Android NDK warning on compiling jni directory in r9d - compilation

Android NDK: WARNING:/cygdrive/e/android-sdk-windows/AndroidWorkspace/muPDF/jni/Android.mk:mu‌​pdfcore: LOCAL_LDLIBS is always ignored for static libraries [armeabi-v7a] Compile : mupdf <= mupdf.c /bin/sh: /cygdrive/c/Users/MEHDI/Downloads/Compressed/android-ndk-r9d-windows-x86/android‌​-ndk-r9d/toolchains/arm-linux-androideabi-4.4.3/prebuilt/windows/bin/arm-linux-an‌​droideabi-gcc: No such file or directory make: * [/cygdrive/e/android-sdk-windows/AndroidWorkspace/muPDF/obj/local/armeabi-v7a/ob‌​js/mupdf/mupdf.o] Error 127

It looks like you're trying to use GCC 4.4.3 which is no longer distributed with the NDK. Did you set NDK_TOOLCHAIN_VERSION in your environment? If so, please undefine it and re-run the command.
Apart from that, the warning is perfectly normal. You should use LOCAL_EXPORT_LDLIBS if you want to export dependent system libraries for your static library. LOCAL_LDLIBS is only used when building a shared library or executable.

ndk-build on Windows does not need cygwin, and some of its components cannot work with cygwin. Run ndk-build.cmd from Windows CMD shell, and avoid hardcoding cygdrive anywhere.
The warning you get is legitimate. You probably have include $(BUILD_STATIC_LIBRARY) in your Android.mk: this module does not use linker, therefore it does not need LOCAL_LDLIBS neither LOCAL_LDFLAGS. I would not worry about this warning, if this is the only problem in your build.
If you need more help with your project, please post the Android.mk file (or fragments of it), and also the Application.mk if you have one.

Related

Why does OMNet++ compiler gets errors for a precompiled package?

I have included an external package callled SoPlex (a folder of .cpp and .h files and the library files) into my OMNet++ project. I have already tested the package in Code::Blocks IDE and it works fine besides some warnings it had: warning: explicit conversion operators only available with -std=c++11 or -std=gnu++11.
It certainly was working in Code::Blocks IDE. But when I want to use it in my OMNet++ project it gives a lot of errors for the SoPlex package like in the picture:
It gives a lot of errors for just the code of SoPlex and not my OMNet++ project code.
Any idea what may cause the problem?
I have used MinGW to compile SoPlex package in Code::Blocks IDE. When I use MinGW GCC in OMNet++ instead of GCC for OMNet++ as current toolchain there is this error fatal error: omnetpp.h: No such file or directory.
Regarding the errors with the 3rd party library. Depending where you put the library inside the src folder, at least that directory must be added as an include dir, otherwise the header files will not be found by the compiler.
As for the problem with the omnetpp.h: OMNeT++ has it's own makefile generator which automatically adds the required include folder (omnetpp_root/include). The generic MinGW GCC toolchain does not. If you want to avoid extra work, always use the omnet toolchain to build your models.

Cross compiling for arm using crystax NDK

The android ndk supplied by google is unable to compile call to c++11 functions such as std::to_string() and std::stoul etc. {I had tried it in r10b one from the official site}. So the suggestion in SO was to try crystax NDK. I have downloaded and placed the root folder next to the google's NDK. All I changed in my root CMakeLists.txt file was:
from:
set(PLATFORM_PREFIX "/some-path/android-ndk-r10b/platforms/android-19/arch-arm")
set(PLATFORM_FLAGS "-fPIC -Wno-psabi --sysroot=${PLATFORM_PREFIX}")
set(CMAKE_CXX_FLAGS "${PLATFORM_FLAGS} -march=armv7-a -mfloat-abi=softfp -mfpu=neon" CACHE STRING "")
To:
set(PLATFORM_PREFIX "/some-path/android-ndk-r8-crystax-1/platforms/android-14/arch-arm")
set(PLATFORM_FLAGS "-fPIC -Wno-psabi --sysroot=${PLATFORM_PREFIX}")
set(CMAKE_CXX_FLAGS "${PLATFORM_FLAGS} -march=armv7-a -mfloat-abi=softfp -mfpu=neon" CACHE STRING "")
and cmake command-line from:
cmake .. -DCMAKE_CXX_COMPILER=/some-path/android-ndk-r10b/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86_64/bin/arm-linux-androideabi-g++ -DCMAKE_C_COMPILER=/some-path/android-ndk-r10b/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc -DANDROID_BUILD=ON -DANDROID_NDK_ROOT=/some-path/android-ndk-r10b
To:
cmake .. -DCMAKE_CXX_COMPILER=/some-path/android-ndk-r8-crystax-1/toolchains/arm-linux-androideabi-4.7/prebuilt/linux-x86_64/bin/arm-linux-androideabi-g++ -DCMAKE_C_COMPILER=/some-path/android-ndk-r8-crystax-1/toolchains/arm-linux-androideabi-4.7/prebuilt/linux-x86_64/bin/arm-linux-androideabi-gcc -DANDROID_BUILD=ON -DANDROID_NDK_ROOT=/some-path/android-ndk-r8-crystax-1
ie., changed from normal ndk to crystax-ndk. The program was compiling fine previously till it tried to compile a file with call to std::to_string() etc. But after the change Cmake gives an error that it is unable to compile a simple test program because:
/some-path/android-ndk-r8-crystax-1/toolchains/arm-linux-androideabi-4.7/prebuilt/linux-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.7/../../../../arm-linux-androideabi/bin/ld:
error: cannot find -lcrystax
I can see libcrystax.a and .so in directorie:
/some-path/android-ndk-r8-crystax-1/sources/crystax/libs/armeabi-v7a
I tried adding link_directories("path-to-above") right at the beginning of the CMakeLists.txt file too, but that didn't solve it either.
It should find it there (after i supply the --sysroot etc above) just like the normal ndk. So how should this be solved ? Any other cmake variable to be set or something ?
I don't know how your cmake-based build system works, but actually if you properly add path /some-path/android-ndk-r8-crystax-1/sources/crystax/libs/armeabi-v7a to linker search paths, it should find libcrystax and link with it successfully.
Please note that NDK have several parts separated each from other - i.e. sysroot, libcrystax, C++ library - all are separated. It is done to work with NDK build system which offer some flexibility choosing C++ standard library implementation, and NDK build system know where to find all of them. In your case this approach is not so good so I suggest you first make standalone toolchain, which contains all things assembled together. In other words, it would be classic cross-compile toolchain which contains sysroot, libcrystax and GNU C++ standard library in places known to compiler/linker without passing of any additional options.
To create such toolchain, cd to NDK root directory and run the following command:
./build/tools/make-standalone-toolchain.sh --system=linux-x86_64 --toolchain=arm-linux-androideabi-4.7 --platform=android-14 --install-dir=$HOME/arm-linux-androideabi
Then use $HOME/arm-linux-androideabi as full standalone toolchain for your cmake-based build system.
Please note, however, that application built with CrystaX NDK r8 will not run on newest Android 5.0 due to changes in Bionic (libc). Previous Android versions (<=4.4) are all fine. We fixed that issue (and many others) in upcoming r10 release which is on final testing stage. In the meantime you could adopt your project to our r8 release and quickly switch to r10 when it done - the same approach will work with r10 as well as with r8.

gcc compiling error on Solaris 10

I want to compile a source code, but there are some compiling errors about __sync_xxx functions (__sync_bool_compare_and_swap etc.)
GCC version on machine is 3.4.3 (it must be gcc 4.1 or over for supporting atomic builtins), so I have downloaded GCC v4.6, copied it to another directory (I didn't remove v3.4.3) then change the $PATH path for GCC but it doesn't work (the same error occurs).
I want to ask that is only changing gcc path with export PATH=... enough for compiling with new GCC?
Use the following configure option when compiling gcc:
--program-prefix=foo --program-suffix=bar
and it will produce bin programs of the form "foo-gcc-bar", so that you may differentiate different builds of gcc.
Replace foo and/or bar with an appropriate "tag" for your build (eg "-4.6" for example).
This way if it doesn't find your toolchain correctly it will fail fast rather than using the 3.4 version.
It also means that different toolchain builds can coexist in the standard installation prefix directories.
We have to use -march=686 switch to get it to work on intel.
Try checking and updating LD_LIBRARY_PATH, to use the lib path for the new gcc installed.

Problems compiling with libraries

I am trying to compile some C++ code which uses the CGAL library on OS X Lion. I downloaded and installed on some directory the CGAL library. Then, when I try to compile the code, using "make";
triangulation.h:18:64: error: CGAL/Exact_predicates_inexact_constructions_kernel.h: No such file or directory
which means it does not find the CGAL lib. I look at the Makefile, and I see that it compiles using the flag
-lCGAL
Wondering how to solve this, I guess I could pass the information about the placement of my compiled library to this variable, but I do not how. I tried with export and so on but it does not recognize it, any hints?
The error message doesn't mean the library isn't found; it means a header file isn't found. The -lCGAL switch does indeed refer to the library. You're going to need a -IXXXXX switch added on to CFLAGS, where XXXXX is the path to the directory containing the CGAL directory which in turn contains Exact_predicates_inexact_constructions_kernel.h .

Unable to build Boost libraries with GCC

I am using Windows 7 64-bit, and want to compile the non-precompiled libraries (specifically, I need Filesystem) from the command line (I do not use MSVC). I have MinGW, but read on the Boost website that MSYS shell is not supported, so I'm trying to compile the libraries from the Windows command prompt.
First of all, running bootstrap.bat results in the following error:
Building Boost.Jam build engine
'cl' is not recognized as an internal or external command,
operable program or batch file.
Failed to build Boost.Jam build engine.
Please consult bjam.log for furter diagnostics.
You can try to obtain a prebuilt binary from
http://sf.net/project/showfiles.php?group_id=7586&package_id=72941
Also, you can file an issue at http://svn.boost.org
Please attach bjam.log in that case.
Plus, there is not bjam.log file anywhere in the boost_root directory.
Disregarding this error, and trying to run the downloaded bjam.exe file, I get another error:
c:/boost_1_45_0/tools/build/v2/build\configure.jam:145: in builds-raw
*** argument error
* rule UPDATE_NOW ( targets * : log ? : ignore-minus-n ? )
* called with: ( <pbin.v2\libs\regex\build\gcc-mingw-4.5.2\debug\address-model64\architecture-x86>has_icu.exe : : ignore-minus-n : ignore-minus-q )
* extra argument ignore-minus-q
(builtin):see definition of rule 'UPDATE_NOW' being called
c:/boost_1_45_0/tools/build/v2/build\configure.jam:179: in configu
re.builds
c:/boost_1_45_0/tools/build/v2/build\configure.jam:216: in object(
check-target-builds-worker)#409.check
etc. with quite a lot of complaints. Setting the 'architecture' and 'address-model' options doesn't help.
Any suggestions?
#Andre
Following Andre's suggestion, I created minGW-bjam that was running for an hour and a half and built most of the libraries, but not the one I need at this moment: Filesystem.
Trying to compile only Filesystem, specifying version 2 with define="BOOST_FILESYSTEM_VERSION=2" and --disable-filesystem3 does not help. I get the following error:
gcc.compile.c++ bin.v2\libs\filesystem\build\gcc-mingw-4.5.2\debug\v3\src\operations.o
In file included from ./boost/filesystem/v3/operations.hpp:24:0,
from libs\filesystem\v3\src\operations.cpp:48:
./boost/filesystem/v3/config.hpp:16:5: error: #error Compiling Filesystem version 3
file with BOOST_FILESYSTEM_VERSION defined != 3
libs\filesystem\v3\src\operations.cpp:647:26: warning:
'<unnamed>::create_symbolic_link_api' defined but not used
"g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -g -DBOOST_ALL_NO_LIB=1 -
DBOOST_FILESYSTEM_DYN_LINK=1 -DBOOST_FILESYSTEM_VERSION=2 -DBOOST_SYSTEM_DYN_LINK=1 -
I"." -c -o "bin.v2\libs\filesystem\build\gcc-mingw-4.5.2\debug\v3\src\operations.o"
"libs\filesystem\v3\src\operations.cpp"
etc. with a lot of ...failed statements.
Any hints here?
It's easy. Just use "bootstrap.bat gcc" to select GCC
The bootstrap script assumes the msvc compiler is available. But you can build bjam by hand without the bootstrap script:
Step into the tools\build\v2\engine\src directory and call "build.bat mingw". It will create a bjam.exe. You can then put it in your %PATH% or perhaps in the root boost directory...
To be honest, I usually build bjam like this with the msvc compiler and use this "msvc-bjam" to build my mingw boost libraries.
So... the first part of the problem was solved by Andre's suggestion.
The second part was solved by setting the variable BOOST_FILESYSTEM_VERSION to 3 everywhere (the error above complains about incompatibility with what is set in file user.hpp). Although this is not the default option for Boost 1.45 that I'm using, it's the only thing that works (i.e. bjam wants to compile version 3 no matter what). So now I have version 3 of the filesystem library, and version 2 for all others, but that doesn't seem to be an issue for the moment.
I do have a problem with using Boost with OpenCV and Eigen libraries, though... off to the next challenge ;)
Since I can't comment yet, I want to add that I ran
bootstrap mingw
to generate b2 properly and then
b2 --build-dir="c:\boost_release" toolset=gcc --build-type=complete "c:\boost_release\stage"
The includes will be located at your boost root folder (boost_1_58_00/boost) and your binaries at the specified build folder.

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