I'm using qmake to generate a Makefile. In my spec file, I override CXX and CC as such:
QMAKE_CC=/home/foo/gcc-4.7.2/bin/gcc
QMAKE_CXX=/home/foo/gcc-4.7.2/bin/g++
Now the generated Makefile uses those versions. However there is a variable called LINK in the generated makefile, which points to g++. Not /home/foo/gcc-4.7.2/bin/g++.
This causes my build to fail at the final step when compiling the executable from all the generated object files.
How do I get qmake to set LINK to /home/foo/gcc-4.7.2/bin/g++ in the generated Makefile?
Currently, I'm changing LINK by hand to get things to work.
You can override LINK in the same way:
QMAKE_LINK=/home/foo/gcc-4.7.2/bin/g++
Related
I have been building a shared library with the Android NDK and now want to build it as a static library. I assumed that all I had to do was change BUILD_SHARED_LIBRARY to BUILD_STATIC_LIBRARY in Android.mk but now when I run ndk-build, absolutely nothing happens. It just comes right back to the command prompt without displaying anything. I tried ndk-build -n and it shows 3 rm commands being executed and nothing else. I tried ndk-build -B and it makes no difference. I tried ndk-build -d and there is nothing in the output related to my source files or the name of the library.
If I change the make file back to build the shared library, it compiles the source and links the .so with no problems.
Anyone have any ideas what could be wrong?
It seems that in order to build a static library, it must be a dependency of something. I was able to build my library as static by adding an Application.mk file with the following line:
APP_MODULES = mylib
We have a problem building out C++ software on Ubuntu Linux with qmake.
Problem is: we use some library, for example OpenCV, that can have different versions in one system.
qmake automatically add -L/usr/lib or -L/usr/lib/x86_64-linux-gnu to g++ arguments, and contents of LIBS variables after it.
So there conflicts with different versions of OpenCV, the system version is used, but we need custom one, located at our build tree.
Are there any methods to change libs order in -L or something else to solve this problem?
There are two components to doing this:
First, you need to make sure to include them in your .pro file correctly. Do this with something like (this is from my current project):
LIBS += L${OPENCV_HOME}/lib \
-lopencv_core \
-lopencv_highgui \
You can replace the environment variable with whatever your path is. I've found it convenient to use environment variables like this because you also need header includes:
INCLUDEPATH += $$(OPENCV_HOME)/include/opencv2 \
$$(OPENCV_HOME)/include/opencv \
$$(OPENCV_HOME)/include
This allows you to create projects and build them correctly.
When you attempt to run them, however, you will likely run into all sorts of issues due to your app finding the wrong libraries (from system libraries like you say) - you need to set your LD_LIBRARY_PATH variable correctly. In this case I have a launch script (you can do this in your user profile or elsewhere) which contains:
export LD_LIBRARY_PATH=${OPENCV_HOME}/lib
Which then looks to that (as well as other) locations on the LD_LIBRARY_PATH first, before system libraries.
Another hack is to exploit the LIBS = $(SUBLIBS) ... part of the Makefile qmake writes.
Namely, invoke the generated Makefile with
make SUBLIBS=-L/path/to/your/opencv
I had the same issue which I fixed by setting QMAKE_LIBDIR to the lib directory of the build tree. QMake automatically added the system library path after this value, thus allowing to correctly detect the desired libraries:
QMAKE_LIBDIR = /path/to/desired/opencvlib
I have two OpenCV versions on my PC, one installed by default in /usr and another installed by compiling the sources in a custom dir (not /usr).
The first worked just fine with Qt, the other didn't. I struggled a lot trying to make the Qt Creator work with my OpenCV compiled sources. So I added -L/opencv_lib_path but it always said 'undefined reference' for some OpenCV API I was using. It simply doesn't want to look there for the libs, it will look in LD_LIBRARY_PATH instead. I tried adding my opencv_lib_path to the LD_LIBRARY_PATH, no joy either.
The only thing that worked was Frodon's solution, just add this in your Qt .pro file and it will work.
QMAKE_LIBDIR = /path_to_installed_opencv/lib
Question is similar to this question
Handling header files dependencies with cmake
I have sample program dir having main.c main.h and CMakeLists.txt
main.h contents are
#ifndef MAIN_H
#define MAIN_H
int t=3;
int y=2;
#endif
main.c contents are
#include <main.h>
#include<stdio.h>
int main(){
printf("%d apple",t);
}
and CMakeLists.txt
PROJECT( test )
AUX_SOURCE_DIRECTORY(. test_SRCS)
include_directories(.)
ADD_EXECUTABLE (main ${test_SRCS})
but cmake is not rebuilding main.c on modification of header file.
I want it to auto-generate header file dependency.
Is it possible using cmake ?
if not is there any other tool which can do that ?
As mentioned in my comment, I have tried out your example and things were working fine: if main.h was modified then main.c would be recompiled.
My installation of CMake (version 2.8.0) told me to add
cmake_minimum_required(VERSION 2.8)
to the CMakeLists.txt file, but that is all of the adjustments I needed.
Answering this for others that google search...
I ran into this problem with one of my projects. As it turns out I added the header to the cpp file after running cmake. Re-running cmake fixed the problem. If you run into this, try that and see if it fixes the issue.
From the cmake 2.8.0 documentation of AUX_SOURCE_DIRECTORY:
It is tempting to use this command to avoid writing the list of source
files for a library or executable target. While this seems to work,
there is no way for CMake to generate a build system that knows when a
new source file has been added. Normally the generated build system
knows when it needs to rerun CMake because the CMakeLists.txt file is
modified to add a new source. When the source is just added to the
directory without modifying this file, one would have to manually
rerun CMake to generate a build system incorporating the new file.
Why do you want to avoid creating a list of files? Such lists generally do not change frequently.
My gcc compiler is at a custom location /my/path/hpgcc
I've downloaded the boost sources. Executed bootstrap.sh, but it fails because it runs with the default gcc.
Looking into it, I see that it fails at the first thing it does: building the Boost.Build engine:
gcc -o bootstrap/jam0 command.c compile.c debug.c expand.c glob.c hash.c hdrmacro.c headers.c jam.c jambase.c jamgram.c lists.c make.c make1.c newstr.c option.c output.c parse.c pathunix.c pathvms.c regexp.c rules.c scan.c search.c subst.c timestamp.c variable.c modules.c strings.c filesys.c builtins.c pwd.c class.c native.c md5.c w32_getreg.c modules/set.c modules/path.c modules/regex.c modules/property-set.c modules/sequence.c modules/order.c execunix.c fileunix.c
(fails because executed with the default gcc, and not my gcc version).
I've tried to change the gcc path in the user-config.jam file, but it doesn't help. Probably because the Boost.Build's build script boost_1_47_0/tools/build/v2/engine/build.sh doesn't use user-config.jam, and just uses the default locations.
Any solution?
Add the line:
using gcc : : /my/path/hpgcc ;
to user-config.jam. user-config.jam will usually be in /path/to/boost/tools/build/v2/, but you can put a custom user-config.jam or site-config.jam in any of the places listed here.
/my/path/hpgcc should be the full path to the g++ executable.
EDIT (Igor Oks) : What eventually solved the problem is that I edited boost_1_47_0/tools/build/v2/engine/build.sh to make it use my custom gcc.
We do this in our build environment by simply defining the PATH and LD_LIBRARY_PATH environment variables to pickup our desired GCC first.
I want to use CUDPP library in my project. I've downloaded sources from project page. Unfortunatly, when I ran "make", there was only static library build. I've looked into Makefile files and haven't found any dynamic lib configuration. I don't want to keep static library with the project - it's totally non-portable way.
My question is: how can I build .so dynamic library of CUDPP, without writing my own Makefile/compiling it manually? Maybe someone already did it?
EDIT: I've replaced "g++" with "g++ -fPIC", "gcc" with "gcc -fPIC" and "nvcc" with "nvcc -Xcompiler -fpic". When I unpack obj files from archive, and link them to shared lib, I've got no error. However, my application crashes at start, when linked with this library.
when you compile pass the flag -Xcompiler -fpic to nvcc. If you link against any cuda libraries make sure you've linked to the shared libs, otherwise you can't link it. Hopefully that's all you need.
Are you also using -shared to create the library? You shouldn't need to extract anything from an archive if it is working correctly.
If you run ldd on your executable it will show you what dynamic linking is required by the app and you can check that the -fPIC etc. worked correctly. Also make sure that the .so library is on your LD_LIBRARY_PATH (sorry if that's obvious, no harm in checking).