Compiling command line with libraries in Linux with GCC

Question

I'm Android developer and engineer in computer vision.

I'm making a project of computer vision with OpenCV on a Mac, with OS X 10.9.5 in Xcode and it's cross-platform, so what I'm doing is a command line to compile into linux and access to it (server).

The problem that I'm having is that the library JSONCPP isn't being recognized. I compile it with:

g++ -I/home/ec2-user/project/opencv/include/249include/include/ -L/home/ec2-user/project/opencv/build/lib/ -L/home/ec2-user/project/lib/ -I/home/ec2-user/project/jsoncpp-master/include/ -g -o binary main.cpp facerecognition.cpp utils.cpp -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_stitching -lopencv_flann -w -std=c++11

Which part of the output is:

/home/ec2-user/project/utils.cpp:2475: undefined reference to `Json::Value::Value(Json::ValueType)'

/home/ec2-user/project/utils.cpp:2478: undefined reference to `Json::Value::Value(Json::ValueType)'

/home/ec2-user/project/utils.cpp:2479: undefined reference to `Json::Value::Value(Json::ValueType)'

/home/ec2-user/project/utils.cpp:2484: undefined reference to `Json::Value::Value(int)'

/home/ec2-user/project/utils.cpp:2484: undefined reference to `Json::Value::append(Json::Value const&)'

/home/ec2-user/project/utils.cpp:2484: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2486: undefined reference to `Json::Value::Value(std::string const&)'

/home/ec2-user/project/utils.cpp:2486: undefined reference to `Json::Value::operator[](char const*)'

/home/ec2-user/project/utils.cpp:2486: undefined reference to `Json::Value::operator=(Json::Value)'

/home/ec2-user/project/utils.cpp:2486: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2487: undefined reference to `Json::Value::Value(Json::Value const&)'

/home/ec2-user/project/utils.cpp:2487: undefined reference to `Json::Value::operator[](char const*)'

/home/ec2-user/project/utils.cpp:2487: undefined reference to `Json::Value::operator=(Json::Value)'

/home/ec2-user/project/utils.cpp:2487: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2488: undefined reference to `Json::Value::append(Json::Value const&)'

/home/ec2-user/project/utils.cpp:2479: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2489: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2491: undefined reference to `Json::StyledWriter::StyledWriter()'

/home/ec2-user/project/utils.cpp:2492: undefined reference to `Json::StyledWriter::write(Json::Value const&)'

/home/ec2-user/project/utils.cpp:2475: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2484: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2486: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2487: undefined reference to `Json::Value::~Value()'

/home/ec2-user/project/utils.cpp:2479: undefined reference to `Json::Value::~Value()'

I have to mention that I have compiled this for Android (NDK) before with a this Makefile:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

OPENCV_CAMERA_MODULES:=off

OPENCV_INSTALL_MODULES:=on

include $(LOCAL_PATH)/jsoncpp/Android.mk

include /Users/rafaelruizmunoz/Desktop/AndroidDevelopment/OpenCV-2.4.9-android-sdk/sdk/native/jni/OpenCV.mk

OPENCV_LIB_TYPE:=SHARED

LOCAL_C_INCLUDES += $(LOCAL_PATH)

LOCAL_C_INCLUDES += /Users/rafaelruizmunoz/OpenCVtry/

LOCAL_C_INCLUDES += /Users/rafaelruizmunoz/Desktop/RD/OpenCVtry/Libraries/jsoncpp-master/include

LOCAL_PATH := jni

LOCAL_ALLOW_UNDEFINED_SYMBOLS := true

LOCAL_MODULE := libXYZ

LOCAL_MODULE_NAME := mylibXYZ

LOCAL_SRC_FILES := facerecognition.cpp androidClass.cpp main.cpp utils.cpp helper.cpp lbp.cpp

LOCAL_LDLIBS += -llog -ldl

LOCAL_CPPFLAGS := -std=c++11

LOCAL_CFLAGS := -w

CFLAGS=-w -g -Wall -Wextra -std=c++11 -Wno-write-strings ../../include/boost

LOCAL_SHARED_LIBRARIES := libJsoncpp libopencv_java

include $(BUILD_SHARED_LIBRARY)

which worked perfectly.

On my Mac it compiles perfectly. What I had to do is the JSONCPP Makefile with Xcode generator and adding as a project:

enter image description here

But I'm getting out of clues for compiling it into Linux.

Would you know what to do? Thanks in advance.

Regards.

You're getting errors compiling utils.cpp which feels more like you're either missing an #include line for the JSON stuff, or (depending what messages you've omitted) it's not finding the included file. It doesn't look like you've got to link/library problems yet. — TripeHound
Hi @TripeHound thank you for your reply. I added a new include: -I/home/ec2-user/project/json/ .... got other errors. Solved them but after that I get the same errors that I've mentioned.... :\ — Rafael Ruiz Muñoz
Can't do much more than repeat the earlier questions: does your utils.cpp have appropriate #include line(s) and are there earlier errors about not finding any include files? — TripeHound

tipaye tipaye · Accepted Answer · 2015-01-19T20:58:24

This is a guess based on your Android makefile, since I can't see the included "BUILD_SHARED_LIBRARIES", but I noticed you've got:

"LOCAL_SHARED_LIBRARIES := libJsoncpp libopencv_java"

I imagine you would need "-lJsoncpp -lopencv_java" on your g++ command line.

You have to be sure both libraries have been built and can be found in one of the "-L" paths

Compiling command line with libraries in Linux with GCC

1 Answers