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Undefined Reference To Gcc Linking Error

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If we link them in one order, we fail: $ gcc simplemain.o -L. -lbar_dep -lfunc_dep ./libfunc_dep.a(func_dep.o): In function 'func': func_dep.c:(.text+0x14): undefined reference to 'bar' collect2: ld returned 1 exit status However, For example, on my system libc.a (the static version of the C library) consists of almost 1500 object files. Separate namespaces for functions and variables in POSIX shells What do you call someone without a nationality? How to apply for UK visit visa after four refusal Are assignments in the condition part of conditionals a bad practice? http://centralpedia.com/undefined-reference/undefined-reference-to-linking-error.html

Here are some additional details to help you debug your problem. Join Date Jun 2014 Posts 4 Can't solve gcc linking error, please help. Reply With Quote 06-24-2014 #9 b2rdark View Profile View Forum Posts Private Message View Articles Just Joined! main assumes it gets the correct memcpy from the C library, but the memcpy it gets linked with does something else. http://stackoverflow.com/questions/12272864/linker-error-on-linux-undefined-reference-to

Linking Error Undefined Reference To Function

Odd. Linking is already a critical part of the compilation time of large systems, since it looks at the whole program and requires quite a bit of memory. But it makes one wonder - what happens if AA needs a symbol from BB, but BB also needs a symbol from AA? more hot questions question feed lang-c about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation

  1. main_using_memcpy.o -lstray_memcpy $ ./a.out Segmentation fault (core dumped) This is the expected behavior.
  2. Don't you have a Hash.cpp to also compile and link?
  3. Why do the Sparkfun and Adafruit Eagle libraries use smaller footprints than the manufacturer's recommended land pattern?
  4. OpenSSL too: /media/sf_BitEagle_Projects/cbitcoin/dependencies/crypto/CBOpenSSLCrypto.c:37: undefined reference to `SHA1' How do I get the linking to work?
  5. current community chat Stack Overflow Meta Stack Overflow your communities Sign up or log in to customize your list.
  6. Is it dangerous to use default router admin passwords if only trusted users are allowed on the network?
  7. Separate namespaces for functions and variables in POSIX shells AWS EC2 SSH from my IP address which has changed Are assignments in the condition part of conditionals a bad practice?
  8. I searched this problem on the web but no answers seemed to consider the makefile.
  9. This is because the driver knows how to provide the correct command-line arguments to the linker itself (ld) with all the support libraries, etc.
  10. 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.

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 Let's put simplefunc.c into a library: $ ar r libsimplefunc.a simplefunc.o $ ranlib libsimplefunc.a $ gcc simplemain.o -L. -lsimplefunc $ ./a.out ; echo $? 22 Works like a charm. Running gcc -o test test.c brings no error and afterwards I can run the program test with ./test. Undefined Reference C++ Thank you!

It's way nicer to just carry libc.a around. To understand why linking order matters, it's first instructional to understand how the linker works with respect to linking libraries and objects together. Anyhow, as you can see the object files and libraries are provided in a certain order on the command-line, from left to right. imported is an undefined symbol; in other words, the linker is expected to find it elsewhere.

To start viewing messages, select the forum that you want to visit from the selection below. ** If you are logged in, most ads will not be displayed. ** Linuxforums now Gcc Undefined Reference To Function And if you're not using a Makefile, well that's the problem. Simple examples The previous section can be hard to digest, so here are some simple examples that show the process in action. So to me everything looks OK!

Undefined Reference To Function C++

Do you want to help us debug the posting issues ? < is the place to report it, thanks ! Otherwise, the next step is skipped. Linking Error Undefined Reference To Function How to create a custom theme in SXA? Undefined Reference To C I have included the headers directory using -I and i'm sure it's being found.

Some suggests would be great, and maybe and explanation of how the linker does its thing. have a peek at these guys Is there a developers image of 16.04 LTS? Partial sum of the harmonic series between two consecutive fibonacci numbers Best way to repair rotted fuel line? Each object code file knows 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 Linker Error Undefined Reference To

I mess about for weeks and you solve the problem in 5 minutes. I have installed gcc on a NSLU2. Development of retrosynthesis plan AWS EC2 SSH from my IP address which has changed How to draw a clock-diagram? http://centralpedia.com/undefined-reference/undefined-reference-to-error-while-linking.html Hot Network Questions How to make Skyscanner, Kiwi, Kayak include ground transfer in the search Does Nietzsche's rejection of Socrates mean that he is a relativist about ethics?

Now, a library is simply a collection of object files. Undefined Reference Gcc Now, suppose this is part of a larger project that consists of many object files and libraries, and somewhere within the project there's a library that contains this code: void memcpy(char* And finally it writes the executable file out to disk.

It depends on the order in which the objects and libraries in the project were fed to the linker.

I am a newbie. GCC version: gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3 On Linux Mint 13 Thank you. But obviously I am missing something fundamental. G++ Undefined Reference To I learned a lot about libraries.

Print some JSON Encode the alphabet cipher What is way to eat rice with hands in front of westerners such that it doesn't appear to be yucky? But it does prove that it's a problem getting the loader/linker to use the installed libraries. Browse other questions tagged gcc openssl or ask your own question. http://centralpedia.com/undefined-reference/undefined-reference-error-while-linking.html Why do you call it a "library" if it's actually just source code?

Update your command to include the file which contains the definition of that function and it should work. vBulletin 2000 - 2016, Jelsoft Enterprises Ltd. Which towel will dry faster? Also, FWIW, I always uses parens around my Makefile variables, so I never new things like "${CC}" worked...

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: For example: /* myapp.h ** Here I will include and define my stuff */ ... #include "mylib.h" ... share|improve this answer edited Sep 28 '12 at 22:12 answered Sep 28 '12 at 21:34 izx 92.1k22216261 add a comment| Your Answer draft saved draft discarded Sign up or log Why does Deep Space Nine spin? "Squeezing out of a dead man" proverb Why can't the second fundamental theorem of calculus be proved in just two lines?

Comments Please enable JavaScript to view the comments powered by Disqus. Then, when it reaches -lc, the object file holding memcpy from the C library does get linked in because by now memcpy is on the undefined list. Didn’t Link Object File This is another common problem. Flags passed to the linker can tweak this process - again, we'll see some examples later.