[CMake] configure_file - false vs "0"

Post by James C. Sutherland
#cmakedefine TEST_VAR_VALUE
configure_file( ${PROJECT_SOURCE_DIR}/src/config.h.in $
{PROJECT_SOURCE_DIR}/src/configure.h )
set( TEST_VAR_VALUE "0" )
/* #undef TEST_VAR_VALUE */
#define TEST_VAR_VALUE 0
So basically cmake is seeing the value of TEST_VAR_VALUE as 0 and
treating it as "false" rather than a value.
Any ideas how to accomplish this?
James

Use the (undocumented) #cmakedefine01.

I already submitted a patch, and the documentation has been fixed in
CVS.

Michael

James C. Sutherland

2009-08-09 16:33:09 UTC

Use the (undocumented) #cmakedefine01.
I already submitted a patch, and the documentation has been fixed in
CVS.
Michael

Thanks! That did it.

James C. Sutherland

2009-08-09 16:39:58 UTC

Use the (undocumented) #cmakedefine01.
I already submitted a patch, and the documentation has been fixed
in CVS.
Michael

Thanks! That did it.

Okay - I spoke too soon. It gave me a partial solution.

What if I want to have something like
#define TEST_VAR_VALUE 5

In the .in file:
#cmakedefine TEST_VAR_VALUE ${TEST_VAR_VALUE}
doesn't work (for reasons mentioned above)

However,
#cmakedefine01 TEST_VAR_VALUE ${TEST_VAR_VALUE}
results in
#define TEST_VAR_VALUE 5 1
if I have
set( TEST_VAR_VALUE 5 )
in my CMakeLists.txt file.

Can I get rid of the trailing value?

Michael Wild

2009-08-09 18:21:42 UTC

Use the (undocumented) #cmakedefine01.
I already submitted a patch, and the documentation has been fixed
in CVS.
Michael

Thanks! That did it.

Okay - I spoke too soon. It gave me a partial solution.
What if I want to have something like
#define TEST_VAR_VALUE 5
#cmakedefine TEST_VAR_VALUE ${TEST_VAR_VALUE}
doesn't work (for reasons mentioned above)
However,
#cmakedefine01 TEST_VAR_VALUE ${TEST_VAR_VALUE}
results in
#define TEST_VAR_VALUE 5 1
if I have
set( TEST_VAR_VALUE 5 )
in my CMakeLists.txt file.
Can I get rid of the trailing value?

Aah, now I see what you want...

#define TEST_VAR_VALUE ${TEST_VAR_VALUE}

is what you want.

James C. Sutherland

2009-08-09 20:49:49 UTC

Post by James C. Sutherland
#cmakedefine TEST_VAR_VALUE
configure_file( ${PROJECT_SOURCE_DIR}/src/config.h.in $
{PROJECT_SOURCE_DIR}/src/configure.h )
set( TEST_VAR_VALUE "0" )
/* #undef TEST_VAR_VALUE */
#define TEST_VAR_VALUE 0
So basically cmake is seeing the value of TEST_VAR_VALUE as 0
and treating it as "false" rather than a value.
Any ideas how to accomplish this?
James

Use the (undocumented) #cmakedefine01.
I already submitted a patch, and the documentation has been fixed
in CVS.
Michael

Thanks! That did it.

Aah, now I see what you want...
#define TEST_VAR_VALUE ${TEST_VAR_VALUE}
is what you want.

But if I do
set( TEST_VAR_VALUE 0 )
then this results in TEST_VAR_VALUE being undefined rather than having
the value of 0 as I want. If the value is anything other than zero it
works. This is what I tried to explain in my original (probably
unclear) post...

Bill Hoffman

2009-08-09 21:07:18 UTC

Post by Michael Wild
#define TEST_VAR_VALUE ${TEST_VAR_VALUE}
is what you want.

No it won't. That is a #define not a #cmakedfine. It will always be
there.

-Bill

Mike Jackson

2009-08-09 21:13:53 UTC

Post by Michael Wild
#define TEST_VAR_VALUE ${TEST_VAR_VALUE}
is what you want.

But if I do
set( TEST_VAR_VALUE 0 )
then this results in TEST_VAR_VALUE being undefined rather than having the
value of 0 as I want. If the value is anything other than zero it works.
This is what I tried to explain in my original (probably unclear) post...

No it won't. That is a #define not a #cmakedfine. It will always be
there.
-Bill

You also need to set the value in the cmake file BEFORE calling the
configure_file() command. So what you really want is the following:

*.cmake file
set( TEST_VAR_VALUE 0 )
configure_file( ${PROJECT_SOURCE_DIR}/src/config.h.in
${PROJECT_SOURCE_DIR}/src/configure.h @ONLY)

and in your config.h.in you will have:
#define TEST_VAR_VALUE @TEST_VAR_VALUE@

This results in TEST_VAR_VALUE _always_ being defined in your
program. It will be defined to what ever you set it to in the *.cmake
file.

--
Mike Jackson ***@bluequartz.net
BlueQuartz Software www.bluequartz.net

Michael Wild

2009-08-09 21:10:58 UTC

Post by James C. Sutherland
#cmakedefine TEST_VAR_VALUE
configure_file( ${PROJECT_SOURCE_DIR}/src/config.h.in $
{PROJECT_SOURCE_DIR}/src/configure.h )
set( TEST_VAR_VALUE "0" )
/* #undef TEST_VAR_VALUE */
#define TEST_VAR_VALUE 0
So basically cmake is seeing the value of TEST_VAR_VALUE as 0
and treating it as "false" rather than a value.
Any ideas how to accomplish this?
James

Use the (undocumented) #cmakedefine01.
I already submitted a patch, and the documentation has been
fixed in CVS.
Michael

Thanks! That did it.

Aah, now I see what you want...
#define TEST_VAR_VALUE ${TEST_VAR_VALUE}
is what you want.

But if I do
set( TEST_VAR_VALUE 0 )
then this results in TEST_VAR_VALUE being undefined rather than
having the value of 0 as I want. If the value is anything other
than zero it works. This is what I tried to explain in my original
(probably unclear) post...

$ cat CMakeLists.txt
cmake_minimum_required( VERSION 2.6 )
project( test )
set( TEST_VAR_VALUE1 0 )
set( TEST_VAR_VALUE2 1 )
set( TEST_VAR_VALUE3 "hello there" )
configure_file( config.h.in ${test_BINARY_DIR}/config.h )

$ cat config.h.in
#define TEST_VAR_VALUE1 ${TEST_VAR_VALUE1}
#define TEST_VAR_VALUE2 ${TEST_VAR_VALUE2}
#define TEST_VAR_VALUE3 ${TEST_VAR_VALUE3}

$ mkdir build && cd build && cmake ..
$ cat config.h
#define TEST_VAR_VALUE1 0
#define TEST_VAR_VALUE2 1
#define TEST_VAR_VALUE3 hello there

Which presumably is what you want... why would you think that
SET(TEST_VAR_VALUE 0) "undefines" it? For that you either use
SET(TEST_VAR_VALUE), or with newer versions of CMake you can use the
clearer UNSET(TEST_VAR_VALUE).

Michael

James C. Sutherland

2009-08-09 22:05:09 UTC