Re: Bug: make fails to execute .BAT files with space in the path, with SHELL=cmd.exe

[Eli Zaretskii]

> Date: Fri, 3 May 2013 10:22:40 +0200
> From: Erik Carstensen <address@hidden>
> Cc: address@hidden
> 
> > Make on Windows cannot support escaping with backslash when the shell
> > is cmd.exe.  And Make in general doesn't support file names with
> > whitespace too well, you need to introduce blanks via variables, for
> > it to work reliably.  The only place where it works well is in the
> > command line itself, but not in variables and certainly not in
> > dependency lists.
> 
> 
> My findings:
> - Space in filenames does work very well in variables, as long as the
> variables are used exclusively in command lines.
> - You are right that it can be tricky to introduce a leading space, but not
> really a big problem. Most people tend to store the space in an
> intermediate variable (the space=$(empty) $(empty) trick)', but I found
> that it's sufficient to just write 'foo=$() xyz'
> - Dependency lists are not a big problem, you just have to escape spaces
> and backslashes properly. It is (fairly) easy to write a function that does
> this. Automatic variables like $@, $< and $^ will be un-escaped, so any
> uses need to be re-quoted or surrounded by double quotes. This is
> practically doable, if you have a limited set of directories that may
> contain space.
> - The only big remaining problem is that there is no way to add a path with
> spaces to VPATH. I have a poor workaround for this (copying needed
> directories to a space-free path before adding them to VPATH). We should
> probably be grateful that a VPATH path cannot contain spaces; e.g., it
> guarantees that %.c always expands to a space-free path.

I agree with all your findings, and they are identical to mine.  But
that is exactly the meaning of "doesn't support file names with
whitespace too well": it sometimes works, sometimes doesn't, sometimes
you can work around the problems with a lot of trial-and-error,
sometimes you can't, no matter what.  IOW, it's unreliable and is best
avoided.