But the underlying implementation would be a few bools/enums,and   
> iterating through them would be easy, while special casingand   
> skipping deemed invalid combinations, like ms runtime and   
> pthreads,and possibly ms runtime and x windows.
> Really, it might surprise folks, but really, basically every single   
> combination works.
> Compilers are very independent of headers and libs and headers and   
> libs are very independent of compilers, aside from a few language   
> extensions like __stdcall. You can generally mix runtimes in the   
> same process, just as you can mix them on the same machine, you just  
>  need to be careful about what you pass to what. If you call fopen,   
> be sure pass the result back to the matching fclose, malloc/free,   
> etc. Startup code, to the extent that it matters, might be a   
> problem, but really, just avoid C++ globals with   
> constructors/destructors anyway, they are always a problem. Modula-3  
>  has its own startup code, and if you were to write "main" in C and   
> link in Modula-3 static .libs, that probably doesn't work...might   
> actually be better to play into whatever the platform's C++   
> constructor story is, as problematic as they (probably always?) are   
> -- i.e. unpredictable/hard-to-control ordering.
>
> (bad editing...and maybe use hex for compression..)
>
> Bringing back cminstall is almost interesting, to promptthe user, or  
>  probe their system, though Quake/cm3 can probe at runtime.if os ==   
> windows_nt   system_cc | findstr version | findstr gcc   else   
> system_cc | findstr visual c++else   system_cc | grep version | grep  
>  gcc   else system_cc | grep visual c++end
>
> inefficient.
>
> anyway, I'll merge current NT386GNU into NT386 and make it chosehow   
> to compile/link which are the main variables today.
> and then decide about cygwin, but probably do like the above,   
> sinceit'll totally share code with NT386 except the naming   
> conventionsand the removal of the -mno-cygwin switch..
>
> I know this seems overly complicated, but it should be   
> exposableeasily enough to users by hiding the choices, presenting   
> three basic ones,and still allow all the obvious and perhaps useful   
> knobs, and iterating throughthe combinations, without creating a   
> combinatorial explosion of source filesor Modula-3 or Quake code.
>   ...Jay
>
>
> From: jayk123 at hotmail.comTo: m3devel at elegosoft.comDate: Tue, 22 Jan   
> 2008 10:48:56 +0000Subject: Re: [M3devel] platform/build_dir is a   
> big tuple?
>
>
> Final answer? I played around with this but just can't accept   
> platforms/build_dirs like:  ntx86msmsmscm3msn  ntx86gccgcccm3cgmsn    
> ntx86gccgcccm3cgxn  ntx86-gggggmn  ntx86-ggixn  ntx86_mmmimmOk, I   
> have one more name here, and then a bit of a change, or a stronger   
> statement of something I had already said.NT386MINGNUOk, I think we   
> (me!) are confusing host and target, MOSTLY.And cm3 might not have   
> them quite divided appropriately.What is a "host"? What is a   
> "target"?MinGWin and Visual C++ output similar results, targetingthe  
>  same runtime (usually), threading library, windowing library.There   
> is a chance for exception handling to diverge however.Well, speaking  
>  of Visual C++ the C/C++ compiler and MinGWinthe gcc environment,   
> yes, very different, not interoperable.MinGWin uses what gcc calls   
> "sjlj" -- setjmp/longjmp exceptions.Very inefficient. But heck, gcc   
> doesn't support __try/__except/__finally,only C++ exceptions, and   
> interop of C++ is often not great,what with name mangling and   
> all.NT386GNU's OUTPUT uses a different runtime, unless you  trim   
> dependencies, possibly a different threading library,  possibly a   
> different windowing library. All this probably  configurable. Again   
> exception handling is a sore point in  that it is the primary C   
> runtime dependency of Modula-3.  If you use Cygwin but say   
> -mno-cygwin, that means  you are targeting NT386. (and don't use   
> pthreads or X Windows;  behavior of exceptions/setjmp/longjmp TBD --  
>  really, need  to not use the -mno-cygwin headers in that case; I'll  
>  check).Perhaps m3core.dll should export  
> m3_setjmp/m3_longjmp..Either  one can do a cross build to the  
> other.Two cm3.exes, two sets of  outputs, that either can  
> produce.NT386 can use gcc or the integrated  backend.  And the gcc  
> it uses can be MinGWin or Cygwin.  (theoretically and probably soon  
> reality) NT386GNU can use either as  well! (also currently theory,  
> but a real possibility)  It isn't GNU  tools, it is GNU runtime.One  
> small area with cm3 might fall down  just slightly is that of    
> cross builds where host and target have  different naming  
> conventions.   -lfoo vs. foo.lib, foo.o vs. foo.obj  are an aspect  
> of the host and   I vaguely recall that cm3 ties  naming convention  
> to ostype.   The appending of .exe is a target  characteristics, but  
> the others are not really.   Naming convention  is really a host  
> thing and not a target thing.The config files are a  mix of host and  
> target information, mostly actually host,  except  for the one line  
> that says TARGET. Most of the target variation is  in cm3,  which  
> always can do any, and cm3cg (which might be nice to  be similar,  
> but that's  another matter and not likely to ever  change, except  
> when AMD64 is the last  architecture standing. :) )If  Windows had  
> "rpath", then SL would be split between HOST_SL and  TARGET_SL.As it  
> stands, SL is HOST_SL.Consider as well the various  versions of  
> Visual C++.They output mostly the same, very  interoperable.Consider  
> optimization switches. Host or  target?Consider version of gcc or  
> Visual C++? Host or target?Well,  inevitably, the host has an affect  
> on the target.  If not the for  the host, the target would not even  
> exist.  Bugs in the host produce  bugs in the target.  etc.(And  
> realize that Cygwin runs on top of an  OS built witha Microsoft  
> compiler, so really there is interop, but  sometimes through a  
> layer.) So there's a risk of saying there is  six+  
> combinations.(host cygwin, host mingwin, host native) x (target   
> nt386, target nt386gnu)  But generally the host is assumed not a   
> factor. I guess "LIBC" could be seperated into several options...You  
>  could actually have code that needs one runtime or another, and  
> they  couldlink together, depending on what they do.. This is  
> something I  don't know if cm3 handles, or anything I have seen. I  
> should be able  to build a static .lib, that includes some C code,  
> that imbues its    clients with build time dependencies. Well, I  
> guess #pragma  comment(linker) is this.So the next tasks are  
> roughly:   Merge my  NT386 and NT386GNU files.   Switching on a  
> variable such as backend  mode.    Introduce a "new" (old) NT386GNU  
> file, perhaps more like  what was already there.    Change NT386GNU  
> back to Posix.    Build  NT386GNU. oh, one more point...while these  
> are two targets from  cm3's point of view, they are PROBABLY the  
> same target to cm3cgand  so only one is needed. I have to check if  
> configure differentiates  between i686-pc-cygwin and  
> i686-pc-mingwin...but I guess it  should...It might actually be  
> profitable to have two bloated  cm3cg.exe's.And they should ship to  
> \cm3\pkg\m3cc\target\host or  host\target and cm3 should know which  
> to run.Blech..four of them  when one would suffice?The detail being  
> mainly what the paths to  .libs look like, unfortunate.Possibly cm3  
> can bridge this gap using  that "broken" feature that symlinks libs  
> into the target  directory,using NTFS hard links, if installroot and  
> root are on the  same volume... (or symlinks on Vista).Or maybe  
> convert the paths as  appropriate, hacky, but saves an extra  
> cm3cg.exe which is good to  avoid. (all the more reason to lump all  
> targets into one file, so  that the host x target matrix collapses  
> to just one axis, host;  andthen you can write stuff in  
> Perl/Python/Java/C# to collapse that  to just one, except for the  
> underlying runtime/interpreter...) Oh,  cm3cg isn't the issue. It is  
> always sitting in the correct directory  and reads one file and  
> writes one file, no slashes.The issue is gcc  as the linker. Again,  
> this is a host issue..and cm3 or the config  file definitely should  
> do the translation.  - Jay
>
>
> From: jayk123 at hotmail.comTo: m3devel at elegosoft.comDate: Mon, 21 Jan   
> 2008 23:01:44 +0000Subject: [M3devel] platform/build_dir is a big   
> tuple?
>
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