CMake configuration: Detecting zlib.h header in windows.

Hi,
   I have having hard time to let cmake configuration detect the zlib
header in windows with "Visual Studio 12" generator. My cmake
configuration goes like

>> Set path, include and lib environment variables to point to zlib
headers and libraries. Cmake version is 2.8.12.2
cmake -G "Visual Studio 12" -D LLVM_TARGETS_TO_BUILD:STRING=%TARG% -D
TARGET_TRIPLE:STRING=%TRIPLE% -D
LLVM_DEFAULT_TARGET_TRIPLE:STRING=%TRIPLE% -D
LLVM_TARGET_ARCH:STRING=%TRIPLE% -D LLVM_ENABLE_PIC:BOOL=ON -D
LLVM_ENABLE_ASSERTIONS:BOOL=ON -D
CMAKE_INSTALL_PREFIX=%win_top_install_dir% -D CMAKE_BUILD_TYPE=%BLDMODE%
-DLLVM_APPEND_VC_REV:BOOL=ON -D LLVM_VENDOR_NAME:STRING=%NAME% -D
LLVM_VENDOR_VERSION:STRING=%VER% %win_top_src_dir%/llvm

As far as I know, cmake tries to compile a simple file with "#include
<zlib.h>" with MSbuild.exe which invokes a project file. MSbuild has its
own environment and ignores the user's environment variables.

Any one face this issue before?
Let me know if you need more details on this.
The bottom line is , I want to set HAVE_ZLIB to 1

You can probably use -DCMAKE_CXX_COMPILER_FLAGS="/IC:\path\to\zlib".

Thanks a lot for the reply Reid.
I guess you meant -DCMAKE_CXX_FLAGS/-DCMAKE_C_FLAGS.
Specifying -DCMAKE_<LANG>_FLAGS="/IC:\path\to\zlib\include" -DHAVE_LIBZ=1
-DCMAKE_EXE_LINKER_FLAGS="/IC:\path\to\zlib\lib\zlib.lib"
-DCMAKE_STATIC_LINKER_FLAGS="/IC:\path\to\zlib\lib\zlib.lib"
-DCMAKE_SHARED_LINKER_FLAGS="/IC:\path\to\zlib\lib\zlib.lib"

I know this is hacky(HAVE_LIBZ=1) but I am happy as long as things work
for me. The checks in cmake/config-ix.cmake to detect zlib library are
written purely for non-windows systems. I also see, in
lib/Support/CMakeLists.txt inclusion of zlib library is not intended for
MSVC.

--Sumanth G