g++ thinks it is a cross compiler..

g++ thinks it is a cross compiler..

[John S]

Stumbled over the problem when i was to compile mySQL using the latest gcc
3.1.
This is surely due my errors and ignorance and not any bug in gcc.
Any suggestions?

Computer is a Athlon MP.
RH Linux 7.2(?) Kernel 2.4.17

Some info about my environment and stuff...

./config.guess
i686-pc-linux-gnu

[root@db gcc-3.1]# /usr/local/gcc3.1/bin/gcc -v
Reading specs from /usr/local/gcc3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with:
./configure --prefix=/usr/local/gcc3.1 --enable-shared --enable-threads=posi
x --disable-checking
Thread model: posix
gcc version 3.1

[root@db gcc-3.1]# /usr/local/gcc3.1/bin/g++ -v
Reading specs from /usr/local/gcc3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with:
./configure --prefix=/usr/local/gcc3.1 --enable-shared --enable-threads=posi
x --disable-checking
Thread model: posix
gcc version 3.1

Konfigurera mysql.
[root@db mysql-3.23.50]# CC=/usr/local/gcc3.1/bin/gcc
CXX=/usr/local/gcc3.1/bin/g++ ./configure
creating cache ./config.cache
checking host system type... i686-pc-linux-gnu
checking target system type... i686-pc-linux-gnu
checking build system type... i686-pc-linux-gnu
checking for a BSD compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking whether make sets ${MAKE}... yes
checking for working aclocal... found
checking for working autoconf... found
checking for working automake... found
checking for working autoheader... found
checking for working makeinfo... found
checking whether to enable maintainer-specific portions of Makefiles... no
checking whether build environment is sane... yes
checking whether make sets ${MAKE}... (cached) yes
checking for gawk... gawk
checking for gcc... /usr/local/gcc3.1/bin/gcc
checking whether the C compiler (/usr/local/gcc3.1/bin/gcc   ) works... yes
checking whether the C compiler (/usr/local/gcc3.1/bin/gcc   ) is a
cross-compiler... no
checking whether we are using GNU C... yes
checking whether /usr/local/gcc3.1/bin/gcc accepts -g... yes
checking for c++... /usr/local/gcc3.1/bin/g++
checking whether the C++ compiler (/usr/local/gcc3.1/bin/g++   ) works...
yes
checking whether the C++ compiler (/usr/local/gcc3.1/bin/g++   ) is a
cross-compiler... yes
checking whether we are using GNU C++... yes
checking whether /usr/local/gcc3.1/bin/g++ accepts -g... yes
checking how to run the C preprocessor... /usr/local/gcc3.1/bin/gcc -E
checking C Compiler version... /usr/local/gcc3.1/bin/gcc gcc (GCC) 3.1
Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see
the source for copying conditions. There is NO warranty; not even for
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
checking C++ compiler version... /usr/local/gcc3.1/bin/g++ g++ (GCC) 3.1
Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see
the source for copying conditions. There is NO warranty; not even for
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
checking for ranlib... ranlib
checking for ld used by GCC... /usr/bin/ld
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking for BSD-compatible nm... /usr/bin/nm -B
checking whether ln -s works... yes
updating cache ./config.cache
loading cache ./config.cache within ltconfig
checking for object suffix... o
checking for executable suffix... no
checking for /usr/local/gcc3.1/bin/gcc option to produce PIC... -fPIC
checking if /usr/local/gcc3.1/bin/gcc PIC flag -fPIC works... yes
checking if /usr/local/gcc3.1/bin/gcc supports -c -o file.o... yes
checking if /usr/local/gcc3.1/bin/gcc supports -c -o file.lo... yes
checking if /usr/local/gcc3.1/bin/gcc supports -fno-rtti -fno-exceptions ...
yes
checking if /usr/local/gcc3.1/bin/gcc static flag -static works... -static
checking if the linker (/usr/bin/ld) is GNU ld... yes
checking whether the linker (/usr/bin/ld) supports shared libraries... yes
checking command to parse /usr/bin/nm -B output... ok
checking how to hardcode library paths into programs... immediate
checking for /usr/bin/ld option to reload object files... -r
checking dynamic linker characteristics... Linux ld.so
checking if libtool supports shared libraries... yes
checking whether to build shared libraries... yes
checking whether to build static libraries... yes
checking for objdir... .libs
creating libtool
updating cache ./config.cache
loading cache ./config.cache
checking for a BSD compatible install... /usr/bin/install -c
checking for bison... bison -y
checking for pdftex... manual.pdf
checking return type of sprintf... configure: error: can not run test
program while cross compiling

Re: g++ thinks it is a cross compiler..

[Peter Kurpis]

I am familiar with this problem on Solaris, but it may be the same thing on Linux.

The heuristic for determining whether g++ is a cross-compiler is (unfortunately)
to build a small program with it, and try to run it.  The problem with this
heuristic is that many systems need help to find libstdc++.so.  If this help
is not set up properly, the executable fails (as it cannot find libstdc++.so),
but the failure is (erroneously) interpreted as g++ being a cross-compiler.

The workaround on some systems (e.g. Solaris, possibly Linux) is to provide a runtime
pointer to the directory containing libstdc++.so, e.g.

	setenv LD_LIBRARY_PATH /usr/local/lib

or

	LD_LIBRARY_PATH=/usr/local/lib

depending on what shell you use.

(I sent a better fix to the autoconf list some months ago, but I don't know whether it 
was incorporated (as I'm not a submitter), nor whether there's been a release since.
If anyone can advise me on going about this, I'd like to make the contribution, as
a lot of people get stuck on this issue.)

> Stumbled over the problem when i was to compile mySQL using the latest gcc
> 3.1.
> This is surely due my errors and ignorance and not any bug in gcc.
> Any suggestions?
> 
> Computer is a Athlon MP.
> RH Linux 7.2(?) Kernel 2.4.17
> 
> Some info about my environment and stuff...
> 
> ./config.guess
> i686-pc-linux-gnu
> 
> [root@db gcc-3.1]# /usr/local/gcc3.1/bin/gcc -v
> Reading specs from /usr/local/gcc3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
> Configured with:
> ./configure --prefix=/usr/local/gcc3.1 --enable-shared --enable-threads=posi
> x --disable-checking
> Thread model: posix
> gcc version 3.1
> 
> [root@db gcc-3.1]# /usr/local/gcc3.1/bin/g++ -v
> Reading specs from /usr/local/gcc3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
> Configured with:
> ./configure --prefix=/usr/local/gcc3.1 --enable-shared --enable-threads=posi
> x --disable-checking
> Thread model: posix
> gcc version 3.1
> 
> Konfigurera mysql.
> [root@db mysql-3.23.50]# CC=/usr/local/gcc3.1/bin/gcc
> CXX=/usr/local/gcc3.1/bin/g++ ./configure
> creating cache ./config.cache
> checking host system type... i686-pc-linux-gnu
> checking target system type... i686-pc-linux-gnu
> checking build system type... i686-pc-linux-gnu
> checking for a BSD compatible install... /usr/bin/install -c
> checking whether build environment is sane... yes
> checking whether make sets ${MAKE}... yes
> checking for working aclocal... found
> checking for working autoconf... found
> checking for working automake... found
> checking for working autoheader... found
> checking for working makeinfo... found
> checking whether to enable maintainer-specific portions of Makefiles... no
> checking whether build environment is sane... yes
> checking whether make sets ${MAKE}... (cached) yes
> checking for gawk... gawk
> checking for gcc... /usr/local/gcc3.1/bin/gcc
> checking whether the C compiler (/usr/local/gcc3.1/bin/gcc   ) works... yes
> checking whether the C compiler (/usr/local/gcc3.1/bin/gcc   ) is a
> cross-compiler... no
> checking whether we are using GNU C... yes
> checking whether /usr/local/gcc3.1/bin/gcc accepts -g... yes
> checking for c++... /usr/local/gcc3.1/bin/g++
> checking whether the C++ compiler (/usr/local/gcc3.1/bin/g++   ) works...
> yes
> checking whether the C++ compiler (/usr/local/gcc3.1/bin/g++   ) is a
> cross-compiler... yes
> checking whether we are using GNU C++... yes
> checking whether /usr/local/gcc3.1/bin/g++ accepts -g... yes
> checking how to run the C preprocessor... /usr/local/gcc3.1/bin/gcc -E
> checking C Compiler version... /usr/local/gcc3.1/bin/gcc gcc (GCC) 3.1
> Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see
> the source for copying conditions. There is NO warranty; not even for
> MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> checking C++ compiler version... /usr/local/gcc3.1/bin/g++ g++ (GCC) 3.1
> Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see
> the source for copying conditions. There is NO warranty; not even for
> MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> checking for ranlib... ranlib
> checking for ld used by GCC... /usr/bin/ld
> checking if the linker (/usr/bin/ld) is GNU ld... yes
> checking for BSD-compatible nm... /usr/bin/nm -B
> checking whether ln -s works... yes
> updating cache ./config.cache
> loading cache ./config.cache within ltconfig
> checking for object suffix... o
> checking for executable suffix... no
> checking for /usr/local/gcc3.1/bin/gcc option to produce PIC... -fPIC
> checking if /usr/local/gcc3.1/bin/gcc PIC flag -fPIC works... yes
> checking if /usr/local/gcc3.1/bin/gcc supports -c -o file.o... yes
> checking if /usr/local/gcc3.1/bin/gcc supports -c -o file.lo... yes
> checking if /usr/local/gcc3.1/bin/gcc supports -fno-rtti -fno-exceptions ...
> yes
> checking if /usr/local/gcc3.1/bin/gcc static flag -static works... -static
> checking if the linker (/usr/bin/ld) is GNU ld... yes
> checking whether the linker (/usr/bin/ld) supports shared libraries... yes
> checking command to parse /usr/bin/nm -B output... ok
> checking how to hardcode library paths into programs... immediate
> checking for /usr/bin/ld option to reload object files... -r
> checking dynamic linker characteristics... Linux ld.so
> checking if libtool supports shared libraries... yes
> checking whether to build shared libraries... yes
> checking whether to build static libraries... yes
> checking for objdir... .libs
> creating libtool
> updating cache ./config.cache
> loading cache ./config.cache
> checking for a BSD compatible install... /usr/bin/install -c
> checking for bison... bison -y
> checking for pdftex... manual.pdf
> checking return type of sprintf... configure: error: can not run test
> program while cross compiling
> 
> 
>