VPATH not working with Makefile Rule - makefile

I have added another rule to a Makefile to attempt to build a C shared library that uses SWIG to wrap the functions for Java using JNI
The additional rule looks like this (basically lifted from one of the SWIG java examples)
java: $(program_C_SRCS)
$(SWIG) -java $(SWIGOPT) $(INTERFACEPATH)
$(CC) -c $(CFLAGS) $(JAVACFLAGS) $(program_C_SRCS) $(ISRCS) $(CPPFLAGS) $(JAVA_INCLUDE)
$(JAVALDSHARED) $(CFLAGS) $(program_C_OBJS) $(IOBJS) $(JAVA_DLNK) $(LDFLAGS) -o $(JAVA_LIBPREFIX)$(TARGET)$(JAVASO)
javac *.java
problem I have is that my VPATH doesn't seem to work with the *.c files anymore
I noticed that this rule causes all the .c files to compiled as one call to gcc rather than a separate call to gcc for the compilation of each .o file
my previous rules for compilation without any JNI stuff look like this:
.PHONY: all clean
all: $(program_DEBUG_NAME) $(program_RELEASE_NAME)
# original rule to build library in src dir (no longer inc. in all)
$(program_NAME): $(program_C_OBJS)
$(LINK.c) -shared -Wl,-soname,$# $^ -o $#
# new rules to build debug/release libraries and place them in relevant build
# dirs
$(program_DEBUG_NAME): $(DEBUG_OBJS)
$(DEBUG_LINK.c) -shared -Wl,-soname,$# $^ -o $(BUILD_DIR)/debug/$#
$(program_RELEASE_NAME): $(RELEASE_OBJS)
$(RELEASE_LINK.c) -shared -Wl,-soname,$# $^ -o $(BUILD_DIR)/release/$#
# rule to build object files (replaces implicit rule)
$(BUILD_DIR)/debug/%.o: %.c
$(DEBUG_LINK.c) $< -c -o $#
$(BUILD_DIR)/release/%.o: %.c
$(RELEASE_LINK.c) $< -c -o $#
and these work with VPATH no problem
my VPATH statement looks like this:
VPATH = ../../pulse_IO/src ../../../g2/src

Look at your rule:
java: $(program_C_SRCS)
...
$(CC) -c $(CFLAGS) $(JAVACFLAGS) $(program_C_SRCS) ...
...
Suppose program_C_SRCS is foo.c, and the path is somewhere/foo.c. Without VPATH, this rule doesn't run at all because Make can't find foo.c. With VPATH, Make finds it, and knows that the real prereq is somewhere/foo.c. But you have $(program_C_SRCS) in your rule:
java: somewhere/foo.c
...
$(CC) -c $(CFLAGS) $(JAVACFLAGS) foo.c ...
...
This fails because there is no foo.c (locally).
Try this:
java: $(program_C_SRCS)
...
$(CC) -c $(CFLAGS) $(JAVACFLAGS) $^ ...
...
(The use of automatic variables like $^ is the reason your previous rules worked.)

Related

BSD make & GNU make

I have Makefile. This runs on FreeBSD with gmake and make. In BSD Make command not output log same with gmake.
$ gmake
compile main.cpp
linking myout
$ make
c++ -O2 -pipe -c main.cpp -o main.o
linking myout
$ cat Makefile
TARGET = myout
default: $(TARGET)
SRCS = main.cpp
OBJS = $(SRCS:%.cpp=%.o)
default: $(BIN)
%.o: %.cpp
#echo compile $<
#$(CXX) -c $< -o $#
$(TARGET): $(OBJS)
#echo linking $#
#$(CXX) $(OBJS) -o $#
clean:
#rm -f $(OBJS) $(TARGET)
According to the FreeBSD make documentation, it doesn't support pattern rules. So your rule here:
%.o: %.cpp
#echo compile $<
#$(CXX) -c $< -o $#
in FreeBSD make is just an explicit rule telling make how to build the literal file %.o from the literal file %.cpp. Since you don't try to build a file named %.o (you're trying to build main.o), this rule is ignored / never used.
It looks like if you want something that will work the same way between both versions of make you'll have to restrict yourself to the POSIX standard suffix rules format, like this:
.SUFFIXES: .cpp .o
.cpp.o:
#echo compile $<
#$(CXX) -c $< -o $#
The default build utilities are different. FreeBSD uses a different implementation of make than GNU/Linux. The respective man pages outline differences.
https://forums.freebsd.org/threads/difference-gmake-gnu-and-freebsd-make.28784/

How to save modules in a separate directory using a makefile

I am compiling some of my own FORTRAN code using a simple makefile but dislike having my code directory cluttered up with *.mod and *.o files.
Is there a simple way I can edit my makefile so that these compiled files are placed in a separate directory (something like ./obj/ )? I've searched through here and google to find a few examples but I can't get any of them working. Probably as I have very little experience of makefiles and fortran (have only coded C until now).
Below is my current makefile:
LIBBASE=/my/lib/dir/
HDF5LIB=$(LIBBASE)/hdf5/lib
HDF5INCLUDE=$(LIBBASE)/hdf5/include
MYLIB_LIB=$(LIBBASE)/mylib
MYLIB_INCLUDE=$(LIBBASE)/mylib
LIBS=-L$(HDF5LIB) -lhdf5 -lhdf5_fortran -lhdf5hl_fortran \
-L$(MYLIB_LIB) -lmylib
INC=-I./ -I$(HDF5INCLUDE) -I$(MYLIB_INCLUDE) -DINCLUDE_MYLIB
# Compiler
F90 = ifort
CC = ifort
FLAGS = -g -O2 -openmp
# ------ No machine-specific paths/variables after this -----
FSOURCE = my_structures my_constants my_utils my_prog MainMOD
OBJECTS = my_structures.o my_constants.o my_utils.o my_prog.o
all: $(FSOURCE)
MainMOD: MainMOD.F90
$(F90) $(FLAGS) -o $# $(INC) MainMOD.F90 $(LIBS) $(OBJECTS)
my_structures: my_structures.F90
$(F90) $(FLAGS) -c $(INC) imager_structures.F90 $(LIBS)
my_prog: my_prog.F90
$(F90) $(FLAGS) -c $(INC) my_prog.F90 $(LIBS)
my_constants: my_constants.F90
$(F90) $(FLAGS) -c $(INC) preproc_constants.F90 $(LIBS)
utils: my_utils.F90
$(F90) $(FLAGS) -c $(INC) my_utils.F90 $(LIBS)
clean:
rm -f $(FSOURCE) $(OBJECTS)
# Compilation rules
$(OBJ_DIR)\\%.o: %.F90
$(F90) $(FLAGS) -c $# $<
# Rule to prevent make from identifying Fortran .mod files as Modula2 source
# files
%.o : %.mod
First, the way Makefile works is based on that targets and sources are in the same directory. For sure, you can do the opposite, but Makefile wasn't designed with that option in mind so you'll have to make your recipes a bit ugly.
Now, if I really wanted to have object files in a separate directory and wasn't bounded by using make only, I'd use cmake which in contrast to make assumes that sources are separated from the build files.
If you still want to go with make, then I think you need to fix one thing.
From
$(OBJ_DIR)\\%.o: %.F90
to
$(OBJ_DIR)/%.o: %.F90
Also,
%.o : %.mod
is not required if you put
.SUFFIXES:
on the very first line of the file. This will turn off all implicit rules since you don't use them anyway.

Compiling for Multiple Targets

I want to compile my program both to linux and windows using g++ and mingw respectively. The only difference between the compilations is the compiler to use and output file name.
A single make command should produce both output files. What is the best way to achieve this with as little duplications in the makefile as possible?
How about this:
linux-name: CC:=g++
windows-name: CC:=mingw
linux-name windows-name:
$(CC) whatever -o $#
EDIT:
What I wrote above is only the new part of the makefile; I assumed that the rest of the makefile was implied. To be more explicit:
all: linux-name windows-name
linux-name: CC:=g++
windows-name: CC:=mingw
linux-name windows-name: foo.o bar.o baz.o SomethingElse
$(CC) $(CCFLAGS) whatever $^ -o $#
%.o: %.cc
$(CC) $(CFLAGS) -I$(INC_DIR) whatever -c $< -o $#
SomethingElse:
build somehow

Makefile include file for same targets

I have a large project using recursive Make. Almost all the Makefiles are the same though. I'm basically building all the object files into the same directory like this:
$(OBJ)/%.o: %.c
$(COMPILE) ${INCLUDES} -c $< -o $#
$(OBJ)/%.o: %.cpp
${CXX} ${INCLUDES} ${FLAGS} -c -fPIC $< -o $#
Is it possible to put these targets in an include file so I don't have to put the same lines in every Makefile?
include I've only used for shared variables and when I tested this using include it did not work.

Makefile: target with pattern does not work

My Makefile looks like this:
BIN = bin
OBJECTS = object1.o \
object2.o \
object3.o
HDR = $(OBJECTS:%.o=%.h) header1.h header2.h
MAIN = main.c
CC = gcc
CFLAGS = -Wall -g -std=c99 -fstack-protector-all
LDFLAGS = -lpthread
$(BIN): $(OBJECTS) $(MAIN)
$(CC) $(CFLAGS) $(LDFLAGS) -o $# $^
%.o: %.c $(HDR)
$(CC) $(CFLAGS) -c $< -o $#
It seems that the %.o: %.c $(HDR) rule is not used. When invoking with option make -r it says that there's no rule to make target object.o. The build of each object file should depend on every header file. What am I missing?
Edit: I should mention that when doing echo $(HDR) than it looks like the variable contains the right values:
object1.h object2.h object3.h header1.h header2.h
In the declaration of HDR, try $(OBJECTS:.o=.h) instead. Or, better yet, use gcc -MM or the like to generate your dependencies instead.
A pattern rule can't have auxilliary dependencies like ${HDR}.
Use:
%.o : %.c
$(CC) $(CFLAGS) -c $< -o $#
${OBJECTS}: ${HDR}
Ok, the given Makefile should work, I had a typo in one of the header file names.
It's a pitty, but make doesn't warn about that. It seems that when a pattern based rule is missing a prerequisite than it's just ignored. The built-in .o creation rule is used instead.
Jonathan Leffler's proposal of ${OBJECTS}: ${HDR} brought that up, because than there's an error regarding "no rule to make target misspelled.h" - I would have expected that from my rule too.
So I can just agree to fluffy, it's better to use auto-generated dependencies instead.

Resources