2.1.1.4 Using Autotools

It is often faster and simpler to use GNU autotools than to write your own makefiles. In this section, we provide an autoconf macro WITH_MYSQL that can be used to add a --with-mysql option to a configure file, and that automatically sets the correct compiler and linker flags for given MySQL installation.

All of the examples in this chapter include a common mysql.m4 file defining WITH_MYSQL. A typical complete example consists of the actual source file and the following helper files:

• acinclude

• configure.in

• Makefile.m4

automake also requires that you provide README, NEWS, AUTHORS, and ChangeLog files; however, these can be left empty.

To create all necessary build files, run the following:

aclocal
autoconf
automake -a -c
configure --with-mysql=/mysql/prefix/path

Normally, this needs to be done only once, after which make will accommodate any file changes.

Example 1-1: acinclude.m4. 

m4_include([../mysql.m4])

Example 1-2: configure.in. 

AC_INIT(example, 1.0)
AM_INIT_AUTOMAKE(example, 1.0)
WITH_MYSQL()
AC_OUTPUT(Makefile)

Example 1-3: Makefile.am. 

bin_PROGRAMS = example
example_SOURCES = example.cc

Example 1-4: WITH_MYSQL source for inclusion in acinclude.m4. 

dnl
dnl configure.in helper macros
dnl

AC_DEFUN([WITH_MYSQL], [
  AC_MSG_CHECKING(for mysql_config executable)

  AC_ARG_WITH(mysql, [  --with-mysql=PATH path to mysql_config binary or mysql prefix dir], [
  if test -x $withval -a -f $withval
    then
      MYSQL_CONFIG=$withval
    elif test -x $withval/bin/mysql_config -a -f $withval/bin/mysql_config
    then
     MYSQL_CONFIG=$withval/bin/mysql_config
    fi
  ], [
  if test -x /usr/local/mysql/bin/mysql_config -a -f /usr/local/mysql/bin/mysql_config
    then
      MYSQL_CONFIG=/usr/local/mysql/bin/mysql_config
    elif test -x /usr/bin/mysql_config -a -f /usr/bin/mysql_config
    then
      MYSQL_CONFIG=/usr/bin/mysql_config
    fi
  ])

  if test "x$MYSQL_CONFIG" = "x"
  then
    AC_MSG_RESULT(not found)
    exit 3
  else
    AC_PROG_CC
    AC_PROG_CXX

    # add regular MySQL C flags
    ADDFLAGS=`$MYSQL_CONFIG --cflags`

    # add NDB API specific C flags
    IBASE=`$MYSQL_CONFIG --include`
    ADDFLAGS="$ADDFLAGS $IBASE/storage/ndb"
    ADDFLAGS="$ADDFLAGS $IBASE/storage/ndb/ndbapi"
    ADDFLAGS="$ADDFLAGS $IBASE/storage/ndb/mgmapi"

    CFLAGS="$CFLAGS $ADDFLAGS"
    CXXFLAGS="$CXXFLAGS $ADDFLAGS"

    LDFLAGS="$LDFLAGS "`$MYSQL_CONFIG --libs_r`" -lndbclient"
    LDFLAGS="$LDFLAGS "`$MYSQL_CONFIG --libs_r`" -lndbclient"

    AC_MSG_RESULT($MYSQL_CONFIG)
  fi
])