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Undefined Reference To Function In Shared Library


Code: /usr/bin/g++ -I/usr/include/libxml2 -l/usr/lib/libxml2.so -Xlinker -zmuldefs -fPIC -c a.cpp I am NOT an expert - but something like that should work - or maybe : Code: g++ -fPIC -Xlinker -zmuldefs -l/usr/lib/libxml2.so The system searches only /lib and /usr/lib, by default. Why do people move their cameras in a square motion? To perform the linkage, if you are using an IDE you can normally simply add the library to your project, if using the command line, once again please see my series weblink

What you almost certainly can do is link libxml along with libabc in the final linking stage. For example, when you create an executable and forget to include the file with the main function, you'll get something like: /usr/lib/x86_64-linux-gnu/crt1.o: In function '_start': (.text+0x20): undefined reference to 'main' collect2: Wait, is it, really? Is it correct to write "teoremo X statas, ke" in the sense of "theorem X states that"?

Undefined Reference To Function In Shared Library

Were students "forced to recite 'Allah is the only God'" in Tennessee public schools? I have downloaded and built the library, I have done a 'make install' to put the resulting .a file into /usr/lib/ and the .h files into /usr/include It appears to be Position-Independent Code (PIC) PIC stands for position-independent code. Find first non-repetitive char in a string How is the ATC language structured?

When the linker finds a directory that contains either libtest.a or libtest.so, the linker stops search directories. To understand why linking order matters, it's first instructional to understand how the linker works with respect to linking libraries and objects together. If you used a static archive instead, the archive is included in all 10 programs. Linking Error Undefined Reference To Function For example, in this C code: int imported(int); static int internal(int x) { return x * 2; } int exported(int x) { return imported(x) * internal(x); } The names of the

Thank you. –fiatjaf Dec 5 '12 at 17:17 add a comment| up vote 0 down vote Alternatively you can add the header and library path to your global variables. With your command you link your program agains a static library, in the format libOpenCL.a. If the object has been added to the link, it's treated as described above - its undefined and exported symbols get added to the symbol table. jersey99 2015-09-23 21:31:38 UTC #3 Do you mean: In my library.h, I should say #include "library/library-helper.h" ?

A C compiler will not mangle names; it will use whichever name you give to your function or variable. Undefined Reference To Library Function Browse other questions tagged ubuntu build compiler-errors static-libraries linker-error or ask your own question. Don't you have a Hash.cpp to also compile and link? The basics Let's start by defining the scope of this article: first, my examples are demonstrating the use of the gcc and binutils toolchain on Linux.

Undefined Reference To Function In Static Library

but i think the problem is that in first application i am including header files of libxml2 in my code and then make a shared object library of it. http://www.cplusplus.com/forum/unices/137841/ For example, to compile and link a program compute.c which uses trigonometric functions such as sin and cos, you must invoke this code: % gcc -o compute compute.c –lm If you Undefined Reference To Function In Shared Library Because libtiff uses libjpeg and libz, the shared-library versions of these two are also drawn in (a shared library can point to other shared libraries that it depends on). Undefined Reference To Library C++ This consideration has no impact on you, as the programmer, except that you must remember to use the -fPIC flag when compiling code that will be used in a shared library.

Suppose that you use this: % gcc -o app app.o -L. -ltest -Wl,-rpath,/usr/local/lib Then, when app is run, the system will search /usr/local/lib for any required shared libraries. have a peek at these guys share|improve this answer answered Oct 16 '11 at 9:25 Geoffroy 7,40832470 1 The last remark about static linking isn't true. Converting Game of Life images to lists USB in computer screen not working more hot questions question feed about us tour help blog chat data legal privacy policy work here advertising Directories named by -I are searched before the standard system include directories. Undefined Reference To Function C++

Since -lstray_memcpy was provided after main_using_memcpy.o on the command-line, it gets linked in. The linker searches a standard list of directories for the library, which is actually a file named liblibrary.a. Note that ldd will list an additional library called ld-linux.so, which is a part of GNU/Linux's dynamic linking mechanism. http://cygnussoft.com/undefined-reference/c-error-undefined-reference-to-function.html But in our case this amounts to: $ gcc -L. -lstray_memcpy main_using_memcpy.o -lc When the linker sees -lstray_memcpy, the symbol table does not yet have an undefined entry for memcpy, so

because i think i am linking it in compilation using Code: /usr/bin/g++ -I/usr/include/libxml2 -Xlinker -zmuldefs -fPIC -c a.cpp /usr/bin/g++ -I/usr/include/libxml2 -Xlinker -zmuldefs -fPIC -c b.cpp /usr/bin/g++ -I/usr/include/libxml2 -Xlinker -zmuldefs -fPIC -c Ld Undefined Reference To Function Any program that uses a C function (such as printf or malloc) will be linked against the C runtime library. main assumes it gets the correct memcpy from the C library, but the memcpy it gets linked with does something else.

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For example, consider an application that supports "plug-in" modules, such as a Web browser. If you want to write a program that has a int main() function in it, always make sure that you choose “Console Application”, otherwise the IDE may configure the linker to This is not the case on Windows; if a DLL references another DLL, it must find it when building that DLL. Undefined Reference C++ Archive files traditionally use a .a extension rather than the .o extension used by ordinary object files.

So many files is making the IDE slow, so just give it a moment to load things if you know you clicked the button already github.com a couple tweaks to examples It also reduces download times if your program is being downloaded from the Web. Listing 2.7 (test.c) Library Contents int f () {  return 3; } Listing 2.8 (app.c) A Program That Uses Library Functions int main () {  return f (); } Now suppose http://cygnussoft.com/undefined-reference/makefile-undefined-reference-to-function.html Jul 9, 2014 at 8:06pm UTC kbw (7986) Windows and Unix reference dependent libraries differently.

Red balls and Rings Is it correct to write "teoremo X statas, ke" in the sense of "theorem X states that"? Wrong Project Type The linker error regarding WinMain above can occur in a number of situations, particularly when you are using a C++ IDE such as CodeBlocks or Visual Studio. The functions in a shared library may be loaded at different addresses in different programs, so the code in the shared object must not depend on the address (or position) at so kindly anyone guide me where i need corrections Adv Reply Page 1 of 3 123 Last Jump to page: Quick Navigation Programming Talk Top Site Areas Settings Private Messages

Assuming the memcpy here was packed into the libstray_memcpy.a library: $ gcc -L. share|improve this answer answered Mar 21 '10 at 16:08 David Wheeler 95163 7 +1 Oh, thank you! contact us FAQ Forum Quick Links Unanswered Posts New Posts View Forum Leaders FAQ Contact an Admin Forum Community Forum Council FC Agenda Forum Governance Forum Staff Ubuntu Forums Code of Let's see what comes out of it.

If a shared library that is linked into your program is installed outside those directories, it will not be found, and the system will refuse to run the program. IIRC, you can look with nm what is in your .so and what does it refer to. For each new click of the circle-plus to add a .h and a .cpp file, you get a file in the directory with your current sketch. [Ah, I see @ScruffR beat The return value from this function is a void * that is used as a handle for the shared library.

Traditionally, linker technology has lagged behind compilers, mostly because it’s generally more fun to build a compiler than to build a linker.