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 $(SO)
You need to link the objects (*.o) into a static executable, not the shared lib (.so) .so can be opened by the run-time dynamic linker or via a dlopen() call.
Related
I am trying to link to a shared library. But I kept getting the undefined reference error. The following is makefile:
LIBDIR :=./lib
LIB :=-lminus
OBJDIR :=objdir
SOURCES=$(wildcard ./src/*.c)
OBJS :=$(patsubst ./src/%.c, $(OBJDIR)/%.o, $(SOURCES))
INCPATH = -Ilib -Isrc
vpath %.h ./src ./lib
vpath %.c ./src ./lib
optest : $(OBJS)
cc -o optest $(OBJS)
$(OBJDIR)/main.o : main.c add.h mul.h did.h minus.h
cc $(INCPATH) -o $# -c $< -L$(LIBDIR) $(LIB)
$(OBJDIR)/%.o: %.c %.h | $(OBJDIR)
cc -o $# -c $<
$(OBJDIR):
mkdir $#
clean :
rm -rf $(OBJDIR)
rm -f optest
rm -f ./src/*.o
The shared library is called libminus, which is put in the ./lib directory. The main function in main.c uses the function minus defined in this library. I searched online, people met this problem before. Most of their problems were solved after the shared libraries were put after the object files in the rule command. I also tried this, but it didn't work for me. The error I got is as follows:
mkdir objdir
cc -o objdir/mul.o -c ./src/mul.c
cc -o objdir/did.o -c ./src/did.c
cc -Ilib -Isrc -o objdir/main.o -c ./src/main.c -L./lib -lminus
cc -o objdir/add.o -c ./src/add.c
cc -o optest objdir/mul.o objdir/did.o objdir/main.o objdir/add.o
objdir/main.o: In function `main':
main.c:(.text+0xa5): undefined reference to `minus'
collect2: error: ld returned 1 exit status
makefile:11: recipe for target 'optest' failed
make: *** [optest] Error 1
Can any one give some suggestion? Thank you.
You're putting the lib stuff into the wrong rule:
$(OBJDIR)/main.o : main.c add.h mul.h did.h minus.h
cc $(INCPATH) -o $# -c $< -L$(LIBDIR) $(LIB)
This just compiles main.c to main.o. The -L and $(LIB) don't belong here. They have to be in the build recipe of this rule, which links the executable:
optest : $(OBJS)
cc -o optest $(OBJS)
I am using pro*c in AIX,I want make my .pc file compile to a .so libary. And link it. This is my directory:
ls
connect.pc func.c get_log.pc main.c makefile sql_err.pc
This is my makefile:
#Makefile
CC = cc -g -brtl
CFLAGS = -g -c
ESQL = proc
RM = rm -f
MYHOME = /home/xxx
OBJ = main.o func.o
LIBOBJ = get_log.o connect.o sql_err.o
DBINC = -I$(ORACLE_HOME)/precomp/public
DBLIB = -L$(ORACLE_HOME)/lib -lclntsh
INCLUDE = -I$(MYHOME)/include
.SUFFIXES: .pc .c .o
.pc.o:
$(ESQL) include=$(MYHOME)/include iname=$*.pc
$(CC) -o $*.o $(CFLAGS) $*.c $(INCLUDE) $(DBINC) $(DBLIB)
$(RM) $*.c
$(RM) $*.lis
libmydb.so:$(LIBOBJ)
$(CC) -qmkshrobj -o $# $(LIBOBJ) $(DBLIB)
mv $# $(MYHOME)/lib
query:$(OBJ)
cc -o $# $(OBJ) -L$(MYHOME)/lib -lmydb
mv $# $(MYHOME)/bin
func.o:func.c
$(CC) -c $(CFLAGS) $< $(INCLUDE)
main.o:main.c
$(CC) -c $(CFLAGS) $< $(INCLUDE)
clean:
rm -f *.o *.lis
when I make I get this:
.......
cc -g -brtl -o sql_err.o -g -c sql_err.c -I/home/xxx/include -I/oracle/product/10.2.0/precomp/public -L/oracle/product/10.2.0/lib -lclntsh
rm -f sql_err.c
rm -f sql_err.lis
cc -g -brtl -qmkshrobj -o libmydb.so get_log.o connect.o sql_err.o -L/oracle/product/10.2.0/lib -lclntsh
mv libmydb.so /home/xxxlib
when it done mv libmydb.so ,it exit!!!without wrong message.why?? I also need my .c to compile to .o and finally to an executable file query link libmydb.so.
when I change the squeuce like this put .c.o before .pc.o:
query:$(OBJ)
cc -o $# $(OBJ) -L$(MYHOME)/lib -lmydb
mv $# $(MYHOME)/bin
func.o:func.c
$(CC) -c $(CFLAGS) $< $(INCLUDE)
main.o:main.c
$(CC) -c $(CFLAGS) $< $(INCLUDE)
.pc.o:
$(ESQL) include=$(MYHOME)/include iname=$*.pc
$(CC) -o $*.o $(CFLAGS) $*.c $(INCLUDE) $(DBINC) $(DBLIB)
$(RM) $*.c
$(RM) $*.lis
libmydb.so:$(LIBOBJ)
$(CC) -qmkshrobj -o $# $(LIBOBJ) $(DBLIB)
mv $# $(MYHOME)/lib
it give this message,although I have libmydb.so last step:
prepaid(wmfe)/home/xxx/src>make
cc -g -brtl -c -g -c main.c -I/home/xxx/include
cc -g -brtl -c -g -c func.c -I/home/xxx/include
cc -o query main.o func.o -L/home/xxx/lib -lmydb
ld: 0706-006 Cannot find or open library file: -l mydb
ld:open(): A file or directory in the path name does not exist.
make: 1254-004 The error code from the last command is 255.
Stop.
I can't handle this ,very strange,Help!!
By default make will make the first rule in your makefile, but it must not start with a dot. So the default rule in your makefile is libmydb.so and that is being built.
That rule is only dependent on the LIBOBJ and OBJ is not a dependency so it doesn't care about those. It doesn't exit with no reason, it exits because it has done the job you defined for it. There is no error to report.
If you change the order then the default rule is changed and it tries to compile query. This has no dependencies to the library, so it doesn't try to compile that.
If you want to compile everything you should have, for example, a rule all that lists the dependencies. In this case probably libmydb.so and query at least, in correct order. If this is the first rule it will be the default and your compilation will succeed.
This question already has answers here:
Trying to include a library, but keep getting 'undefined reference to' messages
(3 answers)
Closed 8 years ago.
I am trying to include this file in my project: http://cairo.sourcearchive.com/documentation/1.9.4/backtrace-symbols_8c-source.html
But it requires linking against BFD. I have both binutils and binutils-devel installed. I have tried linking with -lbfd as well as directly to /usr/lib64/libbfd.so and /usr/lib64/libbfd.a (which both do exist). I also tried searching pkg-config to see if there was a different flag I should be using, but there is no reference to BFD or binutils in pkg-config.
No matter what I've tried I get the following errors:
undefined reference to 'bfd_init'
undefined reference to 'bfd_openr'
undefined reference to 'bfd_check_format'
undefined reference to 'bfd_checkformat_matches'
undefined reference to 'bfd_close'
undefined reference to 'bfd_map_over_sections'
First I am compiling my logger and the backtrace-symbols.c file I linked to above (as the logger is where I intend to use this for printing traces). Then I am linking those two object files together into a combined object file:
CC = clang
CFLAGS = -g -Wall -c
SOURCE = simplog.c
OBJ = simplog.o, simplog-temp.o, backtrace-symbols.o
all:
$(CC) $(CFLAGS) $(SOURCE); mv simplog.o simplog-temp.o; \
$(CC) -ansi $(CFLAGS) backtrace-symbols.c; \
ld -r simplog-temp.o backtrace-symbols.o -o simplog.o
clean:
rm -f $(OBJ)
Then I am linking this object file into my main project:
CC= clang++
PROG= ./bin/chiplus8
OBJS= ./src/main.o ./src/Chip8.o ./src/EmuCPU.o ./src/SimpleLogger/simplog.o
LIBS=
CXXFLAGS= -g -Wall -std=c++11 $(shell pkg-config --cflags ${LIBS})
LDFLAGS= $(shell pkg-config --static --libs ${LIBS})
all: logger $(PROG)
$(PROG): $(OBJS)
mkdir -p ./bin/
$(CC) -g -rdynamic -o $(PROG) $(LDFLAGS) -lbfd -liberty $(OBJS)
rm -f $(OBJS)
logger:
cd ./src/SimpleLogger; make clean all
clean:
rm -f $(PROG) $(OBJS)
I'm really not sure what I need to do to get this to link properly anymore. Is there something I'm missing?
Change:
$(PROG): $(OBJS)
mkdir -p ./bin/
$(CC) -g -rdynamic -o $(PROG) $(LDFLAGS) -lbfd -liberty $(OBJS)
rm -f $(OBJS)
To this:
$(PROG): $(OBJS)
mkdir -p ./bin/
$(CC) -g -rdynamic -o $(PROG) $(LDFLAGS) $(OBJS) -lbfd -liberty
rm -f $(OBJS)
Object files have to be placed before libraries with the compilation command. See this question.
I am making my first Makefile for a simple shell system. I need to make library files but for some reason the library section is not working out. In the error message it says the library files do no exist (obviously).
Am I missing something obvious that could fix this? Also, is there any other way I can make this Makefile more efficient?
# Beginning of Makefile
OBJS = obj/shutil.o obj/parser.o obj/sshell.o obj/history.o obj/hash_table.o obj/variables.o
HEADER_FILES = include/shell.h include/parser.h include/history.h include/hash_table.h include/variables.h
EXECUTABLE = sshell
LIBS = lib/libshell.so lib/libparser.so lib/libhistory.so lib/libhash_table.so lib/libvariables.so
LIBCFLAGS = $(CFLAGS) -D_REENTRANT -fPIC
CFLAGS = -Wall
CC = gcc
# End of configuration options
#What needs to be built to make all files and dependencies
all: $(EXECUTABLE)
#Create the main executable
$(EXECUTABLE): $(OBJS) $(LIBS)
$(CC) -o $(EXECUTABLE) obj/sshell.o -Llib -lparser -lshell -lhistory -lhash_table -lvariables
#Create the library files
$(LIBS): $(OBJS)
$(CC) $(LIBCFLAGS) -shared -o $(LIBS) $(OBJS)
#Recursively build object files
obj/%.o: src/%.c
$(CC) $(CFLAGS) -I./include/ -c $< -o $#
#Define dependencies for objects based on header files
#We are overly conservative here, parser.o should depend on parser.h only
$(OBJS) : $(HEADER_FILES)
clean:
-rm -f $(EXECUTABLE) obj/*.o lib/*.so lib/*.a
-rm -f .sshell_history.txt
run: $(EXECUTABLE)
(export LD_LIBRARY_PATH=lib; ./$(EXECUTABLE))
# End of Makefile
Thanks!
-Lily Banks
Edit:
Before I tried to change it, here is what I had with regards to library files.
$(LIBS): $(OBJS)
$(CC) -shared -o lib/libparser.a obj/parser.o
$(CC) -shared -o lib/libshell.a obj/shutil.o
$(CC) -shared -o lib/libhistory.a obj/history.o
$(CC) -shared -o lib/libhash_table.a obj/hash_table.o
$(CC) -shared -o lib/libvariables.a obj/variables.o
The problem with this was that it compiled each file five times which is not efficient at all. So what I was trying to do was do it all in one go.
Edit2:
#Create the library files
lib/libparser.so: obj/parser.o
$(CC) $(LIBFLAGS) -shared lib/libparser.a -o $#
lib/libshell.so: obj/shutil.o
$(CC) $(LIBFLAGS) -shared lib/libshell.a -o $#
lib/libhistory.so: obj/history.o
$(CC) $(LIBFLAGS) -shared lib/libhistory.a -o $#
lib/libhash_table.so: obj/hash_table.o
$(CC) $(LIBFLAGS) -shared lib/libhash_table.a -o $#
lib/variables.so: obj/variables.o
$(CC) $(LIBFLAGS) -shared lib/libvariables.a -o $#
Unfortunately, here is the error I am getting:
make: *** No rule to make target `lib/libvariables.so', needed by `sshell'. Stop.
Thoughts?
Edit3:
#Create the library files
lib/libparser.so: obj/parser.o
$(CC) $(LIBFLAGS) -shared $^ -o lib/libparser.a
lib/libshell.so: obj/shutil.o
$(CC) $(LIBFLAGS) -shared $^ -o lib/libshell.a
lib/libhistory.so: obj/history.o
$(CC) $(LIBFLAGS) -shared $^ -o lib/libhistory.a
lib/libhash_table.so: obj/hash_table.o
$(CC) $(LIBFLAGS) -shared $^ -o lib/libhash_table.a
lib/libvariables.so: obj/variables.o
$(CC) $(LIBFLAGS) -shared $^ -o lib/libvariables.a
This works but is there anything else I need to change? Thanks
You need one set of object files for each library. And the -o flag only takes one argument which is the output file, you are trying to output all the library files which you cannot do with one invocation of gcc.
You need to do something like:
lib/libshell.so: obj/sshell.o
$(CC) $(LIBFLAGS) -shared obj/sshell.o -o lib/libshell.so
lib/libparser.so: obj/parser.o
$(CC) $(LIBFLAGS) -shared obj/parser.o -o lib/libparser.so
for each of the libraries.
This line is completely wrong:
$(LIBS): $(OBJS)
$(CC) $(LIBCFLAGS) -shared -o $(LIBS) $(OBJS)
If you expanded all the variables, this line would look like this (adding line breaks for clarity):
lib/libshell.so lib/libparser.so lib/libhistory.so lib/libhash_table.so lib/libvariables.so: \
obj/shutil.o obj/parser.o obj/sshell.o obj/history.o obj/hash_table.o obj/variables.o
gcc -Wall -D_REENTRANT -fPIC -shared -o lib/libshell.so lib/libparser.so lib/libhistory.so \
lib/libhash_table.so lib/libvariables.so obj/shutil.o obj/parser.o obj/sshell.o obj/history.o \
obj/hash_table.o obj/variables.o
Which, it should be clear, is very not right. It's so not right I can't even really tell what you're trying to accomplish. Do you really want to create one shared library for every .o file, where each shared library contains a single .o? If so why are you trying to link both the .o files AND the shared libraries into a single executable?
If you explain what you are really trying to do, at a higher level, we can help.
gcc 4.7.2
c89
GNU Make 3.82
I am trying compile this program I have using this Makefile. I have only 1 src file at the moment, but I will have more later to include.
I am trying to get the Makefile to create the bin directory if it doesn't exist and put the binary executable in there.
INC_PATH=-I/home/dev_tools/apr/include/apr-1
LIB_PATH=-L/home/dev_tools/apr/lib
LIBS=-lapr-1
RUNTIME_PATH=/home/dev_tools/apr/lib
CC=gcc
CFLAGS=-Wall -Wextra -g -m32 -D_DEBUG -D_THREAD_SAFE -D_REENTRANT -D_LARGEFILE64_SOURCE -O2 $(INC_PATH)
OBJECTS=timeout.o
EXECUTABLE=bin/to
all: build $(EXECUTABLE)
$(EXECUTABLE):
$(CC) -m32 -o $# -Wl,-rpath,$(RUNTIME_PATH), $(LIB_PATH) $(OBJECTS) $(LIBS)
build:
#mkdir -p bin
clean:
rm -rf *~ timeout *.o
I am getting this error:
make
gcc -m32 -o bin/to -Wl,-rpath,/home/dev_tools/apr/lib, -L/home/dev_tools/apr/lib timeout.o -lapr-1
gcc: error: timeout.o: No such file or directory
make: *** [bin/to] Error 1
When I remove the $(OBJECTS) I get the following:
gcc -m32 -o bin/to -Wl,-rpath,/home/dev_tools/apr/lib, -L/home/dev_tools/apr/lib -lapr-1
/usr/bin/ld: cannot find : No such file or directory
collect2: error: ld returned 1 exit status
make: *** [bin/to] Error 1
Not sure where I am going wrong with this.
You have not specified how to build the target timeout.o.
You need to add the following code:
timeout.o: timeout.c
$(CC) $(CFLAGS) -c -o $# $<
If you end up with more source file that you need compiled, you can use a pattern matching rule like this:
%.o: %.c
$(CC) $(CFLAGS) -c $< -o $#
Makefiles can be a bit tricky. Because you want to continue adding more objects to your OBJECT variable, I would actually add a prerequisite to EXECUTABLE to make sure all of your objects are compiled. From there, the automatic rule inference should take care of the rest.
Basically replace the line with:
$(EXECUTABLE): $(OBJECTS)
$(CC) -m32 -o $# -Wl,-rpath,$(RUNTIME_PATH), $(LIB_PATH) $(OBJECTS) $(LIBS)
Its showing error because make is not able to find timeout.o file in the current directory.
If you have timeout.c file then add the following to your makefile
OBJECTS: timeout.c
$(CC) -c timeout.c