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Shared Libraries in Linux...
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EntityReborn:
...are giving me a headache.
I have an app, that uses a library, lets call it libMyLib.so.
I have the files for libMyLib in a seperate directory:
Main Solution Directory
|
+-bin
|
+-MyApp
|
+-MyLib
'bin' is where all my targets get placed.
I include it in my libraries I need to link, using "../bin/Debug/libMyLib.so".
I compile it, and it has no problem, but when I run it from the bin/Debug directory in Terminal, I get the following:
--- Quote ---./MyApp: error while loading shared libraries: ../bin/Debug/libMyLib.so: cannot open shared object file: No such file or directory
--- End quote ---
Notice that this error is looking for a bin/bin/Debug/libMyLib.so (extra bin intended) as '.' refers to bin/Debug at the time of running.
This is making me think that the location of the library is hardcoded. Why is that?
LD_DEBUG=libs offers no help, except for listing other (successful) loading libraries (libdl.so, in my current situation).
Speaking of libdl.so, THAT is giving me headaches too, as I ended up needing to give a relative path to including it. (I could not just add "libdl.so" to the librares to link, as it gave me the error "could not find -ldl.so" when trying to compile)
... BAH!
grischka:
Well, first you need to get rid of the hardcoded path prefix, so you would replace
"../bin/Debug/libMyLib.so"
by
"-lMyLib -L../bin/Debug"
Then you need to tell the linker to put a library search path into MyApp, for example (please edit):
"-Wl,-rpath=/home/you/stuff/bin/Debug"
So your link command could look like this:
$ gcc <objects ...> -lMyLib -L../bin/Debug -Wl,-rpath=/home/you/stuff/bin/Debug -o ../bin/Debug/MyApp
Just in case ldd shows what MyApp is supposed to load.
$ ldd MyApp
I'd test this from a terminal first and then teach CodeBlocks to do something to the same effect, possibly with "Full Commandline Logging" turned on.
EntityReborn:
Thanks for the informative reply! I'll test this when I get back from work.
As I've never compiled from the Terminal, this could be interesting, so could you possibly point out places in C::B where I could implement this? (ie does "-lMyLib ...." go into the library linker commands area or the library list?)
Never seen the Full Commandline Logging option, mind pointing that out?
Thankz!
grischka:
--- Quote from: EntityReborn on April 03, 2009, 05:41:08 pm ---(ie does "-lMyLib ...." go into the library linker commands area or the library list?)
--- End quote ---
Maybe to the libraries without the "-l" or to the linker options including the "-l". The GNU linker is somehow amnesic with what it sees on the commmandline so the order might matter.
--- Quote from: EntityReborn on April 03, 2009, 05:41:08 pm ---Never seen the Full Commandline Logging option, mind pointing that out?
--- End quote ---
Mind looking yourself? 8) (Maybe under "Compiler Settings")
EntityReborn:
OK, sorry for the wait, life got in the way. OK, so here is my current output:
--- Quote ----------------- Build: Debug in SDK ---------------
g++ -Wall -g -DBUILD_DLL -c /home/EntityReborn/Desktop/Snippitz/Snippitz.SDK/BoundarySafeVector.cpp -o obj/Debug/BoundarySafeVector.o
g++ -Wall -g -DBUILD_DLL -c /home/EntityReborn/Desktop/Snippitz/Snippitz.SDK/SnippitzEntry.cpp -o obj/Debug/SnippitzEntry.o
g++ -shared obj/Debug/BoundarySafeVector.o obj/Debug/SnippitzEntry.o -o ../bin/Debug/SDKDebug.so
Output size is 5.62 KB
-------------- Build: Debug in Core ---------------
g++ -Wall -g -I../Snippitz.SDK -c /home/EntityReborn/Desktop/Snippitz/Snippitz.Core/Callback.cpp -o obj/Debug/Callback.o
g++ -Wall -g -I../Snippitz.SDK -c /home/EntityReborn/Desktop/Snippitz/Snippitz.Core/OS_APIs.cpp -o obj/Debug/OS_APIs.o
g++ -Wall -g -I../Snippitz.SDK -c /home/EntityReborn/Desktop/Snippitz/Snippitz.Core/PluginManager.cpp -o obj/Debug/PluginManager.o
g++ -Wall -g -I../Snippitz.SDK -c /home/EntityReborn/Desktop/Snippitz/Snippitz.Core/Snippitz.Core.cpp -o obj/Debug/Snippitz.Core.o
g++ -shared -L../bin/Debug obj/Debug/Callback.o obj/Debug/OS_APIs.o obj/Debug/PluginManager.o obj/Debug/Snippitz.Core.o -o ../bin/Debug/CoreDebug.so ../bin/Debug/SDKDebug.so
Output size is 187.32 KB
-------------- Build: Debug in Console ---------------
g++ -Wall -fexceptions -g -I../Snippitz.Core -I../Snippitz.SDK -c /home/EntityReborn/Desktop/Snippitz/Snippitz.Console/Main.cpp -o obj/Debug/Main.o
g++ -L/usr/lib/ -L/home/EntityReborn/Desktop/Snippitz/bin/Debug/ -o ../bin/Debug/ConsoleDebug obj/Debug/Main.o -lCoreDebug.so /usr/lib/libdl.so
/usr/bin/ld: cannot find -lCoreDebug.so
collect2: ld returned 1 exit status
Process terminated with status 1 (0 minutes, 4 seconds)
1 errors, 0 warnings
--- End quote ---
I have tried so many different variations of paths, messing with -Wl, --rpath, etc and this is just getting ridiculous.
Is my setup a bad one? Granted I started this project in XP, so it was just logical to place shared libs in the same directory, but still. I can send the project if needed. Basically all I want to do is be able to compile my program using libraries in the output folder, and then when the program runs, it looks in . instead of wherever.
One small note, I MUST put /usr/lib/libdl.so, I can't put just libdl.so when linking that library. Is this correct? I thought programs/the linker looked in that directory by default. Adding /usr/lib to linker search paths doesn't seem to work, and I get "Can't find -ldl.so".
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