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undefined reference to main for shared library
(1 answer)
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 2 years ago.
I am justing wondering what the error means here if anyone can help me.
g++ -o Try2 student.o studentlist.o
Undefined first referenced
symbol in file
main /usr/local/lib/gcc/sparc-sun-solaris2.10/4.8.4/crt1.o
ld: fatal: Symbol referencing errors. No output written to Try2
collect2: error: ld returned 1 exit status
Related
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Why does the order in which libraries are linked sometimes cause errors in GCC?
(9 answers)
Closed 5 months ago.
I am trying to implement my own thumbnail provider by following Microsoft's thumbnail provider code sample. The code has been coming together nicely, but now I needed to figure out a way to compile (on Windows). MSYS2 appears to be a popular option.
g++ -shared -o GrmgThumbnailProvider.dll -lshlwapi -lgdi32 Dll.cpp GrmgThumbnailProvider.cpp
This causes errors:
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\Zyl\AppData\Local\Temp\cc5HnXOH.o:Dll.cpp:(.text$_ZN13CClassFactory14QueryInterfaceERK5_GUIDPPv[_ZN13CClassFactory14QueryInterfaceERK5_GUIDPPv]+0x31): undefined reference to `QISearch'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\Zyl\AppData\Local\Temp\ccXzQLhd.o:GrmgThumbnailProvider.cpp:(.text+0x36f): undefined reference to `__imp_CreateDIBSection'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\Zyl\AppData\Local\Temp\ccXzQLhd.o:GrmgThumbnailProvider.cpp:(.text$_ZN18CGrmgThumbProvider14QueryInterfaceERK5_GUIDPPv[_ZN18CGrmgThumbProvider14QueryInterfaceERK5_GUIDPPv]+0x31): undefined reference to `QISearch'
collect2.exe: error: ld returned 1 exit status
The libraries are definitely found: g++ complains if I change the library names in the -l argument to some nonsense. How is it these references cannot be resolved despite the required libraries being both present and found?
QISearch
CreateDIBSection
This question already has answers here:
How to use the fmt library without getting "Undefined symbols for architecture x86_64"
(3 answers)
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed last year.
I'd like to make a python-like dynamic integer class in C++ as an experiment. It requires me to change many integers to string types. As in here: https://www.zverovich.net/2013/09/07/integer-to-string-conversion-in-cplusplus.html it states that fmt format_int will be best for that kind of job.
So I installed fmt with command sudo apt-get install libfmt-dev
I added a header #include <fmt/format.h>
Used it in a simple test main
int main()
{
std::cout<<fmt::format_int(124236695253045068).str();
}
And tried to compile with g++ -lfmt -std=c++17 dynamic\ mem.cc
Output of the compiler is as follows:
/usr/bin/ld: /tmp/ccLBcSNm.o: in function `fmt::v6::format_int::format_decimal(unsigned long long)':
dynamic mem.cc:(.text._ZN3fmt2v610format_int14format_decimalEy[_ZN3fmt2v610format_int14format_decimalEy]+0x94): undefined reference to `fmt::v6::internal::basic_data<void>::digits'
/usr/bin/ld: dynamic mem.cc:(.text._ZN3fmt2v610format_int14format_decimalEy[_ZN3fmt2v610format_int14format_decimalEy]+0xad): undefined reference to `fmt::v6::internal::basic_data<void>::digits'
/usr/bin/ld: dynamic mem.cc:(.text._ZN3fmt2v610format_int14format_decimalEy[_ZN3fmt2v610format_int14format_decimalEy]+0xfa): undefined reference to `fmt::v6::internal::basic_data<void>::digits'
/usr/bin/ld: dynamic mem.cc:(.text._ZN3fmt2v610format_int14format_decimalEy[_ZN3fmt2v610format_int14format_decimalEy]+0x113): undefined reference to `fmt::v6::internal::basic_data<void>::digits'
/usr/bin/ld: /tmp/ccLBcSNm.o: in function `std::make_unsigned<long>::type fmt::v6::internal::to_unsigned<long>(long)':
dynamic mem.cc:(.text._ZN3fmt2v68internal11to_unsignedIlEENSt13make_unsignedIT_E4typeES4_[_ZN3fmt2v68internal11to_unsignedIlEENSt13make_unsignedIT_E4typeES4_]+0x2b): undefined reference to `fmt::v6::internal::assert_fail(char const*, int, char const*)'
collect2: error: ld returned 1 exit status
Do you have any ideas what went wrong? I don't usually link non-standard libraries so I don't have any idea what to do about it.
Use
$ g++ -std=c++17 dynamic\ mem.cc -lfmt
fmt is provided as a static library (.a). With those, the order is important as the linker takes out of a library only the objects which are needed to provide symbols to other objects or libraries which precede them in the command line. If you start with a library, there is only main which is missing and usually libraries don't provide main, so they are ignored. When putting the library after your source code, the symbols missing in your code are searched in the library.
(In case of circular dependencies, you may even have to provide a library several times)
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
C++ Error: undefined reference to `main'
(2 answers)
Closed 1 year ago.
This post was edited and submitted for review 1 year ago and failed to reopen the post:
Duplicate This question has been answered, is not unique, and doesn’t differentiate itself from another question.
I have been trying to fix this error for days now. Every time I try to run code in cpp on Mac I get this error message
Undefined symbols for architecture x86_64:
"_main", referenced from:
implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I'm thinking it has something to do with either the linker or the clang file, let me know what I need to do to fix this
-- I just fixed this, it was a problem with my settings, thank you.
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
undefined reference to `WinMain#16'
(7 answers)
I cannot figure out the "undefined reference to Winmain#16 error"
(1 answer)
Closed 2 years ago.
Im installed mingw and vs code on my system , i followed all the steps,added to environment variable and all but when im running simple hello world program it gives this error:
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../libmingw32.a(main.o):(.text.startup+0xc0): undefined reference to `WinMain#16'
collect2.exe: error: ld returned 1 exit status
My code :
#include<iostream
using namespace std;
int main(){
cout<<"Hello World"<<endl;
return 0;
}
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 8 years ago.
I am learning emscripten compiler. And now I have an error when compiling this
source code.
I use gcc and it works fine.
But, when using emscripten with this command:
./emcc game.cpp main.cpp painter.cpp field.cpp snake.cpp -s LEGACY_GL_EMULATION=1 -o a.html
I get this error.:
warning: unresolved symbol: _ZTVN10__cxxabiv120__si_class_type_infoE`
What are the issues here?
Try em++ isntead of emcc. I am not too familiar with emscripten, but the missing symbol is the vtable for __cxxabiv1::__si_class_type_info, so you probably need to link the libcxxabi.