Subject: [PATCH] compile: remove .Tpo file upon failure

From: Jim Meyering <[email-masked]>
Date: Mon, 30 May 2016 21:08:25 -0700

I was annoyed not to be able to use automake's latest-from-master
while preparing for a diffutils release: "make distcheck" would fail
with a single left-over .Tpo file under gnulib-tests.

Here is the patch that solved the problem for me.
Comments welcome. I expect to push to master in a day or two.
From c6dff7e2cac2e8dc5407c77998ef0ac2ba538891 Mon Sep 17 00:00:00 2001
From: Jim Meyering <[email-masked]>
Date: Mon, 30 May 2016 17:07:52 -0700
Subject: [PATCH] compile: remove .Tpo file upon failure

When generating a .deps/base.Po file, we
first write to a temporary .Tpo file, so the final creation can be atomic,
via mv's rename.  However, when generation of the .Tpo fails, we stop
the process and do not remove that temporary file.  And nothing else
ever deletes it, either.  Hence, in the unusual case in which one
expects a compilation to fail during a successful build (gnulib's
test-verify.sh does precisely this), a .deps/test-verify.Tpo file
would be left behind, and that would in turn cause a "make distcheck"
failure because that file would exist in one build+distclean
hierarchy but not in the distribution tarball.
* lib/am/depend2.am: Ensure that the temporary file is removed
upon failure.
* t/distcheck-Tpo.sh: New file.
* t/list-of-tests.mk (handwritten_TESTS): Add it.
---
 lib/am/depend2.am  | 10 ++++++----
 t/distcheck-Tpo.sh | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 t/list-of-tests.mk |  1 +
 3 files changed, 65 insertions(+), 4 deletions(-)
 create mode 100644 t/distcheck-Tpo.sh

diff --git a/lib/am/depend2.am b/lib/am/depend2.am
index 87f62a8..d1478b9 100644
--- a/lib/am/depend2.am
+++ b/lib/am/depend2.am
@@ -42,8 +42,9 @@ if %?NONLIBTOOL%
 ?!GENERIC?%OBJ%: %SOURCE%
 if %FASTDEP%
 	%VERBOSE%$(am__set_depbase) && \
-	%COMPILE% -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ %SOURCEFLAG% %XSOURCE% && \
-	$(am__mv) $$depbase.Tpo $$depbase.Po
+	%COMPILE% -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ %SOURCEFLAG% %XSOURCE%; \
+	if test $$? = 0; then $(am__mv) $$depbase.Tpo $$depbase.Po; \
+	  else rm -f $$depbase.Tpo; false; fi
 else !%FASTDEP%
 if %AMDEP%
 	%VERBOSE%source='%SOURCE%' object='$@' libtool=no @AMDEPBACKSLASH@
@@ -56,8 +57,9 @@ endif !%FASTDEP%
 ?!GENERIC?%OBJOBJ%: %SOURCE%
 if %FASTDEP%
 	%VERBOSE%$(am__set_depbase) && \
-	%COMPILE% -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ %SOURCEFLAG% $$($(CYGPATH_W) %XSOURCE%) && \
-	$(am__mv) $$depbase.Tpo $$depbase.Po
+	%COMPILE% -MT $@ -MD -MP -MF $$depbase.Tpo -c -o $@ %SOURCEFLAG% $$($(CYGPATH_W) %XSOURCE%); \
+	if test $$? = 0; then $(am__mv) $$depbase.Tpo $$depbase.Po; \
+	  else rm -f $$depbase.Tpo; false; fi
 else !%FASTDEP%
 if %AMDEP%
 	%VERBOSE%source='%SOURCE%' object='$@' libtool=no @AMDEPBACKSLASH@
diff --git a/t/distcheck-Tpo.sh b/t/distcheck-Tpo.sh
new file mode 100644
index 0000000..9d7900c
--- /dev/null
+++ b/t/distcheck-Tpo.sh
@@ -0,0 +1,58 @@
+#! /bin/sh
+# Copyright (C) 2016 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Ensure that the 'make distcheck'-run distcleancheck does not fail
+# due to a leftover .deps/base.Tpo file when part of a successful build
+# involves a failed attempt to create a .deps/base.Po file.
+
+. test-init.sh
+
+cat >> configure.ac <<END
+AC_PROG_CC
+AC_OUTPUT
+END
+
+cat > foo.c <<\END
+#ifndef FAIL
+int main() { return 0; }
+#else
+int x[no_such];
+#endif
+END
+
+cat > Makefile.am <<\END
+TESTS = foo bar.test
+check_PROGRAMS = foo
+EXTRA_DIST= bar.test foo.c
+END
+
+cat > bar.test <<END
+#!/bin/sh
+rm -f foo.o
+$MAKE AM_CFLAGS=-DFAIL foo.o && exit 1
+exit 0
+END
+chmod a+x bar.test
+
+$ACLOCAL
+$AUTOCONF
+$AUTOMAKE -a
+./configure
+
+# We can build the distribution.
+run_make -M distcheck
+
+:
diff --git a/t/list-of-tests.mk b/t/list-of-tests.mk
index f1c47bb..060b3ed 100644
--- a/t/list-of-tests.mk
+++ b/t/list-of-tests.mk
@@ -433,6 +433,7 @@ t/distcheck-override-infodir.sh \
 t/distcheck-pr9579.sh \
 t/distcheck-pr10470.sh \
 t/distcheck-pr18286.sh \
+t/distcheck-Tpo.sh \
 t/dmalloc.sh \
 t/doc-parsing-buglets-colneq-subst.sh \
 t/doc-parsing-buglets-tabs.sh \
-- 
2.7.4