Issue with cross compile and --64

Issue with cross compile and --64

[Matthew Stock]

Hi folks,

Looking for some guidance from folks on how to resolve a problem I'm
running into.  Short version is that I have a custom 32-bit CPU core
with a target for binutils, gcc and newlib target (hobby stuff).  I
haven't updated the toolchain in about 9 months or so, and this time
around it failed when building gcc, complaining that my cross-gas
didn't recognize --64:

make[2]: Entering directory '/home/mstock/projects/gnutools/build/gcc/gcc'
g++ -c   -g -O2     -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE
-fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall
-Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute
-Wconditionally-supported -Woverloaded-virtual -pedantic
-Wno-long-long -Wno-variadic-macros -Wno-overlength-strings
-fno-common  -DHAVE_CONFIG_H  -DGENERATOR_FILE -I. -Ibuild
-I../../../gcc/gcc -I../../../gcc/gcc/build
-I../../../gcc/gcc/../include  -I../../../gcc/gcc/../libcpp/include  \
    -o build/genmodes.o ../../../gcc/gcc/genmodes.cc
/home/mstock/cross/bexkat1-elf/bin/as: unrecognized option '--64'

Host and build are Linux, target is bexkat1-elf (custom).

For this group, my question: is this an issue with my gas port, or
should I be looking at gcc?  The intersection of issues here are
unique enough where google hasn't really helped.  Thanks for any
suggestions.

Matt

Re: Issue with cross compile and --64

[Jan Beulich]

On 21.03.2023 15:55, Matthew Stock wrote:
> Hi folks,
> 
> Looking for some guidance from folks on how to resolve a problem I'm
> running into.  Short version is that I have a custom 32-bit CPU core
> with a target for binutils, gcc and newlib target (hobby stuff).  I
> haven't updated the toolchain in about 9 months or so, and this time
> around it failed when building gcc, complaining that my cross-gas
> didn't recognize --64:
> 
> make[2]: Entering directory '/home/mstock/projects/gnutools/build/gcc/gcc'
> g++ -c   -g -O2     -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE
> -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall
> -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute
> -Wconditionally-supported -Woverloaded-virtual -pedantic
> -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings
> -fno-common  -DHAVE_CONFIG_H  -DGENERATOR_FILE -I. -Ibuild
> -I../../../gcc/gcc -I../../../gcc/gcc/build
> -I../../../gcc/gcc/../include  -I../../../gcc/gcc/../libcpp/include  \
>     -o build/genmodes.o ../../../gcc/gcc/genmodes.cc
> /home/mstock/cross/bexkat1-elf/bin/as: unrecognized option '--64'
> 
> Host and build are Linux, target is bexkat1-elf (custom).
> 
> For this group, my question: is this an issue with my gas port, or
> should I be looking at gcc?

I think a different question needs asking: Why is it your gas which
gets invoked? genmodes is a build tool, i.e. to be compiled for your
Linux environment. The compiler, when passing --64, expects (I guess)
to invoke an x86 gas (or whatever your build system is), which would
understand --64.

Jan

Re: Issue with cross compile and --64

[Andreas Schwab]

On Mär 21 2023, Matthew Stock wrote:

> make[2]: Entering directory '/home/mstock/projects/gnutools/build/gcc/gcc'
> g++ -c   -g -O2     -DIN_GCC  -DCROSS_DIRECTORY_STRUCTURE
> -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall
> -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute
> -Wconditionally-supported -Woverloaded-virtual -pedantic
> -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings
> -fno-common  -DHAVE_CONFIG_H  -DGENERATOR_FILE -I. -Ibuild
> -I../../../gcc/gcc -I../../../gcc/gcc/build
> -I../../../gcc/gcc/../include  -I../../../gcc/gcc/../libcpp/include  \
>     -o build/genmodes.o ../../../gcc/gcc/genmodes.cc
> /home/mstock/cross/bexkat1-elf/bin/as: unrecognized option '--64'

This is supposed to be using the system assembler, since this compiles a
build tool.  Did you perhaps modify $PATH to include
/home/mstock/cross/bexkat1-elf/bin?  You should not do that.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

Re: Issue with cross compile and --64

[Matthew Stock]

On Tue, Mar 21, 2023 at 11:14 AM Andreas Schwab <schwab@suse.de> wrote:
>
> This is supposed to be using the system assembler, since this compiles a
> build tool.  Did you perhaps modify $PATH to include
> /home/mstock/cross/bexkat1-elf/bin?  You should not do that.

Thanks Andreas and Jan for your suggestions.  I made sure that it
isn't in my path, and still get the same error when running configure
and make from a clean build directory.  Not sure why the system g++ is
deciding that it should use the cross as.  I'm using this as my
configure line:

../../gcc/configure --target=bexkat1-elf --disable-nls
--enable-languages=c,c++ --without-headers --disable-libssp
--prefix=/home/mstock/cross

In any event, since this appears to be a gcc behavior I'll take it
offline and continue to narrow it down.  I've never seen this behavior
before, but it might be a gcc bug with the main branch.  I'll start
there.

Thanks again for the pointers.

Matt