1

I'm attempting to build GCC 10.5 for an older version of QNX on an x86 platform in an Ubuntu 20.04 x86_64 environment. I downloaded the gcc-10.5.0.tar.xz file from GNU's FTP server and ran the following commands:

tar -xvf gcc-10.5.0.tar.xz
cd gcc-10.5.0
./contrib/download_prerequisites
cd ..
mkdir bin-qnx63-i386
cd bin-qnx63-i386
./../gcc-10.5.0/configure $(options)
make

These are the current options in $(options):

  • --host=x86_64-pc-linux-gnu
  • --target=i386-pc-nto-qnx6.3.0
  • --prefix=/usr/local/nyab
  • --program-prefix=nyab-
  • --disable-multilib
  • --enable-threads=posix
  • --enable-tls
  • --enable-version-specific-runtime-libs
  • --enable-languages=c,c++
  • --disable-libada
  • --disable-libgm2
  • --enable-default-pie
  • --enable-werror
  • --enable-checking
  • --enable-valgrind-annotations
  • --with-sysroot=/opt/qnx630/target/qnx6

In addition, I've copied ar, as, ld and ranlib from the SDK to /usr/local/nyab/i386-pc-nto-qnx6.3.0/bin as directed here. After an initial failed run, I copied the CRT libraries from the SDK to /usr/local/nyab/i386-pc-nto-qnx6.3.0/lib as that appeared to be needed as well.

This setup seems to work until I get to the i386-pc-nto-qnx6.3.0/libstdc++-v3 directory where it fails. Looking at config.log the issue seems to stem from the following line:

/usr/local/nyab/i386-pc-nto-qnx6.3.0/bin/ld: cannot open /opt/qnx630/target/qnx6x86/lib/crtbegin.o: No such file or directory

The correct path is /opt/qnx630/target/qnx6/x86/lib.

I've attempted to modify the --with-sysroot option to include trailing slashes, but that seems to have no effect. Next, I created a small C file:

#include <stdio.h>

int main(void) {
    printf("Hello, world!\n");
    return 0;
}

I passed it to the compiler using the flags of the failing command plus the flag to spit out additional information (formatted for StackOverflow):

/home/nyab/gcc/bin-qnx63-i386/./gcc/xgcc -B/home/nyab/gcc/bin-qnx63-i386/./gcc/ \
    -B/usr/local/nyab/i386-pc-nto-qnx6.3.0/bin/ \
    -B/usr/local/nyab/i386-pc-nto-qnx6.3.0/lib/ \
    -isystem /usr/local/nyab/i386-pc-nto-qnx6.3.0/include \
    -isystem /usr/local/nyab/i386-pc-nto-qnx6.3.0/sys-include \
    -v -o /tmp/test -g -O2 /tmp/test.c

And found that GCC is creating the incorrect paths (newlines added for the incorrect paths):

...
COLLECT_GCC_OPTIONS='-B' '/home/nyab/gcc/bin-qnx63-i386/./gcc/' '-B' '/usr/local/nyab/i386-pc-nto-qnx6.3.0/bin/' '-B' '/usr/local/nyab/i386-pc-nto-qnx6.3.0/lib/' '-isystem' '/usr/local/nyab/i386-pc-nto-qnx6.3.0/include' '-isystem' '/usr/local/nyab/i386-pc-nto-qnx6.3.0/sys-include' '-v' '-o' '/tmp/test' '-g' '-O2' '-mtune=generic' '-march=pentiumpro'
 /home/nyab/gcc/bin-qnx63-i386/./gcc/collect2 -V -Y P,

/opt/qnx630/target/qnx6x86/lib

 -Qy -m i386nto --dynamic-linker /usr/lib/ldqnx.so.2 -o /tmp/test /usr/local/nyab/i386-pc-nto-qnx6.3.0/lib/crt1.o /usr/local/nyab/i386-pc-nto-qnx6.3.0/lib/crti.o

/opt/qnx630/target/qnx6x86/lib/crtbegin.o

 -L/home/nyab/gcc/bin-qnx63-i386/./gcc -L/usr/local/nyab/i386-pc-nto-qnx6.3.0/bin -L/usr/local/nyab/i386-pc-nto-qnx6.3.0/lib /tmp/ccb1wUOU.o -lgcc -lc -lgcc /usr/local/nyab/i386-pc-nto-qnx6.3.0/lib/crtend.o /usr/local/nyab/i386-pc-nto-qnx6.3.0/lib/crtn.o
...

I have confirmed crtbegin.o is in /usr/local/nyab/i386-pc-nto-qnx6.3.0/lib although it was copied from /opt/qnx630/target/qnx6/x86/lib. Does anyone know where I went wrong or what to try next?

Matthew Sherwood
  • 15
  • 5
  • It might be worth taking a look at QNX's patches to the gcc build tree to find out if there was anything they needed to change to make their build system work. The sources are posted on their community website here: http://community.qnx.com/viewvc/tools/gcc/?root=core-dev-tools&system=exsy1011 – Will Miles Jul 21 '23 at 01:52

1 Answers1

0

Short answer

Modify SYSROOT_SUFFIX_SPEC in <src-dir>/gcc/config/i386/nto.h to /86.

Long answer

GCC uses spec files to determine how to call itself and other programs with their appropriate command line arguments. Thorough investigation of <src-dir>/gcc/gcc.c will show you how these files are created or read in to the program. Since we fail during linker invocation, the LINK_SPEC definition matters here. For this QNX build, its found in <src-dir>/gcc/config/i386/nto.h. The two lines that matter are:

...
   %{!YP,*:%{p:-Y P,%R/lib} \
    %{!p:-Y P,%R/lib}} \
...

The spec language reference linked earlier says %R is "the concatenation of target_system_root and target_sysroot_suffix." The target_sysroot_suffix is actually defined in the nto.h file under the SYSROOT_SUFFIX_SPEC preprocessor macro. Cross referencing this definition with other definitions in mti-linux.h and st.h, the specification in nto.h is missing the forward slash at the beginning. Changing the value from x86 to /x86 will get you past this issue.

Matthew Sherwood
  • 15
  • 5