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Undefined Reference Gcc Error


We'll see more of this later. Just a bunch of object files glued together. We can use the --undefined flag to tell the linker - "buddy, here's a symbol I want you to add to the undefined list". This code compiles perfectly in all my other computers, and I do include -lm in my makefile. check over here

Former boss asking me to do presentations What was the first operating system to feature a separate kernel? very lightweight low power microcontroller with memory? I searched this problem on the web but no answers seemed to consider the makefile. Does the reciprocal of a probability represent anything? my review here

Gcc Undefined Reference To Function

The linker adds this undefined entry only after it sees main_using_memcpy.o. I thought opkg would automatically get the latest available. 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: up vote 2 down vote favorite I have to build a library for a school project and use that library in a small aplication.

  • Assuming the memcpy here was packed into the libstray_memcpy.a library: $ gcc -L.
  • The full step that it fails on with error looks like this: gcc -g -O2 -fopenmp -L/usr/lib -lcfitsio -lm -o lenstool_tab e_nfwg.o lenstool_tab.o midpnt.o nrutil.o polint.o qromo.o read_bin.o lenstool_tab.o: In function
  • Adv Reply February 14th, 2011 #2 Arndt View Profile View Forum Posts Private Message Ubuntu Cappuccino Scuro Join Date May 2006 Beans 1,787 Re: compiling with gcc and "undefined reference
  • Browse other questions tagged compiling gcc c or ask your own question.

Ask Ubuntu works best with JavaScript enabled current community chat Unix & Linux Unix & Linux Meta your communities Sign up or log in to customize your list. Put together, you get a situation where linker errors, and the reasons for them, can be cryptic in the extreme. Circular dependency The corollary above is an important summary of the linking process - it's certainly much more practical to keep in mind because it's so short. Undefined Reference To Gcc Linker Error Not the answer you're looking for?

It's better to make it as fast as possible for well-behaved programs (that got their linking order right), and provide special options like groups for the difficult circular dependency cases. I mess about for weeks and you solve the problem in 5 minutes. Why is this Sudoku Skyscraper Failing? But any ideas about how can I implement this fix?

Consider a linker invocation: $ gcc main.o -L/some/lib/dir -lfoo -lbar -lbaz The linker is almost always invoked through the compiler driver gcc when compiling C or C++ code. Undefined Reference To Error Rate this:Like this:Like Loading... The full linker invocation command of gcc is pretty complex, and can be examined by passing the -### flag to gcc. Thank you Neill I am a newbie.

Undefined Reference To In C

more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed https://ubuntuforums.org/showthread.php?t=1687827 When I look in common.h I find int initLog(int useSyslog, char *logfile,int debugSwitch); and looking in common.c (also in the same directory) I find int initLog(int useSyslog, char *logfile,int debugSwitch) { Gcc Undefined Reference To Function The other is the -### flag that gcc accepts and as a result shows the full commands it passes to the underlying tools. Undefined Reference To G++ Simple examples The previous section can be hard to digest, so here are some simple examples that show the process in action.

On the beagleboard it's version 4.3.3, but on my computer it's 4.7.3, but I don't know how to get a later version. http://centralpedia.com/undefined-reference/undefined-reference-to-error-in-gcc.html Why are only passwords hashed? making new symbol from two symbols How to fix a bent lens mount hook? Integer function which takes every value infinitely often Number sets symbols in LaTeX Trick or Treat polyglot Why is this Sudoku Skyscraper Failing? Undefined Reference C++

The definition is in the library itself. This is a very important feature of static linking. How to create a torus with divided cuts that correspond to the direction of the torus How could a language that uses a single word extremely often sustain itself? this content c++ c gcc linker undefined-reference share|improve this question edited Sep 26 '15 at 6:46 alk 45.2k53497 asked Mar 15 '14 at 16:35 jamie_y 1961211 add a comment| 1 Answer 1 active

http://www.network-theory.co.uk/docs/gccintro/gccintro_25.html Dyamic linking (with shared libraries signalled by the .so extensions in Linux) is the default behavior of the linker, because it always produces relatively slim executables or objects, as compared Gcc Undefined Reference To Sqrt Why was Susan treated so unkindly? vBulletin ©2000 - 2016, Jelsoft Enterprises Ltd.

c linker beagleboard math.h share|improve this question asked Jun 19 '13 at 21:59 Ann 1581413 1 Does -lm appear after your object files?

External libraries all require similar procedures for deployment (e.g., -lgsl for the GNU Science Library). It's way nicer to just carry libc.a around. In our case this makes the link error go away even though the libraries are specified only once: $ gcc simplemain.o -L. -Wl,--undefined=bar -lbar_dep -lfunc_dep $ ./a.out ; echo $? 24 Gcc Undefined Reference To Static Library 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

The answer is: it depends - the result can be either correct or a segmentation fault. The linker goes over all the objects in the library. How to make Skyscanner, Kiwi, Kayak include ground transfer in the search Using DC in transformers? have a peek at these guys Why not?

Compatible toolchains (like clang instead of gcc) apply too. It then patches up the addresses the compiler could not provide. As long as you keep it in mind, linker errors and related problems should be easy to understand. Traditionally, linker technology has lagged behind compilers, mostly because it’s generally more fun to build a compiler than to build a linker.

Browse other questions tagged c gcc ld shared-libraries or ask your own question. I've installed this program on a Mac before without issue but now I'm using Ubuntu 14 and I get this error. We can pass them to the linker in reversed order and it still works: $ gcc simplemain.o simplefunc.o $ ./a.out ; echo $? 22 Now let's do something different. This brings us to the most important corollary of the linking process outlined above: If object or library AA needs a symbol from library BB, then AA should come before library

share|improve this answer edited Feb 28 '13 at 17:20 answered Feb 28 '13 at 16:58 Mike 22.4k1262126 It's my fault, I've edited the post so it's now accurate. What is way to eat rice with hands in front of westerners such that it doesn't appear to be yucky? more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed Using this option has a significant performance cost.

What is way to eat rice with hands in front of westerners such that it doesn't appear to be yucky? Try int finite(double x); or int finitef(float x);. Why does my capsule collider fall without my object (Unity)? I read a suggestion in another thread to modify config.status to include -lm, but it was not clear where to do that.