Date: Tue, 23 Feb 1999 10:45:27 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: "Salvador Eduardo Tropea (SET)" <salvador AT inti DOT gov DOT ar>
cc: djgpp-workers AT delorie DOT com
Subject: Re: Bug in make?
In-Reply-To: <m10Eznb-000S2TC@inti.gov.ar>
Message-ID: <Pine.SUN.3.91.990223104506.13846C-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Reply-To: djgpp-workers AT delorie DOT com


On Mon, 22 Feb 1999, Salvador Eduardo Tropea (SET) wrote:

> make -f m2.mak
> make.exe[1]: Entering directory `c:/980127/new/new/9901/mail/pp'
> E:\DJ\BIN/make.exe -f m3.mak
> make.exe[1]: *** [pepe.c] Error -1

Sigh.  This is an unfortunate side-effect of the backslash problem
(the file README.DOS explicitly tells you to stay away of backslashes
as much as you can).  Currently, you cannot use backslashes in
commands except as escape characters or in pairs, like in
"E:\\DJ\\BIN/make.exe".

I will try to see what can possibly be done to correct this, at least
in part, but don't hold your breath: it's a tough one to solve.
Here's why.

  - Many Makefiles which come from Unix expect the backslash to quote
    any character, not just " and '.  For example, they might use "\$"
    to get a dollar, or "\ " to get a space.  We don't want to break
    these cases.

  - Some non-DJGPP programs invoked by Make choke on Unix-style path
    names, so the user must have a way of passing backslashed names if
    that is required.  

For these and several other reasons, and, more generally, since Make
cannot possibly know what is it that the user is trying to accomplish,
it should not (IMHO) blindly replace backslashes with forward slashes.

> Even when the solution is just be coherent and use $(MAKE) in all the places:

The use of $(MAKE) is not just for coherency; it is to ensure that you
invoke the same executable throughout the job.  If you don't use
$(MAKE), you can get all kinds of surprises, like if a Makefile
tinkers with PATH, or if there's a local file called `make.bat', or if
the top-level Makefile was run with a program called something like
`gmake' etc.  For these reasons, you should always use $(MAKE) in
recursive Makefiles.

> 1) It works in Linux.

Small wonder, indeed: Linux doesn't have to cope with the backslash
schizophrenia.

> 2) I don't see why "E:\DJ\BIN/make.exe -f m3.mak" should fail.

Because the backslashes are stripped, and what DOS gets from spawnvpe
is "E:DJBIN/make.exe", which fails.

> 3) The variable should be expanded with forward slashes.

Every variable or just $(MAKE)?

If you mean every variable, I think it's wrong: it will prevent you
from ever having a variable with backslashes.

But even if you mean to have a special treatment for $(MAKE), I'm not
sure it should be done.  Somebody could say something like this:

     command.com /c $(MAKE)

This won't work with forward slashes.  It's a mess...