[Bug sanitizer/60892] GCC (libsanitizer) fails to build with Linux 2.6.21 headers.

[gcc at mailinator dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60892

John Simon <gcc at mailinator dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |gcc at mailinator dot com

--- Comment #3 from John Simon <gcc at mailinator dot com> ---
Fails here when building GCC 8.1.0, too.

uname -a:
Linux MACHINE 2.6.16.60-0.85.1-bigsmp #1 SMP Thu Mar 17 11:45:06 UTC 2011 i686
i686 i386 GNU/Linux

gcc --version:
gcc (GCC) 4.1.2 20070115 (SUSE Linux)

But: configure now explicit warns:

*** This configuration is not supported in the following subdirectories:
     gnattools gotools target-libada target-libhsail-rt target-libgfortran
target-libbacktrace target-libgo target-libffi target-libobjc
target-liboffloadmic target-libsanitizer

steps done:

* download, unpack, build (in source tree) and install gmp, isl, mpfr, mpc (in
that order) to a non-standard (=user) directory
  * for each using `./configure --prefix=/some/userdir
"CPATH=/some/userdir/include" "LD_FLAGS=-L/some/userdir/lib"
  * using same CPATH for make/make check`
* download and unpack gcc 8.1.0
* apply patch for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85921
* mkdir gcc-8.1.0-build && cd gcc-8.1.0-build
* `../gcc-8.1.0/configure --prefix=/some/userdir --disable-multilib
--enable-languages=c,c++ "CPATH=/some/userdir/include"
"LDFLAGS=-L/some/userdir/lib" "LIBRARY_PATH=/some/userdir/lib"
* nice make -j6 BOOT_CFLAGS='-O2 -march=native' CPATH="/some/userdir/include"
"LIBRARY_PATH=/some/userdir/lib" bootstrap-lean

Workaround (theory, make bootstrap-lean isn't finished yet): add
--disable-libsanitizer to configure.


The solution for "everything seems to work, bootstrapping fails" seems to be to
just check if the missing defines are available during configure of
libsanitizer. A fail during configure is a "clean fail", a compiler error
isn't.