[Bug bootstrap/41180] can not build gcc 4.4.1 on Snow Leopard Mac OS X 10.6

[mrs at apple dot com]

------- Comment #26 from mrs at apple dot com  2009-09-03 00:20 -------
First, config.guess is orthogonal to the entire discussion, because of that, we
never need to mention it again.

Next, we do a case analysis of every combination of host/target and buildÂ…  We
engineer each case to work as desired.  Once that is done, you'll discover that
we absolutely do need the i386 case to set -m32.  If that isn't done, the
compiler defaults to 64-bit, and that runs counter to the command implied by
the i386, which is to generate 32-bit code.  So, the fragment I sent is
absolutely required, unchanged.  You can know this is true by configure
--build=i386-apple-darwin10 on a 64-bit SL box and running file on gcc/expr.o. 
If it is 64-bit, it is wrong.

-m32 should never be set because the x86_64 case.  x86_64 means 64-bit, so, the
most it implies is -m64.  For this reason, #19 must be wrong.  x86_64 implying
-m64 is useful for gcc's that default to 32-bit code-gen.  I don't have that in
my tree, as I don't have to worry much about older systems and older compilers.
 For the FSF tree, it would be nice to have that.  You can know this is true by
configuring --build=x86_64-apple-darwin on a Leopard box (where gcc defaults to
32-bit) and running file on gcc/expr.o.  If it is 32-bit, it is wrong.

darwin10 supports and runs on 32-bit only processors.  In that case, x86_64
isn't the default code-gen, contrary to your statement in #22.

It is improper to test target in #20, as target has no influence. 
--host=i386-apple-darwin --target=arm-elf implies -m32.  Build one, then run
file gcc/expr.o.  If that file is 64-bit, it is wrong.

The changes to configure.ac are independent of config.guess, so your assertion
that the changes are only appropriate after config.guess is accepted, is wrong.
 You can see this by configure --build=i386-apple-darwin10 and running file
gcc/expr.o and noticing it is wrong currently on SL.  It is says 64-bit, it is
wrong.

For the comment in #24, no, that isn't its only purpose.  The purpose of it
would be to allow one to configure --host=i386-apple-darwin10
--build=i386-apple-darwin10, and have gcc do what it is told to do, which is to
generate 32-bit binaries.

Now, all that aside, you only need to change the patches I suggested, if there
is an error in them.  You've not identified one error, therefore you don't need
to change them.  If you want to change them, please explain the error.

Lastly, tentative_cc won't work as well as setting CC.  My comment in #15 is
wrong, CC must be used.

As for the libraries.  You have to build them appropriately, and give to gcc,
the appropriate libs.  I build them universal, so what I give gcc is trivially,
always good.  If you build just one architecture, you have to build the
libraries with the same 32/64-bitness as you want to build the compiler.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41180