I compiled a program by statically linking external libraries on XCode. However, I am having errors on how to dynamically link those libraries.
For Static Linking, I did
1. Went to Build Phases, Link Binary with Libraries, Chose the static .a libraries
2. Went to Build settings and modified the Header Search path to the header files directory
3. Modified the Library search path to the static library directory.
I compiled the program and it works.
Then I am trying to dynamic linking
1. Went to Build Phases, Link Binary with Libraries, removed the static .a libraries and added the .dylib libraries (they are in the same directory)
2. Tried compiling - But I am getting 'Library not loaded:#loader_path/(lib name).dylib.. Reason: image not found'.
Am I missing one of the paths? What am I doing wrong?
Solved it by adding DYLD_LIBRARY_PATH environment variable.
Make sure that dynamic libraries are not in the same directory as the static libraries. This creates a conflict. I created a separate directory and copied all the dynamic libraries I needed to that directory
Went to Build Phases, Link Binary with Libraries, Chose the dynamic libraries I needed
Went to Build settings and modified the Header Search path to the header files directory
Modified the Library search path to the dynamic library directory.
Created an environment variable by (menu) Product -> Scheme -> Edit Scheme. Under 'Environment Variables', created a 'DYLD_LIBRARY_PATH' variable and pointed it to my dynamic library directory.
It works :)
Related
I have some problems with linking my macOS app against C libraries.
I have several question related to this issue.
It is better to link app against dynamic or static libraries taking into account that this will be very custom libraries rather not shared with other apps?
I have linked my macOS Xcode app against ~14 static libraries .a and it works fine. I have reconfigured CMakeLists.txt making this libraries and now Xcode project doesn't work. The main change was changing the directory I have
"$(SRCROOT)/../../c/<project_name>/outputs/lib/apple/static"
But now I have both static (.a) and dynamic (.dylib) libraries in the same path
"$(SRCROOT)/../../c/server/outputs/lib/apple"
I don't know whether this should matter, but linking against static libraries causes that after running my Xcode project it complains that it cannot load lib.dylib So maybe it finds this dynamic library under Library Search Paths and tires to load them but don't find them linked?
So I tired to link Xcode macOS app against .dylib libraries and instead of static .a libraries added them in Link Binary with Libraries. The problem is that the error not finding library now also occurs.
Maybe I should change something here ? But what If I will distribute my app to some other computers that will not have libraries in this specific location. How can I include dynamic libraries in Xcode bundle in order to be always findable.
I know I added maybe to many question. But would like to know how to the best solve this issue? Better to link statically or dynamically and then how to correctly achieve this avoiding this error.
UPDATE
It seems that when linking against .dylib it only works when I add path to this library directory to Runpath Search Paths.
It also seems that when I link against static library .a it works when .dylib isn't in the same directory (I moved .a library into /static subdirectory) and then for this moved library error isn't showing any more. But isn't there way to link statically when there is .a and .dylib libraries inside the same directory?
I know this is an old question but it's one of the top results when searching google for "Xcode static linking."
I recently encountered this issue when integrating with Intel IPP, which puts static and dynamic libs in the same directory.
If I used the standard Xcode linking method of adding the library via the "Build Phases | Link Binary with Libraries," Xcode translated that UI into a command line that looked like this:
clang++ ... -L/my/path -lstatic1 -lstatic2 ...
But that causes the linker to prefer the DLL instead of the static library in the same directory.
I worked around this by removing the entries from the "Build Phases | Link Binary with Libraries" window, and adding full relative paths to the libraries in the "Build Settings | Other linker flags" entry:
../../path/to/lib/libstatic1.a ../../path/to/lib/libstatic2.a
This caused Xcode to translate the UI into a command line that looked like this:
clang++ ... ../../path/to/lib/libstatic1.a ../../path/to/lib/libstatic1.a ...
Which linked the libraries statically.
Finally, I have linked this Xcode macOS project with multiple dynamic C libraries (.dylib).
REMARK
In order to link with static libraries (.a) They cannot be placed side by side with dynamic libraries! path/project_name/outputs/lib/apple/*.dylib and then place static libs under path: path/project_name/outputs/lib/apple/static/.a As XCode tries to link dynamic libraries if they found them on Libraries Search Path in Build Settings.
DYNAMIC C LIBRARIES LINKIN IN XCODE
Add dynamic libraries to Build Phases tab and Link Binaries with Libraries section as on the image
Embed all this dynamic libraries in output macOS Application Wrapper
You get something like this:
Then in Build setting add Libraries Search Paths
And finally add Runtime Search Paths in Build Settings
I'm having an issue compiling a static library using Code::Blocks 13.12. I need to use a third party static library from within my own static library. So, I have libOtherLib.a and I'm trying to build libMyLib.a and link in libOtherLib.a. The problem is that the linker is not including libOtherLib.a during the linking phase of the build. Here is some additional information:
I am using the GNU GCC Compiler
In Project build options for the whole project (not specifically Debug or Release)
I have added libOtherLib.a in the Link Libraries list in the Linker Settings
I have added the path to libOtherLib.a in the Search directories -> Linker list
I have added the path to the .h file for libOtherLib.a in the Search directories -> Compiler list
The library compiles completely fine (produces bin/Debug/libMyLib.a with no errors)
Any help would be greatly appreciated. I have an inkling that it is related to this being a Static Library rather than an application (console or otherwise), but I'm not sure how or why. I did change the build target Type to "Console Application" in the Project Properties window and it looked like it was linking in libOtherLib.a, but it had other errors because this code is meant to be a library rather than an application.
Here is the linker command that is executed at the end of the build. libOtherLib.a is not there anywhere, that is the problem, just not sure what the solution is.
ar -r -s bin/Debug/libMyLib.a <all of my .o files>
Possible causes of the problem would also be nice - if this is mostly like the compiler, the linker, the setup or Code::Blocks itself.
When building a static library you are just putting together a bunch of object files into an entity easier to ship and use. There is no linking done when building a static library.
The unresolved references from your library are dealt with when building an application or certain shared objects. You'd just ship your library and require that users also supply the library your library deoends on when building.
If you want to include the library you are depending on in your library you can extract the object files from tgat library and include them into your library. Although technically possible it is questionable if you have the rights to do so. Also, that is normally not the way things are done and I'd recommend against doing so.
You can't link a static library in anoter static library.
However,you can do this:
Suppose MyPrograme.exe need to link static library libMyLib.a,make MyPrograme.exe also link libOtherLib.a.
Since libMyLib.a is static library,there is no need to link libMyLib.a.Just inclue the headers.
When build a static library,it will only be compiled,not be linked.
Despite all this "linking is not the right term for this" philosophy, you can patch Code::Blocks compiler configuration to support this, for example for the GCC/G++ compiler.
http://green-candy.osdn.jp/codeblocks_config.html
The idea is that you replace the "Link object files to static library" script in the "Advanced compiler options" window of GCC with:
rm -f $static_output
$lib_linker -r -s -T $static_output $link_objects
$lib_linker -r -c -T $static_output $link_options
Then you can put the relative path to your "libOtherLib.a" in the "Other linker options" editbox of your projects. This mod is not really officially endorsed but it works in my projects, so you get static libs in static libs just like in MS Visual Studio!
I have seen several other answers in order to add a library to my C+= project in eclipse.I have tried to add the path to the linker in Miscellaneous section using -L"and the path of the folder" and -l"the name without the lib prefix in the begging and the .so at the end"
I try to add libxl library so i use -lxl (for libxl.so) and -L/home/username/libxl3.5.3.0/lib/ (which the location of the lib file).
I have also tried to give it under the Linker menu and adding the name and the path in the Libraries section.
I get error that: /usr/bin/ld does not find -lxl file and it returns error
I am using -static to linker in order to make an executable that has the all the libs included but when i do not use -static the problem with the lib resolves from build but still when i try to run the program i get error that i the program can not open shared file libxl.so cause the file does not exist.How can i fix this?
When you add the library name to a C++ project in eclipse, do not prefix it with -l. Eclipse will do this for you when it invokes the compiler. For example if you want the boost_regex library, just input boost_regex not lboost_regex. Eclipse will do the rest for you. Or in your specific case, just use xl not lxl. You don't need the - either, nor the -L before paths as erenon points out in the comment below. Note that the above applies to the method of adding libraries using the Project->Properties->C/C++ General->Paths and Symbols dialog form for adding libraries using the Libraries and Library Paths tabs.
You are trying to link statically to a shared library. In my experience I have always used *.a files rather than *.so files to employ static linkage. This other answer Static link of shared library function in gcc seems to suggest that you are not actually able to link statically to *.so files.
I have 3rd parties libraries that don't placed under "/usr/lib".
I defined their path in eclipse library search path .
The project compile and linkage well, but when i run project i got exception that library doesn't found.
if i copy the 3rd party library to "/usr/lib" than it run ok.
I believe that this is path issue (i am new to cpp), how do i configure this in eclipse ?
Thank you
First of all, since it's crashing during runtime, you are linking against dynamic libraries (libWhatever.so), so you have to add your library path to the LD_LIBRARY_PATH environment variable. Otherwise, you could force the linker to link statically to static libraries (libWhatever.a), using the -static flag.
I pulled out an application that I wrote in C++ using the sfml library, but I'm having trouble setting up the library in Eclipse. I specified the include path, the lib path and included all the necessary .so libraries to link to. the application compiles fine but it complains at runtime about missing libraries. Why is this happening? Didn't I include the path to the libraries in the project settings already? I have even tried to place all the .so's in the executable directory with no luck.
There is only the name of the shared lib stored in the executable. At program startup the dynamic linker then searches for the specified libs in its search paths. You can add/specify search paths by placing them colon separated in the environment variable LD_LIBRARY_PATH or by specifying them in /etc/ld.so.conf (at least if you use some unix based OS). On windows the whole PATH environment variable is used when searching for dynamic-link libraries (DLL).
To see the paths of shared libraries used by a given application run ldd applicationPath.