Gcc Linker Error Undefined Reference
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C++ Undefined Reference To Class
[duplicate] up vote 9 down vote favorite 2 Possible Duplicate: What is an undefined reference/unresolved external symbol error and how do I fix it? Trying to compile my program via g++ -o prog1 main.cpp -std=c++0x I get the error: /tmp/cc1pZ8OM.o: In function `main': main.cpp:(.text+0x148): undefined reference to `Hash::insert(int, char)' collect2: error: ld returned 1 exit status main.cpp #include
error message (or “unresolved external symbol, for Visual C++ users). This is not actually a message from the compiler, but is emitted by the linker, so the first thing to do is to understand what undefined reference to static variable c++ the linker is, and what it does. Linker 101 To understand the linker, you have
Linker Error Undefined Reference To
to understand how C++ programs are built. For all but the very simplest programs, the program is composed of multiple C++ source
C++ Undefined Reference To Function In Class
files (also known as “translation units”). These are compiled separately, using the C++ compiler, to produce object code files (files with a .o or a .obj extension) which contain machine code. Each object code file knows http://stackoverflow.com/questions/14557657/linker-error-c-undefined-reference nothing about the others, so if you call a function from one object file that exists in another, the compiler cannot provide the address of the called function. This is where the the linker comes in. Once all the object files have been produced, the linker looks at them and works out what the final addresses of functions in the executable will be. It then patches up the addresses the compiler could not https://latedev.wordpress.com/2014/04/22/common-c-error-messages-2-unresolved-reference/ provide. It does the same for any libraries (.a and .lib files) you may be using. And finally it writes the executable file out to disk. The linker is normally a separate program from the compiler (for example, the GCC linker is called ld) but will normally be called for you when you use your compiler suite’s driver program (so the GCC driver g++ will call ld for you). Traditionally, linker technology has lagged behind compilers, mostly because it’s generally more fun to build a compiler than to build a linker. And linkers do not necessarily have access to the source code for the object files they are linking. Put together, you get a situation where linker errors, and the reasons for them, can be cryptic in the extreme. Undefined reference Put simply, the “undefined reference” error means you have a reference (nothing to do with the C++ reference type) to a name (function, variable, constant etc.) in your program that the linker cannot find a definition for when it looks through all the object files and libraries that make up your project. There are any number of reasons why it can’t find the definition – we’ll look at the commonest ones now. No Definition Probably the most common reason for unresolved reference errors is that you simp
Get Kubuntu Get Xubuntu Get Lubuntu Get UbuntuStudio Get Mythbuntu Get Edubuntu Get Ubuntu-GNOME Get UbuntuKylin Ubuntu Code of Conduct Ubuntu Wiki Community Wiki Other Support Launchpad Answers Ubuntu IRC Support AskUbuntu Official https://ubuntuforums.org/showthread.php?t=1687827 Documentation User Documentation Social Media Facebook Twitter Useful Links Distrowatch Bugs: Ubuntu PPAs: Ubuntu Web Upd8: Ubuntu OMG! Ubuntu Ubuntu Insights Planet Ubuntu Activity Page Please read before SSO login Advanced Search Forum The Ubuntu http://www.cplusplus.com/forum/unices/137841/ Forum Community Ubuntu Specialised Support Development & Programming Programming Talk [SOLVED] compiling with gcc and "undefined reference to xxx" Having an Issue With Posting ? Do you want to help us debug the posting issues undefined reference ? < is the place to report it, thanks ! Results 1 to 4 of 4 Thread: compiling with gcc and "undefined reference to xxx" Thread Tools Show Printable Version Subscribe to this Thread… Display Linear Mode Switch to Hybrid Mode Switch to Threaded Mode February 14th, 2011 #1 NeillHog View Profile View Forum Posts Private Message Visit Homepage Gee! These Aren't Roasted! Join Date Jul 2007 Location The Bavarian Alps undefined reference to Beans 129 DistroKubuntu 7.10 Gutsy Gibbon compiling with gcc and "undefined reference to xxx" I have run up against a wall. I really appreciate any and all help because I am so out of my depth. I have installed gcc on a NSLU2. Running gcc -o test test.c brings no error and afterwards I can run the program test with ./test. test.c #include
project on Windows and I am trying to port it to unix. I have installed Ubuntu 14 and I have create Makefiles to compile those projects. I have a project that generates a shared library (.so) and another project that generates an executable. When I generate the shared library I dont have any problem, but the nightmare begins when I try to compile the executable. When I try to compile it I am having a lot of undefined references. The wierd thing is that the compiler finds all the .so dependencies but I am having undefined references for all of them. This is the makefile of this project: 1
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program_NAME := MyExecutable program_ODIR := $(INTERMEDIATE_FILES)unix/$(program_NAME)/Release/ program_SDIR := ./ program_OUTDIR := ../bin/unix/Release/ program_SRCS := $(wildcard $(program_SDIR)*.cpp) program_OBJS := $(program_SRCS:.cpp=.o) program_ODIR_OBJS := $(patsubst $(program_SDIR)%,$(program_ODIR)%,$(program_OBJS)) program_INCLUDE_DIRS := ../MySharedLib/include/ $(CPP_INCLUDE_PATH)glm/ \ $(CPP_INCLUDE_PATH)websocketpp/ $(CPP_INCLUDE_PATH)boost/ $(CPP_INCLUDE_PATH) program_LIBRARY_DIRS := $(program_OUTDIR) $(CPP_LIB_PATH)x86_64-linux-gnu/ program_LIBRARIES := MySharedLib boost_system GLEW glut GL CPPFLAGS += $(foreach includedir,$(program_INCLUDE_DIRS),-I$(includedir)) LDFLAGS += $(foreach librarydir,$(program_LIBRARY_DIRS),-L $(librarydir)) LDFLAGS += $(foreach library,$(program_LIBRARIES),-l$(library)) CXX=g++ -std=gnu++0x -v all: main-build main-build: target $(program_ODIR)%.o: $(program_SDIR)%.cpp $(CXX) -c $(CPPFLAGS) -o $@ $< target: $(program_ODIR_OBJS) $(CXX) $(LDFLAGS) $(program_ODIR_OBJS) -o $(program_OUTDIR)$(program_NAME) clean: @- $(RM) $(program_OUTDIR)$(program_NAME) @- $(RM) $(program_ODIR_OBJ