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author | Stefano Lattarini <stefano.lattarini@gmail.com> | 2014-12-19 15:10:09 +0100 |
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committer | Stefano Lattarini <stefano.lattarini@gmail.com> | 2014-12-19 21:00:19 +0100 |
commit | e7c14d967b5bfa587c4a9fc847126b39198b7463 (patch) | |
tree | a7e0d4558e4cdecb6079ddc779dc184f8a8a3cb3 /lib | |
parent | 26aaa1c22db47d2a0ffdb4de79d196164c1e3b18 (diff) | |
download | automake-e7c14d967b5bfa587c4a9fc847126b39198b7463.tar.gz |
Improve detection of GNU make, avoiding "Arg list too long" errors.
Such errors could take place when the main makefile included too many
sub-makefiles, making $(MAKEFILE_LIST) too long and causing the
recipes $(am__is_gnu_make) to exceed the shell's command-line length
limits. This is not a theoretical issue: it could happen for projects
having lots of C/C++ sources and using automatic dependency tracking,
which created an included .Po sub-makefile for each of such sources.
Fixes http://debbugs.gnu.org/18744
* lib/am/header-vars.am (am__is_gnu_make): Fix the logic to avoid
the use of $(MAKEFILE_LIST).
* NEWS: Update.
Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/am/header-vars.am | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/lib/am/header-vars.am b/lib/am/header-vars.am index d25efa612..9283903a1 100644 --- a/lib/am/header-vars.am +++ b/lib/am/header-vars.am @@ -1,5 +1,5 @@ ## automake - create Makefile.in from Makefile.am -## Copyright (C) 1994-2013 Free Software Foundation, Inc. +## Copyright (C) 1994-2014 Free Software Foundation, Inc. ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by @@ -27,9 +27,36 @@ VPATH = @srcdir@ ## DESTDIR = ## Shell code that determines whether we are running under GNU make. -## This is somewhat of an hack, and might be improved, but is good -## enough for now. -am__is_gnu_make = test -n '$(MAKEFILE_LIST)' && test -n '$(MAKELEVEL)' +## +## Why the this needs to be so convoluted? +## +## (1) We can't unconditionally use make functions or special variables +## starting with a dot, as those cause non-GNU implmentations to +## crash hard. +## +## (2) We can't use $(MAKE_VERSION) here, as it is also defined in some +## non-GNU make implementations (e.g., FreeBSD make). But at least +## BSD make does *not* define the $(CURDIR) variable -- it uses +## $(.CURDIR) instead. +## +## (3) We can't use $(MAKEFILE_LIST) here, as in some situations it +## might cause the shell to die with "Arg list too long" (see +## automake bug#18744). +## +## (4) We can't use $(MAKE_HOST) unconditionally, as it is only +## defined in GNU make 4.0 or later. +## +am__is_gnu_make = { \ + if test -z '$(MAKELEVEL)'; then \ + false; \ + elif test -n '$(MAKE_HOST)'; then \ + true; \ + elif test -n '$(MAKE_VERSION)' && test -n '$(CURDIR)'; then \ + true; \ + else \ + false; \ + fi; \ +} ## Shell code that determines whether the current make instance is ## running with a given one-letter option (e.g., -k, -n) that takes |