Re: [CMake] pkg-config and Cross_compiling
On Monday 07 July 2008, Hendrik Sattler wrote:
Zitat von Alexander Neundorf [EMAIL PROTECTED]:
On Wednesday 02 July 2008, Hendrik Sattler wrote:
Am Mittwoch, 2. Juli 2008 18:59:37 schrieb Wookey:
...
Additionally, I found that the include paths are another source of
problems, not fully covered by the cmake cross compiling, yet. You
really have to -I any path that is not known and specific to the cross
compiler, using INCLUDE_DIRECTORIES(). This is not done automatically
for the changed ROOT_PATH, yet.
Can you please explain more detailled ? I don't understand what you mean.
If you find such problems, please report them in the cmake bugtracker.
If you include a non-standard header file in your program:
#include foo/bar.h
and foo sits /path/to/non-native (e.g. /opt/cross-root/usr/include
with /opt/cross-root being CMAKE_FIND_ROOT_PATH), then it will not be
found. How could it, the compiler doesn't know about /opt/cross-root
as it is installed somewhere else. So you must tell the compiler with
-I/opt/cross-root/usr/include that it should look there. Currently, I
do something like:
foreach ( dir ${CMAKE_FIND_ROOT_PATH} )
foreach ( inc usr/local/include usr/include include )
I think /usr/local/include isn't always part of the built-in search path, but
usr/include and include look good.
if ( EXISTS ${dir}/${inc} )
include_directories( SYSTEM ${dir}/${inc} )
endif ( EXISTS ${dir}/${inc} )
endforeach ( inc )
endforeach ( dir )
That make it just work. Same goes for pkg-config.
If I do a find_* in cmake first to find that include, that will solve
that, sure.
Yes, that would be the general advice for that kind of problems.
What do the other cmake devs think ?
Is it the authors fault if he didn't search for the correct header using
FIND_PATH() or should we add these include dirs automatically ?
Beside that, what would you think about using -nostdinc ?
Alex
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Re: [CMake] pkg-config and Cross_compiling
Am Mittwoch, 2. Juli 2008 18:59:37 schrieb Wookey: I tried to fix the FindPkgConfig.cmake file to automaticaly do this, but found that it uses execute_process to call pkg-config and there seems to be no way to set an environment variable with this call. Am I missing something? Fixing this module to look in CMAKE_FIND_ROOT_PATH when cross-compiling seems like the best fix to me, but there may be a better way? Yes, that should be fixed. It should work to use SET() to set an environment variable and the child process from EXECUTE_PROCESS should get the copy of that environment. BUT: you must use PKG_CONFIG_LIBDIR instead of PKG_CONFIG_PATH! Additionally, I found that the include paths are another source of problems, not fully covered by the cmake cross compiling, yet. You really have to -I any path that is not known and specific to the cross compiler, using INCLUDE_DIRECTORIES(). This is not done automatically for the changed ROOT_PATH, yet. So eventually, the cross-compiled programs ends up including the wrong files :-( You have to be careful with that... The CMAKE_TOOLCHAIN_FILE can be used to set both, but this could also be handled automatically. HS ___ CMake mailing list CMake@cmake.org http://www.cmake.org/mailman/listinfo/cmake
Re: [CMake] pkg-config and Cross_compiling
On 2008-07-02 19:39 +0200, Hendrik Sattler wrote:
Am Mittwoch, 2. Juli 2008 18:59:37 schrieb Wookey:
I tried to fix the FindPkgConfig.cmake file to automaticaly do this,
but found that it uses execute_process to call pkg-config and there
seems to be no way to set an environment variable with this call. Am I
missing something? Fixing this module to look in
CMAKE_FIND_ROOT_PATH when cross-compiling seems like the best fix to
me, but there may be a better way?
Yes, that should be fixed. It should work to use SET() to set an environment
variable and the child process from EXECUTE_PROCESS should get the copy of
that environment. BUT: you must use PKG_CONFIG_LIBDIR instead of
PKG_CONFIG_PATH!
Ah, so I do - well done. That will avoid native libs being found.
I got the impression that SET() only set CMAKE variables, not
environment ones, but maybe they ammount to the same thing?
fx: reads docs again Ah, yes there is the ENV{} syntax. Brill. that
means I can now add
IF (CMAKE_CROSSCOMPILING)
SET(ENV{PKG_CONFIG_LIBDIR} ${CMAKE_FIND_ROOT_PATH}/lib/pkgconfig/)
to the toolchain file and that works fine.
Putting that in FindPkgConfig.cmake should do the trick.
Additionally, I found that the include paths are another source of problems,
not fully covered by the cmake cross compiling, yet. You really have to -I
any path that is not known and specific to the cross compiler, using
INCLUDE_DIRECTORIES(). This is not done automatically for the changed
ROOT_PATH, yet.
Yes. I found that too. I added:
IF (CMAKE_CROSSCOMPILING)
INCLUDE_DIRECTORIES(BEFORE ${CMAKE_FIND_ROOT_PATH}/include)
to my toolchain file, but it would have been nice is cmake did it for
me.
Wookey
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Principal hats: Balloonz - Toby Churchill - Aleph One - Debian
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