replicate a legacy old gcc-3.4.0 arm-elf cross-toolchain?

[Jonathan Wakely]

On Sun, 15 Sept 2024 at 12:11, Dennis Luehring via Gcc-help
<gcc-help@gcc.gnu.org> wrote:
>
> (i hope im in the right list)
>
> Story:
>
> I got a 20 years old arm-elf cross-toolchain under a properitary old
> Cygwin 1.42x installation on an old Windows XP
> its gcc 3.4, binutils 2.15 and newlib 1.12.0 - so everything is just old :)
> the toolchain builds a firmware
>
> Goals:
>
> out of curiosity i want to rebuild the (as near as possible)exact
> cross-toolchain versions (on linux) and replace the old Cygwin stuff fully
>
> currently im using Debian 7 to build a x64 version of these old versions
> of gcc/binutils/newlib (newer distros/gcc fail to build due to glibc
> header differences, etc.)
> (with this simple script https://pastebin.com/UCFcS8qp) and the
> resulting toolchain runs flawless under my x64 Ubuntu 23.04 - its not
> fully correct configured but a good start
>
> im using
>
> gcc -V: https://pastebin.com/BkCm3YXg
> gcc -dumpspecs: https://pastebin.com/7Y2YX9kt
> gcc -print-multi-lib: https://pastebin.com/4zghUcZ1
>
> to get the build-specs etc. from the old gcc
>
> Question:
>
> -can i directly use the dumpspecs for building? (i want to be exact as
> possible and there are so many settings in den dumped specs)
> -how can i get the libstdc++ build settings? (im missing the used
> exception model)

They're given as arguments to the top-level configure. So the gcc -v
output shows them.
Any libstdc++ build settings not shown in the gcc -v output use the
defaults for that target used by that GCC versions. So if you are
using the same GCC version configured for the same target, you should
get the same defaults for anything not set by arguments to the
top-level configure.

That's the theory anyway, sometimes there are bugs where a native
build chooses slightly different defaults to a cross build. Those are
considered bugs, and should be fixed. But since you're using an
ancient GCC there may well be such bugs lurking there, which might
have been fixed more recently.


> -are there other config stuff that i need to replicate? (gcc related)
>
> thx for any tips
>