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source: code/branches/dynamicmatch/cmake/CompareVersionStrings.cmake @ 6692

Last change on this file since 6692 was 2710, checked in by rgrieder, 16 years ago

Merged buildsystem3 containing buildsystem2 containing Adi's buildsystem branch back to the trunk.
Please update the media directory if you were not using buildsystem3 before.

  • Property svn:eol-style set to native
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1# Computes the relationship between two version strings.  A version
2# string is a number delineated by '.'s such as 1.3.2 and 0.99.9.1.
3# You can feed version strings with different number of dot versions,
4# and the shorter version number will be padded with zeros: 9.2 <
5# 9.2.1 will actually compare 9.2.0 < 9.2.1.
6#
7# Input: a_in - value, not variable
8#        b_in - value, not variable
9#        result_out - variable with value:
10#                         -1 : a_in <  b_in
11#                          0 : a_in == b_in
12#                          1 : a_in >  b_in
13#        optional argument - TRUE or default FALSE:
14#              When passing 1.2.3 and 1.2 and this switch is on
15#              the function will actually compare 1.2 < 1.2
16#              Caution: Only the first string is adjusted!
17#
18# Written by James Bigler.
19# Extended with an optional argument by Reto Grieder
20
21FUNCTION(COMPARE_VERSION_STRINGS a_in b_in result_out)
22  # Additional argument can be a switch to change compare behaviour
23  SET(cut_first ${ARGN})
24
25  # Replace '.' with ';' to allow easy tokenization of the string.
26  STRING(REPLACE "." ";" a ${a_in})
27  STRING(REPLACE "." ";" b ${b_in})
28
29  # Check the size of each list to see if they are equal.
30  LIST(LENGTH a a_length)
31  LIST(LENGTH b b_length)
32
33  # Pad the shorter list with zeros.
34
35  IF(a_length LESS b_length)
36    # a is shorter
37    SET(shorter a)
38    MATH(EXPR pad_range "${b_length} - ${a_length} - 1")
39  ELSE(a_length LESS b_length)
40    # b is shorter
41    SET(shorter b)
42    SET(first_longer a)
43    MATH(EXPR pad_range "${a_length} - ${b_length} - 1")
44  ENDIF(a_length LESS b_length)
45
46  # PAD out if we need to
47  IF(NOT pad_range LESS 0)
48    FOREACH(pad RANGE ${pad_range})
49      # Since shorter is an alias for b, we need to get to it by dereferencing shorter.
50      IF(cut_first AND first_longer)
51        LIST(REMOVE_AT a -1) # remove last element
52      ELSE(cut_first AND first_longer)
53        LIST(APPEND ${shorter} 0)
54      ENDIF(cut_first AND first_longer)
55    ENDFOREACH(pad)
56  ENDIF(NOT pad_range LESS 0)
57
58  SET(result 0)
59  SET(index 0)
60  FOREACH(a_version ${a})
61    IF(result EQUAL 0)
62      # Only continue to compare things as long as they are equal
63      LIST(GET b ${index} b_version)
64      # LESS
65      IF(a_version LESS b_version)
66        SET(result -1)
67      ENDIF(a_version LESS b_version)
68      # GREATER
69      IF(a_version GREATER b_version)
70        SET(result 1)
71      ENDIF(a_version GREATER b_version)
72    ENDIF(result EQUAL 0)
73    MATH(EXPR index "${index} + 1")
74  ENDFOREACH(a_version)
75
76  # Copy out the return result
77  SET(${result_out} ${result} PARENT_SCOPE)
78ENDFUNCTION(COMPARE_VERSION_STRINGS)
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