I recently started a small project in C++. I created a simply Makefile:
output: main.o google_api.o
g++ main.o google_api.o -o output
rm *.o
clear
./output
main.o: main.cpp
g++ -c main.cpp
test.o: google_api.cpp google_api.h
g++ -c google_api.cpp
And when I compile my code I get the next error -
non-aggregate type 'vector' cannot be initialized
with an initializer list
I am check for this issue and find that I need to add -std=c++11 support to my makefile to fix the problem. I add this command to the code:
g++ -std=c++11 main.o google_api.o -o output
But this is not make any change. I would love if someone can help me to fix this problem. Thanks
change this:
main.o: main.cpp
g++ -c main.cpp
to:
main.o: main.cpp
g++ -std=c++11 -c main.cpp
You may as well use something like this as basis for your Makefile:
CXX=g++
CXXFLAGS=-g -Wall -MMD -std=c++11
LDLIBS=-lm # list libs here
output: main.o google_api.o
clean:
$(RM) *.o *.d output
-include $(wildcard *.d)
There are also similar questions on stackoverflow: Makefile c++11 support
Related
I'm still learning how to set up a Makefile and I'm kind of lost here. I'm using windows and currently trying to fire up my Makefile for small C++ SDL project.
I have 3 .cpp files:
main.cpp
window.cpp
rect.cpp
As well as 2 extra header files:
Window.h
rect.h
So having trouble setting up everything on a Makefile
This is what i currently have:
CXXFLAGS = -Ideps/include -std=c++0x
LXXFLAGS = -Ldeps/lib -lmingw32 -lSDL2main -lSDL2
cup: main.o
g++ main.o -o cup $(LXXFLAGS)
main.o: main.cpp
g++ main.cpp -c $(CXXFLAGS)
window.o: window.cpp
g++ window.cpp -c
rect.o: rect.cpp
g++ rect.cpp -c
But I'm getting a bunch of undefined reference errors for my constructors on my command prompt.
Help please!
From the Makefile contents I read that cup binary is only created from main.o and it does not link window.o nor rect.o, which is where probably those missing references are defined. At the very least I would update the primary rule to say:
cup: main.o window.o rect.o
g++ $(LXXFLAGS) -o cup $^
Thus said, you could make even more use from implicit rules that are built into make, and, if following the standard naming for linking flags, the Makefile could be reduced even further to just a linking line (as compilation rules are implicit), e.g.:
$ cat Makefile
CXXFLAGS = -Ideps/include -std=c++0x
LDFLAGS = -Ldeps/lib
LDLIBS = -lmingw32 -lSDL2main -lSDL2
cup: main.o window.o rect.o
$(LINK.cc) $^ $(LDLIBS) -o $#
Output:
$ make
g++ -Ideps/include -std=c++0x -c -o main.o main.cpp
g++ -Ideps/include -std=c++0x -c -o window.o window.cpp
g++ -Ideps/include -std=c++0x -c -o rect.o rect.cpp
g++ -Ideps/include -std=c++0x -Ldeps/lib main.o window.o rect.o -lmingw32 -lSDL2main -lSDL2 -o cup
i'm trying to use the boost_math libs on OS X (i'm not using Xcode), specifically the one containing the error function
I downloaded and compiled boost_1_60_0 myself (using bootstrap.sh and following the instructions.) I didn't use home-brew or something else, which might be why my installation seems so screwed up.
What i'm trying to include in my Szabo.hpp is this:
#include <boost/math/special_functions/erf.hpp>
My makefile goes like this:
LIB_FLAGS = -L/Documents/boost_1_60_0/stage/lib -lboost_math
ALL_OBJECTS = main.o Gaussienne.o Grille.o Szabo.o
all: $(ALL_OBJECTS)
g++ -o hydrogene $(ALL_OBJECTS) $(LIB_FLAGS)
Gaussienne.o: Gaussienne.cpp
g++ -o Gaussienne.o -c Gaussienne.cpp -W -Wall -ansi
main.o: Gaussienne.hpp Grille.hpp main.cpp Szabo.o
g++ -o main.o -c main.cpp -W -Wall -ansi
Grille.o: Grille.cpp Gaussienne.cpp
g++ -o Grille.o -c Grille.cpp -W -Wall -ansi
Szabo.o: Szabo.cpp Gaussienne.cpp
g++ -o Szabo.o -c Szabo.cpp -W -Wall -ansi
clean:
rm -rf *.o
mrproper: clean
rm -rf hydrogene
I get no linking error from g++, however i got:
In file included from Szabo.cpp:12:
./Szabo.hpp:21:10: fatal error: 'boost/math/special_functions/erf.hpp' file not found
#include <boost/math/special_functions/erf.hpp>
^
1 error generated.
Can you please provide help on how to fix this? Thanks in advance
Ok so apparently likes this, it works:
LIB_FLAGS = -L/Users/devolution/Documents/boost_1_60_0/stage/lib -lboost_math_tr1
I_FLAGS = -I/Users/devolution/Documents/boost_1_60_0/
ALL_OBJECTS = main.o Gaussienne.o Grille.o Szabo.o
all: $(ALL_OBJECTS)
g++ -o hydrogene $(ALL_OBJECTS) $(LIB_FLAGS)
Gaussienne.o: Gaussienne.cpp
g++ -o Gaussienne.o -c Gaussienne.cpp -ansi ${I_FLAGS}
main.o: Gaussienne.hpp Grille.hpp main.cpp Szabo.o
g++ -o main.o -c main.cpp -ansi ${I_FLAGS}
Grille.o: Grille.cpp Gaussienne.cpp
g++ -o Grille.o -c Grille.cpp -ansi ${I_FLAGS}
Szabo.o: Szabo.cpp Gaussienne.cpp
g++ -o Szabo.o -c Szabo.cpp -ansi ${I_FLAGS}
.PHONY: clean mrproper
clean:
rm -rf *.o
mrproper: clean
rm -rf hydrogene
Is there a way to pass I_FLAGS?
You've compiled Boost's separately-compiled libraries, which is great, but you didn't copy the headers to your toolchain's include path. Indeed, most of Boost is comprised of header-only libraries, so this is arguably the more crucial step of installing Boost.
The internet tells me you may be able to find the default header search path with the following command at shell:
gcc -x c++ -v -E /dev/null
(https://stackoverflow.com/a/19852298/560648)
When you find it, copy the distribution's boost subdirectory to it.
And, yes, having home-brew install Boost for you would have been much easier… probably one command!
I am doing a c++ project with multiple source files and trying to get used to using makefiles. I want to be able to debug this program with gdb. If I use the following command in Terminal to compile, it works fine:
g++ -o main -g *.cpp
But if I just call make it doesn't generate a debug file (the .dSYM file) even though it compiles the program fine. I assume this has something to do with creating the individual object files first. Here is my makefile:
all: main.o sort.o bubble.o quickSort.o rbs.o
g++ -g -o main *.o -Wall -O2
main.o: main.cpp
g++ -c main.cpp
sort.o: sort.cpp sort.h
g++ -c sort.cpp
bubble.o: bubble.cpp bubble.h
g++ -c bubble.cpp
quickSort.o: quickSort.cpp quickSort.h
g++ -c quickSort.cpp
rbs.o: rbs.cpp rbs.h
g++ -c rbs.cpp
clean:
rm *.o
How do I create the main.dSYM debug file when using a makefile like this?
If you want the debug files, you must compile all of the components with -g.
The crude way to do this would be to add -g to every object rule:
all: main.o sort.o bubble.o quickSort.o rbs.o
g++ -g -o main *.o -Wall -O2
main.o: main.cpp
g++ -c -g main.cpp
sort.o: sort.cpp sort.h
g++ -c -g sort.cpp
bubble.o: bubble.cpp bubble.h
g++ -c -g bubble.cpp
quickSort.o: quickSort.cpp quickSort.h
g++ -c -g quickSort.cpp
rbs.o: rbs.cpp rbs.h
g++ -c -g rbs.cpp
But that doesn't leave you the option of building without debug information. And there's a lot of redundancy in this makefile. Let's take this in stages. First, we put in automatic variables to simplify the rules:
all: main.o sort.o bubble.o quickSort.o rbs.o
g++ -g -o main $^ -Wall -O2
main.o: main.cpp
g++ -c -g $<
sort.o: sort.cpp sort.h
g++ -c -g $<
bubble.o: bubble.cpp bubble.h
g++ -c -g $<
quickSort.o: quickSort.cpp quickSort.h
g++ -c -g $<
rbs.o: rbs.cpp rbs.h
g++ -c -g $<
Now we see that all of the *.o rules have the same command, which reminds us that Make already knows how to build foo.o from foo.cpp, with a command that looks like:
$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c
So all we have to do is add -g to CXXFLAGS, and we can omit the commands entirely:
CXXFLAGS += -g
all: main.o sort.o bubble.o quickSort.o rbs.o
g++ -g -o main $^ -Wall -O2
sort.o: sort.h
bubble.o: bubble.h
quickSort.o: quickSort.h
rbs.o: rbs.h
Now that that's in order, we can set up two top-level targets, main and debug, and change CXXFLAGS only for the latter:
debug: CXXFLAGS += -g
main debug: main.o sort.o bubble.o quickSort.o rbs.o
g++ -g -o $# $^ -Wall -O2
sort.o: sort.h
bubble.o: bubble.h
quickSort.o: quickSort.h
rbs.o: rbs.h
You can improve this even more, but that should get you started.
I have made a Makefile for my CMSC 202 course project, 'Blackjack'. It does everything I need it to and it works perfectly. You may be asking why I posted here then, this is because I have no idea how it works and I didn't use any other resources but myself to create it.
Here is my Makefile code.
# Object files to either reference or create
OBJECTS = Proj2.o Blackjack.o Deck.o Card.o Hand.o Player.o
# The executable file that will be created at the end
EXEC = Proj2.out
# The flags to use for compilation
FLAGS = -Wall
# The code compiler to use for compilation
CC = g++
# Perform action on all object files (May or may not exist)
all: $(OBJECTS)
$(CC) $(FLAGS) -o $(EXEC) $(OBJECTS)
Here is the terminal output when I call make in the terminal.
g++ -c -o Proj2.o Proj2.cpp
g++ -c -o Blackjack.o Blackjack.cpp
g++ -c -o Deck.o Deck.cpp
g++ -c -o Card.o Card.cpp
g++ -c -o Hand.o Hand.cpp
g++ -c -o Player.o Player.cpp
g++ -Wall -o Proj2.out Proj2.o Blackjack.o Deck.o Card.o Hand.o Player.o
Can anyone tell me how the .o files are being compiled? It does not look like they are being prompted to be compiled with that g++ -c -o $.o $.cpp command anywhere in the Makefile. Nor did I state to use any .cpp files.
Thank you in advance for your help.
Edit
Thanks to all your great help, this is now the terminal output I receive when using make.
g++ -Wall -c -o Proj2.o Proj2.cpp
g++ -Wall -c -o Blackjack.o Blackjack.cpp
g++ -Wall -c -o Deck.o Deck.cpp
g++ -Wall -c -o Card.o Card.cpp
g++ -Wall -c -o Hand.o Hand.cpp
g++ -Wall -c -o Player.o Player.cpp
g++ -Wall -o Proj2.out Proj2.o Blackjack.o Deck.o Card.o Hand.o Player.o
Thank you so much to all of you who have contributed.
Make has a set of implicit rules (see here for a reference). For instance
Compiling C++ programs
`n.o' is made automatically from `n.cc' or `n.C' with a command of the form
`$(CXX) -c $(CPPFLAGS) $(CXXFLAGS)'.
Most make's will also use this rule for .cpp files.
When make sees there's a x.o requirement for one of your targets, it will try to see if it can generate x.o using implicit rules, and in your case find it can do it starting from a .cpp file.
This Makefile uses implicit rules which are a great way to reduce duplication.
By default the first target will be built, here all. It depends on a number
of object files listed in a variable $OBJECTS, e.g. Proj2.o who's
dependencies aren't listed in the Makefile. Now if make sees an input file in the current directory
with a matching name, e.g. Proj2.cpp it will try
to build Proj2.o from it (there are other implicit rules for sources in
other languages). Proj2.o would then be built by default with the command
$(CXX) $(CXXFLAGS) -c -o Proj2.o
where $(CXX) the name of the C++ compiler (g++ in your case).
The explicit build step for all assembles all the object files into the
target executable.
Looking at above build command you'll notice a small problem in your Makefile. Since the flags to the C++ compiler are given in a variable FLAGS and not the standard CXXFLAGS no warnings will be emitted when building the object files. Using the standard name would fix this (you do want warnings, maybe even more than -Wall gives you).
So, I'm making a program to test the efficiency of certain data structures. I have all the .h files and I made a very terrible makefile that probably is wrong, although it seems to work up to a point. Instead of making .o files it makes .gch files, so when it tries to acces all the .o files they are not found. This is my makefile
prog1: main.o dsexceptions.o BinarySearchTree.o SplayTree.o RedBlackTree.o AvlTree.o
g++ -Wall -g -o prog1 main.o dsexceptions.h.gch BinarySearchTree.h.gch SplayTree.h.gch RedBlackTree.h.gch AvlTree.h.gch
main.o: main.cpp AvlTree.h RedBlackTree.h SplayTree.h BinarySearchTree.h dsexceptions.h
g++ -Wall -g -c main.cpp
#shape.o: shape.cpp shape.h grid.h
# g++ -Wall -g -c shape.cpp
dsexceptions.o: dsexceptions.h
g++ -Wall -g -c dsexceptions.h
BinarySearchTree.o: BinarySearchTree.h dsexceptions.h
g++ -Wall -g -c BinarySearchTree.h
SplayTree.o: SplayTree.h dsexceptions.h
g++ -Wall -g -c SplayTree.h
RedBlackTree.o: RedBlackTree.h dsexceptions.h
g++ -Wall -g -c RedBlackTree.h
AvlTree.o: AvlTree.h dsexceptions.h
g++ -Wall -g -c AvlTree.h
clean:
rm -f main main.exe main.o dsexceptions.o BinarySearchTree.o SplayTree.o RedBlackTree.o AvlTree.o *.gch
You don't want to feed your .h files to the compiler. Only compile the .cpp file, which should include your .h files. (The .gch files are precompiled headers.) You don't need .o files for your headers, just #include them in your .cpp file.
prog1: main.o
g++ -Wall -g -o prog1 main.o
main.o: main.cpp AvlTree.h RedBlackTree.h SplayTree.h BinarySearchTree.h dsexceptions.h
g++ -Wall -g -c main.cpp
clean:
rm -f prog1 main.o
You already have the solution from bstpierre, but just for fun here's my version of your makefile:
CC = g++ -Wall -g -o $#
MODULE = AvlTree BinarySearchTree RedBlackTree SplayTree
OBJECTS = $(addsuffix .o,$(MODULES))
prog1: main.o dsexceptions.o $(OBJECTS)
$(CC) $^
main.o: $(addsuffix .h,$(MODULES))
$(OBJECTS) main.o : %.cpp %.h dsexceptions.h
$(CC) -c $<
clean:
rm -f main main.exe *.o *.gch
And just for good measure, here is my SConstruct, because SCons's so much better :)
Program('main.cpp') # Yeah, it's that simple :)
You can look at SCons here.