I'm trying to install PintOS on my local Ubuntu 14.04 machine. When I try to run make to compile the utilities. I get the following error.
ankitkal#ankitkal-Inspiron-5521:~/os/pintos/src/utils$ ls
backtrace Makefile pintos pintos.~1.55.~ pintos-mkdisk setitimer-helper.o squish-unix.c
CVS Makefile~ pintos~ pintos-gdb setitimer-helper.c squish-pty.c
ankitkal#ankitkal-Inspiron-5521:~/os/pintos/src/utils$ make
gcc -lm setitimer-helper.o -o setitimer-helper
setitimer-helper.o: In function `main':
setitimer-helper.c:(.text+0xbe): undefined reference to `floor'
collect2: error: ld returned 1 exit status
make: *** [setitimer-helper] Error 1
ankitkal#ankitkal-Inspiron-5521:~/os/pintos/src/utils$
The maths library (for the <math.h> header which is used in setitimer-helper.c) is not getting linked properly. When I look into the Makefile, this is the output.
ankitkal#ankitkal-Inspiron-5521:~/os/pintos/src/utils$ cat Makefile
all: setitimer-helper squish-pty squish-unix
CC = gcc
CFLAGS = -Wall -W
LDFLAGS = -lm
setitimer-helper: setitimer-helper.o
squish-pty: squish-pty.o
squish-unix: squish-unix.o
clean:
rm -f *.o setitimer-helper squish-pty squish-unix
Please tell me how to fix it. I'm using gcc-4.8.6 by the way.
gcc -lm setitimer-helper.o -o setitimer-helper
The problem is in the order of your arguments to GCC. Try this:
gcc -o setitimer-helper setitimer-helper.o -lm
This is because of the way that ld resolves undefined symbols when linking. Basically, the way you had it before, ld first sees -lm and says "I have no reason to include this library". It then includes your setitimer-helper.o which has an unresolved reference to floor. After that, there are no more libraries to consider, and floor remains unresolved.
If -lm comes afterward, it is able to resolve the reference to floor.
Related
I'm new to C programming, and I'm trying to compile this Simple training example with GCC on Ubuntu 12.10.
Looks like fann.h should not be included (as stated on the file itself), so I included fixedfann.h instead.
First attempt (without include, just to see what the compiler will ask for):
$ gcc main.c -o output
/tmp/cckKyM92.o: In function `main':
main.c:(.text+0x62): undefined reference to `fann_create_standard'
main.c:(.text+0x7a): undefined reference to `fann_set_activation_function_hidden'
main.c:(.text+0x8e): undefined reference to `fann_set_activation_function_output'
main.c:(.text+0xba): undefined reference to `fann_train_on_file'
main.c:(.text+0xce): undefined reference to `fann_save'
main.c:(.text+0xda): undefined reference to `fann_destroy'
collect2: ld returned 1 exit status
fann_create_standard is on fann.h and fann.c. As fann.h is included by fixedfann.h, and fann.h should not be included directly, I believe I have to compile fann.c and fixedfann.c, and link then (tell me if I'm doing any mistake, I'm still not familiar with this "linking" stuff).
So I did:
$ gcc fann/fixedfann.c -o fann/fixedfann.o
fann/fixedfann.c:22:20: fatal error: config.h: No such file or directory
compilation terminated.
and then I did:
$ gcc fann/fixedfann.c -o fann/fixedfann.o -include fann/include/config.h
fann/fixedfann.c:22:20: fatal error: config.h: No such file or directory
compilation terminated.
Now, why it's not finding the config.h file here?
--update
Thanks #JonathanLeffler, I could make some steps here. But now I'm stuck at:
$ gcc fann/fixedfann.c -o fann/fixedfann.o -I./fann/include/ -lm
/usr/lib/gcc/i686-linux-gnu/4.6/../../../i386-linux-gnu/crt1.o: In function `_start':
(.text+0x18): undefined reference to `main'
collect2: ld returned 1 exit status
and, with grep, I could not find any reference to main on the fann folder... Also no function _start, and I don't know who is linking this crt1.o... Any idea what's wrong here?
--update2
Ok, I got the .o files using Harmeet's Makefile, now I'm trying to link everything.
I created the main.o with gcc -c main.c, and I tried:
gcc -o output main.o fann/fixedfann.o -lm
(-lm for the libmath, that is needed) and I got:
main.c:(.text+0xba): undefined reference to `fann_train_on_file'
This fann_train_on_file is on fann_train_data.c, so I tried:
gcc -o output main.o fann/fixedfann.o fann/fann_train_data.o -lm
but I got lots of multiple definition of... errors... :/
Looks like fann_train_data.o is already included/linked, but if so, why it's not finding fann_train_on_file?
--update3
I'm still really stuck here... Any idea of which (if any) of this two lines should work?:
gcc -o output main.o hello.o fann/fixedfann.o fann/fann_train_data.o -lm
or
gcc -o output main.o hello.o fann/fixedfann.o -lm
--update for Harmeet
The output was:
$ make
gcc -L./fann -lfann main.o -o main
main.o: In function `main':
main.c:(.text+0x62): undefined reference to `fann_create_standard'
main.c:(.text+0x7a): undefined reference to `fann_set_activation_function_hidden'
main.c:(.text+0x8e): undefined reference to `fann_set_activation_function_output'
main.c:(.text+0xba): undefined reference to `fann_train_on_file'
main.c:(.text+0xce): undefined reference to `fann_save'
main.c:(.text+0xda): undefined reference to `fann_destroy'
collect2: ld returned 1 exit status
make: *** [main] Error 1
You can use ar to make a static library and work with that.
Create a Makefile under your hello-fann-3/fann/ folder with the following contents -
SOURCES = $(wildcard *.c)
OBJECTS = $(SOURCES:.c=.o)
CFLAGS = -c -Iinclude
all: libfann.a
libfann.a: $(OBJECTS)
ar rcs $# $^
%.o: %.c
gcc $(CFLAGS) $^
Then use the make command in hello-fann-3/fann/ to build the static library. The above Makefile will generate libfann.a that you can link to your program.
Create a Makefile under your hello-fann-3/ folder with the following contents -
SOURCES = $(wildcard *.c)
OBJECTS = $(SOURCES:.c=.o)
CFLAGS = -c -I./fann/include
LFLAGS = -L./fann -lfann
main: $(OBJECTS)
gcc $(LFLAGS) $^ -o $#
%.o: %.c
gcc $(CFLAGS) $^
Then use the make command in hello-fann-3/ to build the main program.
In your main.c, you must include fan.h like -
#include "fann.h"
If you do not understand the Makefile, you can read about it here -
http://www.gnu.org/software/make/manual/html_node/index.html
You just need to link the fann library.
If you compile manually do this
gcc main.c -lfann -lm -o main
then simply run it like
./main
If you are on Ubuntu and you faced the following error
./main: error while loading shared libraries: libfann.so.2: cannot open shared object file: No such file or directory
Then run
sudo ldconfig
If you are using NetBeans, then simply Right click on your project -> Properties -> Build -> Linker,
then in the Libraries section click on the browse button [...] then in the new window click on Add Library...
Then add fann library (for example my fann library path is: /usr/local/lib/libfann.a) and click Ok
A fellow helped me, and we came to this line that compiled everything, and make the executable:
$ gcc fann/fann.c fann/fann_io.c fann/fann_train.c fann/fann_train_data.c fann/fann_error.c fann/fann_cascade.c main.c -Ifann/include -lm
And this is the answer.
That said, this is exactly what fixedfann.c is doing (include all this .c files). But if I try:
$ gcc fann/fixedfann.c main.c -Ifann/include -lm
..I get:
undefined reference to `fann_train_on_file'
This fann_train_on_file is on fann_train_data.c, which is included by fixedfann.c, so why it is undefined? I don't know... :/
--update
I realized that:
$ gcc fann/fixedfann.c main.c -Ifann/include -lm
will work if I comment the headers on fixedfann.c:
//#include "config.h"
//#include "fixedfann.h"
#include "fann.c"
#include "fann_io.c"
#include "fann_train.c"
#include "fann_train_data.c"
#include "fann_error.c"
#include "fann_cascade.c"
DESCRIPTION:
I have a library libshell.a, inside of it is the function ord_interna that i'm attempting to use, however it seems i linked it wrong, could you guys fix my error, so i dont make it in the future? Cheers,
Error:
/tmp/ccn5lbmJ.o: In function `main':
minishell.c:(.text+0x4e): undefined reference to `ord_interna'
collect2: error: ld returned 1 exit status
make: *** [minishell.o] Error 1
Makefile:
CC=gcc
CFLAGS=-Wall -pedantic -c
all: microshell
microshell: minishell.o
gcc minishell.o -o microshell
minishell.o: minishell.c
gcc minishell.c minishell.h entrada_minishell.c entrada_minishell.h ejecutar.c ejecutar.h libshell.a
clean:
rm -rf *o microshell
From your makefile, I'm guessing you have these source files:
minishell.c
entrada_minishell.c
ejecutar.c
And that you want to compile them, and then link them all together with libshell.a to create an executable called microshell. In that case, you want something like:
CC=gcc
CFLAGS=-Wall -pedantic
all: microshell
microshell: minishell.o entrada_minishell.o ejecutar.o
$(CC) -o $# $^ -L. -lshell
You can add a clean target if you want, but just that should get you going.
Editorial notes:
it's really weird to put header files on the compilation line; I assumed you didn't actually want to do that.
You should look into gcc's -MMD flag to do automatic dependency generation.
I was auditing cs107 at stanford online
The problem I ran into is with assignment 6, when I type "make" in terminal, the error message pops up. Basically, I miss two header files, which I guess can be got from the pre-compiled .lib file. But somehow it just doesn't work.
Here's part of the original make file:
CFLAGS = -D_REENTRANT -g -Wall -D__ostype_is_$(OSTYPE)__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function $(DFLAG)
LDFLAGS = -L/usr/class/cs107/assignments/assn-6-rss-news-search-lib/$(OSTYPE) -L/usr/class/cs107/lib -lexpat -lrssnews $(PLATFORM_LIBS) $(THREAD_LIBS)
PFLAGS= -linker=/usr/pubsw/bin/ld -best-effort -threads=yes -max-threads=1000
Edit:
When I said "This is supposed to compile even without threading implementation", I meant that it should compile without FURTHER threading implementation by students.
So here's the error message with thread:
gcc -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -c -o rss-news-search.o rss-news-search.c
rss-news-search.c: In function ‘main’:
rss-news-search.c:109:3: warning: implicit declaration of function ‘InitThreadPackage’ [-Wimplicit-function-declaration]
gcc rss-news-search.o -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -L/home/h/cs107/assn-6-rss-news-search-lib/linux -L/usr/class/cs107/lib -L. -lexpat -lrssnews -lnsl -lpthread -lthread_107_linux -o rss-news-search
/usr/bin/ld: cannot find -lthread_107_linux
collect2: ld returned 1 exit status
make: *** [rss-news-search] Error 1
here's the error message without $(THREAD_LIBS):
gcc -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -c -o rss-news-search.o rss-news-search.c
rss-news-search.c: In function ‘main’:
rss-news-search.c:109:3: warning: implicit declaration of function ‘InitThreadPackage’ [-Wimplicit-function-declaration]
gcc rss-news-search.o -D_REENTRANT -g -Wall -D__ostype_is_linux__ -std=gnu99 -I/usr/class/cs107/include/ -Wno-unused-function -L/home/h/cs107/assn-6-rss-news-search-lib/linux -L/usr/class/cs107/lib -L. -lexpat -lrssnews -lnsl -lpthread -o rss-news-search
rss-news-search.o: In function `main':
/home/h/cs107/assn-6-rss-news-search/rss-news-search.c:109: undefined reference to `InitThreadPackage'
collect2: ld returned 1 exit status
make: *** [rss-news-search] Error 1
In the later case, if I comment out "InitThreadPackage", it compiles just fine.
This is the procedure to compile your project:
Create a file assn-6-rss-news-search/thread_107.h, and put this inside:
/* Empty header file */
Copy the library librssnews.a from assn-6-rss-news-search-lib/linux/ to assn-6-rss-news-search/
Modify the file rss-news-search.c by commenting the call to the function : InitThreadPackage on line 109:
//InitThreadPackage(false);
Modify the Makefile to include the path to the current directory (to be able to link to the library you've copied earlier librssnews.a):
The line 27 should look like this:
LDFLAGS = -L/usr/class/cs107/assignments/assn-6-rss-news-search-lib/$(OSTYPE) -L/usr/class/cs107/lib -L. -lexpat -lrssnews $(PLATFORM_LIBS) $(THREAD_LIBS)
Then:
make clean
make
EDIT :
When you got this error cannot find lthread_107_linux, Edit your Makefile to remove this $(THREAD_LIBS) on line 27:
LDFLAGS = -L/usr/class/cs107/assignments/assn-6-rss-news-search-lib/$(OSTYPE) -L/usr/class/cs107/lib -L. -lexpat -lrssnews $(PLATFORM_LIBS)
The class-specific header files, like thread_107.h are found in /usr/class/cs107/include/ on whatever machine the instructor is expecting the students to use. If you're not using that machine, you'll have to copy those include files or make your own.
The expat.h file is from an open source library. You'll need to install the appropriate package on the system you're compiling on. On Ubuntu, that's sudo apt-get install libexpat1-dev, but the package name should be similar on other distributions.
New to C, and try to make my own first library. However gcc says library not found.
with -L/lib/path, it should be ok, but it's not.
FYI, i use Mac os x.
~/c$make
gcc -c -o obj/hellomake.o src/hellomake.c -I./include
gcc -c -o obj/hellofunc.o src/hellofunc.c -I./include
gcc -o hellomake obj/hellomake.o obj/hellofunc.o -I./include -L./lib -lm -llibfunc
ld: library not found for -llibfunc
collect2: ld returned 1 exit status
make: *** [hellomake] Error 1
~/c$ls ./lib
README.txt libfunc.a libfunc1.c libfunc1.o libfunc2.c libfunc2.o
The -l argument automatically prepends the lib part to the library name. So the command should use -lfunc in place of -llibfunc.
Remove lib when linking libfunc. Just use -lfunc.
Use -lfunc, skip the prefix lib.
I am trying to use an external library called iniparser in my C program. I'm using gcc 4.4.
I put the iniparser library in a subdirectory called lib/ header files are in lib/iniparser/src and the library is compiled to lib/iniparser/libiniparser.so.0.
I wrote a short Makefile to compile it, here's the output of make:
gcc -Wall -Wextra -Werror -c -I include/ src/smag_main.c -L lib/iniparser -liniparser -I lib/iniparser/src
gcc -Wall -Wextra -Werror -c -I include/ -L lib/iniparser -liniparser -I lib/iniparser/src src/agros.c
gcc -Wall -Wextra -Werror -c -I include/ -L lib/iniparser -liniparser -I lib/iniparser/src src/main.c
gcc -Wall -Wextra -Werror -L lib/iniparser -liniparser -o agros smag_main.o main.o agros.o
smag_main.o: In function `sec_haskey':
smag_main.c:(.text+0xa9): undefined reference to `iniparser_find_entry'
smag_main.o: In function `parse_config':
smag_main.c:(.text+0x153): undefined reference to `iniparser_load'
smag_main.c:(.text+0x18b): undefined reference to `iniparser_getint'
smag_main.c:(.text+0x1c6): undefined reference to `iniparser_getstring'
smag_main.c:(.text+0x202): undefined reference to `iniparser_getstring'
smag_main.c:(.text+0x261): undefined reference to `iniparser_getstring'
smag_main.c:(.text+0x2c2): undefined reference to `iniparser_getint'
smag_main.c:(.text+0x2d5): undefined reference to `iniparser_freedict'
collect2: ld returned 1 exit status
make: *** [agros] Error 1
First call to gcc compiles smag_main.o successfully, the second one compiles agros.o and the third one main.o. The 4th call is the linker, that will link all those objects into an executable agros. It obviously fails.
It looks like it has problems locating iniparser.so at linking time. How's my call wrong?
I am confused.
(Alternate question, if anyone could explain how to the linking by calling ld directly it would be great).
Try putting a symlink from libiniparser.so.0 to libiniparser.so
cd lib/iniparser/
ln -s libiniparser.so.0 libiniparser.so