Re: [CMake] Hard to do if in Macro
When returning values from a function, you have to use the PARENT_SCOPE
argument of set():
function( test __ANDROID__ RETVAL )
if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
set( ${RETVAL} ${${RETVAL}} qwer2 PASRENT_SCOPE)
message( "Included. " )
endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
if( __ANDROID__ )
set( ${RETVAL} ${${RETVAL}} asdf PARENT_SCOPE)
message( "ALWAYS Included ${__ANDROID__}" )
endif( __ANDROID__ )
endfunction( test )
Petr
On 30 January 2018 at 17:07, J Decker wrote:
> Okay... but then with function I can't set external variables; but if(
> __ANDROID__ ) works.
>
> `result` never changes.
>
> ---
>
> set( __ANDROID__ 1 )
>
> function( test __ANDROID__ RETVAL )
>
> if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
> set( ${RETVAL} ${${RETVAL}} qwer2 )
> message( "Included. " )
> endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
>
> if( __ANDROID__ )
> set( ${RETVAL} ${${RETVAL}} asdf )
> message( "ALWAYS Included ${__ANDROID__}" )
> endif( __ANDROID__ )
>
> endfunction( test )
>
>
> set( result "default" )
>
> test( __ANDROID__ "result" )
> message( "REsult:${result}" )
>
> test( ${__ANDROID__} "result" )
> message( "REsult:${result}" )
>
> test( OFF "result")
> message( "REsult:${result}" )
>
> ---
>
>
>
>
> On Tue, Jan 30, 2018 at 12:35 AM, Petr Kmoch wrote:
>
>> Macros aren't functions, and macro parameters aren't CMake variables.
>> Expanding a macro parameter is effectively *textual* substitution, whereas
>> dereferencing a CMake variable is a semantic one.
>>
>> In other words, inside your macro, the text __ANDROID__ (when not
>> expanded) never refers to the macro parameter. Macro parameters "don't
>> exist" outside of expansion context. The `if(__ANDROID__)` bit therefore
>> always refers to the variable __ANDROID__, never to the macro parameter
>> __ANDROID__.
>>
>> You still don't have to spell out the conditional as explicitly as you're
>> doing it now, but you have to expand the parameter:
>>
>> macro(test __ANDROID__)
>> if(${__ANDROID__})
>> message( "Included. " )
>> endif()
>> endmacro()
>>
>> This is what the evaluation will look like based on how you call it:
>>
>> test(__ANDROID__) -> if(__ANDROID__) -> refers to the variable
>> set(__ANDROID__ 1)
>> test(${__ANDROID__}) -> if(1)
>> set(__ANDROID__ 0)
>> test(${__ANDROID__}) -> if(0)
>> test(OFF) -> if(OFF)
>>
>> CMake macros have a lot of specific and potentially
>> weird/counterintuitive behaviour. In general, you should always write your
>> commands as functions and only resort to macros if you explicitly need
>> their specific behaviour.
>>
>> Petr
>>
>>
>>
>> On 30 January 2018 at 09:11, J Decker wrote:
>>
>>> Why do I have to do
>>>
>>> if( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
>>> endif( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
>>>
>>> in a macro like...
>>> --
>>>
>>> set( __ANDROID__ 1 )
>>>
>>> macro( test __ANDROID__ )
>>>
>>> if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
>>> message( "Included. " )
>>> endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
>>>
>>> if( __ANDROID__ )
>>> message( "ALWAYS Included ${__ANDROID__}" )
>>> endif( __ANDROID__ )
>>>
>>> endmacro( test )
>>>
>>> test( __ANDROID__ )
>>> test( ${__ANDROID__} )
>>> test( OFF )
>>>
>>> --
>>> Output
>>>
>>> Included.
>>> ALWAYS Included __ANDROID__
>>> Included.
>>> ALWAYS Included 1
>>> ALWAYS Included OFF
>>>
>>> --
>>>
>>> Powered by www.kitware.com
>>>
>>> Please keep messages on-topic and check the CMake FAQ at:
>>> http://www.cmake.org/Wiki/CMake_FAQ
>>>
>>> Kitware offers various services to support the CMake community. For more
>>> information on each offering, please visit:
>>>
>>> CMake Support: http://cmake.org/cmake/help/support.html
>>> CMake Consulting: http://cmake.org/cmake/help/consulting.html
>>> CMake Training Courses: http://cmake.org/cmake/help/training.html
>>>
>>> Visit other Kitware open-source projects at
>>> http://www.kitware.com/opensource/opensource.html
>>>
>>> Follow this link to subscribe/unsubscribe:
>>> https://cmake.org/mailman/listinfo/cmake
>>>
>>>
>>
>
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Re: [CMake] Hard to do if in Macro
Okay... but then with function I can't set external variables; but if(
__ANDROID__ ) works.
`result` never changes.
---
set( __ANDROID__ 1 )
function( test __ANDROID__ RETVAL )
if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
set( ${RETVAL} ${${RETVAL}} qwer2 )
message( "Included. " )
endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
if( __ANDROID__ )
set( ${RETVAL} ${${RETVAL}} asdf )
message( "ALWAYS Included ${__ANDROID__}" )
endif( __ANDROID__ )
endfunction( test )
set( result "default" )
test( __ANDROID__ "result" )
message( "REsult:${result}" )
test( ${__ANDROID__} "result" )
message( "REsult:${result}" )
test( OFF "result")
message( "REsult:${result}" )
---
On Tue, Jan 30, 2018 at 12:35 AM, Petr Kmoch wrote:
> Macros aren't functions, and macro parameters aren't CMake variables.
> Expanding a macro parameter is effectively *textual* substitution, whereas
> dereferencing a CMake variable is a semantic one.
>
> In other words, inside your macro, the text __ANDROID__ (when not
> expanded) never refers to the macro parameter. Macro parameters "don't
> exist" outside of expansion context. The `if(__ANDROID__)` bit therefore
> always refers to the variable __ANDROID__, never to the macro parameter
> __ANDROID__.
>
> You still don't have to spell out the conditional as explicitly as you're
> doing it now, but you have to expand the parameter:
>
> macro(test __ANDROID__)
> if(${__ANDROID__})
> message( "Included. " )
> endif()
> endmacro()
>
> This is what the evaluation will look like based on how you call it:
>
> test(__ANDROID__) -> if(__ANDROID__) -> refers to the variable
> set(__ANDROID__ 1)
> test(${__ANDROID__}) -> if(1)
> set(__ANDROID__ 0)
> test(${__ANDROID__}) -> if(0)
> test(OFF) -> if(OFF)
>
> CMake macros have a lot of specific and potentially weird/counterintuitive
> behaviour. In general, you should always write your commands as functions
> and only resort to macros if you explicitly need their specific behaviour.
>
> Petr
>
>
>
> On 30 January 2018 at 09:11, J Decker wrote:
>
>> Why do I have to do
>>
>> if( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
>> endif( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
>>
>> in a macro like...
>> --
>>
>> set( __ANDROID__ 1 )
>>
>> macro( test __ANDROID__ )
>>
>> if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
>> message( "Included. " )
>> endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
>>
>> if( __ANDROID__ )
>> message( "ALWAYS Included ${__ANDROID__}" )
>> endif( __ANDROID__ )
>>
>> endmacro( test )
>>
>> test( __ANDROID__ )
>> test( ${__ANDROID__} )
>> test( OFF )
>>
>> --
>> Output
>>
>> Included.
>> ALWAYS Included __ANDROID__
>> Included.
>> ALWAYS Included 1
>> ALWAYS Included OFF
>>
>> --
>>
>> Powered by www.kitware.com
>>
>> Please keep messages on-topic and check the CMake FAQ at:
>> http://www.cmake.org/Wiki/CMake_FAQ
>>
>> Kitware offers various services to support the CMake community. For more
>> information on each offering, please visit:
>>
>> CMake Support: http://cmake.org/cmake/help/support.html
>> CMake Consulting: http://cmake.org/cmake/help/consulting.html
>> CMake Training Courses: http://cmake.org/cmake/help/training.html
>>
>> Visit other Kitware open-source projects at
>> http://www.kitware.com/opensource/opensource.html
>>
>> Follow this link to subscribe/unsubscribe:
>> https://cmake.org/mailman/listinfo/cmake
>>
>>
>
--
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Re: [CMake] Hard to do if in Macro
Macros aren't functions, and macro parameters aren't CMake variables.
Expanding a macro parameter is effectively *textual* substitution, whereas
dereferencing a CMake variable is a semantic one.
In other words, inside your macro, the text __ANDROID__ (when not expanded)
never refers to the macro parameter. Macro parameters "don't exist" outside
of expansion context. The `if(__ANDROID__)` bit therefore always refers to
the variable __ANDROID__, never to the macro parameter __ANDROID__.
You still don't have to spell out the conditional as explicitly as you're
doing it now, but you have to expand the parameter:
macro(test __ANDROID__)
if(${__ANDROID__})
message( "Included. " )
endif()
endmacro()
This is what the evaluation will look like based on how you call it:
test(__ANDROID__) -> if(__ANDROID__) -> refers to the variable
set(__ANDROID__ 1)
test(${__ANDROID__}) -> if(1)
set(__ANDROID__ 0)
test(${__ANDROID__}) -> if(0)
test(OFF) -> if(OFF)
CMake macros have a lot of specific and potentially weird/counterintuitive
behaviour. In general, you should always write your commands as functions
and only resort to macros if you explicitly need their specific behaviour.
Petr
On 30 January 2018 at 09:11, J Decker wrote:
> Why do I have to do
>
> if( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
> endif( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
>
> in a macro like...
> --
>
> set( __ANDROID__ 1 )
>
> macro( test __ANDROID__ )
>
> if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
> message( "Included. " )
> endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
>
> if( __ANDROID__ )
> message( "ALWAYS Included ${__ANDROID__}" )
> endif( __ANDROID__ )
>
> endmacro( test )
>
> test( __ANDROID__ )
> test( ${__ANDROID__} )
> test( OFF )
>
> --
> Output
>
> Included.
> ALWAYS Included __ANDROID__
> Included.
> ALWAYS Included 1
> ALWAYS Included OFF
>
> --
>
> Powered by www.kitware.com
>
> Please keep messages on-topic and check the CMake FAQ at:
> http://www.cmake.org/Wiki/CMake_FAQ
>
> Kitware offers various services to support the CMake community. For more
> information on each offering, please visit:
>
> CMake Support: http://cmake.org/cmake/help/support.html
> CMake Consulting: http://cmake.org/cmake/help/consulting.html
> CMake Training Courses: http://cmake.org/cmake/help/training.html
>
> Visit other Kitware open-source projects at http://www.kitware.com/
> opensource/opensource.html
>
> Follow this link to subscribe/unsubscribe:
> https://cmake.org/mailman/listinfo/cmake
>
>
--
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[CMake] Hard to do if in Macro
Why do I have to do
if( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
endif( ${M__ANDROID__} EQUAL 1 OR ${M__ANDROID__} STREQUAL "ON")
in a macro like...
--
set( __ANDROID__ 1 )
macro( test __ANDROID__ )
if( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
message( "Included. " )
endif( ${__ANDROID__} EQUAL 1 OR ${__ANDROID__} STREQUAL "ON")
if( __ANDROID__ )
message( "ALWAYS Included ${__ANDROID__}" )
endif( __ANDROID__ )
endmacro( test )
test( __ANDROID__ )
test( ${__ANDROID__} )
test( OFF )
--
Output
Included.
ALWAYS Included __ANDROID__
Included.
ALWAYS Included 1
ALWAYS Included OFF
--
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