If I have a rule like this in my make file:
CC = g++
CFLAGS = -Wall
COMPILE = $(CC) $(CFLAGS) -c
src = A.cpp \
main.cpp
test_src = Test.cpp
test = testAll
OBJFILES := $(patsubst %.cpp,%.o,$(src))
TEST_OBJS := $(patsubst %.cpp,%.o,$(test_src))
%.o: %.cpp
$(COMPILE) -I UnitTest++/src -LUnitTest++/ -l UnitTest++ -o $# $<
I end up including and linking UnitTest++ to non test files such as main and A.cpp
How can I make only make Test classes link with the test libraries?
Specify which files your rule applies to:
$(TEST_OBJS): %.o: %.cpp
$(COMPILE) -I UnitTest++/src -LUnitTest++/ -l UnitTest++ -o $# $<
Related
The results for this topic strangely all did not work.
Finally I found a variant that is logical for me and works from the same order.
CC := g++
CFLAGS := -g -Wall
objects = test helloworld
all: $(objects)
$(objects): %: %.cpp
$(CC) $(CFLAGS) -o $# $<
I have tried a lot and probably fail to fully understand the line %: %.cpp.
My interpretation is: I take from every object the dependency which in turn is based on a file which is then traceable to a .cpp file.
My theory is test expects test.o and then test.cpp.
How do I rewrite this to directory?
I have already read some things with wildcards and a pattern replace.
Like
SRC_DIR := src
OBJ_DIR := obj
SRC_FILES := $(wildcard $(SRC_DIR)/*.cpp)
OBJ_FILES := $(patsubst $(SRC_DIR)/%.cpp,$(OBJ_DIR)/%.o,$(SRC_FILES))
LDFLAGS := ...
CPPFLAGS := ...
CXXFLAGS := ...
main.exe: $(OBJ_FILES)
g++ $(LDFLAGS) -o $# $^
$(OBJ_DIR)/%.o: $(SRC_DIR)/%.cpp
g++ $(CPPFLAGS) $(CXXFLAGS) -c -o $# $<
But the behavior was not the expected.
When 2 cpp files were in the folder the result was
g++ -o helloworld.o helloworld.cpp
g++ -o helloworld.o test.cpp
Or vice versa that only the cpp file was always the same.
I have the feeling to miss something extremely.
Update:
The make version is
GNU Make 4.3
Built for aarch64-unknown-linux-android
The Goal
What I would like to achieve is
src/
Test.cpp
Helloworld.cpp
Obj/
Make :
Obj/
Helloworld.out
Test.out
Try this:
CXX := g++
CXXFLAGS := -g -Wall
TARGETS=obj/test.out obj/helloworld.out
all:$(TARGETS)
obj/%.out:src/%.cpp
$(CXX) $(CXXFLAGS) -o $# $^
clean:
rm obj/*
This is a part of my makefile :
SRC = ./
DIRS = src libs/maths libs/struct
BIN_DIR = ./bin/
SRC_DIRS= $(foreach dir, $(DIRS), $(addprefix $(SRC), $(dir)))
SRC_TEST= $(sort $(SRC_DIRS))
SRCS = $(foreach msrc, $(SRC_DIRS), $(wildcard $(msrc)/*.c))
DEL_PRE = $(foreach target, $(SRCS), $(notdir $(target)))
ADD_PRE = $(foreach target, $(DEL_PRE), $(addprefix $(BIN_DIR), $(target)))
OBJS = $(ADD_PRE:.c=.o)
.PHONY: all clean re
all: $(EXEC)
$(EXEC): $(OBJS)
$(CC) $(OBJS) -o $# $(LDLIBS)
$(OBJS): $(SRCS)
$(CC) -o $# -c $<
When i use make all, i have in output :
gcc -o bin/main.o -c src/main.c
gcc -o bin/cosin.o -c src/main.c
gcc -o bin/pears.o -c src/main.c
gcc -o bin/outil.o -c src/main.c
gcc -o bin/verif.o -c src/main.c
But i would like to have for each target, it assigned dependency :
gcc -o bin/main.o -c src/main.c
gcc -o bin/cosin.o -c libs/maths/cosin.c
gcc -o bin/pears.o -c libs/maths/pears.c
gcc -o bin/outil.o -c libs/struct/outil.c
gcc -o bin/verif.o -c libs/struct/verif.c
How can i fix it ?
This seems like a very common misconception; I just answered effectively this same question yesterday. I'm not sure where it comes from or how to combat it.
This rule:
$(OBJS): $(SRCS)
$(CC) -o $# -c $<
does not somehow magically combine the contents of the OBJS variable and the SRCS variable to figure out how they match up. The variable references are simply expanded, and the result is this:
bin/main.o bin/cosin.o ... : src/main.c libs/maths/cosin.c ...
$(CC) -o $# -c $<
which is the same as if you'd written this:
bin/main.o : src/main.c libs/maths/cosin.c ...
$(CC) -o $# -c $<
bin/cosin.o : src/main.c libs/maths/cosin.c ...
$(CC) -o $# -c $<
...
Now, you can hopefully see why you compile the same file: in every rule you have the same prerequisites, so $< is always the first one, which is always src/main.c.
There are multiple ways to work this but if you really want to have all the source files from different directories compiled into object files in the same directory your job is harder, because there's no common pattern that will match them all. In this case the simplest thing to do is use VPATH for directory search: replace the above rule with this:
$(BIN_DIR)/%.o : %.c
$(CC) -o $# -c $<
then tell make how to find your source files, like this:
VPATH := $(sort $(dir $(SRCS))
Be aware this method can't be used for any source files that are themselves generated output that make is expected to create.
I have the following Makefile:
CXX = g++
CXXFLAGS = -Wall -g
SOURCES := divisor.cpp multiplier.cpp
OBJECTS := ${SOURCES:.cpp=.o}
%.o: %.cpp
$(CXX) -c $(CXXFLAGS) $< -o $#
%: %.o $(OBJECTS)
$(CXX) $(CXXFLAGS) $#.o -o $#.out
$(OBJECTS): %.o: %.cpp
$(CXX) -c $(CXXFLAGS) $< -o $#
clean:
rm -f *.o
What I want this make file is the following:
If I add a source file called 123.cpp to the working directory, I want it to generate its object file and then link the compiled sources specified in $(SOURCES), this means:
g++ -c -Wall -g 123.cpp
g++ multipler.o divisor.o 123.o -o 123
If multiplier.cpp or divisor.cpp has to be generated or updated, I want make to do it.
But I'm failing, because divisor.o and multiplier.o are not automatically generated
How may I achieve this?
Edit
Just to clarify, there are two types of source code files in the working directory: divisor.cpp, multipler.cpp is one type, and any other file, say, 123.cpp is the other type. In a sense, divisor.cpp and multiplier.cpp are requisites to the other source files.
I want to automate the process of compiling the prerequisites and link them when compiling the other files
g++ -c multiplier.cpp
g++ -c divisor.cpp
g++ -c -Wall -g 123.cpp
g++ multipler.o divisor.o 123.o -o 123
Use the wildcard function:
SOURCES := $(wildcard *.cpp)
Then, you can remove your "special" source files:
SPECIAL_SOURCES := divisor.cpp multiplier.cpp
SOURCES := $(filter-out $(SPECIAL_SOURCES),$(SOURCES))
And change your rules to build the stuff you actually want:
$(SPECIAL_OBJECTS) := $(SPECIAL_SOURCES:.cpp=.o)
$(BINARIES) := $(patsubst .cpp,,$(SOURCES))
$(SPECIAL_OBJECTS) : %.o : %.cpp
$(CXX) $(CXXFLAGS) -c -o $# $^
$(BINARIES) : % : %.cpp $(SPECIAL_OBJECTS)
$(CXX) $(CXXFLAGS) -o $# $^
I have written a simple C++ program, and for the first time I want to compile and link it using a makefile. As a challenge I want to make a makefile, which lists all dependencies by itself. I am following this tutorial. My program consist of main.cpp, ext1.cpp and ext1.h. Following the tutorial, I have the following makefile
VPATH = src include
CPPFLAGS = -o include
CC = gcc
SOURCES = main.cpp \
ext1.cpp
-include $(subst .c,.d,$(SOURCES))
%.d: %.c
$(CC) -M $(CPPFLAGS) $< > $#.$$$$; \
sed 's,\($*\)\.o[ :]*,\1.o $# : ,g' < $#.$$$$ > $#; \
rm -f $#.$$$$
When I run this I get the message: make: *** No targets specified and no makefile found. Stop. It is not clear to me what I am missing in my case?
You are trying to do too much at once.
Step 1. Your first makefile should build the executable without attempting automatic dependency detection.
VPATH = include src
CPPFLAGS += -Iinclude
CC = gcc
exec: main.o ext1.o
$(CC) $^ -o $#
%.o: %.cc
$(CC) -c $(CPPFLAGS) $< -o $#
main.o ext1.o: ext1.h
Step 2. Once that works perfectly, you can put the header dependencies in separate files:
makefile:
VPATH = include src
CPPFLAGS += -Iinclude
CC = gcc
exec: main.o ext1.o
$(CC) $^ -o $#
%.o: %.cc
$(CC) -c $(CPPFLAGS) $< -o $#
-include *.d
main.d:
main.o : ext1.h
ext1.d:
ext1.o: ext1.h
Step 3. Once that works perfectly, you can generate the dependency files automatically:
VPATH = include src
CPPFLAGS += -Iinclude
CC = gcc
exec: main.o ext1.o
$(CC) $^ -o $#
%.o: %.cc
$(CC) -c -MMD $(CPPFLAGS) $< -o $#
-include *.d
no make file found ? what name you have given for makefile? make sure its makefile or Makefile if you are just executing command make else you can pass file name to make like this
make -f yourmakefile
and changes suggested by Petr Budnik must work
I have some source .cpp files in the same directory, and I want to compile them as object file.
Some of them needs "extra" libraries (same libs for all files) to be linked with and some of them don't, I'd like to write general rules to match the right files, without writing specific rule for each file with extra flags.
More in detail I want to refactor my Makefile so that I don't have to specify different rules for the source files SourceFileOpenCVNeeded.cpp OCVAlsoHere.cpp TheSameForMe.cpp (now they're few, but they could be many more).
Here is what my makefile actually looks like:
CPP_FILES := $(wildcard src/*.cpp)
OBJ_FILES := $(addprefix obj/,$(notdir $(CPP_FILES:.cpp=.o)))
MAIN_SRC := main.cpp
OCV_LIBS := `pkg-config opencv --libs`
OCV_PATH := `pkg-config opencv --cflags`
MY_LIB := launcher
LD_FLAGS := $(MAIN_SRC) -L. -l$(MY_LIB) $(OCV_LIBS)
CC_FLAGS := -c -fPIC
AR_FLAGS := rcs
STATIC_LIB := lib$(MY_LIB).a
CC := g++
EXEC := test
all: lib main
main:
$(CC) $(LD_FLAGS) -o $(EXEC)
lib: $(OBJ_FILES)
ar $(AR_FLAGS) $(STATIC_LIB) $^
obj/SourceFileOpenCVNeeded.o: src/SourceFileOpenCVNeeded.cpp
$(CC) $(OCV_PATH) $(CC_FLAGS) $(OCV_LIBS) -c -o $# $<
obj/OCVAlsoHere.o: src/OCVAlsoHere.cpp
$(CC) $(OCV_PATH) $(CC_FLAGS) $(OCV_LIBS) -c -o $# $<
obj/TheSameForMe.o: src/TheSameForMe.cpp
$(CC) $(OCV_PATH) $(CC_FLAGS) $(OCV_LIBS) -c -o $# $<
obj/%.o: src/%.cpp
$(CC) $(CC_FLAGS) -c -o $# $<
clean:
rm -f $(OBJ_FILES) $(STATIC_LIB) $(EXEC)
PS: any other improvements that can be added to my Makefile?
You might be able to use target-specific variables, e.g. (not tested)
EXTRA_FLAGS=
obj/TheSameForMe.o: EXTRA_FLAGS="$(OCV_PATH) $(OCV_LIBS)"
obj/%.o: src/%.cpp
$(CC) $(CC_FLAGS) $(EXTRA_FLAGS) -c -o $# $<