Make file in C giving fatal error - c

I am trying to create a makefile in C but i am facing some issues.
I have my main .c, one .c which keeps the functions implementations and one .h which keeps the functions declarations.
When i try to run the makefile, i get a fatal error.
here is my makefile:
INCL = prog.h
SRC = prog.c prog_fun.c
OBJ = $(SRC:.c=.o)
EXE = prog
CC = gcc
CFLAGS = -c
RM = rm -rf
all: prog
prog: prog.o prog_fun.o
gcc -o prog prog.o prog_fun.o
prog.o: prog.c
gcc -c prog.c
prog_fun.o: prog_fun.c prog.h
gcc -c prog.c
clean:
$(RM) $(OBJ) $(EXE)
The error i get is this:
gcc -c prog.c
prog.c:11:19: fatal error: prog.h: No such file or directory
compilation terminated.
Makefile:17: recipe for target 'prog.o' failed
make: *** [prog.o] Error 1
Can anyone please help me with this?

What you are trying to do by using this
prog_fun.o: prog_fun.c header.h
It should be only
prog_fun.o: prog_fun.c
Modify your make file as
xyz#xyz-PC:~$ vi makefile
INCL = header.h
SRC = prog.c prog_fun.c
OBJ = $(SRC:.c=.o)
EXE = prog
CC = gcc
CFLAGS = -c
RM = rm -rf
all: prog
prog: prog.o prog_fun.o
gcc -o prog prog.o prog_fun.o
prog.o: prog.c
gcc -c prog.c header.h
prog_fun.o: prog_fun.c
gcc -c prog_fun.c header.h
clean:
$(RM) $(OBJ) $(EXE)
next run it
xxyz#xyz-PC:~$ make
gcc -c prog.c header.h
gcc -c prog_fun.c header.h
gcc -o prog prog.o prog_fun.o
I hope it will work now and make sure indention is correct(not manual spaces, it should be tab key)

Related

How to build a program with multiple files whith inter files function calls with makefile in C

I am struggling with building a program with multiple files whith inter files function calls with makefile in C. Let's say that I have a main file which call a function call_print_hello() declared in a header file fdeclar_macros.h and written in the file script1.c. The function call_print_hello() itself calls another function print_hello() also declared in fdeclar_macros.h and written in script2.c. I have also a makefile but when I run it I get the following error message:
gcc -g -Wall -c main.c
gcc -g -Wall -c script1.c
gcc -o main main.o script1.o
Undefined symbols for architecture x86_64:
"_call_print_hello", referenced from:
_main in main.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [main] Error 1
Here are the content of the files:
makefile:
CC = gcc
CFLAGS = -g -Wall
main: main.o script1.o
$(CC) -o main main.o script1.o
main.o: main.c fdeclar_macros.h
$(CC) $(CFLAGS) -c main.c
script2.o: script2.c fdeclar_macros.h
$(CC) $(CFLAGS) -c script2.c
script1.o: script1.c fdeclar_macros.h
$(CC) $(CFLAGS) -c script1.c
run: main
./main
clean:
$(RM) -rf justify *.dSYM *.o
main.c:
#include "fdeclar_macros.h"
int main(){
call_print_hello();
return 0;
}
fdeclar_macros.h:
#define NUMBER 3
void print_hello();
void call_print_hello();
script1.c:
#include <stdio.h>
#include "fdeclar_macros.h"
void print_hello(){
printf("hello %d\n", NUMBER);
}
script2.c:
#include "fdeclar_macros.h"
void call_print_hello(){
print_hello();
}
The make target for the main executable does not contain a dependency on script2.o and the rule to build main does not link script2.o into the main executable either.
So the linker tries to build an executable with the content of script2.o missing, but as that content is required, linking fails.
One easy fix would be to change the original rule
main: main.o script1.o
$(CC) -o main main.o script1.o
by adding script2.o:
main: main.o script1.o script2.o
$(CC) -o main main.o script1.o script2.o
I will leave finding more general rules as an exercise to the reader.
NAME = my_programm
CC = gcc
CFLAGS = -Wall -Werror -Wextra
MY_SOURCES = main.c script1.c script2.c
MY_OBJECTS = $(MY_SOURCES:.c=.o)
$(NAME): $(MY_OBJECTS)
#cc $(CFLAGS) $(MY_OBJECTS) -o $(NAME)
clean:
#rm -f $(MY_OBJECTS)
#rm -f $(NAME)
run:
./my_programm

Makefile's output explanation

I wrote the following makefile:
MAIN = main
# Macro nome compilatore
CC = gcc
# Macro flag del compilatore
CFLAGS = -Wall
# Macro file oggetto
OBJS = $(MAIN).o
# Macro libreria matematica
LIBS = -lm
# Target
$(MAIN): $(OBJS)
$(CC) $(CFLAGS) $(OBJS) $(LIBS) -o $(MAIN)
When i run it for the first time, the output is:
gcc -Wall -c -o main.o main.c
gcc -Wall main.o -lm -o main
Can you explain me the first line please? What does it mean?
Thank you for your time.

/usr/bin/ld: cannot find -lioutil in Makefile

I want to do makefile as the following, but I received this error:
gcc frparse.o frtags.o frscan.o frinit.o frstop.o frfoot.o frio.o -L/usr/local/image/lib/sgi -lioutil -lutil -o frparse
/usr/bin/ld: cannot find -lioutil
collect2: error: ld returned 1 exit status
Makefile:17: recipe for target 'frparse' failed
make: *** [frparse] Error 1
I would appreciate it if you guide me.
IMLIB = /usr/local/image/lib/sgi
LLIBS = -lioutil -lutil
it: frparse frcheck pgrep
OBJ = frparse.o frtags.o frscan.o frinit.o frstop.o frfoot.o frio.o
frparse.o: Makefile frparse.h frio.h frproto.h frstop.h frparse.c
frinit.o: Makefile frparse.h frproto.h frinit.c
frscan.o: Makefile frio.h frstop.h frscan.c
frfoot.o: Makefile frparse.h frproto.h frstop.h frfoot.c
frtags.o: Makefile frparse.h frio.h frproto.h frstop.h frtags.c
frstop.o: Makefile frstop.h frstop.c
frio.o: Makefile frio.c
frparse: $(OBJ)
gcc $(OBJ) -L$(IMLIB) $(LLIBS) -o $#
frcheck: frcheck.o
gcc frcheck.o -L$(IMLIB) $(LLIBS) -o $#
pgrep: pgrep.o
gcc pgrep.o -L$(IMLIB) $(LLIBS) -o $#
.c.o:
# cc -c -O2 -mips2 $<
gcc -c -g $<
regarding:
.c.o:
# cc -c -O2 -mips2 $<
gcc -c -g $<
The comment # must ALSO be indented via a <tab> otherwise the recipe never performs the third line
Also, the syntax is a bit obsolete suggest:
%.o:%.c
for the first line of the recipe
However, regarding your question:
Is there actually a library file named libioutil.so in the directory:
/usr/local/image/lib/sgi

Trying to use matlab's libmat.dll, but the compiler doesn't recognize the function from the library

I am trying to use matlab libmat.dll in a C application. To compile my C application I use MinGW, for now I use matlab exemple "matcreate.c" and try to compile it, so the projects consist of only one file : main.c .
Here is the makefile I use :
MATINCLUDE = "C:\Program Files\MATLAB\R2010a\extern\include"
MATLIBRARY = "C:\Program Files\MATLAB\R2010a\bin\win64"
#
CC = gcc
LD = gcc
CFLAGS = -O3 -Wall
LFLAGS = -Wall -O3
LIBS = -I$(MATINCLUDE) -L$(MATLIBRARY)
#
PROG = matTest
LISTEOBJ = \
main.o
.c.o :
$(CC) -c $(CFLAGS) $(LIBS) -o $# $<
all : $(PROG)
$(PROG) : $(LISTEOBJ)
$(LD) -o $(PROG) $(LFLAGS) $(LISTEOBJ) $(LIBS)
clean :
rm -f *.obj
Here is what I get in the console
E:\Users\Desk\Dropbox\matTest>make
gcc -c -O3 -Wall -I"C:\Program Files\MATLAB\R2010a\extern\include" -L"C:\Pr
ogram Files\MATLAB\R2010a\bin\win64" -o main.o main.c
gcc -o Hello_world -Wall -O3 main.o -I"C:\Program Files\MATLAB\R2010a\extern\i
nclude" -L"C:\Program Files\MATLAB\R2010a\bin\win64"
main.o:main.c:(.text.startup+0x48): undefined reference to `matOpen'
main.o:main.c:(.text.startup+0x6e): undefined reference to `mxCreateDoubleMatrix
_730'
e:/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/ld.exe: main.o: ba
d reloc address 0x6e in section `.text.startup'
e:/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/ld.exe: final link
failed: Invalid operation
collect2.exe: error: ld returned 1 exit status
make: *** [Hello_world] Error 1
Why do I have "undefined reference to matOpen'" and "undefined reference to mxCreateDoubleMatrix" ?? those function are declared in mat.h. and I added #include "mat.h" to the begining of main.c
thank you
Looks like you have included the path to the matlab library, but not the library itself. You need to add a -l<libraryname> to your link line.

Undefined reference error in a makefile while creating static library

I have 4 .c files hello.c,here.c,bye.c and main.c.
One header file mylib.h
The contents are as follows
hello.c
#include<stdio.h>
void hello()
{
printf("Hello!\n");
}
here.c
#include<stdio.h>
void here()
{
printf("I am here \n");
}
bye.c
#include<stdio.h>
void bye()
{
printf("Bye,Bye");
}
main.c
#include<stdio.h>
#include "mylib.h"
int main()
{
hello();
here();
bye();
return 1;
}
mylib.h
#ifndef _mylib_
#define _mylib_
void hello();
void here();
void bye();
#endif
The makefile for creating a static lib is :
Makefile
all: myapp
#Macros
#Which Compiler
CC = gcc
#Where to install
INSTDIR = /usr/local/bin
#Where are include files kept
INCLUDE = .
#Options for developement
CFLAGS = -g -Wall -ansi
#Options for release
#CFLAGS = -O -Wall -ansi
#Local Libraries
MYLIB = mylib.a
myapp: main.o $(MYLIB)
$(CC) -o myapp main.o $(MYLIB)
$(MYLIB): hello.o here.o bye.o
ar rcs $# $^
main.o: main.c mylib.h
hello.o: hello.c
here.o: here.c
bye.o: bye.c
clean:
-rm main.o hello.o here.o bye.o $(MYLIB)
install: myapp
#if [ -d $(INSTDIR) ]; \
then \
cp myapp $(INSTDIR);\
chmod a+x $(INSTDIR)/myapp;\
chmod og-w $(INSTDIR)/myapp;\
echo "Installed in $(INSTDIR)";\
else \
echo "Sorry, $(INSTDIR) does not exist";\
fi
Problem: When I execute the command
make -f Makefile all
I get the error:
gcc -o myapp main.o mylib.a
main.o: In function `main':
/home/usr/molly/main.c:7: undefined reference to `hello()'
/home/usr/molly/main.c:8: undefined reference to `here()'
/home/usr/molly/main.c:9: undefined reference to `bye()'
main.o:(.eh_frame+0x12): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status
make: *** [myapp] Error 1
Questions : How do I resolve this? Why is there an undefined reference
This actually works for me. Try rm mylib.a and then make
This works for me with the caveot that you are not specifying an 'all' target:
xxxx#xxxx-desktop:~/Desktop$ make -f Makefile
cc -g -Wall -ansi -c -o main.o main.c
cc -g -Wall -ansi -c -o hello.o hello.c
cc -g -Wall -ansi -c -o here.o here.c
cc -g -Wall -ansi -c -o bye.o bye.c
ar rcs mylib.a hello.o here.o bye.o
cc -o myapp main.o mylib.a
xxxx#xxxx-desktop:~/Desktop$ ./myapp
Hello!
I am here
Bye,Byexxxx#xxxx-desktop:~/Desktop$

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