Hi,
I've noticed that libitm is always rebuild with a non-bootstrap tree even
with merely a sequence of two makes. The reason turns out to be that
installation of unwind.h from libgcc, which is always done with a simple
make:
# make
# make -d
...
dest=../.././gcc/include/tmp$$-unwind.h; \
cp unwind.h $dest; \
chmod a+r $dest; \
sh ../../../gcc/libgcc/../move-if-change $dest
../.././gcc/include/unwind.h
(this is still fine, because it uses move-if-change)
...
make install-leaf DESTDIR=../.././gcc \
slibdir= libsubdir= MULTIOSDIR=.
...
/bin/sh ../../../gcc/libgcc/../mkinstalldirs ../.././gcc/include
/usr/bin/install -c -m 644 unwind.h ../.././gcc/include
This one updates the mtime of gcc/include/unwind.h, and is the problematic
one, ultimately resulting in:
Prerequisite `/matz/gcc/svn/real-trunk/dev/gcc/include/unwind.h' is
newer than target `aatree.lo'.
And all of libitm (our only c++ library) is rebuilt as all objects therein
have a dependency on unwind.h.
There are multiple variants to fix:
a) use install -p (or -C) generally for all INSTALLs in all makefiles
b) use a) for only libgcc Makefile
c) don't repeatedly install the same files on a remake even though nothing
was compiled newly (perhaps some stamp files could be used to make
leaf-install a no-op if nothing new was built?)
I've checked that hardcoding -p for INSTALL in the top-level Makefile
solves this problem (see patch), but perhaps you prefer one of the others
(or can think of something else entirely).
Ciao,
Michael.
Index: configure.ac
===================================================================
--- configure.ac (revision 187708)
+++ configure.ac (working copy)
@@ -93,8 +93,8 @@ srcpwd=`cd ${srcdir} ; ${PWDCMD-pwd}`
# We pass INSTALL explicitly to sub-makes. Make sure that it is not
# a relative path.
-if test "$INSTALL" = "${srcdir}/install-sh -c"; then
- INSTALL="${srcpwd}/install-sh -c"
+if test "$INSTALL" = "${srcdir}/install-sh -c -p"; then
+ INSTALL="${srcpwd}/install-sh -c -p"
fi
# Set srcdir to "." if that's what it is.
Index: config/proginstall.m4
===================================================================
--- config/proginstall.m4 (revision 187708)
+++ config/proginstall.m4 (working copy)
@@ -54,12 +54,12 @@ case $as_dir/ in
echo one > conftest.one
echo two > conftest.two
mkdir conftest.dir
- if "$as_dir/$ac_prog$ac_exec_ext" -c conftest.one conftest.two
"`pwd`/conftest.dir" &&
+ if "$as_dir/$ac_prog$ac_exec_ext" -c -p conftest.one conftest.two
"`pwd`/conftest.dir" &&
test -s conftest.one && test -s conftest.two &&
test -s conftest.dir/conftest.one &&
test -s conftest.dir/conftest.two
then
- ac_cv_path_install="$as_dir/$ac_prog$ac_exec_ext -c"
+ ac_cv_path_install="$as_dir/$ac_prog$ac_exec_ext -c -p"
break 3
fi
fi
