How can I connect modules? - c++

Question

So, I am trying to write Makefile.am that will check the source code and the dependencies for the build.
configure.in
AC_PREREQ([2.68])
AC_INIT([hello], [1.0], [basinbug at yahoo.com])
AC_CONFIG_SRCDIR([src/hello.cpp])
AM_INIT_AUTOMAKE
AC_PROG_CXX
PKG_CHECK_MODULES([GTK], [gtk+-2.0 >= 2.10])
AC_CONFIG_FILES([Makefile src/Makefile])
AC_OUTPUT
src/Makefile.am
bin_PROGRAMS = hello
hello_CFLAGS = $(GTK_CFLAGS)
hello_LDFLAGS = $(GTK_LIBS)
hello_SOURCES = hello.cpp
what happens when i run "make"
Making all in src
make[1]: Entering directory `/home/maza/123/src'
g++ -DPACKAGE_NAME=\"hello\" -DPACKAGE_TARNAME=\"hello\" -DPACKAGE_VERSION=\"1.0\" -DPACKAGE_STRING=\"hello\ 1.0\" -DPACKAGE_BUGREPORT=\"basinbug\ at\ yahoo.com\" -DPACKAGE_URL=\"\" -DPACKAGE=\"hello\" -DVERSION=\"1.0\" -I. -g -O2 -MT hello.o -MD -MP -MF .deps/hello.Tpo -c -o hello.o hello.cpp
hello.cpp:2:21: fatal error: gtk/gtk.h: No such file or directory
compilation terminated.
make[1]: *** [hello.o] Error 1
make[1]: Leaving directory `/home/maza/123/src'
make: *** [all-recursive] Error 1
If I'm going as AC_PROG_CC, they are used for compile the string, through AC_PROG_CXX it is not used

Answer 1

You are telling the autotools that your project is a C++ project (with AC_PROG_CXX) but you are then setting a C flag variable (hello_CFLAGS).
The matching variable for C++ is hello_CXXFLAGS.
That being said neither of those is the correct flag to use for this usage. The correct flag (thanks ptomato) is hello_CPPFLAGS.