I have a problem trying to create a Makefile that compile multiple sorces, generate only a shared library and make an exe with another file wiht the main function.
The sorces also have dependencies.
My Makefile is
CC=gcc
CFLAGS=-Wall -g
BINS=libsensorMotor.so maintarget
all: $(BINS)
libsensorMotor.o: libsensorMotor.cpp sensorMotor.h Adafruit_ADS1015.cpp Adafruit_ADS1015.h wiringPiI2C.c wiringPiI2C.h enumADCGain.h
$(CC) $(CFLAGS) -c libsensorMotor.cpp Adafruit_ADS1015.cpp wiringPiI2C.c
libsensorMotor.so: libsensorMotor.cpp sensorMotor.h
$(CC) $(CFLAGS) -fPIC -shared -o $# libsensorMotor.cpp -lc
maintarget: maintarget.c
$(CC) $(CFLAGS) -o $# $^ -L. -lsensorMotor -pthread
clean:
rm *.o $(BINS)
The script show the errors:
libsensorMotor.so Undefined reference to 'functionXXXX'
maintarget contains the main and use libsensorMotor as a shared library. libsensorMotor depends and include all the rest of the files
The error mention all the functions that libsensorMotor uses from the include sources.
I only need to generate a correct libsensorMotor.so that can use as shared library from any other main file. Internet has many tutorials but are unclear, weird and complicated, and not show how do this simple.
Is not Makefile problem, simply the line
gcc -pthread -lm -o maintarget maintarget.c libsensorMotor.cpp Adafruit_ADS1015.cpp wiringPiI2C.c
sends same error, the compiler not recongnice the function inside the pthread_create while compile C and C++ with gcc
Related
I got an error when try to link (-aarch64-linux-gnu-ld) (the script containing the Makefile was downloaded from https://github.com/Icenowy/aw-el2-barebone). Error is "aarch64-linux-gnu-ld: Error: unable to disambiguate: -nostartfiles (did you mean --nostartfiles ?)
make: *** [Makefile:31: el2-bb.elf] Error 1" How to recode the line 31? of the Makefile
CROSS_COMPILE = /usr/bin/aarch64-linux-gnu-
DEBUG = 1
CC = $(CROSS_COMPILE)gcc
AS = $(CROSS_COMPILE)as
LD = $(CROSS_COMPILE)ld
OBJCOPY = $(CROSS_COMPILE)objcopy
INCLUDES = -I ./include -I ./uboot-headers -ffreestanding
DEFINES = -DSOC_HEADER="\"h6.h\""
ifneq ($(DEBUG),1)
DEFINES += -DNDEBUG
endif
ASFLAGS = $(INCLUDES) $(DEFINES) -D__ASSEMBLY__
CFLAGS = $(INCLUDES) $(DEFINES) -O2
LDSCRIPT = ldscripts/a64.ld
LDSCRIPTS = ldscripts/a64.ld ldscripts/common.ld
LDFLAGS = -nostdlib -nostartfiles -static -T $(LDSCRIPT)
OBJS = start.o init.o uart.o stack.o exceptions.o exception_funcs.o panic.o pgtables.o trapped_funcs.o
all: el2-bb.bin
el2-bb.elf: $(OBJS) $(LDSCRIPTS)
$(LD) $(LDFLAGS) $(OBJS) -o $#
el2-bb.bin: el2-bb.elf
$(OBJCOPY) -O binary $< $#
.PHONY: clean
clean:
rm -f el2-bb.* *.o
-nostartfiles is a gcc option but not an ld option.
If you use gcc to invoke the linker (say with LD=gcc in your Makefile) for making a standalone program that does not use standard startup files, you should use -nostartfiles because gcc links the startup files by default and -nostartfiles disables this.
ld doesn't links any startup files by default, so there is no option to disable linking them. You always pass startup files explicitly to ld. If you don't want startup files, just don't pass them to ld.
In order to see what startup files on your system are create an empty C program:
int main(){}
and compile it:
gcc -c empty.c
gcc -v empty.o
You are likely to see an invocation of ld (or perhaps of collect2, which calls ld) with a long, long list of options and object files.
Now run
gcc -nostartfiles -v empty.o
The .o files are now gone. That's exactly what -nostartfiles does.
When you invoke ld empty.o, these files and options are not there to begin with. In order to make a working program for say a Linux system, you need to pass most of them to ld explicitly. If you are building a program for something other system, you may not need some or all of them. So just don't pass them in.
I'm trying to compile my project and I use the lib ncurse. And I've got some errors when compiler links files.
Here is my flags line in Makefile:
-W -Wall -Werror -Wextra -lncurses
I've included ncurses.h
Some layouts :
prompt$> dpkg -S curses.h
libslang2-dev:amd64: /usr/include/slcurses.h
libncurses5-dev: /usr/include/ncurses.h
libncurses5-dev: /usr/include/curses.h
prompt$> dpkg -L libncurses5-dev | grep .so
/usr/lib/x86_64-linux-gnu/libncurses.so
/usr/lib/x86_64-linux-gnu/libcurses.so
/usr/lib/x86_64-linux-gnu/libmenu.so
/usr/lib/x86_64-linux-gnu/libform.so
/usr/lib/x86_64-linux-gnu/libpanel.s
And here are my erros :
gcc -W -Wall -Werror -Wextra -I./Includes/. -lncurses -o Sources/NCurses/ncurses_init.o -c Sources/NCurses/ncurses_init.c
./Sources/NCurses/ncurses_init.o: In function `ncruses_destroy':
ncurses_init.c:(.text+0x5): undefined reference to `endwin'
./Sources/NCurses/ncurses_init.o: In function `ncurses_write_line':
ncurses_init.c:(.text+0xc5): undefined reference to `mvwprintw'
./Sources/NCurses/ncurses_init.o: In function `ncurses_init':
ncurses_init.c:(.text+0xee): undefined reference to `initscr'
collect2: error: ld returned 1 exit status
Thanks a lot
You need to change your makefile so that the -lncurses directive comes after your object code on the gcc command line, i.e. it needs to generate the command:
gcc -W -Wall -Werror -Wextra -I./Includes/. -o Sources/NCurses/ncurses_init.o -c Sources/NCurses/ncurses_init.c -lncurses
This is because object files and libraries are linked in order in a single pass.
In C++ , I fixed it just by linking the ncurses library .
Here is the command :
g++ main.cpp -lncurses
I got flags to correct order by using LDLIBS variable:
ifndef PKG_CONFIG
PKG_CONFIG=pkg-config
endif
CFLAGS+=-std=c99 -pedantic -Wall
LDLIBS=$(shell $(PKG_CONFIG) --libs ncurses)
man gcc | grep -A10 "\-l library"
-l library
Search the library named library when linking. (The second alternative with the library as a separate argument is only for POSIX
compliance and is not recommended.)
It makes a difference where in the command you write this option; the linker searches and processes libraries and object files
in the order they are specified. Thus, foo.o -lz bar.o searches
library z after file foo.o but
before bar.o. If bar.o refers to functions in z, those functions may not be loaded.
Here is a tutorial for make file in Linux: http://mrbook.org/tutorials/make/
Here is a make file example:
all: hello
hello: main.o factorial.o hello.o
g++ main.o factorial.o hello.o -o hello
main.o: main.cpp
g++ -c main.cpp
factorial.o: factorial.cpp
g++ -c factorial.cpp
hello.o: hello.cpp
g++ -c hello.cpp
clean:
rm -rf *o hello
For me this line is confusing main.o: main.cpp
What does it mean? As I understand, it means target main.o has a main.cpp dependency. But there is no target with main.cpp
It means a target (main.o) has a dependency (main.cpp) which that dependency (main.cpp) itself is not a target. So what is it (main.cpp)?
main.cpp is a file.
From the extension we expect it to be a c++ source file, and the associated rule suggest that this is the case.
The rule will be exectuted any time that main.cpp is newer than main.o (which is also a file).
main.cpp is your source code. The fact that there is no target for main.cpp just means that Make has no way to generate that file. You are expected to create it yourself.
I got an assignment to improve running time of some code. The only problem is, I can't even compile it to run it on my machine in the first place. Every time I try, it stops somewhere in the midst of compiling saying this:
"undefined reference to `boost::re_detail::put_mem_block(void*)'
collect2: ld returned 1 exit status make: * [cpu] Error 1"
This is how makefile looks:
SHELL = /bin/bash
OBJECTS = main.o atom.o molecule.o charges.o pdb.o asa.o amino.o chain.o addition.o string_operation.o pdb_peptide.o protein_chain.o residue_atom.o chain_residue.o residue_contact.o atom_grid.o circles.o atom_space_calculations.o
OBJDIR = obj
VPATH = src:src/ext:$(OBJDIR)
CFLAGS = -O3 -Wall -lm -lboost_regex -L/usr/local/boost/lib
HDIRS = src,src/ext,src/qt_redistributable, usr/lib, usr/local/lib, usr/local/lib/include/boost, /usr/local/lib/lib/
IOPTS = $(addprefix -I, $(HDIRS))
cpu : $(addprefix $(OBJDIR)/, $(OBJECTS) $(CPUOBJS))
g++ $(CFLAGS) -o mcpu $^
$(OBJDIR)/%.o : %.cpp
g++ $(CFLAGS) $(IOPTS) -c $< -o $#
clean :
rm obj/*.o $(PROG)
I'm using Linux Mint x64 and I have tried everything I googled out. Installed the whole boost library in usr/local/lib (for no obvious reason because it didn't help), tried to edit LD PATH (I'm very new to Linux and I have no idea if that went right) and lots of stuff, but this thing doesn't seem to go through. Any help appreciated.
One problem with your makefile happens when you link your program. As you can see in these questions with g++ the order of your arguments at link time is really important. You need to put your libraries after your object files. One easy way to solve would be separating your linker flags (LDFLAGS) from the compiler flags (CFLAGS), and then putting LDFLAGS after $^ (your object files) in the link command.
CFLAGS = -O3 -Wall
LDFLAGS = -L/usr/local/boost/lib -lm -lboost_regex
cpu : $(addprefix $(OBJDIR)/, $(OBJECTS) $(CPUOBJS))
g++ $(CFLAGS) -o mcpu $^ $(LDFLAGS)
$(OBJDIR)/%.o : %.cpp
g++ $(CFLAGS) $(IOPTS) -c $< -o $#
As can be seen in the Catalogue of Built-In Rules:
Linking a single object file
n is made automatically from n.o by running the linker (usually called
ld) via the C compiler. The precise recipe used is:
$(CC) $(LDFLAGS) n.o $(LOADLIBES) $(LDLIBS)
and Variables Used by Implicit Rules:
LDFLAGS
Extra flags to give to compilers when they are supposed to invoke the linker,
ld, such as -L. Libraries (-lfoo) should be added to the LDLIBS variable
instead.
So in this case -lboost_regex should be set or added to LDLIBS, not LDFLAGS.
I have the makefile below and a directory tree :
->project/src/main.c, func.c,
Makefile
->project/exe/
->project/inc/
->project/obj/
cc=gcc
cflags=-c
obj=../obj
exe=../exe
inc=../inc
prog.exe: main.o func.o
$(cc) main.o func.o -o $(exe)/prog.exe
main.o: main.c $(inc)/defs.h
$(cc) $(cflags) main.c
mv main.o $(obj)/
func.o: func.c $(inc)/defs.h
$(cc) $(cflags) func.c
mv func.o $(obj)/
The problem is, the second actions below main.o and func.o (those start with mv) doesn't work (i.e main.o isn't moved to the /obj directory). Is there a problem in the syntax of makefile or anything else?
One apparent problem is that the makefile doesn't build the targets it's supposed to build. I.e.:
prog.exe: main.o func.o
$(cc) main.o func.o -o $(exe)/prog.exe
Doesn't build prog.exe, rather it builds $(exe)/prog.exe, which is a different file. A fix would be:
$(exe)/prog.exe: $(obj)/main.o $(obj)/func.o
$(cc) $^ -o $#
Prefer using automatic variables for the names of input and output files to avoid duplication and silly typos.
You may take care of the indentation with make. It needs real tabs.
See https://superuser.com/questions/224434/what-is-the-character-used-to-indent-the-make-file-rule-recipe