make into another directory summary 

The best way to make generated into another directory is explained in Multi-Architecture Builds Using GNU make http://make.paulandlesley.org/multi-arch.html

where 3 of the following methods are discussed:

  1. Source Copy Method

  2. Explicit Path Method

  3. VPATH Method

The conclusions are:

Still, if you need to go for the Explicit Path Method for its simplicity, follow Paul's Fourth Rule of Makefiles http://make.paulandlesley.org/vpath.html

If you are impatient, here is the summary.

using the Explicit Path Method 

When using the Explicit Path Method, the only reliable way to construct a makefile that will place targets into a remote directory, rather than the current directory, is by prefixing all the targets with that directory path.

We can use some of GNU make's functions to make things a little simpler to read/modify. For example, for a executable program 'foo' that is generated from 'foo.c' and 'bar.c':

PROGS   = foo
OBJECTS = foo.o bar.o

# Shouldn't need to change anything below here...

OBJDIR = ../obj

VPATH = $(OBJDIR)

$(OBJDIR)/%.o : %.c
        $(COMPILE.c) $< -o $@

OBJPROG = $(addprefix $(OBJDIR)/, $(PROGS))

all: $(OBJPROG)

$(OBJPROG): $(addprefix $(OBJDIR)/, $(OBJECTS))
        $(LINK.o) $^ $(LDLIBS) -o $@

This makefile will work correctly in all situations.

Paul said it doesn't need VPATH at all — VPATH is never consulted. But I doubt that if I remove the 'VPATH = ' line, thing will still work.

T

documented on: 2006.10.24

make file not in current directory 

Newsgroups: comp.os.linux.misc,comp.unix.questions
Date: Thu, 27 Mar 2003 08:56:42 -0600
> What is the right way of specifying make rules for files that are
> not in current directory? For example:
> %.ps : %.dvi %.chk

Not all makes are the same, but the implementation I use on Solaris does not allow more than ONE % on the right side. So, I believe this would be an error or not interpretted as you indend. GNU make may be different. What you are trying to do works for me, on Solaris 8, when there is only one % on the right.

Chuck Dillon

make file not in current directory 

> What is the right way of specifying make rules for files that are
> not in current directory?

There is none. The concept (a) does not apply, (b) is meaningless, (c) is ill-conceived.

> %.ps : %.dvi %.chk
>      $(DVIPS) -o $@ $<
> I want it to be a general purpose rule for files that are in current
> directory, and those which aren't. But it seems to me that it does

It is.

> not apply to files not in current directory, correct? How can I make
> it happen?

You probably need to change your perception.

> Further detailed info. I have another rule:
> ps : ${TEX_DEST_DIR}/$(TEX_SOURCE_BASE).ps
> and the .dvi has already been generated in ${TEX_DEST_DIR}. But when
> I issue make, I got:
> make: *** No rule to make target `../../tmp/path/test.ps', needed by `ps'.  Stop.

And where are you when you do this?

How Patterns Match
 A target pattern is composed of a `%' between a prefix and a suffix,
either or both of which may be empty.  The pattern matches a file
name only if the file name starts with the prefix and ends with the
suffix, without overlap.  The text between the prefix and the suffix
is called the "stem".  Thus, when the pattern `%.o' matches the file
name `test.o', the stem is `test'.  The pattern rule prerequisites
are turned into actual file names by substituting the stem for the
character `%'.  Thus, if in the same example one of the prerequisites
is written as `%.c', it expands to `test.c'.
 When the target pattern does not contain a slash (and it usually does
not), directory names in the file names are removed from the file
name before it is compared with the target prefix and suffix.  After
the comparison of the file name to the target pattern, the directory
names, along with the slash that ends them, are added on to the
prerequisite file names generated from the pattern rule's
prerequisite patterns and the file name.  The directories are ignored
only for the purpose of finding an implicit rule to use, not in the
application of that rule.  Thus, `e%t' matches the file name
`src/eat', with `src/a' as the stem.  When prerequisites are turned
into file names, the directories from the stem are added at the
front, while the rest of the stem is substituted for the `%'.  The
stem `src/a' with a prerequisite pattern `c%r' gives the file name
`src/car'.

In any case, the correct way to do what you want is

export VPATH:=$(TEX_SOURCE_DIR)
ps:
     $(MAKE) -C $(TEX_DEST_DIR) foo.ps

I.e. makefiles are expected to be one per dir.

Probably.

Peter

make file not in current directory 

> In any case, the correct way to do what you want is
>
>    export VPATH:=$(TEX_SOURCE_DIR)
>    ps:
>      $(MAKE) -C $(TEX_DEST_DIR) foo.ps
>
> I.e. makefiles are expected to be one per dir.

This is non-portable for those (bsd-based) `make's that do not use -C. I suspect you'd want to use (cd $(TEX_DEST_DIR); $(MAKE) ) instead.

Or something.

~Tim

make, into another directory 

Newsgroups: comp.unix.programmer
Date: Sun, 13 Apr 2003 03:30:12 GMT

I am having difficulties writing a make file that generate files in alternative directories. The problem is mainly on how to generate files from generated files.

Here is an example:

Seems to me that a simple

%.o: %.c

rule can't cover the above two cases. So I'm currently writing two separated rules for it. I want to know that if this (two separated rules) is the only solution?

Thanks for your input, even a 'yes' would help. :-)

make, into another directory 

Yes. (Seriously…)

(two separated rules is the only solution)

Paul D. Smith @gnu.org Find some GNU make tips at: http://www.gnu.org http://make.paulandlesley.org

make, into another directory 

> %.o: %.c
>   gcc -c $CFLAGS $^ -o $@ ;\
>   mv -f $@ obj

That does not work so well since it makes the .o file allways out of date.

These are the kinds of rules the OP will need.

obj/%.o : %.c
        gcc -c $CFLAGS $^ -o $@
obj/%.o : src/%.c
        gcc -c $CFLAGS $^ -o $@
src/%.c : %.l
        lex $LEXFLAGS $^
        mv -f lex.yy.c $@

Gianni Mariani