I am working through a unix-like kernel development tutorial, and have come across a total noob problem I am sure: can anyone tell me what is wrong with this?
SOURCES=boot.o main.o
CFLAGS=-nostdlib -nostdinc -fno-builtin -fno-stack-protector
LDFLAGS=-Tlink.ld
ASFLAGS=-felf
all: $(SOURCES) link
clean:
-rm *.o kernel
link:
ld $(LDFLAGS) -o kernel $(SOURCES)
.s.o:
yasm $(ASFLAGS) $
Thanks in advance
You're using old-fashioned suffix rules, and missing some setup for that (plus an error in the very last line).
Switch to a normal pattern rule instead, no point in trying to fix the old style rule:
%.o: %.s
yasm $(ASFLAGS) $<
Well assuming boot.o and main.o are built using yasm your makefile lack a rule for .o
.o:
yasm $(ASFLAGS) $
Related
I am trying to create a makefile that can compile multiple programs. It has a list of programs and will compile each one separately. Every program has pretty much exactly the same template so I tried this solution:
CFLAGS=-O3 -std=c89 -pedantic -Wall -Wextra -Werror
programs=echo cat yes true false cp
all: $(programs)
$(programs): src/$#.c
$(CC) $(CFLAGS) -o $# $^
clean:
$(RM) $(programs)
install: all
$(CP) $(programs) /usr/local/bin/
For some reason, this doesn't work. I get the error
make: *** No rule to make target 'src/.c', needed by 'echo'. Stop.
I'm trying to make this portable so no GNU extensions. POSIX Make if possible.
Here:
$(programs): src/$#.c
...
You can't use automatic variables like $# in the prerequisite list that way. The rule gets expanded before a target has been specified, so the variable contains nothing. (You can use it this way but it's a headache.)
Use a static pattern rule instead:
$(programs): %: src/%.c
$(CC) $(CFLAGS) -o $# $^
I have a makefile with these rules.
all: $(TARGET)
OBJECTS = file.o
%.o: %.c
$(COMPILER) -c $(FLAGS) &< -o C_$(basename $#).o
%.o: %.s
$(COMPILER) -c $(FLAGS) &< -o S_$(basename $#).o
... The Linker is then called with *.o to link all the object files
I have the same filename file.c and file.s in a src directory. But make is only running the first rule for the object file. Why does it only compile once? And how can I get make to compile both file.c and file.s if they exist in my src folder?
I don't want to have to create a different object file name for a different extension. That would be silly.
Is there a way for me to compile the filename with the both .s and .c extension?
I feel like make can easily do this and I am missing something.
Thank you for the help. If I'm not clear please tell me and I will try to explain it more in depth.
You misunderstand how Make works.
There may be many ways to build a target; Make will use one of them, not all. Anyway, your makefile violates one of Mad Scientist's rules, in that your pattern rules do not build what they claim to build:
%.o: %.c
$(COMPILER) -c $(FLAGS) &< -o C_$(basename $#).o
%.o: %.s
$(COMPILER) -c $(FLAGS) &< -o S_$(basename $#).o
The first doesn't build foo.o, it builds C_foo.o; the second doesn't build foo.o, it builds S_foo.o. I don't know how your linking rule works, but if it depends on foo.o, you're in for trouble.
Try this:
C_%.o: %.c
$(COMPILER) -c $(FLAGS) &< -o $#
S_%.o: %.s
$(COMPILER) -c $(FLAGS) &< -o $#
Then give your linking rule whatever prerequisites you think it should have. If you want it to use both C_foo.o and S_foo.o (which doesn't sound like a good idea), then put both of them in the prerequisite list.
I'm reading through Foundations of GTK+ and in so doing decided to write a simple makefile that would let me run "make " to compile the example program I'd just written. I also stumbled upon a list of compiler directives here that the Gnome team specified will help moving from GTK2 to GTK3, so I wanted to include those.
I'm a make noob for all intents and purposes, so this is what I came up with:
CC = gcc
CFLAGS += -Wall
GTK_DFLAGS = -DGTK_DISABLE_SINGLE_INCLUDES -DGDK_DISABLE_DEPRECATED -DGTK_DISABLE_DEPRECATED -DGSEAL_ENABLE
GTK_CFLAGS = $(shell pkg-config --cflags gtk+-3.0)
GTK_LDFLAGS = $(shell pkg-config --libs gtk+-3.0)
%.o: %.c
$(CC) $(CFLAGS) $(GTK_DFLAGS) $(GTK_CFLAGS) -c -o $# $<
%: %.o
$(CC) $(CFLAGS) $(GTK_DFLAGS) $(GTK_CFLAGS) $(GTK_LDFLAGS) -o $# $<
.PHONY: clean
clean:
rm -f *.o *~
And as you might guess, it doesn't work quite right. I know running pkg-config from inside the makefile isn't an ideal solution, but this is for my small-scale learning projects and not for deployment of any sort. That said, the output is weird to me; it seems like make just ignores any variables after CFLAGS.
Something like:
[patrick#blackbox ch2]$ make helloworld
gcc -Wall helloworld.c -o helloworld
helloworld.c:1:21: fatal error: gtk/gtk.h: No such file or directory
#include <gtk/gtk.h>
^
compilation terminated.
<builtin>: recipe for target 'helloworld' failed
make: *** [helloworld] Error 1
If I add have the contents of GTK_DFLAGS simply tacked onto the end of CFLAGS, they appear on the command line, but the pkg-config variables are still missing.
It's obvious to me that I messed something simple up, but after an hour of vaguely worded Googling, I'm fresh out of ideas as to what it is.
Found the answer, and of course the vocabulary I was missing when asking this question/doing earlier searches.
CC = gcc
CFLAGS += -Wall -std=c11
GTK_DFLAGS = -DGTK_DISABLE_SINGLE_INCLUDES -DGDK_DISABLE_DEPRECATED -DGTK_DISABLE_DEPRECATED -DGSEAL_ENABLE
GTK_CFLAGS := $(shell pkg-config --cflags gtk+-3.0)
GTK_LDFLAGS := $(shell pkg-config --libs gtk+-3.0)
%: %.c
$(CC) $(CFLAGS) $(GTK_DFLAGS) $(GTK_CFLAGS) $(GTK_LDFLAGS) -o $* $*.c
.PHONY: clean
clean:
rm -f *~
This does what I want, which is to compile a single .c file of any name into a program of the same name with the GTK flags I was looking to use.
Thanks to those who contributed!
You need a target for helloworld in your Makefile. Something like this:
helloworld: helloworld.o
$(CC) -o helloworld helloworld.o $(LDFLAGS) $(GTK_LDFLAGS)
I have two files: assign1.c and ports.h.
FYI: I am using avr-gcc.
I built the following makefile, which I also use for another project (and other TARGET) where it works fine.
TARGET = assign2
LIB=
INCLUDE=ports.h
CFLAGS =-mmcu=atmega32 -Wall
CC = avr-gcc
SRC= $(TARGET).c
OBJ= $(SRC:.c=.o)
OBJCOPY = avr-objcopy
FORMAT = ihex
MSG_COMPILING = Compiling:
MSG_LINKING = Linking:
MSG_FLASH = Creating load file for flash:
all:elf hex
elf: $(TARGET).elf
hex: $(TARGET).hex
%.hex: %.elf
#echo $(MSG_FLASH) $#
#echo
$(OBJCOPY) -O $(FORMAT) -R .eeprom $< $#
$(RM) *.elf $(TARGET)
#echo
%.elf: $(OBJ) $(LIB)
#echo $(MSG_LINKING) $#
#echo
$(CC) $(CFLAGS) $^ -o $#
#echo
%.o: $(SRC) $(INCLUDE)
#echo $(MSG_COMPILING) $<
#echo
$(CC) $(CFLAGS) -c $<
#echo
.PHONY : clean
clean:
$(RM) *.o *.hex *.elf $(TARGET)
The terminal prints the following output.
C:\Project>make
Compiling: assign2.c
avr-gcc -mmcu=atmega32 -Wall -c assign2.c
In file included from assign2.c:8:
c:/winavr-20100110/lib/gcc/../../avr/include/util/delay.h:90:3: warning: #warnin
g "Compiler optimizations disabled; functions from <util/delay.h> won't work as
designed"
Linking: assign2.elf
avr-gcc -mmcu=atmega32 -Wall assign2.o -o assign2.elf
Compiling: assign2.c
avr-gcc -mmcu=atmega32 -Wall -c assign2.c
In file included from assign.c:8:
c:/winavr-20100110/lib/gcc/../../avr/include/util/delay.h:90:3: warning: #warnin
g "Compiler optimizations disabled; functions from <util/delay.h> won't work as
designed"
avr-gcc elf.o assign2.elf -o elf
avr-gcc: elf.o: No such file or directory
make: *** [elf] Error 1
rm assign2.o
C:\Project>
For some reason it seems to compile the first file, a second time and doing so crashes.
Can anyone correct me on my errors?
The problem is your pattern rules. You are writing pattern rules like this (after make expands the variables):
%.o: assign2.c ports.h
What this rule tells make is that ANY target it wants to build that matches the %.o pattern, can be built by compiling assign2.c. That's obviously not true: this rule build exactly one target: assign2.o.
So make reads your makefile and wants to build a file named elf. It sees that elf depends on $(TARGET).elf, so it builds that (that's the first compile and link, that works). Then make wants to build elf itself. You haven't declared it to be .PHONY, so make assumes it might be a real target.
Make looks through its built-in rules to find one that will let it build elf, and it finds a built-in rule: % : %.o which it can use to compile a program from a .o file with the same prefix. So now for target elf make wants to try to build a file elf.o. Oho! It sees there's a pattern rule that lets it build any .o file based on the assign2.c source file, so it runs that rule (that's the second compile) expecting it to build elf.o... which it doesn't, obviously.
Then make runs the built-in link recipe, using elf.o which doesn't exist, and fails.
The solution to your problem is two things:
First, you should always declare all your makefile targets that you don't actually want to build as .PHONY so make won't try to build them:
.PHONY: all elf hex
Second, you should never use pattern rules where the prerequisite is not also a pattern (this can be useful in certain very specific situations, but not in general). You should either change those pattern rules to explicit rules:
assign2.elf: $(OBJ) $(LIB)
...
$(OBJ): $(SRC) $(INCLUDE)
...
Or make them into full pattern rules by using the pattern in the prerequisites list as well:
%.elf : %.obj $(LIB)
...
%.o: %.c $(INCLUDE)
...
I get this error when I do the make:
relocation R_X86_64_32 against `vtable for Torch::MemoryDataSet' can not be used
when making a shared object; recompile with -fPIC
It says that I should recompile with the -fPIC option. I did that, adding
the -fPIC option to CFLAGS and CXXFLAGS, but I still get the same error. Is there any way to solve this? I have seen that this problem is related with the use of a 64-bit machine, and it is true that I am using one.
I had this problem quite a while back and if I remember correctly, the fix was moving the placement of -fPIC just after gcc in the command line. Made absolutely no sense, and less so now, but as I remember, that fixed it.
I encountered the same problem, but it had an extra twist. The answer by #clintm solved it, but I thought I would describe my variation of the problem here for future reference...
Makefile on 32-bit machine:
CXX=g++
CXXFLAGS= -O3 -Wall
...
...
%.o: %.c
$(CXX) $(CXXFLAGS) -fpic -c $<
libmylibrary.so: $(OBJECTS)
$(CXX) -shared -Wl,-soname,$# -o $# $(OBJECTS)
This compiled correctly. But the same Makefile failed when I tried it on a 64-bit machine. I changed "-fpic" to "-fPIC" and it still failed. I changed the object rule to:
%.o: %.c
$(CXX) -fPIC $(CXXFLAGS) -c $<
and it still failed.
Finally, I placed "-fPIC" in the actual compiler variable (so that now "-fPIC" appears in the rule for each object and the rule for the shared library):
CXX=g++ -fPIC
CXXFLAGS= -g -O3 -Wall
...
%.o: %.c
$(CXX) $(CXXFLAGS) -c -o $# $<
libalglib.so: $(OBJECTS)
$(CXX) -shared -Wl,-soname,$# -o $# $(OBJECTS)
And it worked!
Let's say you have some makefile like:
CFLAGS = -g -Wall
SOURCES = $(wildcard *.c)
OBJECTS = ...
TARGET = libmyawesomelib.a
all: $(TARGET) main
just add the -fPIC flag like so:
$(TARGET): CFLAGS += -fPIC
$(TARGET): $(OBJECTS)
.
.
.
so on so forth with the rest of the makefile.
I ran into this problem cross-compiling with the android-ndk toolchain. I ended up having to use
CC="$CROSS/bin/arm-linux-androideabi-gcc -pie --sysroot=$SYSROOT"
Neither -fPIC nor -fPIE worked for me in this situation.
I was cross compiling shadowsocks-libev on a CentOS 7 machine, the same problem happened to me, it works perfectly on my laptop with
CC=mipsel-unknown-linux-uclibc-gcc CXX=mipsel-unknown-linux-uclibc-g++ AR=mipsel-unknown-linux-uclibc-ar RANLIB=mipsel-unknown-linux-uclibc-ranlib make SHARED=1 CFLAGS=-fPIC
but on travis ci, it did not work, I have to add -fPIC to CC and CXX in order to get it to work
CC="mipsel-unknown-linux-uclibc-gcc -fPIC" CXX="mipsel-unknown-linux-uclibc-g++ -fPIC" AR=mipsel-unknown-linux-uclibc-ar RANLIB=mipsel-unknown-linux-uclibc-ranlib make SHARED=1
I had this issue after I upgraded gcc. I had one .o file (sqlite) that hadn't been cleaned by the Makefile and as a result I had this issue (assuming because it was compiled with an older version of gcc). After removing that file and rebuilding this error went away.
if the project you'd like to compile has a correct configure script use like this:
$ ./configure 'CFLAGS=-g -O2 -fPIC ....' --enable-some-thing
so the flag will be all the Makefile's rule ...
few days before i've need an elder ver. of VLC to compile on an x64 machine, it has a nice configure script ;-)