I'd like to access a dynamic library using FFI features in the Ren-C Rebol branch. I understand this is possible by building with LibFFI support enabled. What steps do I need to take to enable this?
I mainly use OS X for development, though would also like to be able to build it for use with Linux.
(Note: This is probably the kind of information that should be added to the Wiki, as it is not so much a language question but the kind of thing that is subject to change over time. But, answerable, so...)
If you're using the GNU make method to build (where make -f makefile.boot generates a makefile for you) then you should find some lines in there like:
TO_OS_BASE?= TO_OSX
TO_OS_NAME?= TO_OSX_X64
OS_ID?= 0.2.40
BIN_SUFFIX=
RAPI_FLAGS= -D__LP64__ -DENDIAN_LITTLE -DHAS_LL_CONSTS -O1 ...
HOST_FLAGS= -DREB_EXE -D__LP64__ -DENDIAN_LITTLE ...
Modify the RAPI_FLAGS and HOST_FLAGS lines at the beginning to add -DHAVE_LIBFFI_AVAILABLE. That (-D)efines a preprocessor directive to tell the code it's okay to generate calls to FFI, because you have it available for linking later.
Now to tell it where to find include files. There's a line for includes that should look like:
INCL ?= .
I= -I$(INCL) -I$S/include/ -I$S/codecs/ ...
To the tail of that you need to add something that will look like -I/usr/local/opt/libffi/lib/libffi-3.0.13/include, or similar. The actual directory will depend on where you have libffi on your system. On the OSX system I'm looking at, that has two files in it, ffi.h and ffitarget.h.
(Note: I'm afraid I don't know how these files got on this computer. They didn't ship with the OS, so they came from...somewhere. I don't generally develop on OSX--nor for that matter do I use this FFI. You'll have to consult your local FFI-on-OSX website, or perhaps for support contact Atronix Engineering) who added the FFI features to Rebol.)
Then it's necessary to tell it where you have libffi on your system. You'll find a CLIB line that is likely just CLIB= -lm. You'd change this for example to:
CLIB= -L/usr/local/opt/libffi/lib -lm -lffi
-lffi Tells it to look for the ffi (-l)ibrary, and -lxxx means it assumes the name of the library will be libxxx[something]. -L/usr/local/opt/libffi/lib tells it where to look for it. You'll have to figure out where (if anywhere) you have libffi, and if not get it. If you had it, the directory would have contents something like:
libffi-3.0.13
libffi.6.dylib
libffi.a
libffi.dylib
pkgconfig
I mainly use OS X for development, though would also like to be able to build it for use with Linux.
On Linux it's similar but generally much easier to get the library, as easy as sudo apt-get install libffi-dev. Same step for the RFLAGS and CFLAGS, and it should take care of the location automatically... so you can add just -lffi to CLIB.
Old notes from me:
cat steps-for-lib-ffi-osx
Install libfffi via homebrew
brew install libffi
Add /use/include/libffi to the -I in the generated makefile
Add /usr/local/Cellar/libffi/3.0.13/lib/libffi.a to the OBJS in the
generated makefile
The version 3.0.13 may vary
Related
I have found several interesting links talking about a CPack generator for FreeBSD.
I would like to generate FreeBSD packages; however, whenever I attempt to generate TXZ archives (as directed by the instructions), the generated package isn't compatible with the pkg utility on FreeBSD. They miss the manifest file.
Obviously, CPack is generating raw archives, not pkg-ready archives. I assume I must be missing a step.
However, none of the links above talk about any such step.
Therefore,
How can I tell CPack to generate a FreeBSD-ready package?
(Original author of that code here)
So, there's two things in play here:
you need to be on FreeBSD (so that you have libpkg, which is needed to do the building)
you need to build the devel/cmake package with OPTIONS CPACK (which is not the default)
So:
cd /usr/ports/devel/cmake
make configure and select CPACK
make && make install
Then #Tsyvarev's comment will be the right answer. For the record, the support was deemed experimental, the library API unstable, and the pkg authors have asked me to re-vamp the code to use the current libpkg API so they can drop the old one. Time, though, is the limiting factor.
As a package manager for a Linux distribution, I want to install docs into a separate prefix. With CMake projects, the docs installation location is controlled by CMAKE_INSTALL_DOCDIR from GNUInstallDirs module. Unfortunately, unlike the other directory variables, this one contains the project name so I cannot just use cmake "-DCMAKE_INSTALL_DOCDIR=$myDocPrefix/doc".
With GNU Make, I would run make "DOCDIR=$myDocPrefix/doc/\$(PROJECT_NAME)" and have Make interpolate it but the documentation of CMake’s -D option does not mention interpolation and I understand that CMake uses much more complex system of cache entries where interpolation might be problematic (especially if the referenced variable is not yet in cache).
I could pass tailor-made CMAKE_INSTALL_DOCDIR to each CMake project but would be bothersome as I would have to do that in every package definition manually; being able to define configureCmakeProject function and have it take care of everything automatically would be better. When setting it manually, I would also want to make sure it matches the PROJECT_NAME of the respective CMake project – well, I could resign on that and just use $packageName from the package definition instead but keeping packages as close to upstream as possible is preferred.
Alternately, I could try to grep CMakeLists.txt for project command but that seems fragile and might still result in misalignments. I doubt it is possible to extract it using some CMake API since the project is not configured at the time and we actually need the value to configure the project.
Is there a way I can configure CMAKE_INSTALL_DOCDIR to use custom prefix but still keep the project name set by the CMake project?
I want to include the GNU Scientific Library (GSL) in my Cocoa app so that the user needs not installing it locally first. Like most GNU packages, it's the standard configure / make / make install routine. But this won't work:
./configure --prefix ~/libgsl
make
make install
Since the prefix is local to my computer. And neither is this:
./configure --prefix (path to build folder)/libgsl
make
make install
What I want is essentially the GSL being contained entirely in my application, and I can call its functions without the users downloading anything else.
I'm rather new to Xcode 4 and the build system for Clang/GCC, having coming over from .NET. Any help is much appreciated.
Assuming there is not a framework-style build of the library, the way this is typically done when bundling with 3rd party libraries is to build the package as normal, install it in /usr/local, and configure your project to include and link from there. Building is the easy part though.
The tricky part is bundling up the .app correctly. You need to add a custom build stage (after the others) which first copies all the dependent .dylib files into your app bundle's Frameworks folder (using the environment variables to help; see Xcode docs). Then you need to use install_name_tool to get the app binary to look in the framework dir (as the embedded soname still thinks it is in /usr/local). This part is very fiddly and not well documented.
I've just extracted this from a working project where I use GSL. Just add this as an extra build phase in your XCode project as a Custom Script:
# Framework folder for Example.app
FRAMEWORKS_DIR=${TARGET_BUILD_DIR}/Example.app/Contents/Frameworks
# Create path if it doesn't exsit
mkdir -p ${FRAMEWORKS_DIR}
# Find the original linked path for libgsl
GSLLIB=`otool -L ${TARGET_BUILD_DIR}/Example.app/Contents/MacOS/Example | grep libgsl | cut -d" " -f1`
GSLPATH=`dirname $GSLLIB`
# Copy the dylibs into your app
cp /usr/local/lib/lib{gsl,gslcblas}.0.dylib ${FRAMEWORKS_DIR}
# Update embedded paths
install_name_tool \
-change ${GSLPATH}/libgsl.0.dylib \
#executable_path/../Frameworks/libgsl.0.dylib \
${TARGET_BUILD_DIR}/Example.app/Contents/MacOS/Example
This should work with a simple substitution of your app name.
This is basically the same as what you need to do to build a standalone Qt app, so the docs here are very relevant:
Deploying Qt on the Mac
It is worth reading up on bundles, frameworks and packaging. For example:
Mac OS X Framework Reference
This post is also relevant:
How do I link libraries in Xcode 4?
Note that GSL is published under the GPL, so your app would need to be similarly published in order to respect the license. Shipping the source is necessary, but not sufficient for compliance.
I'm trying to convert our build system at work over to cmake and have run into an interesting problem with the RPMs that it generates (via cpack): It automatically adds all of the dependencies that it thinks your RPM has to its list of required libraries.
In general, that's great, but in my case, it's catastrophic. Unfortunately, the development packages that we build end up getting installed with one our home-grown tool that uses rpm to install them in a separate RPM database from the system one. It's stupid, but I can't change it. What this means is that all of the system libraries that any normal library will rely on (like libc or libpthread) aren't in the RPM database that is being used with our development packages. So, if an RPM for one of our development packages lists system libraries as being required, then we can't install it, as rpm will think that they're not installed (since they're listed in the normal database rather than the one that it's being told to use when installing our packages). Our current build stuff handles this just fine, because it doesn't list any system libraries as dependencies in the RPMs, but cpack automatically populates the RPM's list of required libraries and puts the system libraries in there. I need a way to stop it from doing so.
I tried setting CPACK_RPM_PACKAGE_REQUIRES to "", but that has no effect. The RPM cpack generates still ends up with the system libraries listed as being required. All I can think of doing at this point is to copy the RPM cpack generator and hack it up to do what I want and use that instead of the standard one, but I'd prefer to avoid that. Does anyone have any idea how I could get cpack to stop populating the RPM with required libraries?
See bottom of
http://www.rpm.org/max-rpm/s1-rpm-depend-auto-depend.html
The autoreqprov Tag — Disable Automatic Dependency Processing
There may be times when RPM's automatic dependency processing is not desired. In these cases, the autoreqprov tag may be used to disable it. This tag takes a yes/no or 0/1 value. For example, to disable automatic dependency processing, the following line may be used:
AutoReqProv: no
EDIT:
In order to set this in cmake, you need to do set(CPACK_RPM_PACKAGE_AUTOREQPROV " no"). The extra space seems to be required in front of (or behind) the no in order for it to work. It seems that the RPM module for cpack has a bug which makes it so that it won't let you set some its variables to anything shorter than 3 characters long.
To add to Mark Lakata's answer above, there's a snapshot of the "Maximum RPM" doc
http://www.rpm.org/max-rpm-snapshot/s1-rpm-depend-auto-depend.html
that also adds:
The autoreq and autoprov tags can be used to disable automatic processing of requirements or "provides" only, respectively.
And at least with my version of CPackRPM, there seems to be similar variables you can set e.g.
set(CPACK_RPM_PACKAGE_AUTOREQ " no")
to only disable the automatic dependency processing of 'Requires'.
I want to make a stand-alone exe with cygwin. I have two options:
Staticly link cygwin1.dll
If I can statically link cygwin1.dll, then I can get a stand-alone exe.
Merge cygwin1.dll with myprog.exe
If I can merge cygwin1.dll with my program, the I can get a stand-alone exe.
Do not suggest that I use IlMerge. This will not work because I didn't compile my program with .NET.
Are any of these options possible? If not, is there anything that is possible with this dilemma? Thanx!
Try passing -mno-cygwin as a compiler and linker flag. If your program's requirements are simple enough this will avoid depending on Cygwin libraries and create a standalone EXE.
I can see two possibilities that you might consider reasonable. One would be to build a stub executable with a different compiler (e.g., MinGW -- whatever, just so it doesn't need cygwin) to unpack the main executable and cygwin.dll into a temporary directory, and then spawn that executable. To distribute only a single executable, you'd want to add the main executable and cygwin.dll to the "stub" as binary resources. It's a bit ugly, but pretty straightforward.
The alternative would be to grab the source to cygwin, and build it as a static library. At least in theory, this should be cleaner -- but it's also undoubtedly more work. Getting it to build as purely static code instead of a DLL will almost certainly take some work, though it's hard to even guess how much. Just browsing a bit, it's seems pretty unlikely that it's going to be a quick job of a couple hours, or anything like that (unless there's something there that I missed that already supports building it statically, of course).
More precise answer of Jerry.
Procedure described below should be confronted with your rights and license law! I know it can work but rights to distribute the result (or even perform the procedure) may be (and I'm really feel that are) bounded by Cygwin license. That is because your application will still refer to Cygwin (even though it is useless - but is still in your app)
Assume hello.exe is the name of your great application compiled under Cygwin in great project directory C:\xxx\yyy\zzz\
In the cygwin console go to C:\xxx\yyy\zzz and type
objdump -p hello.exe | grep "DLL Name"
You obtain all DLLs your application uses. Then copy C:\xxx\yyy\zzz to all DLLs listed and specific for cygwin.
Note that your application may invoke other applications (using exec function for example) --- find libraries aplications use and copy this libraries as well as this applications themselves -- to C:\xxx\yyy\zzz.
Maybe you will have to recompile your project with option of kind -L C:\xxx\yyy\zzz or so. Watch all other paths in your sources.
Thus your application becomes independent of Cygwin installation and you can present its functionality to/ share it with ---- other Windows users without Cygwin. But - once more I point and ask you - be aware of proper license and law of Cygwin creators and observe them!