How to choose a specific MinGW installation for eclipse CDT - eclipse

Question

I am using 32-bit eclipse CDT Kelper to manage a piece of code, which I could compile on command line but not with eclipse if I use any up-to-date c++11 feature. CDT tells me that "-std=c++11" is unrecognized.
After turning on the verbose option in project properties\settings\tool settings, I found that eclipse CDT somehow chooses an older version of MinGW that comes with Haskell platform 2013.2:
Configured with: ../gcc-4.5.2/configure --enable-languages=c,c++,ada,fortran,objc,obj-c++ --disable-sjlj-exceptions --with-dwarf2 --enable-shared --enable-libgomp --disable-win32-registry --enable-libstdcxx-debug --enable-version-specific-runtime-libs --disable-werror --build=mingw32 --prefix=/mingw
Thread model: win32
gcc version 4.5.2 (GCC)
COLLECT_GCC_OPTIONS='-O0' '-g3' '-Wall' '-c' '-fmessage-length=0' '-v' '-o' 'src\vaomp_bnb.o' '-shared-libgcc' '-mtune=i386' '-march=i386'
c:/haskell platform/2013.2.0.0/mingw/bin/../libexec/gcc/mingw32/4.5.2/cc1plus.exe -quiet -v -iprefix c:\haskell platform\2013.2.0.0\mingw\bin\../lib/gcc/mingw32/4.5.2/ -dD ..\src\vaomp_bnb.cpp -quiet -dumpbase vaomp_bnb.cpp -mtune=i386 -march=i386 -auxbase-strip src\vaomp_bnb.o -g3 -O0 -Wall -version -fmessage-length=0 -o C:\DOCUME~1\ting\LOCALS~1\Temp\ccWNoh7I.s
GNU C++ (GCC) version 4.5.2 (mingw32)
I searched SO, and there is a similar question a half year ago here. But the answer there was about setting environment variables and didn't solve the problem.
In my case, CDT can find a MinGW GCC, but found the wrong one. I have installed tdm-gcc 64 bit with gcc-4.8.1, and Haskell platform. The tdm-gcc has priority and
gcc --version
on both DOS and MSYS shows
gcc.exe (tdm64-2) 4.8.1
I don't know what heuristic does CDT use to find toolchains. My question is, how can I tell CDT to use the gcc in a specific location, e.g. c:/MinGW?
Note, I can't uninstall the Haskell platform version of gcc as I will need HP.
Thanks,

Answer 1

I figured it out. It seems that Eclipse CDT does not take tdm-gcc MinGW 64-bit because eclipse itself is 32-bit. So it picked up the only 32-bit MinGW it can find, which is the old version from HP.
To verify this, I installed java 1.7 64-bit, and downloaded 64-bit version of Eclipse CDT (Kelper). Now, CDT automatically selects the TDM-GCC 64 version of MinGW gcc.
For those in a similar situation, one additional issue is that the 64-bit CDT - MinGW64 combination combination does not build projects. No binary/executable files are generated even for a newly created HelloWorld c++ project (even though compilation is OK). In my case, I changed the build tool in the project properties..\tool chain. from CDT internal builder to either of the other two options (one is Gnu's and another is a long name), and then the project can be successfully made to generate exe files.