I have a make file:
# Makefile
CC = gcc
SRC = pixel.c
TARGET = pixel.exe
OBJECTS = bmp.o pixel.o
#CFLAGS_W = -Wall -Wl,-subsystem,windows
CFLAGS_W = -Wall
LFLAGS_W = -lSDL2
INCS_W = -I.\SDL2\include
LIBS_W = -L.\SDL2\lib\x64
all: $(TARGET)
$(TARGET): $(OBJECTS)
$(CC) $(INCS_W) $(LIBS_W) $(CFLAGS_W) $(LFLAGS_W) -g -o $(TARGET) $(OBJECTS)
it will build bmp.c, but when it tries to build pixel.c I get the error:
pixel.c:6:10: fatal error: SDL.h: No such file or directory
however, pixel.c has been building fine all the time I was just building it on its own (before I added bmp.c), using the command:
all:
$(CC) $(SRC) $(INCS_W) $(LIBS_W) $(CFLAGS_W) $(LFLAGS_W) -g -o $(TARGET)
I really struggle with makefiles because I just don't use them enough, but this doesn't really feel like a "make" problem.
I'm using mingw32-make and gcc in a windows sandbox.
EDIT:
I have added
.c.o:
$(CC) $(INCS_W) $(LIBS_W) $(CFLAGS_W) $(LFLAGS_W) -g -c $< -o $#
to my makefile, which gets me a step further (I think), but now complains that all of the SDL functions are undefined
C:\Users\WDAGUtilityAccount\Desktop\Projects\Pixel>mingw32-make
gcc -I./SDL2/include -L./SDL2/lib/x64 -Wall -lSDL2 -g -c bmp.c -o bmp.o
gcc -I./SDL2/include -L./SDL2/lib/x64 -Wall -lSDL2 -g -c pixel.c -o pixel.o
gcc -I./SDL2/include -L./SDL2/lib/x64 -Wall -lSDL2 -g -o pixel.exe bmp.o pixel.o
pixel.o: In function `main':
C:\Users\WDAGUtilityAccount\Desktop\Projects\Pixel/pixel.c:119: undefined reference to `SDL_Init'
C:\Users\WDAGUtilityAccount\Desktop\Projects\Pixel/pixel.c:121: undefined reference to `SDL_GetError'
C:\Users\WDAGUtilityAccount\Desktop\Projects\Pixel/pixel.c:126: undefined reference to `SDL_CreateWindow'
C:\Users\WDAGUtilityAccount\Desktop\Projects\Pixel/pixel.c:131: undefined reference to `SDL_GetError'
...
I can get the whole project to compile if I just do this on its own:
SRC = bmp.c pixel.c
...
test:
$(CC) $(SRC) $(INCS_W) $(LIBS_W) $(CFLAGS_W) $(LFLAGS_W) -g -o $(TARGET)
which is fine, it'll do, but it rebuilds everything every time, and I'd like to know why it isn't working anyway :)
Related
I'm trying to write my own makefile for a paho.mqtt project on a Raspberry Pi 4.
I've downloaded & tested the paho.mqtt install and its all working as expected.
So I'm now testing some C code but I just cant figure out the makefile (I'm new to this), my file so far,
NAME = mqtt_test
OBJ = $(NAME).o
LIBS = -libpaho-mqtt3c -libpaho-mqtt3cs
CFLAGS = -Wall -I/usr/local/include -L/usr/local/lib
CC = gcc
EXTENSION = .c
all: $(NAME)
%.o: %$(EXTENSION) $(DEPS)
$(CC) -c -o $# $< $(CFLAGS)
$(NAME): $(OBJ)
$(CC) -o $# $^ $(CFLAGS) $(LIBS)
.PHONY: clean
clean:
#rm -f *.o *~ core $(NAME)
This returns,
gcc -o mqtt_test mqtt_test.o -Wall -I/usr/local/include -L/usr/local/lib -libpaho-mqtt3c -libpaho-mqtt3cs
/usr/bin/ld: cannot find -libpaho-mqtt3c
/usr/bin/ld: cannot find -libpaho-mqtt3cs
collect2: error: ld returned 1 exit status
make: *** [makefile:14: mqtt_test] Error 1
I've checked & the includes and libraries are in the directories I put after the-I and -L flags.
When I look in /usr/bin there is no ld but there are paho files prefixed with paho_ but no library files.
What am I missing?
You don't use -libpaho-mqtt3c (etc.)
The option is -l so when you write -libpaho-mqtt3c the linker is looking for libraries named ibpaho-mqtt3c which of course do not exist: that would be either libibpaho-mqtt3c.a or libibpaho-mqtt3c.so.
You want to use -lpaho-mqtt3c: remove the lib at the front and the extension .a or .so, and add in the option -l.
I am trying to compile using this makefile but got this error. I can compile using school's linux computer with gcc 6.3. I tried using my MacOS mojave using a few different version of gcc from homebrew (gcc-8, gcc-4.9, gcc-6) but I get this error consistently.
CC = gcc-8
OPT = -O3 -g
LIBS = -lz -lcvp -lz
FLAGS = -std=c++11 -L. $(LIBS) $(OPT) -no-pie
OBJ = myprogram.o
DEPS = cvp.h myprogram.h
all: cvp
cvp: $(OBJ)
$(CC) $(FLAGS) -o $# $^
%.o: %.cc $(DEPS)
$(CC) $(FLAGS) -c -o $# $<
.PHONY: clean
clean:
rm -f *.o cvp
Going off information found here: https://github.com/xd009642/tarpaulin/issues/7#issuecomment-317180523
The problem may very well be related to how gcc is built: "Builds of gcc that don't have the --enable-default-pie flag set at compile time because they are too old or have the --disable-default-pie flag just don't have the -no-pie linker flag"
You might need to update or recompile gcc for that environment to be able to use that flag if important to you.
I am trying to use the Lapack and Blas libraries in my Fortran90 code on Linux Mint. I believe I have installed both libraries correctly in the following directory: /usr/local/lib
When I compile my code using a makefile I get the error message:
gfortran -m64 -O3 -fdefault-real-8 -fdefault-double-8 -c MainHPC2.f90
gfortran -m64 MainHPC2.o Central2Scheme.o Central5Scheme.o
WriteDataFiles.o -o P1
MainHPC2.o: In function `MAIN__':
MainHPC2.f90:(.text+0x2b0): undefined reference to `dgesv_'
collect2: error: ld returned 1 exit status
makefile:56: recipe for target 'P1' failed
make: *** [P1] Error 1
My Fortran code is simply trying to call a test function:
call dgesv(nn,nrhsl,al,ldal,ipivl,xl,ldbl,infol)
The makefile I am using is the following:
I believe it is not linking to the libraries properly.
FC = gfortran
FFLAGS = -m64 -O3 -fdefault-real-8 -fdefault-double-8
TARGET_ARCH =
LDFLAGS = -m64
BLIBS = -L/usr/local/lib -llapack -lblas
EXE = P1
.SUFFIXES:
.SUFFIXES: .o .f90 .plt
SRC = \
MainHPC2.f90 \
Central2Scheme.f90 \
Central5Scheme.f90 \
WriteDataFiles.f90 \
$(OBJECTS):
OBJ = ${SRC:.f90=.o}
$(EXE): $(OBJ)
$(FC) $(LDFLAGS) $(OBJ) $(LIBS) -o $(EXE)
%.o : %.f90
$(FC) $(FFLAGS) -c $<
# Define dependencies for modules
# $(OBJ): $(MOD)
clean:
rm -f *.mod *~ core
rm -f *.o
Thank you for your help.
Alex
solution 1
In your makefile, The sections that compile and link never add the $(BLIBS) which contains the BLAS and LAPACK libraries into the linking process.
$(EXE): $(OBJ)
$(FC) $(LDFLAGS) $(OBJ) $(LIBS) $(BLIBS) -o $(EXE)
solution 2
or you made a typo and wrote BLIBS instead of LIBS,
LIBS = -L/usr/local/lib -llapack -lblas
note: This should be more a comment than an answer
I'm doing a Makefile to make objects with the same gcc command. This file looks like this:
SRCLIB = main.c srv.c
OBJLIB = main.o srv.o
CC = gcc
CCFLAGS = -Wall -Werror
$(OBJLIB) : $(SRCLIB)
$(CC) $(CCFLAGS) -c $^ -o $#
The objetive is to execute this like:
gcc -Wall -c read_line.c -o read_line.o
gcc -Wall -c client.c -o client.o
But I don't know how to do it, and everything I tested is not working. Is it even possible to do this in a Makefile?
Your makefile expands to this, after the variables are expanded:
main.o srv.o : main.c srv.c
$(CC) $(CCFLAGS) -c $^ -o $#
In make, using multiple targets in explicit rules like this is the same as writing the rule multiple times, once for each target. So, this is the same as this:
main.o : main.c srv.c
$(CC) $(CCFLAGS) -c $^ -o $#
srv.o : main.c srv.c
$(CC) $(CCFLAGS) -c $^ -o $#
This means that if either of the source files changes, BOTH object files will be recreated (since each object depends on both sources, not just their own source file).
Further, in your compile line you use the variable $^ which expands to all the prerequisites. So your compile lines will expand to:
gcc -Wall -Werror -c main.c srv.c -o main.o
gcc -Wall -Werror -c main.c srv.c -o srv.o
which is illegal: if you use -c with the -o option you can only compile one source file.
Make has built-in rules that already know how to compile files, so there's no need to write your own. You can just write this:
SRCLIB = main.c srv.c
OBJLIB = main.o srv.o
CC = gcc
CCFLAGS = -Wall -Werror
.PHONY: all
all: $(OBJLIB)
and that's all you need.
I have several files needed to be compiled.
here is the command. the sample_client.c dependent on the lsp.o. Now I changed the lsp.c and lsp.h. How can I compile to get this change effective to lsp.o?
the main function is in the sample_client.c, lsp.c does not have a main function.
gcc -g -I/usr/include -g sample_client.c lsp.o lspmessage.pb-c.o -o sample_client -L/usr/lib -lprotobuf-c
Here is my makefile,
CC = gcc
TARGET = sample_client sample_server
CFLAGS += -g -I/usr/include
LDFLAGS += -g -lprotobuf-c -L/usr/lib
all: $(TARGET)
$(TARGET): lsp.o lspmessage.pb-c.o
%.o: %.c
$(CC) -c $(CFLAGS) $< -o $#
clean:
rm -f *.o
rm -f $(TARGET)
However, the lprotobuf-c can not be correctly linked.
run make -f Makefile
I can get the following,
lspmessage.pb-c.o: In function `lspmessage__get_packed_size':
...: undefined reference to `protobuf_c_message_get_packed_size'
lspmessage.pb-c.o: In function `lspmessage__pack':
...: undefined reference to `protobuf_c_message_pack'
I know that I can run this command,
gcc -g -I/usr/include -g sample_client.c lsp.o lspmessage.pb-c.o -o sample_client -L/usr/lib -lprotobuf-c
But what if I change the lsp.c and lsp.h ?
It looks to me like your LDFLAGS isn't correct. Try the following:
LDFLAGS += -L/usr/lib -lprotobuf-c
It looks like you had the directory -L and the library out of order.
Also, I removed the additional call to -g for you.