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Re: backslashes in variable definition
Hi Andrew,
On Mon, 21 Jun 2004, Andrew Suffield wrote:
> On Mon, Jun 21, 2004 at 04:38:23PM +0200, Volker Boerchers wrote:
> > the _SOURCES values of our Makefile.am's are split into multiple lines
> > to improve readability like this
> >
> > libfoo_la_SOURCES = \
> > foo.c \
> > bar.c
> >
> > However if one forgets a backslash the source files after that are
> > silently ignored by automake.
> >
> > libfoo_la_SOURCES = \
> > foo.c # missing '\'
> > bar.c
> >
> > These errors are hard to detect, at least for libraries since missing
> > dependencies are detected later.
>
> You should see the error you get if you do this:
>
> libfoo_la_SOURCES = \
> # foo.c \
> bar.c
hmm, perhaps my mail was capable of being misunderstood. The example
that was attached to my previous mail was
hello_SOURCES = \
hello.c
bar.c
The error appears not until link time, when the bar.o object is
missing (automake 1.5 and 1.7.6). Your example
hello_SOURCES = \
# hello.c \
bar.c
is detected as erroneous by automake 1.5
$ automake || echo error with automake
Makefile.am:9: comment following trailing backslash
error with automake
$ automake --version | grep automake
automake (GNU automake) 1.5
but not by automake 1.7.6:
$ automake || echo error in automake
$ automake --version | grep automake
automake (GNU automake) 1.7.6
BTW there is another interesting case that I have mentioned in my
previous mail
hello_SOURCES = \
hello.c \
bar.c \
automake 1.5 detects that as long as there is a full line after the
last backslash:
$ automake || echo error with automake
Makefile.am:11: blank line following trailing backslash
error with automake
automake 1.7.6 even detects it on the last line:
$ automake || echo error in automake
Makefile.am: trailing backslash on last line
error in automake
It would be nice if automake would generate an error in all these
cases.
Volker
--
Volker Börchers
TECON Systems AG