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author | Nick Alcock <nick.alcock@oracle.com> | 2021-09-27 20:31:21 +0100 |
---|---|---|
committer | Arsen Arsenović <arsen@gcc.gnu.org> | 2023-08-07 22:59:39 +0200 |
commit | ab422974567ae73926c2308c3400b5974d6e09f1 (patch) | |
tree | ae6d0814d300e421fe37fbb06e26af579a95ca82 /fixincludes | |
parent | b48e994077b6cc165ce136428277952a0b8bc9d2 (diff) | |
download | gcc-ab422974567ae73926c2308c3400b5974d6e09f1.zip gcc-ab422974567ae73926c2308c3400b5974d6e09f1.tar.gz gcc-ab422974567ae73926c2308c3400b5974d6e09f1.tar.bz2 |
libtool.m4: fix nm BSD flag detection
Libtool needs to get BSD-format (or MS-format) output out of the system
nm, so that it can scan generated object files for symbol names for
-export-symbols-regex support. Some nms need specific flags to turn on
BSD-formatted output, so libtool checks for this in its AC_PATH_NM.
Unfortunately the code to do this has a pair of interlocking flaws:
- it runs the test by doing an nm of /dev/null. Some platforms
reasonably refuse to do an nm on a device file, but before now this
has only been worked around by assuming that the error message has a
specific textual form emitted by Tru64 nm, and that getting this
error means this is Tru64 nm and that nm -B would work to produce
BSD-format output, even though the test never actually got anything
but an error message out of nm -B. This is fixable by nm'ing *nm
itself* (since we necessarily have a path to it).
- the test is entirely skipped if NM is set in the environment, on the
grounds that the user has overridden the test: but the user cannot
reasonably be expected to know that libtool wants not only nm but
also flags forcing BSD-format output. Worse yet, one such "user" is
the top-level Cygnus configure script, which neither tests for
nor specifies any BSD-format flags. So platforms needing BSD-format
flags always fail to set them when run in a Cygnus tree, breaking
-export-symbols-regex on such platforms. Libtool also needs to
augment $LD on some platforms, but this is done unconditionally,
augmenting whatever the user specified: the nm check should do the
same.
One wrinkle: if the user has overridden $NM, a path might have been
provided: so we use the user-specified path if there was one, and
otherwise do the path search as usual. (If the nm specified doesn't
work, this might lead to a few extra pointless path searches -- but
the test is going to fail anyway, so that's not a problem.)
(Tested with NM unset, and set to nm, /usr/bin/nm, my-nm where my-nm is a
symlink to /usr/bin/nm on the PATH, and /not-on-the-path/my-nm where
*that* is a symlink to /usr/bin/nm.)
ChangeLog:
* libtool.m4 (LT_PATH_NM): Try BSDization flags with a user-provided
NM, if there is one. Run nm on itself, not on /dev/null, to avoid
errors from nms that refuse to work on non-regular files. Remove
other workarounds for this problem. Strip out blank lines from the
nm output.
fixincludes/ChangeLog:
* configure: Regenerate.
gcc/ChangeLog:
* configure: Regenerate.
libatomic/ChangeLog:
* configure: Regenerate.
libbacktrace/ChangeLog:
* configure: Regenerate.
libcc1/ChangeLog:
* configure: Regenerate.
libffi/ChangeLog:
* configure: Regenerate.
libgfortran/ChangeLog:
* configure: Regenerate.
libgm2/ChangeLog:
* configure: Regenerate.
libgomp/ChangeLog:
* configure: Regenerate.
libitm/ChangeLog:
* configure: Regenerate.
libobjc/ChangeLog:
* configure: Regenerate.
libphobos/ChangeLog:
* configure: Regenerate.
libquadmath/ChangeLog:
* configure: Regenerate.
libsanitizer/ChangeLog:
* configure: Regenerate.
libssp/ChangeLog:
* configure: Regenerate.
libstdc++-v3/ChangeLog:
* configure: Regenerate.
libvtv/ChangeLog:
* configure: Regenerate.
lto-plugin/ChangeLog:
* configure: Regenerate.
zlib/ChangeLog:
* configure: Regenerate.
Diffstat (limited to 'fixincludes')
-rwxr-xr-x | fixincludes/configure | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fixincludes/configure b/fixincludes/configure index f1748eb..b977048 100755 --- a/fixincludes/configure +++ b/fixincludes/configure @@ -2941,7 +2941,8 @@ ac_configure="$SHELL $ac_aux_dir/configure" # Please don't use this var. # LT_PATH_NM # ---------- -# find the pathname to a BSD- or MS-compatible name lister +# find the pathname to a BSD- or MS-compatible name lister, and any flags +# needed to make it compatible # LT_PATH_NM # Old names: |