Added commentaries in configure.ac

- Added commentaries by @asalnikov request in comment for Issue #14
- Added aclocal in .gitignore

Author: igormunkin

.gitignore

@@ -38,3 +38,4 @@ config.status
 config.log
 config
 /Makefile
+aclocal.m4

ac-macros/ax-macros.m4

@@ -1,4 +1,11 @@
+# File with user-defined macros
+
 # Wrapper for AC_ARG_ENABLE for basic rules
+# Arguments:
+# $1 - name of the configure option
+# $2 - name of corresponding GOAL to be built
+# $3 - default value (empty string if GOAL not to be nuilt by default or $2)
+# $4 - help string for configure option
 AC_DEFUN([AX_ARG_ENABLE], [
 	AC_ARG_ENABLE([$1], [AS_HELP_STRING([--enable-$1], [$4])], [
 		AS_CASE(["${enableval}"],
@@ -11,23 +18,34 @@ AC_DEFUN([AX_ARG_ENABLE], [
 	])
 ])
 
-# Wrapper for AC_CHECK_PROG with gentle error
+# Wrapper for AC_CHECK_PROG with configure variable and gentle error
+# Arguments:
+# $1 - configure variable for corresponding tool
+# $2 - error string to be shown if tool doesn't exist
 AC_DEFUN([AX_CHECK_PROG], [
 	AC_CHECK_PROG([HAVE_$1], $$1, [true], [false])
 	AS_IF([test "x$HAVE_$1" == "xfalse"], [AC_MSG_ERROR([$2])])
 ])
 
-# Wrapper for AC_CHECK_PROG with gentle error
+# Wrapper for AC_CHECK_PROG with tool name and gentle error
+# Arguments:
+# $1 - tool name
+# $2 - errorstring to be shown if tool doesn't exist
 AC_DEFUN([AX_RAW_CHECK_PROG], [
 	AC_CHECK_PROG([HAVE_$1], $1, [true], [false])
 	AS_IF([test "x$HAVE_$1" == "xfalse"], [AC_MSG_ERROR([$2])])
 ])
 
-# Wrapper for AC_CHECK_LIB for list of functions
+# Wrapper for AC_CHECK_LIB for list of required functions
+# Argumenst:
+# $1 - library name (without 'lib' prefix and extension suffix)
+# $2 - list of required functions
 AC_DEFUN([AX_CHECK_LIB], [
 	for sub in $2
 	do
 		AC_CHECK_LIB([$1], [$sub], [
+			# The check below is necessary for deduplication of $1 library
+			# within LIBS variable
 			AS_IF([echo $LIBS | grep -q "$1"], [], [
 				AS_VAR_APPEND([LIBS], [-l$1])
 			])
@@ -36,4 +54,3 @@ AC_DEFUN([AX_CHECK_LIB], [
 		])
 	done
 ])
-

configure.ac

@@ -2,10 +2,14 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.69])
+# Do not forget to update version.
 AC_INIT([network-tests2], [2.0.1], [Alexey Salnikov <[email protected]>])
 AC_PREFIX_DEFAULT([$HOME/network_tests-$PACKAGE_VERSION])
 
+# Directory with user-defined macros (macros with 'AX_' prefix).
 AC_CONFIG_MACRO_DIR([ac-macros])
+
+# Configure variables declaration.
 # TODO: Change the value for qmake for QT5 later
 AC_ARG_VAR([QMAKE], [Place where qmake-qt4 is installed])
 AC_ARG_VAR([MPICC], [Path to MPI2 compatible C-compiler])
@@ -16,24 +20,31 @@ AC_ARG_VAR([MPI_LIBS], [Additional libs for parallel program])
 AC_ARG_VAR([MPI_LDFLAGS], [Path to additional libs for parallel program])
 AC_ARG_VAR([GOALS], [List of goals to be built])
 
+# Explicitly enables build for network_viewer_qt_v2 component.
 AX_ARG_ENABLE([qt-gui], [" network_viewer_qt_v2 "], [""], [
 	Enable Qt version of network-viewer program (disabled by default)
-]) # network_viewer_qt_v2
+])
+
+# Explicitly enables build for network_test component.
 AX_ARG_ENABLE([network-test], [" network_test "], [" network_test "], [
 	Enable testing (enabled by default)
-]) # network-test
+])
+
+# Explicitly enables build for clustering component.
 AX_ARG_ENABLE([clustering], [" clustering "], [""], [
 	Enable clustering (disabled by default)
-]) # clustering
+])
 
+# Enables build for all components of the project.
 AC_ARG_ENABLE([all], [AS_HELP_STRING([--enable-all], [Enable all modules])], [
 	AS_CASE(["${enableval}"],
 		[yes], [AC_SUBST([GOALS], ["network_test network_viewer_qt_v2 clustering"])],
 		[no],  [],
 		[AC_MSG_ERROR([Bad value ${enableval} for --enable-all])]
 	)
-]) # all
+])
 
+# Checks for non-default specific tools.
 AS_IF([test "x$MPICC" = "x"], [AC_SUBST([MPICC], [mpicc])])
 AS_IF([test "x$MPICXX" = "x"], [AC_SUBST([MPICXX], [mpicxx])])
 # TODO: Change the value for qmake for QT5 later
@@ -61,37 +72,41 @@ AC_FUNC_REALLOC
 AC_FUNC_STRTOD
 AC_CHECK_FUNCS([clock_gettime floor gethostname gettimeofday localeconv memset sqrt strchr strstr])
 
-# Checks for -lnetcdf
+# Checks for required function of netcdf library.
 AX_CHECK_LIB([netcdf], [nc_create nc_sync nc_close nc_enddef nc_def_dim \
 	nc_def_var nc_put_var_int nc_put_vara_double
 ])
 
-# Checks for chosen targets
+# Checks for chosen components
 for target in $GOALS
 do
 	AS_CASE(["$target"],
 		[*"network_viewer_qt"*], [
+			# Checks for tools and libraries required by network_viewer_qt_v2
 			AX_CHECK_PROG([QMAKE], [qmake-qt4 is required but has not been found])
 			AX_RAW_CHECK_PROG([lrelease], [lrelease is required but has not been found])
-			# Checks for libraries.
-			# -lqwt-qt4 -lGLU -lQtOpenGL -lQtGui -lQtCore -lGL -lpthread
 			AX_CHECK_LIB([netcdf], [nc_open nc_inq_varid nc_get_var1 \
 				nc_inq_nvars nc_inq_varids nc_inq_varndims nc_inq_dimlen \
 				nc_inq_vardimid nc_get_vara_double nc_get_var1_int
 			])
+			# TODO: Add checks for libraries.
+			# -lqwt-qt4 -lGLU -lQtOpenGL -lQtGui -lQtCore -lGL -lpthread
 		],
 		[*"network_test"*], [
+			# Checks for tools and libraries required by network_test
 			AX_CHECK_LIB([netcdf], [nc_open nc_get_var_int nc_get_vara_double \
 				nc_inq_dimid nc_inq_dimlen nc_inq_varid
 			])
 		]
 	)
 done
 
+# Use flags of non-MPI compilers for MPI ones
 AS_IF([test "x$MPI_CFLAGS" = "x"], [AC_SUBST([MPI_CFLAGS], $CFLAGS)])
 AS_IF([test "x$MPI_CXXFLAGS" = "x"], [AC_SUBST([MPI_CXXFLAGS], $CXXFLAGS)])
 AS_IF([test "x$MPI_LDFLAGS" = "x"], [AC_SUBST([MPI_LDFLAGS], $LDFLAGS)])
 AS_IF([test "x$MPI_LIBS" = "x"], [AC_SUBST([MPI_LIBS], $LIBS)])
 
+# Define output files to be built from templates
 AC_CONFIG_FILES([config Makefile parus_config.h])
 AC_OUTPUT