Makefile Issue linking Zeromq libs on Linux - c++

I'm working on a project and trying to compile my code. I just moved this code from windows (VC++) to linux and it worked fine on windows but I can't get it to compile on linux.
The program uses zeromq for TCP connections and I am getting multiple errors when I build. Errors of the type:
/usr/local/include/zmq.hpp:372: undefined reference to `zmq_bind'
/usr/local/include/zmq.hpp:415: undefined reference to `zmq_msg_send'
I've installed zeromq via its tarball on my linux machine, and manually added zmq.hpp to the /usr/local/include folder. I suspect that I am doing something wrong in my makefile and thats why I am getting these errors.
I am somewhat weak in creating makefiles so I would greatly appreciate if someone can take a look for me and tell me if there is an obvious issue with my makefile that is causing these issues. Here is my makefile
C = g++
DEBUG = -g
CFLAGS = -g -Wall -std=c++11
LFLAGS = -L/usr/local/lib/
INCLUDES = -I/usr/local/
LIBS = -libzmq.la
SRCS = main.cpp NetworkTestServer.cpp
OBJS = $(SRCS:.cpp=.o)
EXECUTABLE = tester
all: $(SRCS) $(EXECUTABLE)
$(EXECUTABLE): $(OBJS)
$(CC) $(EXECUTABLE) -o $(EXECUTABLE) $(LIBS)
.cpp.o:
$(CC) $(CFLAGS) $< -o $#
clean:
$(RM) *.o *~ $(EXECUTABLE)
Thanks much

Looks to me like your LIBS definition is wrong.
Typically, the lib part is omitted, along with the extension. So, try something like:
LIBS = -lzmq
If that doesn't work, ensure that this library is contained in the location as specified by your LFLAGS variable.

Related

Building a C/C++ program for Windows/MacOS/Linux with dependencies

I need to build a program on Windows, MacOS and Linux which relies on multiples dependencies. I tried to limit them as much as I could but I should ended up using WxWidgets, libcurl, openssl and libarchive.
I choose those dependencies because I must be able to:
compute a md5 hash (openssl)
decompress a zip archive (libarchive)
provide a GUI (WxWidgets)
use HTTPS (libcurl)
I am aware that this might be an overkill to import 5 libraries to only do those 5 things but I do not know any better solution yet. As I am writing this, I'm only using libcurl and openssl and building for Windows, MacOS and Linux is already very difficult for me.
I would like to distribute a standalone executable for each platform in addition to the source code, to build my project, I use the following Makefile :
CXX = g++
NAME = foo
SRC = $(wildcard src/*.cpp)
OBJ = $(SRC:.cpp=.o)
CXXFLAGS = -I./inc -std=c++11 -Wall -Wextra -Werror -g
all : $(NAME)
$(NAME) : $(OBJ)
$(CXX) $(CXXFLAGS) -o $# $^ -lcurl -lssl -lcrypto
clean :
rm -rf $(SRC:.cpp=.o)
fclean : clean
rm -rf $(NAME) test
re : fclean all
reclean : fclean all clean
.PHONY : all clean fclean re reclean
This worked great(even on Windows thanks to MSYS2 and MINGW) until I tried to statically linked each library to distribute a standalone binary :
$(NAME) : $(OBJ)
$(CXX) $(CXXFLAGS) -o $# $^ -lcurl -lssl -lcrypto
becamed
$(NAME) : $(OBJ)
$(CXX) $(CXXFLAGS) -o $# $^ libcurl.a libssl.a libcrypto.a
On Linux(Ubuntu 22.04), I downloaded curl and openssl source codes and built them using -static flags, copied the *.a inside my project's directory and I was done.
Now I'm trying to build curl and openssl on Windows with MSYS2, most of my attempts failed with error messages and took forever(> 30 minutes) to complete the build process. After struggling a little too much time, I finally managed to compile openssl by adding -lcrypto -lcrypt32..?
I do not think I will be able to finish this project with this "building process" as I still need to figure it out how build and link libarchive and WxWidgets. Is there anything I am missed out regarding the building process ? Should I pick others libraries ? Or It is just how it is ?
Thanks for your help.

Issue with Makefile for mysql

I'm having issues linking mysql to my project. I've tried several ways that I found online (I'm new to Makefiles so bear with me) anyway, here's my makefile:
CC=g++
CFLAG=-c
INCLUDES="/Library/mysql"
all:myapp
myapp: main.o Application.o
$(CC) main.o Application.o
main.o: main.cpp
$(CC) $(CFLAGS) main.cpp
Application.o: Application.cpp $(INCLUDES)
$(CC) -lm $(INCLUDES) $(CFLAGS) Application.cpp
clean:
rm -rf *o myapp
mysql.h is #included in the Application.h file. The mysql folder is located in "/Library"
I'm running OS X Mavericks (if that's relevant).
The error is
make: *** No rule to make target `"/Library/mysql"', needed by `Application.o'. Stop.
You should use the variables CXX and CXXFLAGS for C++ compiler and flags, not CC and CFLAGS; those are for C compilers.
When you pass directories to the compiler for searching for headers, you have to prefix them with the -I flag. Also preprocessor flags are best put in the CPPFLAGS variable, so you should use:
CPPFLAGS = -I/Library/mysql
You shouldn't put directories as prefixes for targets, so don't add the $(INCLUDES) (or $(CPPFLAGS)) variable to the prerequisites list of Application.o.

Makefile not using include/library paths?

Well, after 3 hours of researching, I'm about to go insane, so I figure it's time to pass it off to some new eyes.
CXXFLAGS = -g -Wall
OBJS = main.o
PROG = test
INCLUDES = -I /usr/include/mysql -I /usr/local/include
LIBS = -L /usr/lib/mysql -l libmysqlclient.so.15.0.0 -L /usr/local/lib -l libmysqlpp.so.3.1.0
all: $(PROG)
${PROG}: $(OBJS)
$(CXX) $(INCLUDES) -o $(PROG) $(OBJS) $(LIBS)
clean:; $(RM) -f $(PROG) core *.o
There's something wrong with the include paths, because I get errors that mysql_version.h does not exist when it clearly does exist in /usr/include/mysql.
Checking the first part out of the ouput, it says
g++ -g -Wall -c -o main.o main.cpp
which makes me think that I've formatted something in the Makefile wrong (due to the extra spaces and lack of include/library paths). However, I've looked at dozens of manuals and articles on Makefiles and the g++ options and... no progress.
I assume this should be a simple fix. Please, please help (do you sense my despair?).
On another note, do you think specifying the library specifically is necessary? I had this stuff running in XCode just fine, but I'm trying to migrate the code to my web server... the Makefile has stopped all progress, and I figure it's something I should learn from.
In your makefile, you have added your include directives to the linking stage, not the compiling stage.
The lines
${PROG}: $(OBJS)
$(CXX) $(INCLUDES) -o $(PROG) $(OBJS) $(LIBS)
Say to make the program in ${PROG} from object files in ${OBJS} by calling the compiler in ${CXX} passing the include folders (along with your other arguments). Instead, for your variable section, do this:
INCLUDES = -I /usr/include/mysql -I /usr/local/include
CXXFLAGS = -g -Wall ${INCLUDES}
OBJS = main.o
PROG = test
LIBS = -L /usr/lib/mysql -l libmysqlclient.so.15.0.0 -L /usr/local/lib -l libmysqlpp.so.3.1.0
This way your CXXFLAGS (which are used for the compile stage) should now pickup your include directives.

Updating a legacy C makefile to include a C++ source file

I work in a computational biophysics lab. I am not a programmer, although I do get paid to act like one. Here's my problem: the main product of the lab is a ginormous (50+ source files) C program. I need to get our lab's program to work with another lab's toolkit, which just so happens to be in the form of a series of C++ libraries (.a files). I can get the main library for our program to compile using the following makefile:
CC = gcc
#CC = icc
CFLAGS = -g -Wall
#CFLAGS = -xT -openmp -I/opt/local/include -I/usr/local/include -I/opt/GDBM/include
#CFLAGS = -O3 -g -Wall -I/opt/GDBM/include -fopenmp
LIB = mcce.a
AR = ar
ARFLAGS = rvs
SRC = all.c ddvv.c geom_3v_onto_3v.c ins_res.c strip.c\
app.c del_conf.c geom_apply.c line_2v.c vdotv.c\
avv.c del_prot.c geom_inverse.c load_all_param.c vector_normalize.c\
avvvv.c del_res.c geom_move.c load_param.c vector_vminusv.c\
cpy_conf.c det3.c geom_reset.c mxm4.c vector_vplusv.c\
cpy_prot.c det4.c geom_roll.c new_prot.c vector_vxv.c\
cpy_res.c dll.c get_files.c param_get.c param_exist.c\
db_close.c dvv.c iatom.c param_sav.c\
db_open.c free_strings.c ins_conf.c plane_3v.c pdbline2atom.c\
premcce.c init.c load_pdb.c write_pdb.c rotamers.c assign_rad.c get_connect12.c\
surfw.c vdw.c vdw_conf.c shuffle_n.c cmp_conf.c sort_conf.c sort_res.c id_conf.c\
energies.c assign_crg.c coulomb.c coulomb_conf.c\
get_vdw0.c get_vdw1.c relax_water.c relax_h.c monte.c monte2.c ran2.c\
relaxation.c collect_connect.c torsion.c vdw_fast.c hbond_extra.c swap.c quick_e.c\
check_tpl.c zip.c del_dir.c make_matrices.c\
mem_position.c probe.c add_membrane.c load_pdb_no_param.c ga_engine.c rotamers_ga.c compute_patches.c
OBJ = $(SRC:.c=.o)
HEADER = mcce.h
$(LIB): $(OBJ)
$(AR) $(ARFLAGS) $(LIB) $(OBJ)
$(OBJ): $(HEADER)
.c.o:
$(CC) $(CFLAGS) -c $*.c
clean:
rm -f *.o mcce.a
The executable itself then compiles with this makefile:
CC = gcc -g -O3
#CC = icc -xT -static-intel -L/opt/local/lib -L/usr/local/lib
mcce: mcce.c lib/mcce.h lib/mcce.a
# $(CC) -o mcce mcce.c mcce.a /opt/GDBM/lib/libgdbm.a -lm -lz -openmp; cp mcce bin
$(CC) -o mcce mcce.c lib/mcce.a -lgdbm -lm -lz -fopenmp; cp mcce bin
I can get a standalone version of the other lab's code to compile using this other makefile:
OEDIR = ../..
INCDIR = $(OEDIR)/include
LIBDIR = $(OEDIR)/lib
INCS = -I$(INCDIR)
LIBS = -L$(LIBDIR) \
-loezap \
-loegrid \
-loefizzchem \
-loechem \
-loesystem \
-loeplatform \
-lz \
-lpthread -lm
CXX = /usr/bin/c++
RM = rm -f
CXXFLAGS = -m64 -W -Wall -O3 -fomit-frame-pointer -ffast-math
LFLAGS = -m64 -s
TEXT2HEX = ../text2hex
PROGRAMS = other_labs_code
.SUFFIXES: .cpp
.SUFFIXES: .o
.cpp.o:
$(CXX) $(CXXFLAGS) $(INCS) -c $<
.SUFFIXES: .txt
.SUFFIXES: .itf
.txt.itf:
$(TEXT2HEX) $< InterfaceData > $#
all: $(PROGRAMS)
clean:
$(RM) $(PROGRAMS)
$(RM) ii_files core a.out *.itf
$(RM) *.o
other_labs_code.o: other_labs_code.cpp other_labs_code.itf
other_labs_code: other_labs_code.o
$(CXX) other_labs_code.o $(LFLAGS) -o $# $(LIBS)
I know that I have to change the paths of the various libs and stuff, but other than that, how do I combine all of these makefiles into one working product? Also, since some of the source files that go into compiling my program's main library (mcce.a) are going to need to be able to call functions from the C++ source file, it's the library's makefile that I need to modify, right?
I know extremely little about makefiles, so even if someone can just point me in the direction of a tutorial that covers this kind of problem (writing a makefile for a many source file C and C++ program), that may be sufficient.
For bonus points, the C++ FAQ says that:
You must use your C++ compiler when compiling main() (e.g., for static initialization)
Your C++ compiler should direct the linking process (e.g., so it can get its special libraries)
I don't exactly know what those things are supposed to mean, but assuming that I did, are there any other important points like that I should be aware about when combining C and C++?
Preparing the code
C programs cannot just use C++ symbols. Unless the authors of the C++ code arranged for that. This is because some features that C++ offers, such as function overloading (having several functions of the same name but with different formal arguments) demand that the function name be mangled in some way. Else the linker would see the same symbol defined several times. C compilers don't understand this name mangling and therefore cannot use C++ symbols. There are, generally, two possible solutions.
Declare and define all C++ symbols that the C code wants to use within extern "C" { ... } blocks and let your C++ tools handle the linking. The C code does not need to be changed in this case.
Compile the C code with the (exact same) C++ compiler as the C++ code. Fix the C++ compiler's complaints of the C code as they arise. Depending on project size and coding style, this may or may not be a lot of work.
Preparing a master Makefile
I personally try to avoid becoming intimate with other people's Makefiles, especially if they are subject to change or complex. So, assuming generating a Makefile that orchestrates the bits you already have (as opposed to writing one Makefile incorporating everything) is okay, I'd start out with something similar to this:
I'm assuming that
One of the above-mentioned options has been implemented
The code for mcce.a lies in subdirectory mcce/lib/
other_labs_code.cpp lies in other_labs_code/
The main function you want to use lies in ./mystuff.c
the following top-level Makefile may get you started
CXX = c++
CXXFLAGS = -m64 # From other_labs_code/Makefile
LDFLAGS = -m64 -L<path to OEDIR> # From other_labs_code/Makefile
LIBS = -lgdbm -lm -lz # From mcce/lib/Makefile
LIBS += -loezap \ # From other_labs_code/Makefile
-loegrid \
-loefizzchem \
-loechem \
-loesystem \
-loeplatform \
-lpthread
mystuff: mystuff.c mcce/lib/mcce.a other_labs_code/other_labs_code.o
$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) -o $# $^ $(LIBS)
mcce/lib/mcce.a:
cd mcce/lib/ && $(MAKE) CC="$(CXX) -m64" mcce.a
other_labs_code/other_labs_code.o:
cd other_labs_code/ && $(MAKE) other_labs_code.o
Makefile: mcce/lib/Makefile other_labs_code/Makefile
echo "Warning: `pwd`/$# is out of date" >&2
This Makefile will employ the existing sub-project Makefiles to do the compilations. If the sub-project Makefiles have a newer timestamp than this Makefile, potentially rendering it obsolete, then this will be warned about. The linking basically works by combining the required libraries of both sub-projects. I've removed duplicates. The compiler switches are basially those of the original authors since compiling is delegated to the sub-projects. The code both sub-projects generate must be for the same platform. If your compiler is gcc/g++ then either -m64 is the default and therefore redundant in the second project or should be added to the first project. I have illustrated injecting it into the first project without changing their Makefile (using GNU make). NB: This example also causes the first project to be compiled with the C++ compiler.
An extern "C" {...} block located in a C or C++ header file that C code wants to include should look like this
/* inclusion guard etc */
#if defined(__cplusplus)
extern "C" {
#endif
/* C declarations */
#if defined(__cplusplus)
}
#endif
/* inclusion guard etc */
Minor points
In the first posted Makefile, I suggest changing the bottom part to
.c.o:
$(CC) $(CFLAGS) -c -o $# $<
clean:
rm -f $(OBJ) mcce.a
.PHONY: clean
which is a tiny bit cleaner.
The second Makefile is broken. The bottom rule links the binary and then copies it to a directory named bin, if it exists, else a copy of the file is created and named `bin'. If the linking fails, that fact is not propagated to the caller, i.e. the error is ignored. The bottom rule should read
mcce: mcce.c lib/mcce.h lib/mcce.a
$(CC) -o $# mcce.c lib/mcce.a -lgdbm -lm -lz -fopenmp
cp mcce bin/
i.e. the link command should be on its own line and that `bin' is supposed to be a directory should be made explicit.
http://www.gnu.org/software/make/manual/make.html#Introduction

How to link jsoncpp?

How can I link jsoncpp with a C++ program using g++? I tried:
g++ -o program program.cpp -L/path/to/library/files -ljsoncpp, -ljson, -llibjsoncpp
but g++ keeps saying:
/usr/bin/ld: cannot find -lsomething
You could also try using the new Amalgamated version of jsoncpp, which is new as of version 0.6.0.
The Amalgamated version allows you to use jsoncpp by adding just one directory with a couple of header files and one .cpp file to your project. You then can directly compile jsoncpp into your program with no worries about having to link to any jsoncpp libraries.
Look in /path/to/library/files to see what your *.a file is really named. On my system, I link with:
-ljson_linux-gcc-4.4.3_libmt
Some libraries will create a link from lib<name>.a to lib<name>-<version>.a for you, but I don't think that jsoncpp does this automatically. Therefore, you need to specify the complete name when linking.
You basically need to tell the path and the library.
jsoncpp library has pkg-config and you can use the command
`pkg-config --cflags path/to/jsoncpp/build/pkg-config/jsoncpp.pc`
for the include path and
`pkg-config --libs ../jsoncpp/build/pkg-config/jsoncpp.pc`
for linking (when running the command with g++ use the ). To see the single commands which is -L/libraryPath -ljsoncpp) run the commands above in the terminal without the ``.
It is easier to use this commands in a Makefile. As example my Makefile is:
CXX = g++
CXXFLAGS = -std=c++11
INC_PATH = `pkg-config --cflags ../jsoncpp/build/pkg-config/jsoncpp.pc`
LIBS = `pkg-config --libs ../jsoncpp/build/pkg-config/jsoncpp.pc`
SOURCES := $(wildcard *.cpp)
OBJDIR=obj
OBJECTS := $(patsubst %.cpp,$(OBJDIR)/%.o,$(SOURCES))
DEPENDS := $(patsubst %.cpp,$(OBJDIR)/%.d,$(SOURCES))
# ADD MORE WARNINGS!
WARNING := -Wall -Wextra
# .PHONY means these rules get executed even if
# files of those names exist.
.PHONY: all clean
# The first rule is the default, ie. "make",
# "make all" and "make parking" mean the same
all: yourProjectExecutableName
clean:
$(RM) $(OBJECTS) $(DEPENDS) parking
# Linking the executable from the object files
yourProjectExecutableName: $(OBJECTS)
$(CXX) $(WARNING) $(CXXFLAGS) $(INC_PATH) $^ -o $# $(LIBS)
-include $(DEPENDS)
$(OBJDIR):
mkdir -p $(OBJDIR)
$(OBJDIR)/%.o: %.cpp Makefile $(OBJDIR)
$(CXX) $(WARNING) $(CXXFLAGS) $(INC_PATH) -MMD -MP -c $< -o $#
and then in the directory of the file I run make. The final command(s) will be printed out in the Terminal