Re: help cross-compiling gcc

[Kai Ruottu <kai.ruottu@wippies.com>]

Vincent Fortier via Gcc-help kirjoitti 29.12.2022 klo 23.24:
> Hi all,
>
> I've been trying to cross-compile various versions of gcc using the
> Synology DSM6 and DSM7 toolchains and kernel for various archs
> (armv5-7-8, ppc, i686, x64).
>
> Over the years I've been actively working on the SynoCommunity project
> that provides a framework to help integrate free software and generate
> linux packages that can be installed on Synology NAS (ref:
> https://github.com/SynoCommunity/spksrc)
>
> Pertaining to gcc, my first attempt has been to try to build the same
> compiler as the one used on various versions of DSM6 (gcc-4.9) and
> DSM7 (gcc-7.5).
OK...
>    In order to do so I use the Synology provided
> toolchain and prepare the associated kernel with proper platform
> configuration in order to provide its headers.
Not understood. Why you think that you must replace the kernel headers 
coming
with the Synology-made toolchain?
> In extra I look
> forward into applying crosstool-ng patches.
What you do expect finding in these patches?
> As a relatively "simple" example, I've been working on cross-compiling
> for a x86_64 host/target using DSM6 with gcc-4.9.4.  So far I was only
> able to build the gcc C compiler (beginner's luck?).  Enabling any
> other languages fails so has trying newer versions of gcc on that
> particular platform.
For pure curiosity I tried to reproduce the GCC in the 
'r1000-gcc850_glibc226_i686-GPL.txz'
package. But with the "as it is now" stuff in this Synology toolchain - 
with the glibc and kernel
headers being provided. And on my old CentOS 6 / i686 host with a CentOS 
5 / i686 targeted
cross gcc-8.5.0. Everything went ok until hitting in this error when 
compiling libstdc++ :

libtool: compile:  /home/src/gcc-8.5.0/build/./gcc/xgcc -shared-libgcc 
-B/home/src/gcc-8.5.0/build/./gcc -nostdinc++ 
-L/home/src/gcc-8.5.0/build/i686-syno_r1000-linux-gnu/libstdc++-v3/src 
-L/home/src/gcc-8.5.0/build/i686-syno_r1000-linux-gnu/libstdc++-v3/src/.libs 
-L/home/src/gcc-8.5.0/build/i686-syno_r1000-linux-gnu/libstdc++-v3/libsupc++/.libs 
-B/opt/cross/i686-syno_r1000-linux-gnu/bin/ 
-B/opt/cross/i686-syno_r1000-linux-gnu/lib/ -isystem 
/opt/cross/i686-syno_r1000-linux-gnu/include -isystem 
/opt/cross/i686-syno_r1000-linux-gnu/sys-include -D_GNU_SOURCE -D_DEBUG 
-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS 
-DHAVE_RPC_XDR_H=1 -DHAVE_TIRPC_RPC_XDR_H=0 -I. 
-I../../../../libsanitizer/sanitizer_common -I.. -I 
../../../../libsanitizer/include -isystem 
../../../../libsanitizer/include/system -Wall -W -Wno-unused-parameter 
-Wwrite-strings -pedantic -Wno-long-long -fPIC -fno-builtin 
-fno-exceptions -fno-rtti -fomit-frame-pointer -funwind-tables 
-fvisibility=hidden -Wno-variadic-macros -I../../libstdc++-v3/include 
-I../../libstdc++-v3/include/i686-syno_r1000-linux-gnu 
-I../../../../libsanitizer/../libstdc++-v3/libsupc++ -std=gnu++11 
-DSANITIZER_LIBBACKTRACE -DSANITIZER_CP_DEMANGLE -I 
../../../../libsanitizer/../libbacktrace -I ../libbacktrace -I 
../../../../libsanitizer/../include -include 
../../../../libsanitizer/libbacktrace/backtrace-rename.h -g -O2 
-D_GNU_SOURCE -g -Os -MT sanitizer_platform_limits_posix.lo -MD -MP -MF 
.deps/sanitizer_platform_limits_posix.Tpo -c 
../../../../libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc 
-fPIC -DPIC -o .libs/sanitizer_platform_limits_posix.o
../../../../libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc:902:46: 
virhe: ”SCSI_IOCTL_TAGGED_DISABLE” on esittelemättä tällä näkyvyysalueella
    unsigned IOCTL_SCSI_IOCTL_TAGGED_DISABLE = SCSI_IOCTL_TAGGED_DISABLE;
^~~~~~~~~~~~~~~~~~~~~~~~~
../../../../libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc:902:46: 
huom: suggested alternative: ”IOCTL_SCSI_IOCTL_TAGGED_DISABLE”
    unsigned IOCTL_SCSI_IOCTL_TAGGED_DISABLE = SCSI_IOCTL_TAGGED_DISABLE;
^~~~~~~~~~~~~~~~~~~~~~~~~
IOCTL_SCSI_IOCTL_TAGGED_DISABLE
../../../../libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc:903:45: 
virhe: ”SCSI_IOCTL_TAGGED_ENABLE” on esittelemättä tällä näkyvyysalueella
    unsigned IOCTL_SCSI_IOCTL_TAGGED_ENABLE = SCSI_IOCTL_TAGGED_ENABLE;
^~~~~~~~~~~~~~~~~~~~~~~~
../../../../libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc:903:45: 
huom: suggested alternative: ”IOCTL_SCSI_IOCTL_TAGGED_ENABLE”
    unsigned IOCTL_SCSI_IOCTL_TAGGED_ENABLE = SCSI_IOCTL_TAGGED_ENABLE;
^~~~~~~~~~~~~~~~~~~~~~~~
IOCTL_SCSI_IOCTL_TAGGED_ENABLE
make[4]: *** [sanitizer_platform_limits_posix.lo] Virhe 1
make[4]: Poistutaan hakemistosta 
"/media/2c439158-ef3e-4dcf-a63b-03191c302829/home/src/gcc-8.5.0/build/i686-syno_r1000-linux-gnu/libsanitizer/sanitizer_common"
make[3]: *** [all-recursive] Virhe 1

Seemingly the 'include/scsi/scsi.h' was changed either in newer glibcs 
or kernel headers, I don't remember
where these SCSI headers belong. The CentOS 5 and 6 '/usr/include' 
headers still have this :

/*
  * Here are some scsi specific ioctl commands which are sometimes useful.
  */
/* These are a few other constants only used by scsi devices.  */

#define SCSI_IOCTL_GET_IDLUN 0x5382

/* Used to turn on and off tagged queuing for scsi devices.  */

#define SCSI_IOCTL_TAGGED_ENABLE 0x5383
#define SCSI_IOCTL_TAGGED_DISABLE 0x5384

/* Used to obtain the host number of a device.  */
#define SCSI_IOCTL_PROBE_HOST 0x5385

The Synology R1000 headers only mention that these values 0x5383 and 
0x5384 "were once defined".

Let's see what one should do with this problem...