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| author | Tamás Kenéz <tamas.kenez@gmail.com> | 2015-04-29 13:46:16 (GMT) |
|---|---|---|
| committer | Brad King <brad.king@kitware.com> | 2015-04-29 15:25:16 (GMT) |
| commit | 9535b86d3c0d0c124d8ed29a6b3cdb45c150098b (patch) | |
| tree | d67d3288a1008927b768184c08caf813f8aaccae /Help/policy/CMP0054.rst | |
| parent | 036e449c665ce3abe8c11b32c1f73ee9b8a68300 (diff) | |
| download | CMake-9535b86d3c0d0c124d8ed29a6b3cdb45c150098b.zip CMake-9535b86d3c0d0c124d8ed29a6b3cdb45c150098b.tar.gz CMake-9535b86d3c0d0c124d8ed29a6b3cdb45c150098b.tar.bz2 | |
Help: Replace CMP0054 example to show when it makes a difference
The previous example for CMP0054 did not show how critical the policy is
since the result is the same in both cases (NEW and OLD behavior).
Instead show an example when the policy does make a difference.
Diffstat (limited to 'Help/policy/CMP0054.rst')
| -rw-r--r-- | Help/policy/CMP0054.rst | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/Help/policy/CMP0054.rst b/Help/policy/CMP0054.rst index 39f0c40..3754fda 100644 --- a/Help/policy/CMP0054.rst +++ b/Help/policy/CMP0054.rst @@ -16,29 +16,33 @@ Given the following partial example: :: - set(MONKEY 1) - set(ANIMAL MONKEY) + set(A E) + set(E "") - if("${ANIMAL}" STREQUAL "MONKEY") + if("${A}" STREQUAL "") + message("Result is TRUE before CMake 3.1 or when CMP0054 is OLD") + else() + message("Result is FALSE in CMake 3.1 and above if CMP0054 is NEW") + endif() After explicit expansion of variables this gives: :: - if("MONKEY" STREQUAL "MONKEY") + if("E" STREQUAL "") With the policy set to ``OLD`` implicit expansion reduces this semantically to: :: - if("1" STREQUAL "1") + if("" STREQUAL "") With the policy set to ``NEW`` the quoted arguments will not be further dereferenced: :: - if("MONKEY" STREQUAL "MONKEY") + if("E" STREQUAL "") This policy was introduced in CMake version 3.1. CMake version |release| warns when the policy is not set and uses |