Date: Sun, 5 Nov 2006 21:04:47 +0100 From: Jeremie Le Hen <jeremie@le-hen.org> To: freebsd-hackers@FreeBSD.org Subject: Puzzling variables behaviour in make(1) Message-ID: <20061105200447.GY20405@obiwan.tataz.chchile.org>
next in thread | raw e-mail | index | archive | help
Hello,
I wrote the following piece of Makefile:
% .warning "VAR contains: ${VAR}"
%
% VAR_BACKUP:= ${VAR}
% VAR:= value2
%
% .if ${VAR} == "value2"
% .warning "VAR is overwritable: ${VAR}"
% .else
% .warning "VAR is NOT overwritable: ${VAR}"
% .endif
%
% VAR:= ${VAR_BACKUP}
%
% all:
If I define VAR within the Makefile (VAR:= value1), I get:
% jarjarbinks:~/test/makevars:230# make
% "Makefile", line 3: warning: "VAR contains: value1"
% "Makefile", line 7: warning: "VAR is overwritable: value2"
If I remove the VAR assignment in the Makefile and define it from
the command -line, I get:
% jarjarbinks:~/test/makevars:232# make VAR=value1
% "Makefile", line 3: warning: "VAR contains: value1"
% "Makefile", line 9: warning: "VAR is NOT overwritable: value2"
Note that this behaviour is puzzling since it follows the path as if
{VAR} didn't contain "value2" but the warning message shows it does
contains "value2".
Finally, if I define VAR both from the command-line and within the
Makefile:
% jarjarbinks:~/test/makevars:242# make VAR=value1
% "Makefile", line 3: warning: "VAR contains: value1"
% "Makefile", line 11: warning: "VAR is NOT overwritable: value2"
Same weird behaviour.
Actually I am trying to find a way to tell whether a variable has
been defined from make.conf(5) or src.conf(5) or from the command-line.
According to the code path this method appears to work, but the
value of ${VAR} isn't "correct".
If this is the expected behaviour, I'd be glad to understand the magic
behind this.
Thank you.
Best regards,
--
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20061105200447.GY20405>