[CMake] conflicting types for built-in function 'snprintf'

[Eric Noulard]

2009/7/8 Steven Van Ingelgem <steven at vaningelgem.be>:
> Hi Eric,
>
>
> 1) Your first option wouldn't work because "CMAKE_REQUIRED_FLAGS" isn't
> known by neither try_compile, neither the macro.

Did you try it?

The documentation says:
 CheckFunctionExists
       macro which checks if the function exists

       CHECK_FUNCTION_EXISTS(FUNCTION VARIABLE)

         FUNCTION - the name of the function
         VARIABLE - variable to store the result

       The following variables may be set before calling this macro to modify
       the way the check is run:

         CMAKE_REQUIRED_FLAGS = string of compile command line flags
         CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
         CMAKE_REQUIRED_INCLUDES = list of include directories
         CMAKE_REQUIRED_LIBRARIES = list of libraries to link

and the CheckFunctionExists.cmake makes use of those macros.

>
> 2) Wouldn't work either because try_compile doesn't take command line
> parameters (at least not in this form & unless you will construct the
> makefile from hand inside this script).

try_compile(RESULT_VAR bindir srcfile
                     [CMAKE_FLAGS <Flags>]
                     [COMPILE_DEFINITIONS <flags> ...]
                     [OUTPUT_VARIABLE var]
                     [COPY_FILE <filename> )

thus you should be able to add "-f-no-builtin" to COMPILE_DEFINITIONS?
or may be I miss something?

The trouble I see with the "-f-no-builtin" is that the flag is GCC specific so
you must check that your compiler is GCC before adding it.


> 3) I think this is the only feasible way in fact... Although I find this the
> least nicest way, and as such I didn't try that one.

Agreed that's ugly. I was just trying to be as exhaustive as possible :-)



-- 
Erk
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