cannot find -lpaho-mqtt3c for arm-none-linux-gnueabi-g++ compiler

问题

I have the arm-none-linux-gnueabi-g++ compiler in the below path,

root@user-VirtualBox:~# which arm-none-linux-gnueabi-g++
/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-g++

and I have given the same in DCMAKE_COMPILER path in the build command of paho,

user@user-VirtualBox:~/octane_etk_sample-6.0.0.240/paho.mqtt.c$ cmake -Bbuild -H. -DPAHO_WITH_SSL=OFF -DPAHO_ENABLE_TESTING=OFF  -DCMAKE_C_COMPILER=/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-gcc  -DCMAKE_CXX_COMPILER=/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-g++
-- The C compiler identification is GNU 4.8.1
-- Check for working C compiler: /home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-gcc
-- Check for working C compiler: /home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- CMake version: 3.10.2
-- CMake system name: Linux
-- Timestamp is 2020-04-17T07:33:49Z
-- Configuring done
-- Generating done
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_CXX_COMPILER


-- Build files have been written to: /home/user/octane_etk_sample-6.0.0.240/paho.mqtt.c/build

After this build I have given,

$ sudo cmake --build build/ --target install
$ sudo ldconfig

and I have copied libpaho-mqtt3c.so, libpaho-mqtt3c.so.1, libpaho-mqtt3c.so.1.3.1 from "/home/user/octane_etk_sample-6.0.0.240/paho.mqtt.c/build/src/" to the same folder where this "-lltkcpp_atmel" resides.

Whereas, when I give make it says, cannot find -lpaho-mqtt3c,

root@user-VirtualBox:/home/user/octane_etk_sample-6.0.0.240# make arm
mkdir -p ./bin
arm-none-linux-gnueabi-g++ \
    -Wno-write-strings \
    -Iinclude \
    speedway_embedded_example.cpp -lpaho-mqtt3c \
    -Llib \
    -static -lltkcpp_atmel -lltkcppimpinj_atmel -lxml2_atmel \
    -lssl_atmel -lcrypto_atmel -ldl_atmel \
    -o bin/speedwayr_arm
/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/../lib/gcc/arm-none-linux-gnueabi/4.8.1/../../../../arm-none-linux-gnueabi/bin/ld: cannot find -lpaho-mqtt3c

How to overcome this issue? Is it something wrong while building the paho against arm-none-linux-gnueabi-gcc & g++?

Note 1: Compiler command suggested by David Ranieri

root@user-VirtualBox:/home/mindlogic/octane_etk_sample-6.0.0.240# make arm
mkdir -p ./bin
arm-none-linux-gnueabi-g++ \
    -Wno-write-strings \
    -o bin/speedwayr_arm \
    -Iinclude \
    speedway_embedded_example.cpp -lpaho-mqtt3c \
    -Llib \
    -static -lltkcpp_atmel -lltkcppimpinj_atmel -lxml2_atmel \
    -lssl_atmel -lcrypto_atmel -ldl_atmel
/home/mindlogic/octane_etk-6.0.0.240/arm-toolchain/bin/../lib/gcc/arm-none-linux-gnueabi/4.8.1/../../../../arm-none-linux-gnueabi/bin/ld: cannot find -lpaho-mqtt3c

Note 2:

I have changed the cmake build from

cmake -Bbuild -H. -DPAHO_WITH_SSL=OFF -DPAHO_ENABLE_TESTING=OFF  -DCMAKE_C_COMPILER=/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-gcc  -DCMAKE_CXX_COMPILER=/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-g++

 cmake -Bbuild -H. -DPAHO_WITH_SSL=OFF -DPAHO_ENABLE_TESTING=OFF 
-DPAHO_BUILD_STATIC=True -DCMAKE_C_COMPILER=/home/user/octane_etk-6.0.0.240/arm-toolchain/bin/arm-none-linux-gnueabi-gcc  -DCMAKE_CXX_COMPILER=/home/user/octane_etk-6.0.0.240/arm-toolchain

After building a library as static one, now I can able to compile with "makr arm", successfully i.e., commands given below

root@user-VirtualBox:/home/user/octane_etk_sample-6.0.0.240# make cap
mkdir -p ./bin
arm-none-linux-gnueabi-g++ \
    -Wno-write-strings \
    -Iinclude \
    speedway_embedded_example.cpp \
    -Llib \
    -static -lltkcpp_atmel -lltkcppimpinj_atmel -lxml2_atmel \
    -lssl_atmel -lcrypto_atmel -ldl_atmel -lpaho-mqtt3c-static -ljansson -lpthread \
    -o bin/speedwayr_arm

回答1:

Order matters, try generating the object before linking:

arm-none-linux-gnueabi-g++ \
    -Wno-write-strings \
    -o bin/speedwayr_arm \
    -Iinclude \
    speedway_embedded_example.cpp -lpaho-mqtt3c \
    -Llib \
    -static -lltkcpp_atmel -lltkcppimpinj_atmel -lxml2_atmel \
    -lssl_atmel -lcrypto_atmel -ldl_atmel

来源：https://stackoverflow.com/questions/61266452/cannot-find-lpaho-mqtt3c-for-arm-none-linux-gnueabi-g-compiler

标签

c++

linker