[Buildroot] Allow building a toolchain without (non-trivial) dependencies

[Buildroot] Allow building a toolchain without (non-trivial) dependencies

[Norbert Lange]

Hello,

I would like to have an option to make a reasonable "portable" toolchain,
means no dependencies apart from the C libs (libc libm libdl).

As you see below, I cant run the toolchain without keeping the libs
around and setting the LD path,
limiting its use outside the (locally built) rootfs.

ie. all support libs from gcc should be optionally linked statically

$ ldd cc1plus
linux-vdso.so.1 (0x00007ffdacd5e000)
libisl.so.15 => /usr/lib/x86_64-linux-gnu/libisl.so.15 (0x00007f591aad0000)
libmpc.so.3 => /usr/lib/x86_64-linux-gnu/libmpc.so.3 (0x00007f591a8b7000)
libmpfr.so.4 => not found
libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f591a633000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f591a42f000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f591a09c000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f5919ce2000)
/lib64/ld-linux-x86-64.so.2 (0x00007f591ae78000)
libmpfr.so.6 => /usr/lib/x86_64-linux-gnu/libmpfr.so.6 (0x00007f5919a60000)

Kind regards,
Norbert

[Buildroot] Allow building a toolchain without (non-trivial) dependencies

[Yann E. MORIN]

Norbert, All,

On 2018-03-28 20:57 +0200, Norbert Lange spake thusly:
> I would like to have an option to make a reasonable "portable" toolchain,
> means no dependencies apart from the C libs (libc libm libdl).
> 
> As you see below, I cant run the toolchain without keeping the libs
> around and setting the LD path,
> limiting its use outside the (locally built) rootfs.
> 
> ie. all support libs from gcc should be optionally linked statically
> 
> $ ldd cc1plus
> linux-vdso.so.1 (0x00007ffdacd5e000)
> libisl.so.15 => /usr/lib/x86_64-linux-gnu/libisl.so.15 (0x00007f591aad0000)
> libmpc.so.3 => /usr/lib/x86_64-linux-gnu/libmpc.so.3 (0x00007f591a8b7000)
> libmpfr.so.4 => not found
> libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f591a633000)
> libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f591a42f000)
> libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f591a09c000)
> libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f5919ce2000)
> /lib64/ld-linux-x86-64.so.2 (0x00007f591ae78000)
> libmpfr.so.6 => /usr/lib/x86_64-linux-gnu/libmpfr.so.6 (0x00007f5919a60000)

Not so long ago, we introduced the notion of 'SDK', whereby you build
your toolchain, and as many libraries you want (which can be none for
a pure toolchain), and distribute that as an SDK, as explained in the
manual:

https://buildroot.org/downloads/manual/manual.html#_using_the_generated_toolchain_outside_buildroot

This is basically a three-step procedure:

  - first, you generate the SDK,

  - then you distribute the content of the host/ directory (supposedly
    as a tarball or other such archive),

  - the user extracts it and run a script that fixes the SDK for local
    use (presumable in another directory).

That is more flexible than just doing a static link of the toolchain,
and covers the case of distributing the toolchain too, so there we go...
;-)

Regards,
Yann E. MORIN.

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'

[Buildroot] Allow building a toolchain without (non-trivial) dependencies

[Norbert Lange]

Its more flexible, more complicated and the non-discriminating path
search and replace script is just asking for some silent breakage
haunting you once a year.

Different tastes I guess, I would be looking for something that's the
clean, bare minimum without all the auxiliary build-time tools (m4).
My plan was letting build-root run, then do a manual "DESTDIR=/hugo
make install" just on gcc, C library and binutils.

The other way is issue as far as I understood, using externally
toolchains with buildroot. Looks like I am gonna try that.

Thanks anyway.

Kind regards,
Norbert

2018-03-28 21:25 GMT+02:00 Yann E. MORIN <yann.morin.1998@free.fr>:
> Norbert, All,
>
> On 2018-03-28 20:57 +0200, Norbert Lange spake thusly:
>> I would like to have an option to make a reasonable "portable" toolchain,
>> means no dependencies apart from the C libs (libc libm libdl).
>>
>> As you see below, I cant run the toolchain without keeping the libs
>> around and setting the LD path,
>> limiting its use outside the (locally built) rootfs.
>>
>> ie. all support libs from gcc should be optionally linked statically
>>
>> $ ldd cc1plus
>> linux-vdso.so.1 (0x00007ffdacd5e000)
>> libisl.so.15 => /usr/lib/x86_64-linux-gnu/libisl.so.15 (0x00007f591aad0000)
>> libmpc.so.3 => /usr/lib/x86_64-linux-gnu/libmpc.so.3 (0x00007f591a8b7000)
>> libmpfr.so.4 => not found
>> libgmp.so.10 => /usr/lib/x86_64-linux-gnu/libgmp.so.10 (0x00007f591a633000)
>> libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f591a42f000)
>> libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f591a09c000)
>> libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f5919ce2000)
>> /lib64/ld-linux-x86-64.so.2 (0x00007f591ae78000)
>> libmpfr.so.6 => /usr/lib/x86_64-linux-gnu/libmpfr.so.6 (0x00007f5919a60000)
>
> Not so long ago, we introduced the notion of 'SDK', whereby you build
> your toolchain, and as many libraries you want (which can be none for
> a pure toolchain), and distribute that as an SDK, as explained in the
> manual:
>
> https://buildroot.org/downloads/manual/manual.html#_using_the_generated_toolchain_outside_buildroot
>
> This is basically a three-step procedure:
>
>   - first, you generate the SDK,
>
>   - then you distribute the content of the host/ directory (supposedly
>     as a tarball or other such archive),
>
>   - the user extracts it and run a script that fixes the SDK for local
>     use (presumable in another directory).
>
> That is more flexible than just doing a static link of the toolchain,
> and covers the case of distributing the toolchain too, so there we go...
> ;-)
>
> Regards,
> Yann E. MORIN.
>
> --
> .-----------------.--------------------.------------------.--------------------.
> |  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
> | +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
> | +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
> | http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
> '------------------------------^-------^------------------^--------------------'