undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev in Qt?

jsulm · 18 Aug 2021, 13:11

@Vivek_A Please take a look at https://doc.qt.io/qt-5/qmake-variable-reference.html#libs
and fix your LIBS (hint: you need to add .lib not .dll).

Vivek_A · 18 Aug 2021, 13:13

@jsulm hi, its build using mingw64 so there is only .a file not .lib .
full file is llibmongocxx.dll.a , this pro file command is generate by this IDE not manually written .

jsulm · 19 Aug 2021, 07:04

@Vivek_A Please take a look at the link I gave you and compare with what you did...
Should be

LIBS += C:/mongo-cxx-driver/lib/llibbsoncxx.dll

Vivek_A · 19 Aug 2021, 07:07

@jsulm

LIBS += C:/mongo-cxx-driver/lib/llibbsoncxx.dll

INCLUDEPATH += C:/mongo-cxx-driver/include/mongocxx/v_noabi
DEPENDPATH += C:/mongo-cxx-driver/include/mongocxx/v_noabi

Output:

g++: error: C:\mongo-cxx-driver\lib\llibbsoncxx.dll: No such file or directory
Makefile.Release:233: recipe for target 'release\RTLSController.exe' failed

jsulm · wrote on 19 Aug 2021, 07:07

@Vivek_A said in undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev in Qt?:

C:\mongo-cxx-driver\lib\llibbsoncxx.dll

So, does this file exist? And I mean exact this path.

JonB · 19 Aug 2021, 07:11

@Vivek_A said in undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev in Qt?:

g++: error: C:\mongo-cxx-driver\lib\llibbsoncxx.dll: No such file or directory

Originally you had -llibbsoncxx.dll. I am thinking the leading -l was an argument to the linker, followed by the DLL file name? Which would make it LIBS += C:/mongo-cxx-driver/lib/libbsoncxx.dll (only one l)?

However, this is a separate matter from whether you should be specifying a .dll here, I thought you would need either a .lib (MSVC) or a .a (MinGW)...?

jsulm · 19 Aug 2021, 07:13

@JonB I wanted the OP to find that out :-) This is something a developer should do first before asking in a forum. Really basic stuff.

JonB · 19 Aug 2021, 07:14

@jsulm
Whoops, sorry for treading on your toes!

However I have amended my answer above since you saw it. Is one supposed to specify any DLL file in LIBS += ...?

jsulm · 19 Aug 2021, 07:23

@JonB It should be .lib, yes. But OP claims there is no .lib file, but I'm not a Windows developer.

JonB · J jsulm 19 Aug 2021, 07:14

@jsulm
A .lib will not do him, as he is using MinGW/gcc. I now see he wrote earlier:

full file is llibmongocxx.dll.a

That is an unusual naming convention! If that is really the case, and applies to llibbsoncxx.dll.a too, then it would indeed seem to be as he wrote. But the error message

g++: error: C:\mongo-cxx-driver\lib\llibbsoncxx.dll: No such file or directory

shows what MinGW seems actually to be looking for, no mention of a .a suffix. So I'm not sure what is going on....

Vivek_A · 19 Aug 2021, 07:25

@jsulm ok, i understand idid this

LIBS += C:/mongo-cxx-driver/lib/libbsoncxx.dll.a

INCLUDEPATH += C:/mongo-cxx-driver/include/mongocxx/v_noabi
DEPENDPATH += C:/mongo-cxx-driver/include/mongocxx/v_noabi

included but error that said first remains

./release\main.o:main.cpp:(.text+0x1d): undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev'
./release\main.o:main.cpp:(.text+0xee): undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceD1Ev'
./release\main.o:main.cpp:(.text+0x14e): undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceD1Ev'

if you dont know about windows side of this , then its ok.
@JonB i have doubt , the compiler is mingw 32 and i build the mongdb in mingw 64 is this makes any issues

jsulm · wrote on 19 Aug 2021, 07:25

@Vivek_A You need to link at least one more lib containing the missing symbols (libmongocxx I guess).

JonB · wrote on 19 Aug 2021, 07:28

@Vivek_A said in undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev in Qt?:

LIBS += C:/mongo-cxx-driver/lib/libbsoncxx.dll.a

This looks much more reasonable than before!

Now as @jsulm says it looks like you need some further similars for other library files required to link successfully.

@JonB i have doubt , the compiler is mingw 32 and i build the mongdb in mingw 64 is this makes any issues

I am not sure what you are saying. It will not be possible to mix 64-bit-compiled code with 32-bit-compiled code in one executable. The compiler's bit-ness is not at issue, rather only whichever bit-ness it is generating code for.

Start by trying what @jsulm has pointed out, then deal with bit-ness if there is still an error.....

Vivek_A · 19 Aug 2021, 12:01

@JonB modified

LIBS += C:/mongo-cxx-driver/lib/libbsoncxx.dll.a
LIBS += C:/mongo-cxx-driver/lib/libmongocxx.dll.a
INCLUDEPATH += C:/mongo-cxx-driver/include/mongocxx/v_noabi
DEPENDPATH += C:/mongo-cxx-driver/include/mongocxx/v_noabi

INCLUDEPATH += C:/mongo-cxx-driver/include/bsoncxx/v_noabi
DEPENDPATH += C:/mongo-cxx-driver/include/bsoncxx/v_noabi

clean & rebuilded
Output:

./release\main.o:main.cpp:(.text+0x19): undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev'
./release\main.o:main.cpp:(.text+0x23): undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceD1Ev'
collect2.exe: error: ld returned 1 exit status

Vivek_A · wrote on 19 Aug 2021, 12:01

@Vivek_A anybody help...is that compiler problem

./debug\main.o: In function `Z5qMainiPPc':
E:/vivek/dw_tdoa_controller7/dw_tdoa_controller/main.cpp:36: undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceC1Ev'
E:/vivek/dw_tdoa_controller7/dw_tdoa_controller/main.cpp:36: undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceD1Ev'
E:/vivek/dw_tdoa_controller7/dw_tdoa_controller/main.cpp:36: undefined reference to `_imp___ZN8mongocxx7v_noabi8instanceD1Ev'
collect2.exe: error: ld returned 1 exit status


Makefile:36: recipe for target 'debug' failed
mingw32-make[1]: *** [debug\RTLSController.exe] Error 1
mingw32-make: *** [debug] Error 2
17:25:51: The process "C:\Qt\Qt5.11.2\Tools\mingw530_32\bin\mingw32-make.exe" exited with code 2.
Error while building/deploying project dw_controller (kit: Desktop Qt 5.11.2 MinGW 32bit)
When executing step "Make"

SGaist · wrote on 19 Aug 2021, 18:54

Try inverting the order of the libraries you are linking.

Vivek_A · 23 Aug 2021, 11:42

@SGaist tried , still same error , i think its not in the linking of lib, may be the installation or compiler problem... what u think???

mrjj · 23 Aug 2021, 12:40

@Vivek_A

Hi
I saw this line
building/deploying project dw_controller (kit: Desktop Qt 5.11.2 MinGW 32bit)

but you said " its build using mingw64 "

So are your 32 bit app trying to load 64 bit DLL ?

Vivek_A · M mrjj 23 Aug 2021, 11:42

@mrjj hi sir, i build and installed mongocxx driver using ming64. The app running in Qt is Desktop Qt 5.11.2 MinGW 32bit, ie a mingw 32 bit compiler

SGaist · 24 Aug 2021, 05:25

The question is: did you build the MongoDB C++ library in 32 or 64 bit ?

If the later then you can't use them with to build a 32bit application. Beside compiler, architecture matters as well. You can't mix and match 32 and 64 bit when building librairies or applications.