I'm trying to organize the files of my project, as all of them are in the root directory, and change the Makefile, as it is too long and very repetitive. So I make the following 3 directories:
include : Contains all of the .h files
src : Contains all of the .c files
obj : It is empty for the moment but after compilation, it will contain all of the .o files
So my first goal was to make the .o files and put them in the /obj directory and the Makefile I made is the following :
#paths
INCLUDE = include
SOURCE = src
OBJS = obj
# compiler
CC = gcc
#flags
CFLAGS = -Wall -g -pedantic -I$(INCLUDE)
VFLAGS = --leak-check=full -v
OB = $(OBJS)/space.o $(OBJS)/command.o $(OBJS)/screen.o $(OBJS)/graphic_engine.o $(OBJS)/game.o $(OBJS)/object.o $(OBJS)/player.o $(OBJS)/game_reader.o $(OBJS)/die.o $(OBJS)/set.o $(OBJS)/inventory.o $(OBJS)/link.o $(OBJS)/game_loop.o
build: $(OB)
$(OBJS)/%.o: $(SOURCE)/%.c $(INCLUDE)/%.h
$(CC) -c $< $(CFLAGS) -o $#
When I run it, all the .o files are made and placed in the obj directory but the last and I get the folloing error :
make: *** No rule to make target 'obj/game_loop.o', needed by 'build'. Stop.
In the OB variable, I changed the position of the game_loop and noticed that the previous .o files were made and the compilation stopped again at the game_loop file.
I want help to overcome this error and help to continue making the
Makefile
Related
Automate the compilation of auto-generated C files with regular C files
We have developed a program "cperformer" that is able to generate a C file from a text file (to keep it simple).
It is a kind of "meta-compiler" that generates C file as output. Thus, we would like to improve the usage of this "C generator" by automating the generation of each C file as a first step of a makefile, and then compile and link together all of these generated C files with other C files already present with GCC in the same makefile.
Makefile 1
C_GEN :=./cperformer -n
CC :=gcc
CFLAGS :=-I.
#List all .c files generated from .text files
AUTO_SRCS = $(wildcard *.text)
AUTO_OBJS_C := $(patsubst %.text,%_alg.c,$(AUTO_SRCS))
$(info *INFO* Text files = $(AUTO_SRCS))
#List all .c files to compile (auto-generated or not)
SRCS = $(AUTO_OBJS_C)
SRCS += $(wildcard *.c)
OBJS := $(patsubst %.c,%.o,$(SRCS))
$(info *INFO* C files = $(SRCS))
# Main target rule
target : $(OBJS)
$(CC) -o $# $(OBJS) $(CFLAGS)
# Pre-compilation step (some C files generation)
prelim $(AUTO_OBJS_C): $(AUTO_SRCS)
$(C_GEN) $<
# Pre-compilation step (object files generation)
%.o: %.c
$(CC) -c -o $# $< $(CFLAGS)
all: prelim target
clean :
rm -f TARGET $(OBJS) *_alg*
Error 1
$ make all
*INFO* Text files = file3.text file2.text file1.text
*INFO* C files = file3_alg.c file2_alg.c file1_alg.c linked_list.c main.c
./cperformer -n file3.text
Compiling: file3.text ...
No error.
Done.
gcc -c -o file3_alg.o file3_alg.c -I.
./cperformer -n file3.text
Compiling: file3.text ...
No error.
Done.
gcc -c -o file2_alg.o file2_alg.c -I.
gcc: error: file2_alg.c: No such file or directory
gcc: fatal error: no input files
compilation terminated.
make: *** [Makefile:29: file2_alg.o] Error 1
It fails because the "cperformer" program is asked to generate the same C file each time "file3.c" so GCC don't find "file2.c" as expected and it aborts the compilation.
Makefile 2
Replace the C generative rule of the above makefile with the use of "%" :
# Pre-compilation step (some C files generation)
%.c: %.text
$(C_GEN) $<
Error 2
make: *** No rule to make target 'file3_alg.o', needed by 'target'. Stop.
Nothing compiles here.
Makefile 3
The dirty fix
batch_c_generation :
#$(foreach TXT_FILE, $(AUTO_SRCS), $(C_GEN) $(TXT_FILE);)
This is kind of working but remains very dirty because it re-generates all C files at each build and some duplication errors appear when it is not properly cleared between each make.
How can I fix the makefile ?
You were close -- simply fix your pattern rule to look like this:
%_alg.c : %.text
$(C_GEN) $<
As #tripleee mentioned, the reason your makefile1 rule failed was that it expands to something like:
file2_alg.c file1_alg.c: file2.text file1.text
$(CGEN) $<
In this case $< expands to the first dependency which will always be file2.text...
In your makefile2 example, you used %.c instead of %_alg.c (and hence there's no rule to build file2_alg.c, and therefore no rule to build file2_alg.o)
I am working on project, where i use couple of .c and .h files.
I created Makefile where i actualize executable program based on changes in all of these files.
Problem is, when i use make, program is compiled, but when i execute program, it runs without any change. I need to save ( working in vim so :w ) all included files, even when i changed only one.
If i don't save all these files, program is compiled, but executes the same thing as it did before change.
Could someone explain me why is that ?
Makefile code :
CC=gcc
CFLAGS=-WALL
execFile: execFile.o functions.h newDataTypes.h
Thank you.
The reason you are not getting execFile updated is because you're NOT updating it. Or at least you don't seem to be in this particular case.
There are many ways to get about doing this. However since you are using gcc and I assume you're using gnu make the following is probably the best solution you can execute1.
Given the files:
-rw-r--r-- 1 user sudo 73 Nov 4 22:54 exeFile.c
-rw-r--r-- 1 user sudo 74 Nov 4 22:54 exeFile.h
-rw-r--r-- 1 user sudo 90 Nov 4 22:55 hello_world.c
-rw-r--r-- 1 user sudo 888 Nov 4 23:03 Makefile
cat exeFile.c
#include <stdio.h>
#include "exeFile.h"
int main()
{
hello_world();
}
exeFile.h
#ifndef _EXEFILE_H
#define _EXEFILE_H
extern void hello_world();
#endif
hello_world.c
#include <stdio.h>
#include "exeFile.h"
void hello_world()
{
printf("Hello World\n");
}
you can set up a make file that generates dependencies and ensures that the program will always be compiled correctly:
CC=gcc
CFLAGS=-Wall
SOURCES=exeFile.c hello_world.c
EXE=exeFile
OBJ=$(SOURCES:%.c=%.o)
DEPDIR := .deps
$(shell mkdir -p $(DEPDIR) >/dev/null)
DEPFLAGS = -MT $# -MMD -MP -MF $(DEPDIR)/$*.Td
COMPILE.c = $(CC) $(DEPFLAGS) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c
COMPILE.cc = $(CXX) $(DEPFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c
POSTCOMPILE = #mv -f $(DEPDIR)/$*.Td $(DEPDIR)/$*.d && touch $#
%.o: %.c
%.o: %.c $(DEPDIR)/%.d
$(COMPILE.c) $(OUTPUT_OPTION) $<
$(POSTCOMPILE)
%.o : %.cc
%.o : %.cc $(DEPDIR)/%.d
$(COMPILE.cc) $(OUTPUT_OPTION) $<
$(POSTCOMPILE)
%.o : %.cxx
%.o : %.cxx $(DEPDIR)/%.d
$(COMPILE.cc) $(OUTPUT_OPTION) $<
$(POSTCOMPILE)
$(DEPDIR)/%.d: ;
.PRECIOUS: $(DEPDIR)/%.d
$(EXE): $(OBJ)
$(CC) -o $# $(OBJ) $(LDFLAGS)
clean:
$(RM) $(OBJ) $(EXE)
dev-clean: clean
$(RM) -r $(DEPDIR)
include $(wildcard $(patsubst %,$(DEPDIR)/%.d,$(basename $(SOURCES))))
Let's go over the relevant parts about dependencies
DEPDIR =
This implementation places dependency files into a subdirectory named .deps .
$(shell mkdir -p $(DEPDIR) 2>/dev/null)
GCC does not create subdirectories for output, this line ensures that the DEPDIR directory always exists.
DEPFLAGS = ...
These are GCC-specific flags which tell the compiler to generate dependency info.
-MT $#
Set the name of the target in the generated dependency file.
-MMD
Generate dependency information in addition to compiling. -MMD omits system headers from the generated dependencies: if you prefer to preserve system headers as prerequisites, use -MD instead.
-MP
Adds a make target for each prerequisite in the list, this avoids errors when deleting files.
-MF $(DEPDIR)/$*.Td
Write the generated dependency file to a temporary file $(DEPDIR)/$*.Td e.g. hello_world.c will generate hello_world.Td as temp dependency content for use in Makefile.
POSTCOMPILE = ...
First rename the generated temporary dependency file to the real dependency file. We do this in a separate step to side-step compile errors. Next we explicitly touch the files to avoid a gcc bug.
%.o : %.c
Delete the built-in rules for building object files from .c files, so that our rule is used instead. Do the same for the other built-in rules.
... $(DEPDIR)/%.d
Declare the generated dependency file as a prerequisite of the target, so that if it’s missing the target will be rebuilt.
$(DEPDIR)/%.d: ;
Create a pattern rule with an empty recipe, so that make won’t fail if the dependency file doesn’t exist.
.PRECIOUS: $(DEPDIR)/%.d
Mark the dependency files precious to make, so they won’t be automatically deleted as intermediate files.
include ...
Include the dependency files that exist: translate each file listed in SOURCES into its dependency file. Use wildcard to avoid failing on non-existent files.
1 See Auto-Dependencies Generation for details.
Fix:
Tell make that the executable depends only on the object file and the object file depends on the header files:
execFile: execFile.o
execFile.o: functions.h newDataTypes.h
Explanation:
In order to build your executable two steps are needed:
compilation of C source files (that include header files) to produce object files,
linking of the object files to produce the executable.
So, when changing your header files you must re-compile, that is re-built the object files, not just re-link that would produce the same executable from the same object files.
In your Makefile the dependencies are not properly defined. You did not tell make that the object file (execFile.o) shall be rebuilt when your header files change. Instead, you told it that the executable (execFile) shall be rebuilt.
First of all, your dependencies are mistaken. Your executable does not depend on the .h header files, as they are using only at compilation time. The dependencies are normally between .o files and .h files, as when you modify one .h file, the including .c file must be compiled to generate the .o file. so in case you have execFile.o (which, on lack of complete information, I'll suppose it depends on execFile.c, which #includes functions.h and newDataTypes.h, the rule should be:
execFile.o: execFile.c functions.h newDataTypes.h
As it has been pointed out in other responses, there's no need to write the command to build the .o file, as there is a default rule like this:
.c.o:
$(CC) $(CFLAGS) -o $# -c $<
(observe there's a -c option to the compiler indicating to compile only and don't link, we'll return here below) which means that once you detect the .o is outdated (as the dependencies on .c and .hs mark) it will be compiled with the above command, which result in:
gcc -Wall -o execFile.o -c execFile.c
making the appropiate compilation.
Other thing is the dependencies of the executable file. These have to be included, as make(1) doesn't know which object files form your final executable. In this case, assuming you have your program execFile depend on execFile.o and a.o, b.o and c.o, I normally use to write:
execFile_objs = execFile.o a.o b.o c.o
execFile: $(execFile_objs)
$(CC) $(LDFLAGS) -o $# $(execFile_objs)
so any of the .os is changed (because an indirect change in a source file) the whole program is linked again (but only the touched files are compiled)
NOTE
In the case (not normal) that you have a Makefile to create a program that has only one source file and several include files you can compile each time the whole thing each time you modify one source file, in this way:
execFile: execFile.c functions.h newDataTypes.h
$(CC) $(CFLAGS) $(LDFLAGS) -o $# execFile.c
This will execute
gcc -Wall -o execFile execFile.c
Observe that there is no -c (compile only, don't link) option in this command.
There's no mention of the include files (they are included because of the #include directives in the code... and you only state here that the executable depends also (and have to be built) in case any of the .h files are modified.
Automatic dependency rules are a little confusing at first, as they induce you to think there are such rules to make any kind of file from any other kind of file (well, there are for .c -> .o files, and .c -> <nothing> to compile directly to an executable) normally you have to include dependencies in such cases when your target depends on more files than the automatic rule states. In such cases, it is very important not to include any command, so the compiler selects the automatic rule (when you don't include a command to generate the target, the make(1) program tries to use a default rule for it, or nothing at all if you have not included commands, it only assumes your dependencies are indirect through this fake target --- and, as this fake target is not built in the process, it will fail always and be followed)
I have a project that includes many source files in different folder locations. For some reason my Makefile can either do one of the following but not both at the same time (which is what I really want):-
1) Compile all files into a separate directory
2) Perform the compilation ONCE, gcc needs to be called once only as this significantly reduces the compilation time.
This is a code snippet that works to achieve option 1:-
INCLDDIRS := "The needed include directories"
CFLAGS = "some c flags"
C_SOURCE = "Many many source files in different directories"
C_SOURCE_NAMES = $(notdir $(C_SOURCE))
OBJECT_DIRECTORY = ObjDir
C_OBJECTS = $(addprefix $(OBJECT_DIRECTORY)/, $(C_SOURCE_NAMES:.c=.o) )
all: $(OBJECT_DIRECTORY) $(C_OBJECTS)
$(OBJECT_DIRECTORY):
mkdir ObjDir
$(OBJECT_DIRECTORY)/%.o:%.c
$(CC) $(CFLAGS) $(INCLDDIRS) -c -o $# $<
For some reason the above compiles each c source file individually and generates an object file (i.e. gcc is called for all source files). Which is not what I want. However, at least all generated files are located in ObjDir
and this is the code snippet that works to achieve option 2:-
INCLDDIRS := "The needed iclude directories"
CFLAGS = "some c flags"
C_SOURCE = "Many many source files in different directories"
C_SOURCE_NAMES = $(notdir $(C_SOURCE))
OBJECT_DIRECTORY = ObjDir
C_OBJECTS = $(OBJECT_DIRECTORY)/*.o
all: $(OBJECT_DIRECTORY) $(C_OBJECTS)
$(OBJECT_DIRECTORY):
mkdir ObjDir
$(C_OBJECTS): (C_SOURCE)
$(CC) $(CFLAGS) $(INCLDDIRS) -c $(C_SOURCE)
For the above snippet, all files are compiled once (i.e. gcc is called only once) but the object files are generated at the same location as the Makefile and not into a separate directory. I do not want to mv the files after they are generated as this is not the cleaner solution.
My Question is:
What do I have to do to my Makefile so that compilation is performed once and that the object files are generated into a separate directory?
The makefile you want will look something like this.
INCLDDIRS := "The needed include directories"
CFLAGS = "some c flags"
C_SOURCE = "Many many source files in different directories"
C_SOURCE_NAMES = $(notdir $(C_SOURCE))
OBJECT_DIRECTORY = ObjDir
BINARY := your_binary
all: $(BINARY)
$(OBJECT_DIRECTORY):
mkdir $#
$(OBJECT_DIRECTORY/$(BINARY): $(C_SOURCE) | $(OBJECT_DIRECTORY)
$(CC) $(CFLAGS) $(INCLDDIRS) -o $# $^
It uses an order-only prerequisite for the output directory (so make knows to create it first but not count it as causing a rebuild).
It lists the source files as the prerequisites of the output binary and uses them all on the compilation line.
The main problem with this makefile, and with your goal, is that a change to any source file will cause every source file to be recompiled from scratch. That's fairly inefficient as far as incremental work goes. (That's why the default idea is to use intermediate object files. You trade some from-clean speed off against incremental speed.)
The reason your second makefile didn't work correctly is that, in a clean directory, the C_OBJECTS variable has no value. Your wildcard $(OBJECT_DIRECTORY)/*.o matches nothing.
That said it was also incorrect in that it listed every source file as a prerequisite for every object file which isn't at all correct.
This question already has answers here:
Building multiple executables with similar rules
(5 answers)
Closed 9 years ago.
I am having a directory called test where make file should be. i am having subdirectory called sub1, sub2, sub3.
test/Makefile
test/sub1
test/sub2
test/sub3
I want to create exe1 by compiling sub1, exe2 by compiling sub2 and exe3 from sub3.
Can i add more than one directory in vpath?? or any other solution
You could simply have a very simple makefile in the test directory, just going into the subdirectories and calling makefiles in them. The subdirectories have makefiles that builds normally, but simply put the executable in the parent directory.
First of all: Yes you could add more than one directory in vpath. Each entry is separated with a colon ':'
vpath %.c test/sub1:test/sub2:test/sub3
But you'll getting into trouble as soon you have the same filename (with different content) in two directories. Consider:
test/Makefile
test/sub1/main.c
test/sub1/foo.c
test/sub1/bar.c
...
test/sub2/main.c
test/sub2/blish.c
test/sub3/blash.c
...
test/sub3/main.c
test/sub3/okEnoughForNow.c
And your makefile containing:
vpath %.c sub1:sub2:sub3
exe1.exe : main.c foo.c bar.c
gcc -o $# $^
exe2.exe : main.c blish.c blash.c
gcc -o $# $^
exe3.exe : main.c okEnoughForNow.c
gcc -o $# $^
The result would be:
gcc -o exe1.exe sub1/main.c sub1/foo.c sub1/bar.c
gcc -o exe2.exe sub1/main.c sub2/blish.c sub2/blash.c
gcc -o exe3.exe sub1/main.c sub3/okEnoughForNow.c
As you can see, all exe's contain sub1/main.c as this is the main.c found first; Its path appears first on the vpath.
Joachim's Approach is definitive a simple, and very common solution. I would choose it as well if the programs in your subfolders are completely unrelated: You could have in each directory a makefile containing something like:
SRC := $(wildcard *.c)
%.exe : $(SRC)
gcc -o $# $^
Assuming, all .c files in each of your sub* shall be part of your program, and there are no subfolders in your sub's. Otherwise you'll need a different approach to scan your .c files, or specify them individually.
In your main makefile you can run for each subfolder a new instance of make, using those makefiles. Which gives you a main Makefile like:
# Get all subfolders name without trailing slash
PROGS := $(patsubst %/,%,$(wildcard */))
# Each subfolder can be made by calling make in
# that folder. A file prog.exe is created.
.PHONY : $(PROGS)
$(PROGS) :
$(MAKE) -C $# prog.exe
# Now every .exe depends on its subfolder, calls
# Make there - see rule above and copies the
# prog.exe from there into the root, with the name
# of the subfolder. (Alternatively you could use
# mv instead of cp)
%.exe : %
cp $</prog.exe $#
Assuming the name of your .exe is the same as the directory name and all subfolders are containing programs.
However, calling make from a running make instance (recursive make) can cause a real headache as soon as there are any dependencies between the generated files of the subfolders.
Another solution:
A different approach whithout using recursive make is having rules dynamically created. In that case your main Makefile could look like this. (I'm again assuming all subfolders are containing programs, all subfolders are flat, and all .c files in those subfolders are part of your program) This has the advantage that you'll have to maintain just one makefile, and there can be any dependency between the different programs. But still it has the disadvantage that you cannot manage your different programs seperately.
That's the complete makefile:
%.exe :
gcc -o $# $^
PROGS := $(patsubst %/,%,$(wildcard */))
$(foreach P,$(PROGS),$(eval OBJ_$(P) := $(wildcard $(P)/*.c)))
$(foreach P,$(PROGS),$(eval $(P).exe : $(OBJ_$(P))))
.PHONY : all
all : $(addsuffix .exe,$(PROGS)
We're starting with a rule for compiling: Any .exe is generated by invoking gcc having all prerequisites as source files.
%.exe :
gcc -o $# $^
Then, next step is to obtain all "programs" by scanning for all subfolders and stripping off the trailing slash
PROGS := $(patsubst %/,%,$(wildcard */))
The next step is to create for each program a variable containig all Sources. Note the eval function expands, and passes everything to make as it has been written in the Makefile.
$(foreach P,$(PROGS),$(eval SRC_$(P) := $(wildcard $(P)/*.c)))
Thus the line above, with your sub1, sub2 and sub3 will become:
SRC_sub1 := $(wildcard sub1/*.c)
SRC_sub2 := $(wildcard sub2/*.c)
SRC_sub3 := $(wildcard sub3/*.c)
The eval function can even be used to create rules:
$(foreach P,$(PROGS),$(eval $(P).exe : $(SRC_$(P))))
So this will expand to (assuming the file structure in the example above)
sub1.exe : sub1/main.c sub1/foo.c sub1/bar.c
sub2.exe : sub2/main.c sub2/blish.c sub2/blash.c
sub3.exe : sub3/main.c sub3/okEnoughForNow.c
Now we have three rules without a recipe. Make says "if you have a rule without recipe, and an implicit rule that matches can be found, this rule is used with the prerequisites added from the rule that does not have the recipe" Thus, for those 3 rules the implicit rule of %.exe above applies.
Basically that's the trick. For your convenience you can add
.PHONY : all
all : $(addsuffix .exe,$(PROGS))
So make all makes everything.
Extension:
If you'd like to be able to make the .o files seperately as well, you could add one more implicit rule like:
%.o : %.c
gcc -c -o $# $<
and make your programs dependent on the .o rather than on the .c files:
$(foreach P,$(PROGS),$(eval OBJ_$(P) := $(patsubst %.c,%.o,$(wildcard $(P)/*.c))))
$(foreach P,$(PROGS),$(eval $(P).exe : $(OBJ_$(P))))
Then you'll have your .exe dependend on the .o that can be found by changing .c into .o after scanning all sources. Via the implicit rule chain %.o : %.c make will know what to do.
I am working on a C project which contains around 200 .c files and some .h files. Not all of these 200 files are required in the final product. Currently around 180 files needs to be compiled. We have a file "compile_only_these.c" which includes these 180 *.c files required for the project. Our makefile compiles only this file instead of individual .c files.
/* file: compile_only_these.c*/
#include "file1.c"
#include "file2.c"
.
.
.
#include "file180.c"
But I think including .c files is a bad idea. Because every time I modify any of these files, all files are compiled again.
Can you suggest a better way to compile these files.
More info:
All .c files are in same folder "../project/src"
I keep adding new .c files which are required to be compiled. I dont want to modify Makefile every-time I add a new file.
I still want to keep those 20 .c files which I am not compiling right now. I may use it in future. Deleting these files are moving them to other directory is not a solution
What you need is a variable in the makefile, a list of required object files, like this:
OBJS := file1.o file2.o ... file180.o
You can have Make construct it from the compile_only_these.c file like this:
OBJS := $(shell sed -e '/\#include/!d' -e 's/\#include "\(.*\)\.c"/\1.o/' compile_only_these.c)
Do you also need a hand with the rule that uses these objects to construct the final product?
As already mentioned, it's sort of a weird way to manage a project, but given what you have to work with, you might try something along this approach...
CC = gcc
OBJFILE = myprog
# Tweak to match whatever you compile with normally
CFLAGS = -O2 -Wall -std=c89 -pedantic
LDFLAGS= # Extra flags here, for example -lm -pthread
RM = rm -f
SRCS = $(wildcard *.c)
OBJS = $(SRCS:.c=.o)
$(OBJFILE):$(OBJS)
$(CC) -o $# $^ $(LDFLAGS)
clean:
$(RM) core *~ $(OBJS) $(OBJFILE)
You will obviously need to adjust the path(s) for the specifics of your build hierarchy if you want to do more in your make than just compile this list of files, but this is a general approach for grabbing all files with wildcard substitution.