cpp wrong default search path for include files?

["Jan Ekkel" <jan dot ekkel at acq dot nl>]

problem desciption: The preprocessor powerpc-eabi-pp seems to look for 
header files in $prefix/$target/include while the files are in

$exec-prefix/$target/include

Hi,

I'm building gcc including newlib for powerpc-eabi under cygwin. The build 
succeeds, however cpp does not find the newlib header files (e.g. stdlib.h) 
when

building an application. It seems the default search path differs from the 
real location of these files, see the output of 'powerpc-eabi-cpp -v' :


$ powerpc-eabi-cpp -v
Using built-in specs.
COLLECT_GCC=powerpc-eabi-cpp
COLLECT_LTO_WRAPPER=/acqtools/windows/libexec/gcc/powerpc-eabi/4.5.0/lto-wrapper.exe
Target: powerpc-eabi
Configured with: 
/src/gcc/gcc-4.5.0/configure --target=powerpc-eabi --prefix=/acqtools --enable-languages=c,c++ 
--with-g
nu-as --with-gnu-ld --with-newlib --with-gxx-include-dir=/acqtools/powerpc-eabi/include 
--exec-prefix=/acqtools/windows
-v
Thread model: single
gcc version 4.5.0 (GCC)
COLLECT_GCC_OPTIONS='-E' '-v'
/acqtools/windows/libexec/gcc/powerpc-eabi/4.5.0/cc1.exe -E -quiet -v -
ignoring nonexistent directory 
"/acqtools/windows/lib/gcc/powerpc-eabi/4.5.0/../../../../../powerpc-eabi/sys-include"
#include "..." search starts here:
#include <...> search starts here:
/acqtools/windows/lib/gcc/powerpc-eabi/4.5.0/include
/acqtools/windows/lib/gcc/powerpc-eabi/4.5.0/include-fixed
/acqtools/windows/lib/gcc/powerpc-eabi/4.5.0/../../../../../powerpc-eabi/includeEnd of search list.The preprocessor searches /acqtools/powerpc-eabi/include(/acqtools/windows/lib/gcc/powerpc-eabi/4.5.0/../../../../../powerpc-eabi/include, which is$prefix/$target/include ), but the files are in/acqtools/windows/powerpc-eabi/include(/acqtools/windows/lib/gcc/powerpc-eabi/4.5.0/../../../../powerpc-eabi/include, whi).Perhaps cpp uses the --prefix as a start, while it should use --exec-prefix?My question: where does cpp get it's default include path from? And perhapssomebody knows how to fix this?---------------------------------------------------My build configuration:  cygwin-1.7.5  binutils-2.20  gcc-4.5.0  newlib 1.18.0  gmp 5.0.1  mpc-0.8.2  mpfr-2.4.2Configuration of gcc:/src/gcc/gcc-4.5.0/configure \--target=powerpc-eabi \--prefix=/acqtools \--enable-languages=c,c++ \--with-gnu-as \--with-gnu-ld \--with-newlib \--with-gxx-include-dir=/acqtools/powerpc-eabi/include \--exec-!
prefix=/acqtools/windows \-v 2>&1 | tee configure.outJan.