I have simple C-code and big libname.so, with libname.h of corse.
I tryed gcc -L. -lurpcadc -o -I Ctest.c, i did preliminarily export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/way/to/lib, but i caught next errors:
/tmp/cc4jgpfg.o: In function `main':
Ctest.c:(.text+0x10): undefined reference to `func_from_lib'
...
collect2: error: ld returned 1 exit status
What i need to do?
It is too simple, but sometimes I have problems with this kind of thing.
gcc Ctest.c -I. -L. -lname -o Ctest
Headings were searched in the wrong place.
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I'm trying to compile my project and I use the lib ncurse. And I've got some errors when compiler links files.
Here is my flags line in Makefile:
-W -Wall -Werror -Wextra -lncurses
I've included ncurses.h
Some layouts :
prompt$> dpkg -S curses.h
libslang2-dev:amd64: /usr/include/slcurses.h
libncurses5-dev: /usr/include/ncurses.h
libncurses5-dev: /usr/include/curses.h
prompt$> dpkg -L libncurses5-dev | grep .so
/usr/lib/x86_64-linux-gnu/libncurses.so
/usr/lib/x86_64-linux-gnu/libcurses.so
/usr/lib/x86_64-linux-gnu/libmenu.so
/usr/lib/x86_64-linux-gnu/libform.so
/usr/lib/x86_64-linux-gnu/libpanel.s
And here are my erros :
gcc -W -Wall -Werror -Wextra -I./Includes/. -lncurses -o Sources/NCurses/ncurses_init.o -c Sources/NCurses/ncurses_init.c
./Sources/NCurses/ncurses_init.o: In function `ncruses_destroy':
ncurses_init.c:(.text+0x5): undefined reference to `endwin'
./Sources/NCurses/ncurses_init.o: In function `ncurses_write_line':
ncurses_init.c:(.text+0xc5): undefined reference to `mvwprintw'
./Sources/NCurses/ncurses_init.o: In function `ncurses_init':
ncurses_init.c:(.text+0xee): undefined reference to `initscr'
collect2: error: ld returned 1 exit status
Thanks a lot
You need to change your makefile so that the -lncurses directive comes after your object code on the gcc command line, i.e. it needs to generate the command:
gcc -W -Wall -Werror -Wextra -I./Includes/. -o Sources/NCurses/ncurses_init.o -c Sources/NCurses/ncurses_init.c -lncurses
This is because object files and libraries are linked in order in a single pass.
In C++ , I fixed it just by linking the ncurses library .
Here is the command :
g++ main.cpp -lncurses
I got flags to correct order by using LDLIBS variable:
ifndef PKG_CONFIG
PKG_CONFIG=pkg-config
endif
CFLAGS+=-std=c99 -pedantic -Wall
LDLIBS=$(shell $(PKG_CONFIG) --libs ncurses)
man gcc | grep -A10 "\-l library"
-l library
Search the library named library when linking. (The second alternative with the library as a separate argument is only for POSIX
compliance and is not recommended.)
It makes a difference where in the command you write this option; the linker searches and processes libraries and object files
in the order they are specified. Thus, foo.o -lz bar.o searches
library z after file foo.o but
before bar.o. If bar.o refers to functions in z, those functions may not be loaded.
I'm executing this makefile to compile a Fortran code using gfortran, gcc, netcdf and mpich2 libraries.
When the make script executes the following command,
gfortran -O3 -I/home/santiago/Install/mpich2_sam/include -I/home/santiago/Install/netcdf_sam/include /home/santiago/Modeling/SAM6.8.2/SRC/fft.f
I get the following message:
/usr/lib/gcc/x86_64-redhat-linux/4.8.3/../../../../lib64/crt1.o: In
function _start': (.text+0x20): undefined reference tomain'
collect2: error: ld returned 1 exit status
I have found similar error messages in forums, but I didn't saw how to apply the solutions in my problem.
Could someone please guide me solving this problem?
If you are building a library, you might need -c flag in
.f.o:
${FF77} ${FFLAGS} $<
i.e.
.f.o:
${FF77} ${FFLAGS} -c $<
The same applies for
.f90.o:
${FF90} ${FFLAGS} -c $<
.c.o:
${CC} ${CFLAGS} -I$(SAM_SRC)/TIMING $(NOTIMERS) -c $<
I have a fortran code (pardiso_1.f) and it needs some libraries (BLAS, lapack and Pardiso libraries) to be compiled. When I try to compile it, I link libraries before compilation and I write this line in linux terminal:
gfortran pardiso_1.f -L/home/behnam/Pardiso -lpardiso412-GNU450-X86-64 -L/usr/lib -lblas -llapack -fopenmp
and it works perfectly.
However I have to run the code using makefile. I am so new in writing makefiles and I do not know how to do the linkage. I have written this makefile. could anyone help me to find out what is wrong with that?
FC = gfortran
OPT = -O2
PROGRAMS = pardiso_1
all: $(PROGRAMS)
FFLAGS = -fopenmp
#### BLAS, LAPACK and PTHREAD libraries
LBLAS = /usr/lib/
###location of pardiso file
LIBMKL = /home/behnam/PS2/
#### Series of libraries
LIBRARIES= -llapack -lblas -lpthread -lm -lpardiso412-GNU430-X86-64
PATHFC = /usr/bin/
nlace: ${PATHFC}${FC} ${OPT} ${FFLAGS} -I${PROGRAMS} -o nlace.exe \
-L${LIBMKL} -lpardiso412-GNU430-X86-64\
-L${LBLAS} ${LIBRARIES}
clean:
rm -f *.o *.exe fort.* *~ *.mod
veryclean: clean
rm -f *~ $(PROGRAMS)
The errors are:
behnam#meen-392430:~/testing$ make
make: Warning: File `Makefile' has modification time 23 s in the future
gfortran -fopenmp pardiso_1.f -o pardiso_1
/tmp/ccYNexaH.o: In function `MAIN__':
pardiso_1.f:(.text+0xb3): undefined reference to `pardisoinit_'
pardiso_1.f:(.text+0x2ae): undefined reference to `pardiso_chkmatrix_'
pardiso_1.f:(.text+0x36e): undefined reference to `pardiso_chkvec_'
pardiso_1.f:(.text+0x44c): undefined reference to `pardiso_printstats_'
pardiso_1.f:(.text+0x5ae): undefined reference to `pardiso_'
pardiso_1.f:(.text+0x860): undefined reference to `pardiso_'
pardiso_1.f:(.text+0xb78): undefined reference to `pardiso_'
pardiso_1.f:(.text+0xe00): undefined reference to `pardiso_'
collect2: ld returned 1 exit status
make: *** [pardiso_1] Error 1
Your makefile does not contain the -L/home/behnam/Pardiso part of your command line.
Your rule for PROGRAMS does not contain a recipe that includes the library calls. I presume you want something like your nlace rule, but right now, make is not calling any of your -L switches as part of its operation.
I was trying to compile a simple opengl program on msys using g++. To my surprise the linker was complaining on undefined references:
$ g++ -mwindows -lopengl32 glut_md2.cpp
C:\Users\...\cceQtYAy.o:glut_md2.cpp:(.text+0x67a): undefined reference to `glGenTextures#8'
C:\Users\...\cceQtYAy.o:glut_md2.cpp:(.text+0x696): undefined reference to `glBindTexture#8'
....
After googling for a while I found that the problem was in g++ arguments order:
$ g++ glut_md2.cpp -mwindows -lopengl32
--- all ok! ---
The interesting thing is that the correct argument orders in g++ is in the first example. That is:
$ g++ --help
Usage: g++.exe [options] file...
....
Am I missing something? Why moving options after the file argument makes a compilation success? I never had this issue when compiling natively on linux...
I bumped into this problem once or twice, you should put -L and -l at the end of command line. g++ doesn't link, it invokes ld and pass arguments, ld man:
The linker will search an archive only once, at the location where it
is specified on the command line. If the archive defines a symbol
which was undefined in some object which appeared before the archive
on the command line, the linker will include the appropriate file(s)
from the archive. However, an undefined symbol in an object appearing
later on the command line will not cause the linker to search the
archive again.
ld -o /lib/crt0.o hello.o -lc
I'm trying to build something against GStreamer from git. They have some magic process that makes pkg-config happy, but if I run it, I get a .la file:
$ pkg-config --libs gstreamer-1.0
/home/blong/gst/head/gstreamer/gst/libgstreamer-1.0.la -lgobject-2.0 -lglib-2.0
And that causes problems for GCC:
g++ -o example switchtrackexample.cpp `pkg-config --libs --cflags gstreamer-1.0`
# comes out as: g++ -o example switchtrackexample.cpp -pthread -I/home/blong/gst/head/gstreamer -I/home/blong/gst/head/gstreamer/libs -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include /home/blong/gst/head/gstreamer/gst/libgstreamer-1.0.la -lgobject-2.0 -lglib-2.0
/usr/bin/ld: error: /home/blong/gst/head/gstreamer/gst/libgstreamer-1.0.la:8:8: invalid character
/usr/bin/ld: error: /home/blong/gst/head/gstreamer/gst/libgstreamer-1.0.la:8:8: syntax error, unexpected $end
/usr/bin/ld: error: /home/blong/gst/head/gstreamer/gst/libgstreamer-1.0.la: not an object or archive
# lots of undefined references here
I've read some things suggesting I should be able to use libtool to compile this, but I can't figure out how. What am I supposed to do with this .la file?
It figures, right after I asked this, I found this answer by Julien Moutte:
Add :
libtool --mode=link
in front of your build command.
Following that advice, I get this, which works:
libtool --mode=link g++ -o example switchtrackexample.cpp `pkg-config --cflags --libs gstreamer-1.0`