# ===========================================================================

#           http://autoconf-archive.cryp.to/ax_compare_version.html

# ===========================================================================

#

# SYNOPSIS

#

#   AX_COMPARE_VERSION(VERSION_A, OP, VERSION_B, [ACTION-IF-TRUE], [ACTION-IF-FALSE])

#

# DESCRIPTION

#

#   This macro compares two version strings. Due to the various number of

#   minor-version numbers that can exist, and the fact that string

#   comparisons are not compatible with numeric comparisons, this is not

#   necessarily trivial to do in a autoconf script. This macro makes doing

#   these comparisons easy.

#

#   The six basic comparisons are available, as well as checking equality

#   limited to a certain number of minor-version levels.

#

#   The operator OP determines what type of comparison to do, and can be one

#   of:

#

#    eq  - equal (test A == B)

#    ne  - not equal (test A != B)

#    le  - less than or equal (test A <= B)

#    ge  - greater than or equal (test A >= B)

#    lt  - less than (test A < B)

#    gt  - greater than (test A > B)

#

#   Additionally, the eq and ne operator can have a number after it to limit

#   the test to that number of minor versions.

#

#    eq0 - equal up to the length of the shorter version

#    ne0 - not equal up to the length of the shorter version

#    eqN - equal up to N sub-version levels

#    neN - not equal up to N sub-version levels

#

#   When the condition is true, shell commands ACTION-IF-TRUE are run,

#   otherwise shell commands ACTION-IF-FALSE are run. The environment

#   variable 'ax_compare_version' is always set to either 'true' or 'false'

#   as well.

#

#   Examples:

#

#     AX_COMPARE_VERSION([3.15.7],[lt],[3.15.8])

#     AX_COMPARE_VERSION([3.15],[lt],[3.15.8])

#

#   would both be true.

#

#     AX_COMPARE_VERSION([3.15.7],[eq],[3.15.8])

#     AX_COMPARE_VERSION([3.15],[gt],[3.15.8])

#

#   would both be false.

#

#     AX_COMPARE_VERSION([3.15.7],[eq2],[3.15.8])

#

#   would be true because it is only comparing two minor versions.

#

#     AX_COMPARE_VERSION([3.15.7],[eq0],[3.15])

#

#   would be true because it is only comparing the lesser number of minor

#   versions of the two values.

#

#   Note: The characters that separate the version numbers do not matter. An

#   empty string is the same as version 0. OP is evaluated by autoconf, not

#   configure, so must be a string, not a variable.

#

#   The author would like to acknowledge Guido Draheim whose advice about

#   the m4_case and m4_ifvaln functions make this macro only include the

#   portions necessary to perform the specific comparison specified by the

#   OP argument in the final configure script.

#

# LAST MODIFICATION

#

#   2008-04-12

#

# COPYLEFT

#

#   Copyright (c) 2008 Tim Toolan <toolan@ele.uri.edu>

#

#   Copying and distribution of this file, with or without modification, are

#   permitted in any medium without royalty provided the copyright notice

#   and this notice are preserved.

dnl #########################################################################

AC_DEFUN([AX_COMPARE_VERSION], [

  AC_PROG_AWK

  # Used to indicate true or false condition

  ax_compare_version=false

  # Convert the two version strings to be compared into a format that

  # allows a simple string comparison.  The end result is that a version

  # string of the form 1.12.5-r617 will be converted to the form

  # 0001001200050617.  In other words, each number is zero padded to four

  # digits, and non digits are removed.

  AS_VAR_PUSHDEF([A],[ax_compare_version_A])

  A=`echo "$1" | sed -e 's/\([[0-9]]*\)/Z\1Z/g' \

                     -e 's/Z\([[0-9]]\)Z/Z0\1Z/g' \

                     -e 's/Z\([[0-9]][[0-9]]\)Z/Z0\1Z/g' \

                     -e 's/Z\([[0-9]][[0-9]][[0-9]]\)Z/Z0\1Z/g' \

                     -e 's/[[^0-9]]//g'`

  AS_VAR_PUSHDEF([B],[ax_compare_version_B])

  B=`echo "$3" | sed -e 's/\([[0-9]]*\)/Z\1Z/g' \

                     -e 's/Z\([[0-9]]\)Z/Z0\1Z/g' \

                     -e 's/Z\([[0-9]][[0-9]]\)Z/Z0\1Z/g' \

                     -e 's/Z\([[0-9]][[0-9]][[0-9]]\)Z/Z0\1Z/g' \

                     -e 's/[[^0-9]]//g'`

  dnl # In the case of le, ge, lt, and gt, the strings are sorted as necessary

  dnl # then the first line is used to determine if the condition is true.

  dnl # The sed right after the echo is to remove any indented white space.

  m4_case(m4_tolower($2),

  [lt],[

    ax_compare_version=`echo "x$A

x$B" | sed 's/^ *//' | sort -r | sed "s/x${A}/false/;s/x${B}/true/;1q"`

  ],

  [gt],[

    ax_compare_version=`echo "x$A

x$B" | sed 's/^ *//' | sort | sed "s/x${A}/false/;s/x${B}/true/;1q"`

  ],

  [le],[

    ax_compare_version=`echo "x$A

x$B" | sed 's/^ *//' | sort | sed "s/x${A}/true/;s/x${B}/false/;1q"`

  ],

  [ge],[

    ax_compare_version=`echo "x$A

x$B" | sed 's/^ *//' | sort -r | sed "s/x${A}/true/;s/x${B}/false/;1q"`

  ],[

    dnl Split the operator from the subversion count if present.

    m4_bmatch(m4_substr($2,2),

    [0],[

      # A count of zero means use the length of the shorter version.

      # Determine the number of characters in A and B.

      ax_compare_version_len_A=`echo "$A" | $AWK '{print(length)}'`

      ax_compare_version_len_B=`echo "$B" | $AWK '{print(length)}'`

      # Set A to no more than B's length and B to no more than A's length.

      A=`echo "$A" | sed "s/\(.\{$ax_compare_version_len_B\}\).*/\1/"`

      B=`echo "$B" | sed "s/\(.\{$ax_compare_version_len_A\}\).*/\1/"`

    ],

    [[0-9]+],[

      # A count greater than zero means use only that many subversions

      A=`echo "$A" | sed "s/\(\([[0-9]]\{4\}\)\{m4_substr($2,2)\}\).*/\1/"`

      B=`echo "$B" | sed "s/\(\([[0-9]]\{4\}\)\{m4_substr($2,2)\}\).*/\1/"`

    ],

    [.+],[

      AC_WARNING(

        [illegal OP numeric parameter: $2])

    ],[])

    # Pad zeros at end of numbers to make same length.

    ax_compare_version_tmp_A="$A`echo $B | sed 's/./0/g'`"

    B="$B`echo $A | sed 's/./0/g'`"

    A="$ax_compare_version_tmp_A"

    # Check for equality or inequality as necessary.

    m4_case(m4_tolower(m4_substr($2,0,2)),

    [eq],[

      test "x$A" = "x$B" && ax_compare_version=true

    ],

    [ne],[

      test "x$A" != "x$B" && ax_compare_version=true

    ],[

      AC_WARNING([illegal OP parameter: $2])

    ])

  ])

  AS_VAR_POPDEF([A])dnl

  AS_VAR_POPDEF([B])dnl

  dnl # Execute ACTION-IF-TRUE / ACTION-IF-FALSE.

  if test "$ax_compare_version" = "true" ; then

    m4_ifvaln([$4],[$4],[:])dnl

    m4_ifvaln([$5],[else $5])dnl

  fi

]) dnl AX_COMPARE_VERSION