CODEWITHSUNDEEP
gcclinker
betapatch
betapatch

Reputation: 153

local gcc build links system dynamic libraries

i build and installed gcc-4.6.4 into my home dir (i don't have root proviliges). When I link a few object files to an executable with g++, it links the "wrong" libstdc++.so.6.

It does not use the newer one wich is located in the install dir but the one of the system.

Is there a way to specify an exclusive search path for libraries?

My bashrc:

PATH=$PATH:/home/testuser/selfcompiled/gcc-4.6.4/bin:/usr/local/cuda/bin
export PATH

C_INCLUDE_PATH=/home/testuser/selfcompiled/gcc-4.6.4/include 
export C_INCLUDE_PATH

CPLUS_INCLUDE_PATH=/home/testuser/selfcompiled/gcc-4.6.4/include 
export CPLUS_INCLUDE_PATH

LIBRARY_PATH=/home/testuser/selfcompiled/gcc-4.6.4/lib:/home/testuser/selfcompiled/gcc-4.6.4/lib64/lib
export LIBRARY_PATH

LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib:/usr/local/cuda/lib64:/usr/local/cuda/cudaprof/bin:/home/testuser/selfcompiled/gcc-4.6.4/lib:/home/testuser/selfcompiled/gcc-4.6.4/lib64/lib
export LD_LIBRARY_PATH

GCC_EXEC_PREFIX=/home/testuser/selfcompiled/gcc-4.6.4/lib/gcc/
export GCC_EXEC_PREFIX

COMPILER_PATH=/home/testuser/selfcompiled/gcc-4.6.4/bin/:/home/testuser/selfcompiled/gcc-4.6.4/libexec/:/home/testuser/selfcompiled/gcc-4.6.4/lib/gcc/
export COMPILER_PATH

Even if I specify the dir with the local libstdc++.so.6 via g++ -L...., the one located in /usr/... is linked to the executable according to ldd.

Thanks very much!

Upvotes: 0

Views: 431

Answers (2)

Employed Russian
Employed Russian

Reputation: 213375

I am guessing you have built 64-bit executable. This path:

/home/testuser/self‌​compiled/gcc-4.6.4/lib64/lib

looks wrong, and should likely be:

/home/testuser/self‌​compiled/gcc-4.6.4/lib64

To use it, set LD_LIBRARY_PATH, or better use -Wl,-rpath=/home/testuser/self‌​compiled/gcc-4.6.4/lib64

Upvotes: 0

rubenvb
rubenvb

Reputation: 76519

Nothing goes wrong when linking (or you'd get a linker error to symbols not present in the old library version).

This is a runtime thing. This:

LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib:/usr/local/cuda/lib64:/usr/local/cuda/cudaprof/bin:/home/testuser/selfcompiled/gcc-4.6.4/lib:/home/testuser/selfcompiled/gcc-4.6.4/lib64/lib
export LD_LIBRARY_PATH

Should be

LD_LIBRARY_PATH=/home/testuser/selfcompiled/gcc-4.6.4/lib:/home/testuser/selfcompiled/gcc-4.6.4/lib64/lib:$LD_LIBRARY_PATH:/usr/local/cuda/lib:/usr/local/cuda/lib64:/usr/local/cuda/cudaprof/bin
export LD_LIBRARY_PATH

The executable loader needs to look at your new libraries first, before it looks at the old ones. Of course, there is strong binary compatibility, so if no new symbols are used, the old libs will do just fine.

Upvotes: 1

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