### 2.3 Building sources using Automake ¶

It is much easier if you use GNU Automake instead of writing your own Makefiles. If you do that, you do not have to worry about finding and invoking the `pkg-config` script at all.

You can use `PKG_CHECK_MODULES` macro, or, libgcrypt also provides an extension to Automake that does all the work for you.

Macro: AM_PATH_LIBGCRYPT ([minimum-version], [action-if-found], [action-if-not-found]) ¶

  Check whether Libgcrypt (at least version minimum-version, if given) exists on the host system. If it is found, execute action-if-found, otherwise do action-if-not-found, if given.

  Additionally, the function defines `LIBGCRYPT_CFLAGS` to the flags needed for compilation of the program to find the `gcrypt.h` header file, and `LIBGCRYPT_LIBS` to the linker flags needed to link the program to the Libgcrypt library.

  This macro locates for `libgcrypt.pc`, with cross-compile support.

You can use the defined Autoconf variables like this in your `Makefile.am`:

    AM_CPPFLAGS = $(LIBGCRYPT_CFLAGS)
    LDADD = $(LIBGCRYPT_LIBS)