I am able to run and compile my c example program with openssl using
gcc azureconn.c -o azureconn -lssl -lcrypto
but when I try to compile using makefile with LDLIBS flag in make file, it result into error as undefined reference OPENSSL_Init
Below is my make file
DEFINES = $(GDEFINES)
INCLUDES = $(DIR_PATH)
CFLAGS = $(GCFLAGS) $(DEFINES) $(INCLUDES) -D_GNU_SOURCE
LDLIBS = -lssl -lcrypto
MAIN_OBJECTS = xxxx.o yyy.o zzz.o \
aaaa.o
all: $(MAIN_OBJECTS)
mv $(MAIN_OBJECTS) $(BIN_PATH)
%.o: %.c
$(CC) $(CFLAGS) -c $< -o $# $(LDLIBS)
clean:
rm -rf *.o
Error
undefined reference to `OPENSSL_init_ssl' collect2: error: ld returned
1 exit status
Since you've changed your question. Which module has the main(...) function in it? I assumed it was azureconn.c since you said you can compile with this.
gcc azureconn.c -o azureconn -lssl -lcrypto
Try using a rule like this to build your executable;
azureconn:
$(CC) $(CFLAGS) azureconn.c -o $# $(LDLIBS)
The %.o:%.c rule is not typically used to link, just create object files as the name implies
Related
I am trying to compile a C language library as a shared object on my new install of Fedora 22. The project compiled fine on my old install of Fedora 20. But now, when I run my makefile:
CC=gcc
vpath %.c src
vpath %.h inc
CFLAGS = -fPIC
INCLUDE = -Iinc -I/usr/include -I/usr/local/include
LIBPATH = -L/usr/lib -L/lib64
LIBS = -lportaudio -lm -lpthread -ldl
OBJ_PATH = ./objs
SRCS = my_code1.c my_code2.c # etc.
OBJS = $(SRCS:.c=.o)
.PHONY: libmylib.so
all: libmylib.so
debug: $(CFLAGS) += -DDEBUG -O0 -g3 -DPD
debug: all
release: $(CFLAGS) += -DTESTING -O2 -DPD -funroll-loops -fomit-frame-pointer
release: all
%.o: %.c
$(CC) $(CFLAGS) $(INCLUDE) $(LIBPATH) $(LIBS) -c -o $# $^
libmylib.so: $(OBJS)
$(CC) -shared -Wl,-soname,libmylib.so \
-Wl,--no-undefined $(OBJS) -lc -lportaudio -ldl -lm -lpthread
mv libmylib.so ./bin
mv *.o $(OBJ_PATH)
clean:
rm $(OBJ_PATH)/*.o
rm bin/libmylib.so
I get very many undefined reference errors:
my_code1.o: In function `func_in_my_code1':
my_code1.c:(.text+0x1b8): undefined reference to `func_from_my_code2'
my_code2.o: In function `func_in_my_code2':
my_code2.c:(.text+0x310): undefined reference to `func_from_my_func1'
The functions in question are most certainly defined in the code. Presumably these are compiled into .o files in the compile stage.
The exact same build environment worked on my previous fedora installation. I am at a loss as to why I should get these errors.
Also, if I compile without the -Wl,--no-undefined flag, it compiles fine, but when I try to load the library from another application, it tosses the same set of undefined errors.
This may have nothing to do with the new version of Fedora. It is possible that there are some environment variables or something that didn't make through to my new install, but I have no idea what they could be.
Apparently I now need to insert the extern keyword into these functions. The code compiled and ran perfectly well before... I would like to reiterate, for posterity's sake, that I did post the entire makefile in my question.
I have object code that I have compiled using -fPIC switch in clang that also used the -shared switch. I have then linked all of these into a single .so shared object. Now I want to link this into a single executable file, I'm told by the man page that I should be able to do this using the
ld command and the -l switch. But when I do this, I get the following error:
ld -r -L./ -l:libmymath.so simpleone
ld: attempted static link of dynamic object `libmymath.so'
make: *** [simpleone] Error 1
I have tried doing the same thing with the -dy switch, but it gives me the same error.
I really don't understand why this wouldn't be working.
Here is the makefile I am using to do all of this.
CC= clang
LD= ld -r
CFLAGS= -std=gnu99 -g -Oz -c
CSECFL= -fPIC -I -L
CFLAG3= -shared
RM= /bin/rm -f
OBJ= math.o my*.o
SO= libmymath.so
all: math my_add my_mul
math: math.c
$(CC) $(CFLAGS) $#.c $(CSECFL)
my_add: my_add.c
$(CC) $(CFLAGS) $#.c $(CSECFL)
my_mul: my_mul.c
$(CC) $(CFLAGS) $#.c $(CSECFL)
simplemath: $(OBJ)
$(CC) $(OBJ) -o $#
simplemath.o: $(OBJ)
$(LD) $(OBJ) -o $#
lib1: my_add.o
$(CC) $(CFLAG3) my_add.o -o $(SO)
lib2: $(OBJ)
$(CC) $(CFLAG3) my_mul.o -o $(SO)
lib3: $(OBJ)
$(CC) $(CFLAG3) math.o -o $(SO)
simpleone: $(OBJ)
$(LD) -L./ -l:libmymath.so $#
clean:
$(RM) *.o simplemath* *.t $(SO)
You need to link the objects (*.o) into a static executable, not the shared lib (.so) .so can be opened by the run-time dynamic linker or via a dlopen() call.
I am trying to create my first makefile. I tested my program by using the following commands:
Command 1: gcc -Wall -ggdb3 -std=c99 -o file1 file1.c -lm -lpthread -l
Command 2: gcc -Wall -ggdb3 -std=c99 -o file2 file2.c -lm -lpthread
Everything works great. Then I created a makefile (please see below). I keep getting an error message. Can someone take a look at my code and give me a hint on what the problem is?
file2.o: In function `seed_primes':
file2.c:(.text+0x461): undefined reference to `sqrt'
file2.c:(.text+0x466): undefined reference to `sqrt'
file2:(.text+0x533): undefined reference to `sqrt'
file2.o: In function `create_threads':
file2.c:(.text+0x668): undefined reference to `pthread_create'
file2.c:(.text+0x6b5): undefined reference to `pthread_join'
file2.o: In function `next_seed':
file2.c:(.text+0x860): undefined reference to `sqrt'
collect2: ld returned 1 exit status
make: *** [file2] Error 1
Here is my makefile:
CC=gcc
DEBUG=-ggdb3
CFLAGS=#(DEBUG) -Wall -lm -lpthread -lrt -l
PROGS=file1 file2
all: $(PROGS)
file1: file1.o
$(CC) $(CFLAGS) -o file1 file1.o
file1.o: file1.c
$(CC) $(CFLAGS) -c file1.c
file2: file2.o
$(CC) $(CFLAGS) -o file2 file2.o
file2.o: file2.c
$(CC) $(CFLAGS) -c file2.c
clean:
rm -f $(PROGS) *.o *~
You've set CFLAGS to an empty string because of the # comment character (you probably intended to use a $ instead).
You should not set libraries into CFLAGS; they belong in LDLIBS.
You don't need the file1: rule, the file2: rule, or the object file rules.
CC = gcc
DEBUG = -ggdb3
CFLAGS = $(DEBUG) -Wall
LDLIBS = -lm -lpthread -lrt -l
PROGS = file1 file2
all: $(PROGS)
clean:
rm -f $(PROGS) *.o *~
NB: LDLIBS and the related LDFLAGS are not 100% uniform across variants of make. LDFLAGS should be used for library paths; LDLIBS is for the library names (-lxyz etc).
If you need different libraries for the two programs, you will need to create separate build rules (as you had originally), or use conditional macro assignments (GNU make).
You put all of your flags in CFLAGS which makes them appear before the object files in the command line. Notice that your test commands didn't do that.
Change your flags:
CFLAGS=$(DEBUG) -Wall
LDFLAGS=-lm -lpthread -lrt
And then in the recipes:
$(CC) $(CFLAGS) -o file1 file1.o $(LDFLAGS)
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Linker errors when compiling against glib…?
Okay, I know this may be a duplicate, but I can't find any other answer to my problem.
I am trying to install Pintos and when I run 'make' in the src/utils directory, I get the error that there is an undefined reference to 'floor'. I checked the makefile and here's what I got:
all: setitimer-helper squish-pty squish-unix
# 2207718881418
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
I tried adding LIBS = -lm but that didn't help.
Output of make:
gcc -lm setitimer-helper.o -o setitimer-helper
setitimer-helper.o: In function `main':
setitimer-helper.c:(.text+0xbb): undefined reference to `floor'
collect2: ld returned 1 exit status
make: *** [setitimer-helper] Error 1
Any solutions to this dilemma?
Your original makefile defines a bunch of variables
CC = gcc
# etc
and lists some dependencies
setitimer-helper: setitimer-helper.o
# etc
but doesn't have any recipes giving the exact commands to be used to remake the targets, except for the clean rule. This means that built-in implicit rules will be used; e.g., to link setitimer-helper the following built-in rule will be used:
$(CC) $(LDFLAGS) $^ $(LDLIBS) -o $#
For setitemer-helper, the automatic variables are filled in using the relevant dependency:
$(CC) $(LDFLAGS) setitimer-helper.o $(LDLIBS) -o setitimer-helper
and from this you can see how the remaining variables -- $(CC), $(LDFLAGS), and $(LDLIBS) -- were filled in to give the output of make that you saw.
As various people have noted, you need to make sure that -lm goes at the end of the link command so that it can be used to satisfy references to library functions like floor(). At the moment, your makefile sets $(LDFLAGS) to -lm, but that variable is used at the start of the link command.
The conventional variables are set up in this built-in rule so that LDFLAGS can be used for options (a.k.a. "flags") that (historically) need to be at the start of the link command, and LDLIBS can be used for libraries that need to be specified after the *.o object files.
So to fix this in terms of the makefile you are using, you need to remove -lm from the LDFLAGS variable that is defined, and instead add another variable definition for LDLIBS:
LDLIBS = -lm
(I'm oversummarising slightly: the built-in rule also contains $(TARGET_ARCH) and $(LOADLIBES), but those aren't of interest here.)
It's compiled in wrong order, the way to proceed is:
CC = gcc
CFLAGS = -Wall -W
LDFLAGS = -lm
myprog: myprog.o more_code.o
${CC} ${CFLAGS} myprog.o more_code.o ${LDFLAGS} -o myprog
myprog.o: myprog.c
${CC} ${CFLAGS} -c myprog.c
more_code.o: more_code.c
${CC} ${CFLAGS} -c more_code.c
clean:
\rm myprog.o more_code.o myprog
More info: http://www.physics.utah.edu/~p5720/rsrc/make.html
Can you show me in terms of the original makefile?
I can try :)
CC = gcc
CFLAGS = -Wall -W
LDFLAGS = -lm
OBJECTS = setitimer-helper.o squish-pty.o squish-unix.o
all: setitimer-helper
setitimer-helper: $(OBJECTS)
${CC} ${CFLAGS} $(OBJECTS) ${LDFLAGS} -o setitimer-helper
setitimer-helper.o: setitimer-helper.c
${CC} ${CFLAGS} -c setitimer-helper.c
squish-pty.o: squish-pty.c
${CC} ${CFLAGS} -c squish-pty.c
squish-unix.o: squish-unix.c
${CC} ${CFLAGS} -c squish-unix.c
And since you are new to Makefile, it's a good idea to add -Wextra -pedantic to CFLAGS
I have 3 functions separated in .c files and the main.c I would like to make the make file, I wrote in the file:
# Indicate that the compiler is the gcc compiler
CC=gc
# Indicate to the compiler to include header files in the local folder
CPPFLAGS = -I
main: method1.o
main: method2.o
main: method3.o
main: method4.o
main.o: main.h
Whereas method 1,2,3,4 is the functions of the main .c and I have the following problem when I type make in the shell:
make
gcc -I -c -o method1.o method1.c
/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu/crt1.o: In function `_start':
(.text+0x20): undefined reference to `main'
collect2: ld returned 1 exit status
make: *** [method1.o] Error 1
if your project contains the following files: method1.c method2.c method3.c method4.c and main.c
you can use the following make file
CPPFLAGS=-I/path/to/header/files
CC=gcc
all: main
%.o: %.c
$(CC) $(CPPFLAGS) -c -o $# $^
main: method1.o method2.o method3.o method4.o main.o
$(CC) -o $# $^
The issue is in your CPPFLAGS definition:
# Indicate to the compiler to include header files in the local folder
CPPFLAGS = -I
According to the comment above it, it misses a .:
CPPFLAGS = -I.
Otherwise, gcc will treat the -c that comes after -I in your command line as the name of a directory where it can search for headers. Thus, as far as gcc is concerned there's no -c option, and it will attempt to link method1.c as a complete application, hence the error message complaining that there's no main function.
CC=gcc
CPPFLAGS=-I include
VPATH=src include
main: main.o method1.o method2.o method3.o method4.o -lm
$(CC) $^ -o $#
main.o: main.c main.h
$(CC) $(CPPFLAGS) -c $<
method1.o: method1.c
$(CC) $(CPPFLAGS) -c $<
method2.o: method2.c
$(CC) $(CPPFLAGS) -c $<
method3.o: method3.c
$(CC) $(CPPFLAGS) -c $<
method4.o: method4.c
$(CC) $(CPPFLAGS) -c $<
it worked like this