binutils-gdb/libbacktrace
Nick Alcock caf606c90d libtool.m4: fix the NM="/nm/over/here -B/option/with/path" case
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.
2022-03-25 12:02:35 +00:00
..
aclocal.m4
alloc.c
allocfail.c
allocfail.sh
atomic.c
backtrace-supported.h.in
backtrace.c
backtrace.h
btest.c
ChangeLog
ChangeLog.jit
config.h.in
configure
configure.ac
dwarf.c
edtest2.c
edtest.c
elf.c
fileline.c
filetype.awk
install-debuginfo-for-buildid.sh.in
instrumented_alloc.c
internal.h
macho.c
Makefile.am
Makefile.in
mmap.c
mmapio.c
mtest.c
nounwind.c
pecoff.c
posix.c
print.c
read.c
README
simple.c
sort.c
state.c
stest.c
test_format.c
testlib.c
testlib.h
ttest.c
unittest.c
unknown.c
xcoff.c
xztest.c
ztest.c

The libbacktrace library
Initially written by Ian Lance Taylor <iant@google.com>

The libbacktrace library may be linked into a program or library and
used to produce symbolic backtraces.  Sample uses would be to print a
detailed backtrace when an error occurs or to gather detailed
profiling information.

The libbacktrace library is provided under a BSD license.  See the
source files for the exact license text.

The public functions are declared and documented in the header file
backtrace.h, which should be #include'd by a user of the library.

Building libbacktrace will generate a file backtrace-supported.h,
which a user of the library may use to determine whether backtraces
will work.  See the source file backtrace-supported.h.in for the
macros that it defines.

As of September 2012, libbacktrace only supports ELF executables with
DWARF debugging information.  The library is written to make it
straightforward to add support for other object file and debugging
formats.