[Bug bootstrap/53731] New: [4.7] Bootstrap fails for libgfortran on Solaris 10 x86 with error "Where has __float128 gone?"

["windward at gmx dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53731

             Bug #: 53731
           Summary: [4.7] Bootstrap fails for libgfortran on Solaris 10
                    x86 with error "Where has __float128 gone?"
    Classification: Unclassified
           Product: gcc
           Version: 4.7.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: windward@gmx.com


Created attachment 27665
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27665
Details

GCC 4.7.1 fails to bootstrap on Solaris 10 due to a linker / multilib problem
affecting the configure script.

In file included from ./kinds.h:75:0,
                 from
/opt/SP/build/gcc/gcc-4.7.1/libgfortran/libgfortran.h:232,
                 from /opt/SP/build/gcc/gcc-4.7.1/libgfortran/fmain.c:4:
/opt/SP/build/gcc/gcc-4.7.1/libgfortran/kinds-override.h:40:5: error: #error
"Where has __float128 gone?"
gmake[6]: *** [fmain.lo] Error 1
gmake[6]: Leaving directory
`/opt/SP/build/gcc/gcc-4.7.1-build/i386-pc-solaris2.10/amd64/libgfortran'

Root cause is that the check for __float128 in the configure script fails since
the linker does not use the 64bit libgcc due to a wrong LD_LIBRARY_PATH
definition passed to the configure script (see attachment).

configure:24967: checking whether we have a usable __float128 type
configure:25054: /opt/SP/build/gcc/gcc-4.7.1-build/./gcc/xgcc
-B/opt/SP/build/gcc/gcc-4.7.1-build/./gcc/ -B/opt/SP/gcc/g
cc-4.7.1/i386-pc-solaris2.10/bin/
-B/opt/SP/gcc/gcc-4.7.1/i386-pc-solaris2.10/lib/ -isystem
/opt/SP/gcc/gcc-4.7.1/i386-p
c-solaris2.10/include -isystem
/opt/SP/gcc/gcc-4.7.1/i386-pc-solaris2.10/sys-include  -m64 -o conftest
-std=gnu99 -g -O2
 -march=core2 -mfpmath=sse -msse3 -mno-ssse3 -mno-avx
-I/opt/SP/gcc/gcc-4.7.1/include -I/opt/SP/gcc/current/include -I/u
sr/sfw/include   conftest.c  >&5
ld: warning: file
/opt/SP/gcc/current/lib/gcc/platform/current//libgcc.a(_divtc3.o): wrong ELF
class: ELFCLASS32
Undefined                       first referenced
 symbol                             in file
__divtc3                            /var/tmp//cc6TdICW.o
__divtf3                            /var/tmp//cc6TdICW.o
__multf3                            /var/tmp//cc6TdICW.o
ld: fatal: Symbol referencing errors. No output written to conftest
collect2: error: ld returned 1 exit status


One workaround is to add MULTISUBDIR to the HOST_LIB_PATH_gcc in the Makefile.
I patched ./Makefile.in and the build works, although I don't know if this is
the right way to achieve this...

@@ -629,7 +629,7 @@ HOST_LIB_PATH = $(HOST_LIB_PATH_bfd)$(HO

 # Define HOST_LIB_PATH_gcc here, for the sake of TARGET_LIB_PATH, ouch
 @if gcc
-HOST_LIB_PATH_gcc =
$$r/$(HOST_SUBDIR)/gcc$(MULTISUBDIR)$(GCC_SHLIB_SUBDIR):$$r/$(HOST_SUBDIR)/prev-gcc$(MULTISUBDIR)$(GCC_SHLIB_SUBDIR):
+HOST_LIB_PATH_gcc =
$$r/$(HOST_SUBDIR)/gcc$(GCC_SHLIB_SUBDIR):$$r/$(HOST_SUBDIR)/prev-gcc$(GCC_SHLIB_SUBDIR):
 @endif gcc