Am Mon, 2002-03-11 um 00.12 schrieb Phil Edwards: > I'm one of the libstdc++-v3 people, and I've been making occasional > halfhearted attempts to move our configury to 2.5x. I had another go > this weekend, which led me to the autoconf mail archives and this thread. > So here's a status update: > > > > The AC_TRY_RUN/AC_PROG_CC issue is supposed to be solved with > > > autoconf-2.5x, because AC_PROG_CC doesn't try to run an executable > > > anymore. I.e. basically, cross-compilation is supposed not to be any > > > different from native compilation. > > > > Really? I'll have to poke at this again with 2.52. It certainly did > > not work in 2.50. > > And it's still broken in 2.52. :-( Well, ... I am using it for cross-compilation.
I know, there are details, where I do think cross-compilation support is broken, but this is different topic ... > AC_PROG_CC tries to do something in > the "checking for C compiler default output" section which fails (cannot > create executables) when cross-compiling. If I edit the configure script > to ignore the error, I get two steps further: > > checking for C compiler default output... > checking whether the C compiler works... yes > checking whether we are cross compiling... yes > checking for executable suffix... configure: error: cannot compute EXEEXT: >cannot compile and link This result means that your C compiler is not able to link and/or compile at the time this check is run. If building libstdc++ standalone/outside of the gcc-source tree, this would be a strong indication for your toolchain to be actually broken. If building inside of the gcc-source-tree, there are various things which can go wrong. E.g. this check might be run at a time when the c-toolchain is incomplete and not yet usable. It could also be the side-effect of something else, e.g. the toplevel configure script setting the canonicalization names to something which is incompatible to autoconf-2.52 (--host etc.), rsp. the toolchain might also be broken itself (several gnu-cross-toolchains are in pretty bad shape.) Could you please check the part of the config.log corresponding to the failing AC_PROG_CC for the actual reason of the breakdown you are observing? > I've seen references in this thread to a macro called AC_NO_EXECUTABLES, > but that's undocumented in the 2.52 manual, so I don't know what to do > with that. Non-documented == Don't use! :) > The AC_PROG_CC documentation says, "See section 11. Manual Configuration, > for more on support for cross compiling," but that section doesn't say a > thing about cross-compiling. This is Akim's baby :) > I'll wait for 2.53 before trying again. AFAIK, not much has changed wrt. cross-compilation with 2.53. (You don't seem to be aware that it already has been released.). Ralf
