Undefined reference to Apache ARR functions

grob115 · 01-25-2012, 10:04 AM

Hi, need some expert advice on how to build a C++ project using the log4cxx lib. For some reason the liblog4cxx.a lib keeps on complaining that it can't find references to APR functions.

Can someone check the following to see if I may have missed anything? Thanks!!

Code:

apache@buildbox:/appvol/apache/lib/apr-1.4.5> ./configure --prefix=/appvol/apache/lib/apr-1.4.5/bin
apache@buildbox:/appvol/apache/lib/apr-1.4.5> make
apache@buildbox:/appvol/apache/lib/apr-1.4.5> make install

apache@buildbox:/appvol/apache/lib/apr-util-1.4.1> ./configure --prefix=/appvol/apache/lib/apr-util-1.4.1/bin
apache@buildbox:/appvol/apache/lib/apr-util-1.4.1> make
apache@buildbox:/appvol/apache/lib/apr-util-1.4.1> make install

Build log4cxx

Code:

apache@buildbox:/appvol/apache/lib/apache-log4cxx-0.10.0> ./configure --with-apr=/appvol/apache/lib/apr-1.4.5/bin/bin/apr-1-config --with-apr-util=/appvol/apache/lib/apr-util-1.4.1/bin/bin/apu-1-config --prefix=/appvol/apache/lib/apache-log4cxx-0.10.0/bin
apache@buildbox:/appvol/apache/lib/apache-log4cxx-0.10.0> make
apache@buildbox:/appvol/apache/lib/apache-log4cxx-0.10.0> make install

Build process above have generated both .so and .a files. Am moing the .a file into a sub-directory so when I build my project I can use the static .a lib.

Code:

apache@buildbox:/appvol/apache/lib/apache-log4cxx-0.10.0> mkdir static
apache@buildbox:/appvol/apache/lib/apache-log4cxx-0.10.0> cp liblog4cxx.a ./static/.

Bulding my custom app "myapp" with log4cxx. Note for some reason it keeps on complaning about the APR functions not found.

Code:

g++ -g -o myapp *.o -L/appvol/apache/lib/apache-log4cxx-0.10.0/bin/lib/static -L/usr/local/lib64 -L/usr/lib64 -llog4cxx -lm -ldl -lpthread -lrt
/appvol/apache/lib/apache-log4cxx-0.10.0/bin/lib/static/liblog4cxx.a(file.o): In function `log4cxx::File::getPath(log4cxx::helpers::Pool&) const':
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/file.cpp:121: undefined reference to `apr_filepath_encoding'
/appvol/apache/lib/apache-log4cxx-0.10.0/bin/lib/static/liblog4cxx.a(file.o): In function `log4cxx::File::mkdirs(log4cxx::helpers::Pool&) const':
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/file.cpp:238: undefined reference to `apr_dir_make_recursive'
/appvol/apache/lib/apache-log4cxx-0.10.0/bin/lib/static/liblog4cxx.a(file.o): In function `log4cxx::File::lastModified(log4cxx::helpers::Pool&) const':
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/file.cpp:182: undefined reference to `apr_stat'
.......................
/appvol/apache/lib/apache-log4cxx-0.10.0/bin/lib/static/liblog4cxx.a(socket.o): In function `Socket':
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:36: undefined reference to `apr_socket_create'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:47: undefined reference to `apr_sockaddr_info_get'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:53: undefined reference to `apr_socket_connect'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:62: undefined reference to `apr_socket_addr_get'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:71: undefined reference to `apr_sockaddr_ip_get'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:62: undefined reference to `apr_socket_addr_get'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:71: undefined reference to `apr_sockaddr_ip_get'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:36: undefined reference to `apr_socket_create'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:47: undefined reference to `apr_sockaddr_info_get'
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/socket.cpp:53: undefined reference to `apr_socket_connect'
/appvol/apache/lib/apache-log4cxx-0.10.0/bin/lib/static/liblog4cxx.a(strftimedateformat.o): In function `log4cxx::helpers::StrftimeDateFormat::format(std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, long long, log4cxx::helpers::Pool&) const':
/appvol/apache/lib/apache-log4cxx-0.10.0/src/main/cpp/strftimedateformat.cpp:44: undefined reference to `apr_strftime'
collect2: ld returned 1 exit status

NevemTeve · 01-25-2012, 10:29 AM

I might be wrong, but if you want to resolve from libapr-1.so then you should use linker flag -lapr-1
(Or you could use libtool)

grob115 · 01-26-2012, 10:04 AM

Hi, sorry am not following on why I need to resolve from "libapr-1.so". All I know is per the following link, In need to specify the "--with-apr" and "--with-apr-util" flags for "path to non-default location for APR" and "path to non-default location for APR-Util". However, the site isn't really clear to what exact path I need to specify. What I did notice is that the ./configure for log4cxx says I need to provide the same path I specified for the --prefix option when running ./configure for APR and APR-UTIL, or the path to the apr-1-config and apu-1-config files. I did both (the code pasted above showed I did the latter) but still have the same issue.
http://logging.apache.org/log4cxx/bu...autotools.html

Can you tell me where you saw the "-lapr-1" flag?

NevemTeve · 01-27-2012, 02:31 AM

Eventually apr_socket_create comes from /somepath/lib[64]/libapr-1.so, so if you want to link without unresolved externs, specify flags -L/somepath/lib[64] -lapr-1
If you used libtool, it would do that automagically.

grob115 · 01-27-2012, 10:17 AM

Ah of course!!! I was thinking about it as a switch to be passed to ./configure for one of the three APR, APR-UTIL, or log4cxx.
However, isn't the ./configure for log4cxx supposed to have compiled it, and linked in the lib from APR, and/or APR-UTIL? Maybe it's done so with a dynamic linking? Can I specify it to use static *.a libs from APR, APR-UTIL when building the *.a lib for log4cxx?

Also, haven't tested it out but earlier on I was thinking maybe I need to include the header files from APR and/or APR-UTIL with the -I switch when compiling and linking my code. But yeah guess adding the "-lapr-1" flag is properly the answer to it all. Will definitely give it a try.