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Linking Error Undefined Reference To Function

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Reply With Quote Quick Navigation Programming / Scripting Top Site Areas Settings Private Messages Subscriptions Who's Online Search Forums Forums Home Forums Linux Forums Linux Forums Site News / Info Your So change to this: Code: test: test.o ${CC} ${CFLAGS} -o [email protected] $^ ${LDFLAGS} and it should work. 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 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 this contact form

Lack of research or effort. share|improve this answer edited Nov 4 '15 at 20:39 Paul Pettengill 2,99911928 answered Jan 28 '13 at 8:04 Saqlain 8,79331627 add a comment| Not the answer you're looking for? This in itself is important, because a horde of object files is not convenient to deal with. Why do you call it a "library" if it's actually just source code? http://stackoverflow.com/questions/12272864/linker-error-on-linux-undefined-reference-to

Linking Error Undefined Reference To Function

How strange is it (as an undergrad) to email a professor from another institution about possibly working in their lab? Does DFT produces the same output as FFT? 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. Subscribed!

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Strange device identification How do really talented people in academia think about people who are less capable than them? current community chat Stack Overflow Meta Stack Overflow your communities Sign up or log in to customize your list. Don't show this message again Change Settings Privacy Policy Update ARM’s Privacy Policy has been updated. Undefined Reference C++ For instance, -lm will link the math library.

asked 4 years ago viewed 22504 times active 4 years ago Visit Chat Linked 0 “undefined reference to” for symbols in a shared library 117 Ubuntu Linux C++ error: undefined reference This explains why the linking process is the way it is. Crash? There might be other more complex cases but from your question, I hope this would be enough to solve your problem.

But note what happens if the linking order is reversed now: $ gcc -L. -lsimplefunc simplemain.o simplemain.o: In function 'main': simplemain.c:(.text+0x15): undefined reference to 'func' collect2: ld returned 1 exit status Gcc Undefined Reference To Function And linkers do not necessarily have access to the source code for the object files they are linking. Again on my system this gives the following output. Hilbert-irreducible Banach space Number sets symbols in LaTeX Die Liebe höret nimmer auf Why was Susan treated so unkindly?

Undefined Reference To Function C++

Browse other questions tagged linux gcc build linker or ask your own question. go to this web-site Also, FWIW, I always uses parens around my Makefile variables, so I never new things like "${CC}" worked... Linking Error Undefined Reference To Function For more information, see Toolchain Transition in Natty Narwhal. Undefined Reference To C Now, a library is simply a collection of object files.

This is where the the linker comes in. weblink My advisor refuses to write me a recommendation for my PhD application unless I apply to his lab Why does Wikipedia list an improper pronunciation of Esperanto? Using DC in transformers? share|improve this answer answered Jan 28 '13 at 7:53 ForEveR 43.2k25690 add a comment| up vote 0 down vote This is not a compile error, it's a link error. Linker Error Undefined Reference To

Even simple gcc makefiles usually have a line like this: LIBFLAGS =-lc -lpthread -lrt -lstdc++ -lShared -L../shared In this case, it means link the standard C library, among others share|improve this Using linker flags to control the process As I've mentioned above, the linker has a number of interesting flags that can be used to control the process in a fine-grained manner. Assuming the memcpy here was packed into the libstray_memcpy.a library: $ gcc -L. navigate here When the linker finishes, it looks at the symbol table.

Otherwise, the next step is skipped. Undefined Reference Gcc The linker goes over all the objects in the library. Linker 101 To understand the linker, you have to understand how C++ programs are built.

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The Finslerian version of the Nash embedding theorem If two topological spaces have the same topological properties, are they homeomorphic? You just need to reorder the rule to create the executable in the Makefile. How do we play with irregular attendance? G++ Undefined Reference To Let's compile it and look at the symbol table: $ gcc -c x.c $ nm x.o 000000000000000e T exported U imported 0000000000000000 t internal This means: exported is an external symbol

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. 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 But AA can't come both before and after BB on the command-line, right? his comment is here UNIX is a registered trademark of The Open Group.

fraction line in French How to apply for UK visit visa after four refusal Why do the Sparkfun and Adafruit Eagle libraries use smaller footprints than the manufacturer's recommended land pattern? Thus, you will change the command to: gcc -g -O2 -fopenmp -L/usr/lib -o lenstool_tab e_nfwg.o lenstool_tab.o midpnt.o nrutil.o polint.o qromo.o read_bin.o lenstool_tab.o -lcfitsio -lm This should fix your problem. Thank you Neill What are the compilation and linking commands you do to produce vclient? If not, it will create "/usr/lib/x86_64-linux-gnu/libpci.a" which might resolve the problem.

If the linker can't find a specified library you can add a library search path using the -L switch (for example, -L/usr/local/lib). How strange is it (as an undergrad) to email a professor from another institution about possibly working in their lab?