[CMake] Backlashes on Windows: bug or feature?

[Clinton Stimpson]

How about just using forward slashes everywhere and use 
file(TO_NATIVE_PATH ...) for the variable substituted by 
configure_file(...).
That works without problems for me.
Then you don't have to have any "\\" for escaping or "\\\\" for twice 
escaping.

Clint

Pau Garcia i Quiles wrote:
> I forgot to say if I edit the variable value in the Qt GUI and replace
> "C://Intersystems//Cache" with "C:\\Intersystems\\Cache", the
> backslashed value is stored in the cache and shdir.c contains the
> expected output (with '\\').
>
> But if I call CMake form the command line:
>  cmake -DCALLIN_PATH:PATH="C:\\\\Intersystems\\\\Cache"
>
> I get forward slashes in the CMake cache and in the generated shdir.c.
> Interestingly, on Windows only 2 forward slashes make it into the
> CMake cache but on Linux all 4 of them are in the CMake cache.
>
> On Thu, Mar 5, 2009 at 11:14 PM, Pau Garcia i Quiles
> <pgquiles at elpauer.org> wrote:
>   
>> Hello,
>>
>> I started writing a bug report but I'm not really sure if this is a
>> bug or a feature.
>>
>> On Win32, if you assign a path value to a variable in a
>> CMakeLists.txt, then open the CMakeLists.txt with the CMakeQtGui, it
>> will convert all the backslashes to forward-slashes, although this
>> might not be desired.
>>
>> For example, I have this in my CMakeLists.txt:
>>
>> IF( NOT DEFINED CALLIN_PATH )
>>  IF(WIN32)
>>    SET( CALLIN_PATH "C:\\\\Intersystems\\\\Cache" CACHE PATH "Path to
>> the Mgr directory in ISC Cache" FORCE )
>>  ELSE(WIN32)
>>    SET(CALLIN_PATH "/opt/cachesys" CACHE PATH "Path to the Mgr
>> directory in ISC Cache" FORCE )
>>  ENDIF(WIN32)
>> ENDIF( NOT DEFINED CALLIN_PATH )
>>
>> On Win32, the Qt GUI shows CALLIN_PATH as "C://Intersystems//Cache"
>> and clicking "Configure" will store it in the CMake cache as
>> "C://Intersystems//Cache".
>>
>> This is undesired behavior because you may want to use the value of
>> that variable to generate, for instance, a .c or .cpp file. In my
>> case, I have this shdir.c.cmake:
>>
>> char shdir[256]="@CACHEMGRDIR@";
>>
>> Doing:
>>
>> CONFIGURE_FILE( 3rdparty/src/isccache/shdir.c.cmake
>> ${LHDFAMILY_BINARY_DIR}/shdir.c )
>>
>> Creates this shdir.c:
>>
>> char shdir[256]="C://Intersystems//Cache";
>>
>> Which made my application behave oddly because the path is not valid
>> but the file still compiles.
>>
>> This behavior (replacing "\\" with "//") is consistent with what CMake
>> does when invoked from the command line. On the other hand, the (now
>> deprecated) CMakeSetup would not replace "\\" with "//", i. e.
>> CMakeSetup would show CALLIN_PATH as "C:\\Intersystems\\Cache" and
>> would generate this shdir.c, which is exactly what I want:
>>
>> char shdir[256]="C:\\Intersystems\\Cache";
>>
>> In the end, I'm not sure if this is a bug in CMake and the Qt GUI, or
>> it was a bug in CMakeSetup, but the CMakeSetup behavior is what a
>> Win32 user would expect.
>>
>> (it's easy to work around the backslash-to-forwardslash substitution
>> with STRING, but it's not ideal and it's unexpected)
>>
>> --
>> Pau Garcia i Quiles
>> http://www.elpauer.org
>> (Due to my workload, I may need 10 days to answer)
>>
>>     
>
>
>
>