Can't build simple program

[stephenpmorgan]

I must be doing something stupid, but I can't build a simple program with rocksdb. I get a bunch of undefined references from standard functions. Can anyone give me some help? Any help would be appreciated!!

I compile and build with the following commands:
g++ -c -I./include -std=c++11 mytest.cc
g++ -o mytest -L. -lrocksdb mytest.o

The program (mytest.cc) is as follows:

include <assert.h>

include <iostream>

include "rocksdb/db.h"

int
main(int argc, char *argv[])
{
rocksdb::DB *db;
rocksdb::Options options;

options.create_if_missing = true;
options.error_if_exists = true;

rocksdb::Status status = rocksdb::DB::Open(options, "/tmp/testdb", &db);
assert(status.ok());

delete db;

return 0;
}

I get back the following complaints:

mytest.o: In function main':
mytest.cc:(.text+0x11b): undefined reference torocksdb::DB::Open(rocksdb::Options const&, std::string const&, rocksdb::DB**)'
mytest.o: In function rocksdb::Options::Options()':
mytest.cc:(.text._ZN7rocksdb7OptionsC2Ev[_ZN7rocksdb7OptionsC5Ev]+0x15): undefined reference torocksdb::DBOptions::DBOptions()'
mytest.cc:(.text._ZN7rocksdb7OptionsC2Ev[_ZN7rocksdb7OptionsC5Ev]+0x27): undefined reference to `rocksdb::ColumnFamilyOptions::ColumnFamilyOptions()'
collect2: error: ld returned 1 exit status

[igorcanadi]

Hmm looking. How did you build rocksdb? make shared_lib?

[stephenpmorgan]

just "make"

[igorcanadi]

Hey, I just tried the same thing and it works for me:

icanadi@icanadi-mbp1 rocksdb $ g++ -c -I./include -std=c++11 mytest.cc
icanadi@icanadi-mbp1 rocksdb $ g++ -o mytest -L. -lrocksdb mytest.o -lbz2 -lz -lsnappy
icanadi@icanadi-mbp1 rocksdb $ ./mytest

Can you please try make clean; make?

[stephenpmorgan]

I just tried again after "make clean; make" and got the same results (the build didn't work in the same way). I guess my environment must be screwed up (but how?). I'm building with g++ 4.7.2 on ubuntu 12.10. Do I need g++ 4.8?

[igorcanadi]

You shouldn't need g++ 4.8.

Can you try:

1. building with 2.8 release? (branch 2.8.fb)
2. linking with shared library (you can make it with make shared_lib)

[igorcanadi]

Let me try the same thing on ubuntu 12.10

[igorcanadi]

Reproed the issue on ubuntu 12.10. Looking

[igorcanadi]

It looks like you have to specify library after your .o file. So your second command should be:

g++ -o mytest mytest.o -L. -lrocksdb -lsnappy -lpthread -lbz2 -lz -lrt

(also added other libraries you need to link with)

[stephenpmorgan]

You're right--that works for me. Sorry for the bother.