My previous nm patch handled all cases but one -- if the user set NM in
the environment to a path which contained an option, libtool's nm
detection tries to run nm against a copy of nm with the options in it:
e.g. if NM was set to "nm --blargle", and nm was found in /usr/bin, the
test would try to run "/usr/bin/nm --blargle /usr/bin/nm --blargle".
This is unlikely to be desirable: in this case we should run
"/usr/bin/nm --blargle /usr/bin/nm".
Furthermore, as part of this nm has to detect when the passed-in $NM
contains a path, and in that case avoid doing a path search itself.
This too was thrown off if an option contained something that looked
like a path, e.g. NM="nm -B../prev-gcc"; libtool then tries to run
"nm -B../prev-gcc nm" which rarely works well (and indeed it looks
to see whether that nm exists, finds it doesn't, and wrongly concludes
that nm -p or whatever does not work).
Fix all of these by clipping all options (defined as everything
including and after the first " -") before deciding whether nm
contains a path (but not using the clipped value for anything else),
and then removing all options from the path-modified nm before
looking to see whether that nm existed.
NM=my-nm now does a path search and runs e.g.
/usr/bin/my-nm -B /usr/bin/my-nm
NM=/usr/bin/my-nm now avoids a path search and runs e.g.
/usr/bin/my-nm -B /usr/bin/my-nm
NM="my-nm -p../wombat" now does a path search and runs e.g.
/usr/bin/my-nm -p../wombat -B /usr/bin/my-nm
NM="../prev-binutils/new-nm -B../prev-gcc" now avoids a path search:
../prev-binutils/my-nm -B../prev-gcc -B ../prev-binutils/my-nm
This seems to be all combinations, including those used by GCC bootstrap
(which, before this commit, fails to bootstrap when configured
--with-build-config=bootstrap-lto, because the lto plugin is now using
--export-symbols-regex, which requires libtool to find a working nm,
while also using -B../prev-gcc to point at the lto plugin associated
with the GCC just built.)
Regenerate all affected configure scripts.
* libtool.m4 (LT_PATH_NM): Handle user-specified NM with
options, including options containing paths.
This copies in libbacktrace from the gcc repository as it was in the
commit 62e420293a293608f383d9b9c7f2debd666e9fc9. GDB is going to
start using this library soon.
A dependency between GDB and libbacktrace has already been added to
the top level Makefile, so, after this commit, when building GDB,
libbacktrace will be built first. However, libbacktrace is not yet
linked into GDB, or used by GDB in any way.
It is possible to stop libbacktrace being built by configuring the
tree with --disable-libbacktrace.
This commit does NOT update src-release.sh, that will be done in the
next commit, this commit ONLY imports libbacktrace from gcc. This
means that if you try to make a release of GDB from exactly this
commit then the release tar file will not include libbacktrace.
However, as libbacktrace is an optional dependency this is fine.
