Selon Paolo Bonzini <[EMAIL PROTECTED]>: > > > There is a Standard'Default_Bit_Order so it's the same as Word_Size: we > just > > loose "source" documentation (and gain less diff between target file). > > Yes, but Arnaud said that system-* constants are written down for a > reason. I don't understand *what* is the reason, but that's just > because I have no clue (among other things) of what parts of the Ada RTS > are installed.
Arnaud was quite clear about the reason: "The idea currently is to make these values explicit so that when people read system.ads, they know right away what the right value is." My take is that it's not a strong blocking point and that integrated multilib build is more useful to Ada users (and GCC developpers) than this limited form of documentation, being able to do -m32 on x86_64 or powerpc/sparc is nice to have after all :). > If it was up to me, I would make the system.ads file automatically > generated (except for the latter 20%, which would have to be specified > in some way). That would simplify multilibbing, but is moot unless > there is a guarantee that this 20% is *totally* derivable from the > target triplet, so that no conceivable flag combination can affect it. > If this guarantee is not there, any attempt to multilib the Ada RTS is > going to be a sore failure. On a given target triplet you can still have multiple Ada RTS for example for different thread libraries or exception models. These choices are expressed in gcc/ada/Makefile.in and as I said it doesn't look very hard to update it to handle multilibs as they currently exist. Laurent
