Writing your Own Makefile - unix

I am trying to write a Makefile but it is showing
Make: Don't know how to make cc. Stop.
what I am doing is this :-
Hello.c
#include<stdio.h>
extern int print();
int main(){
print();
return 0;
}
print.c
#include<stdio.h>
int print(){
printf("hello\n");
return 0;
}
Makefile
all: OUT
OUT: cc Hello.o print.o -o OUT
Hello.o: Hello.c\
cc -c Hello.c
print.o: print.c \
cc -c print.c
clean: rm -f *.o
clobber: rm -f OUT
when I am writing make
$>make
Make: Don't know how to make cc. Stop.
$>make clean
Make: Don't know how to make rm. Stop.
what thing I am missing..
I am newbie with this make and makefile, so please suggest me some good tutorials on this
I changed to this :-
all: OUT
OUT:; #cc Hello.o print.o -o OUT
Hello.o:; #cc -c Hello.c
print.o:; #cc -c print.c
clean:; #rm -f *.o
clobber:; #rm -f OUT
showing error:-
cc: warning 1913:Hello.o' does not exist or cannot be read
cc: warning 1913: print.o' does not exist or cannot be read
ld: I/O error, file "Hello.o": No such file or directory
Fatal error.
*** Error exit code 1

The rules must be on a different line than the targets, indented with a hard tab:
all: OUT
OUT: Hello.o print.o
cc Hello.o print.o -o OUT
Hello.o: Hello.c
cc -c Hello.c
print.o: print.c
cc -c print.c
clean:
rm -f *.o
clobber:
rm -f OUT
But this can be simplified by relying on implicit rules and generalized by using some variables:
all: OUT
OUT: Hello.o print.o
$(CC) $(CFLAGS) $^ -o $#
clean:
rm -f *.o
clobber:
rm -f OUT

Related

GNU Make: always build pre-targets but don't rebuild target

Imagine my Makefile has something like:
CXXFLAGS = -O3 ${INCLUDES} --std=c++17 -g ${AUTO_ARGUMENT}
COMPILE.cc = $(CXX) $(DEPFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c
.PHONY: all directories
all: directories programs
directories: obj
obj:
mkdir obj
programs: Foo
Foo: obj/Foo.o
${CXX} obj/Foo.o ${LDFLAGS} -o Foo
obj/%.o : %.cpp
$(COMPILE.cc) $(OUTPUT_OPTION) $<
clean:
rm -rf Foo obj
I can execute make and it will create the obj subdirectory then do a nice compile and link. Works great. But if I do make clean Foo, it's going to fail. The clean removed the subdir and because I bypassed all to just make a single target, it doesn't recreate obj.
So I can do this:
Foo: directories obj/Foo.o
${CXX} obj/Foo.o ${LDFLAGS} -o Foo
But then it ALWAYS does the link:
$ make
g++ obj/Foo.o -o Foo
$ make
g++ obj/Foo.o -o Foo
But if I remove the directories part from Foo:
$ make
make: Nothing to be done for 'all'.
This is even worse:
obj/%.o : directories %.cpp
$(COMPILE.cc) $(OUTPUT_OPTION) $<
So, my question... Is there some way that I can tell an individual target to do some of the pre-setup without that target then always being rebuilt? I could probably make fake targets like this:
makeFoo: directories Foo
But that's annoying. I could also have all be:
all: setup programs
setup: directories
And then do make setup Foo. That's only moderately annoying. What I'd really like is the rule for the objects to ensure the directory exists without adding any spam or unnecessary rebuilds. I suppose I could add something to that particular rule to ensure the directory exists:
obj/Foo.o: Foo.cpp
if [ -d obj ]; then \
mkdir obj \
fi
$(COMPILE.cc) $(OUTPUT_OPTION) $<
Is there a cleaner way?
Thanks to Andreas, I made some adjustments. Here's my entire sample Makefile:
CXXFLAGS = -O3 ${INCLUDES} --std=c++17 -g ${AUTO_ARGUMENT}
COMPILE.cc = $(CXX) $(DEPFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c
.PHONY: all directories
all: directories programs
directories: | obj
obj:
mkdir obj
programs: Foo
Foo: obj/Foo.o
${CXX} obj/Foo.o ${LDFLAGS} -o Foo
obj/%.o : %.cpp | obj
$(COMPILE.cc) $(OUTPUT_OPTION) $<
clean:
rm -rf obj Foo
And here are my runs:
$ make clean Foo
rm -rf obj Foo
mkdir obj
g++ -O3 --std=c++17 -g -c -o obj/Foo.o Foo.cpp
g++ obj/Foo.o -o Foo
$ make Foo
make: 'Foo' is up to date.
The trick was order-only dependencies -- the pipe thing. See the rule for obj/%.o and directories. Note that it works the same if I do it this way or if my obj/%.o rule used directories instead.

Makefile | How to check only once whether an output dir already exists?

Currently the shell script checks for the existence of intended object directory right before each compiler call. How do I modify my Makefile so that the code checks only once before it moves on to compiling all the prerequisites?
Here is my Makefile:
#########################################################
## BUILD TASKS ##
#########################################################
HDIR := hdr
SDIR := src
ODIR := obj
EXET := a
OBJS := main.o mainhdr.o testcode.o
OSRC := $(addprefix $(ODIR)/, $(OBJS))
CXX := g++
CXXFLAGS := -I$(HDIR) -g -Wall -std=c++17
## BUILD DIRECTIVE:
all: $(EXET)
$(EXET): $(OSRC)
$(CXX) $(CXXFLAGS) $^ -o $#
$(ODIR)/%.o: $(SDIR)/%.cpp
if [ ! -d "$(ODIR)" ]; then mkdir $(ODIR); fi
$(CXX) -c $(CXXFLAGS) $^ -o $#
## foo.bak: foo.bar
## if [ ! -d "$(ODIR)" ]; then mkdir $(ODIR); fi
#########################################################
## CLEAN TASK ##
#########################################################
.PHONY: clean
clean:
rm -r $(EXET) $(ODIR)
I have tried putting:
foo.bak: foo.bar
if [ ! -d "$(ODIR)" ]; then mkdir $(ODIR); fi
as suggested here right before the clean task, but that doesn't seem to work. I could be understanding it wrong, but isn't that the Makefile is executed recursively so by putting that block of code at the end it should be at the tip of recursion and thus executed before everything else?
On newer gnu-make, you can use 'order-only-prerequisites`. This eliminate the timestamp checking, and only required that the prerequisite will exists. This works well to ensure that directories will be created before files are stored into them, and can significantly speedup build jobs
$(ODIR):
mkdir $(ODIR)
# Note pipe '|' to separate order only prereq.
$(ODIR)/%.o: $(SDIR)/%.cpp | $(ODIR)
$(CXX) -c $(CXXFLAGS) $^ -o $#
See: https://www.gnu.org/software/make/manual/make.html#Prerequisite-Types

Issue generating MOC files for QT using a makefile

Hello i am trying to generate MOC files for QT using a makeifle.
The problem is a command is executing from somewhere and i can't find from where....
This is my makefile
BUILD = Build
### SOURCES ###
SRC = Src/Main\
Src/DialogBox/DialogBox
### MOC SOURCES ###
MOC_SRC = Src/DialogBox/DialogBox
### OBJECTS ###
OBJ = $(addsuffix .o, $(addprefix $(BUILD)/, $(SRC)))
OBJ += $(addsuffix .moc.o, $(addprefix $(BUILD)/, $(MOC_SRC)))
### INCLUDES ###
INC = TOO MANY INCLUDES TO PUT HERE....
### LINKER FLAGS ###
LDFLAGS = -LC:/Qt/5.15.0/mingw81_32/lib
LDLIBS = -lQt5Quick -lQt5PrintSupport -lQt5Qml -lQt5Network -lQt5Widgets -lQt5Gui -lQt5Core
### COMPILER FLAGS
CFLAGS = $(INC)
### COMPILER ###
CC = g++
### QT MOC ###
MOC = moc
all: $(BUILD)/test.exe
$(BUILD)/test.exe: $(OBJ)
#echo LINKING $^
#$(CC) $(LDFLAGS) -o $# $^ $(LDLIBS)
$(BUILD)/%.o: %.cpp
#echo COMPILING $<
#mkdir -p $(subst /,\,$(dir $#))
#$(CC) $(CFLAGS) -M -MT $# -o $(patsubst %.o, %.d, $#) $<
#$(CC) $(CFLAGS) -o $# -c $<
$(BUILD)/%.moc.cpp: %.h
#echo MOCCING $<
$(MOC) $< -o $#
#echo MOC END
-include $(OBJ:.o=.d)
.PHONY: clean
clean:
#echo CLEANING......
#rm -rf $(BUILD)/Src $(BUILD)/test.exe
This is the result:
COMPILING Src/Main.cpp
COMPILING Src/DialogBox/DialogBox.cpp
MOCCING Src/DialogBox/DialogBox.h
moc Src/DialogBox/DialogBox.h -o Build/Src/DialogBox/DialogBox.moc.cpp
MOC END
g++ -c -o Build/Src/DialogBox/DialogBox.moc.o Build/Src/DialogBox/DialogBox.moc.cpp
In file included from Build/Src/DialogBox/DialogBox.moc.cpp:10:0:
Build/Src/DialogBox/../../../Src/DialogBox/DialogBox.h:4:19: fatal error: QDialog: No such file or directory
#include "QDialog"
^
compilation terminated.
make: *** [<builtin>: Build/Src/DialogBox/DialogBox.moc.o] Error 1
rm Build/Src/DialogBox/DialogBox.moc.cpp
Basically i have only two source files: Main.cpp and DialogBox.cpp.
I want to generate MOC file from DialogBox.h.
The problem is this command:
g++ -c -o Build/Src/DialogBox/DialogBox.moc.o Build/Src/DialogBox/DialogBox.moc.cpp
I don't understand why it's executing...
EDIT:
Even after:
MOCCING Src/DialogBox/DialogBox.h
moc Src/DialogBox/DialogBox.h -o Build/Src/DialogBox/DialogBox.moc.cpp
MOC END
no such file Build/Src/DialogBox/DialogBox.moc.cpp exists.Why?
I finally fixed it.As #G.M. suggested in the comments, probably an implicit rule is executing so i decided to write my own to avoid that.
I added this:
$(BUILD)/%.moc.o: $(BUILD)/%.moc.cpp
#echo COMPILING MOC $<
#mkdir -p $(subst /,\,$(dir $#))
#$(CC) $(CFLAGS) -M -MT $# -o $(patsubst %.o, %.d, $#) $<
#$(CC) $(CFLAGS) -o $# -c $<
and everything works fine.
The complete makefile:
BUILD = Build
### SOURCES ###
SRC = Src/Main\
Src/DialogBox/DialogBox
### MOC SOURCES ###
MOC_SRC = Src/DialogBox/DialogBox
### OBJECTS ###
OBJ = $(addsuffix .o, $(addprefix $(BUILD)/, $(SRC)))
OBJ += $(addsuffix .moc.o, $(addprefix $(BUILD)/, $(MOC_SRC)))
### INCLUDES ###
INC = TOO MANY INCLUDES TO PUT HERE....
### LINKER FLAGS ###
LDFLAGS = -LC:/Qt/5.15.0/mingw81_32/lib
LDLIBS = -lQt5Quick -lQt5PrintSupport -lQt5Qml -lQt5Network -lQt5Widgets -lQt5Gui -lQt5Core
### COMPILER FLAGS
CFLAGS = $(INC)
### COMPILER ###
CC = g++
### QT MOC ###
MOC = moc
all: $(BUILD)/test.exe
$(BUILD)/test.exe: $(OBJ)
#echo LINKING $^
#$(CC) $(LDFLAGS) -o $# $^ $(LDLIBS)
$(BUILD)/%.o: %.cpp
#echo COMPILING $<
#mkdir -p $(subst /,\,$(dir $#))
#$(CC) $(CFLAGS) -M -MT $# -o $(patsubst %.o, %.d, $#) $<
#$(CC) $(CFLAGS) -o $# -c $<
$(BUILD)/%.moc.o: $(BUILD)/%.moc.cpp
#echo COMPILING MOC $<
#mkdir -p $(subst /,\,$(dir $#))
#$(CC) $(CFLAGS) -M -MT $# -o $(patsubst %.o, %.d, $#) $<
#$(CC) $(CFLAGS) -o $# -c $<
$(BUILD)/%.moc.cpp: %.h
#echo GENERATING MOC $<
#$(MOC) $< -o $#
-include $(OBJ:.o=.d)
.PHONY: clean
clean:
#echo CLEANING......
#rm -rf $(BUILD)/Src $(BUILD)/test.exe

Makefile errors when I change a directory name

I have a Makefile that compiles, but I want to change the name of one of the directories from "release" to "objects". This is the original Makefile -
# This makefile compiles ....
INCLUDE = -I/usr/include/X11 -I/usr/local/include -I/usr/local/include/FL/images -I/usr/include/freetype2
CC=g++
CFLAGS=-w -D LINUX -O3 -fpermissive
OBJDIR=release # HERE IS THE DIRECTORY I WANT TO CHANGE
SRCDIR=src
LDFLAGS= -L/usr/X11R6/lib$(LIBSELECT) -lpthread -lfltk -lXext -lXft -lfontconfig -lXinerama -lpthread -ldl -lm -lX11
SOURCES_RAW= robot_driver_agent.cpp robot_driver_position.cpp robot_driver_priorityqueue.cpp main.cpp robot_driver_tree.cpp robot_driver_stack.cpp robot_driver_grid.cpp robot_driver_path.cpp grid_analyzer.cpp tcpserver.cpp tcpclient.cpp servercontrol.cpp clientcontrol.cpp robot.cpp udpserver.cpp udpclient.cpp owncontrol.cpp guiwindow.cpp rs232.cpp
TARGET:= go
TARGETD:= go_d
OBJECTS:=$(SOURCES_RAW:.cpp=.o)
OBJECTS:=$(patsubst %.o, $(OBJDIR)/%.o, $(OBJECTS))
SOURCES:=$(SOURCES_RAW)
SOURCES:=$(patsubst %.cpp, $(SRCDIR)/%.cpp, $(SOURCES))
all: $(TARGET)
$(TARGET): $(OBJECTS)
$(CC) -w -D LINUX $(INCLUDE) $^ -o $# $(LDFLAGS)
release/%.o: src/%.cpp
test -d $(OBJDIR) || mkdir $(OBJDIR)
$(CC) -g -c $< $(CFLAGS) -o $#
debug: $(TARGETD)
$(TARGETD): $(OBJECTS)
$(CC) -w -D LINUX $(INCLUDE) $^ -o $# $(LDFLAGS)
%.o: $(SRCDIR)/%.cpp
$(CC) -c -g $< $(CFLAGS)-o $#
.PHONY : clean
clean:
rm -f $(OBJDIR)/*.o
rm -f $(TARGET) $(TARGETD)
All I do is change the OBJDIR symbol to "objects" so it would just be -
OBJDIR=objects
But when I do that, I get the error -
make: *** No rule to make target `objects/robot_driver_agent.o', needed by `go'.
What am I missing? Is "objects" a word reserved for something in make so I can't use it for directories? Is it something in the make file that I need to change? Honestly, I don't know that much about makefiles so any help at all would be great. Thanks.
You have a rule:
release/%.o: src/%.cpp
...
So that when OBJDIR=release and Make wants to build release/robot_driver_agent.o, it knows just what to do. Then you try OBJDIR=objects, it wants to build objects/robot_driver_agent.o, and it doesn't know how because there's no rule that fits. Try changing the rule to:
$(OBJDIR)/%.o: src/%.cpp
...

How to include clean target in Makefile?

I have a Makefile that looks like this
CXX = g++ -O2 -Wall
all: code1 code2
code1: code1.cc utilities.cc
$(CXX) $^ -o $#
code2: code2.cc utilities.cc
$(CXX) $^ -o $#
What I want to do next is to include clean target so that every time
I run make it will automatically delete the existing binary files of code1 and code2 before creating the new ones.
I tried to put these lines at the very end of the makefile, but it doesn't work
clean:
rm -f $#
echo Clean done
What's the right way to do it?
The best thing is probably to create a variable that holds your binaries:
binaries=code1 code2
Then use that in the all-target, to avoid repeating:
all: clean $(binaries)
Now, you can use this with the clean-target, too, and just add some globs to catch object files and stuff:
.PHONY: clean
clean:
rm -f $(binaries) *.o
Note use of the .PHONY to make clean a pseudo-target. This is a GNU make feature, so if you need to be portable to other make implementations, don't use it.
In makefile language $# means "name of the target", so rm -f $# translates to rm -f clean.
You need to specify to rm what exactly you want to delete, like rm -f *.o code1 code2
By the way it is written, clean rule is invoked only if it is explicitly called:
make clean
I think it is better, than make clean every time. If you want to do this by your way, try this:
CXX = g++ -O2 -Wall
all: clean code1 code2
code1: code1.cc utilities.cc
$(CXX) $^ -o $#
code2: code2.cc utilities.cc
$(CXX) $^ -o $#
clean:
rm ...
echo Clean done

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