[CMake] set variable in if block

[Juan Sanchez]

Hello,

I am trying to set a variable in an IF block, but it doesn't appear in
the resulting cache or makefile.  This is on Linux.  Note that when I
run cmake, the ${OSNAME} variable is printed, but the ${FOOBAR} variable
ends up blank.

Thanks,

Juan

IF (${OSNAME} STREQUAL "Linux64")
  MESSAGE ("${OSNAME}")
  SET (FOOBAR "-m64 -Wall -fPIC -I${PERLLIB} -I${PSTORE}/include")
ENDIF (${OSNAME} STREQUAL "Linux64")

MESSAGE ( "COMPILE_FLAGS ${FOOBAR}")