mirror of git://gcc.gnu.org/git/gcc.git
ab42297456
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. |
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| .. | ||
| ChangeLog | ||
| ChangeLog.jit | ||
| Makefile.am | ||
| Makefile.in | ||
| README | ||
| aclocal.m4 | ||
| alloc.c | ||
| allocfail.c | ||
| allocfail.sh | ||
| atomic.c | ||
| backtrace-supported.h.in | ||
| backtrace.c | ||
| backtrace.h | ||
| btest.c | ||
| config.h.in | ||
| configure | ||
| configure.ac | ||
| dwarf.c | ||
| edtest.c | ||
| edtest2.c | ||
| elf.c | ||
| fileline.c | ||
| filetype.awk | ||
| install-debuginfo-for-buildid.sh.in | ||
| instrumented_alloc.c | ||
| internal.h | ||
| macho.c | ||
| mmap.c | ||
| mmapio.c | ||
| mtest.c | ||
| nounwind.c | ||
| pecoff.c | ||
| posix.c | ||
| print.c | ||
| read.c | ||
| 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 | ||
| zstdtest.c | ||
| ztest.c | ||
README
The libbacktrace library Initially written by Ian Lance Taylor <iant@golang.org> 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. In general the functions provided by this library are async-signal-safe, meaning that they may be safely called from a signal handler. 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 October 2020, libbacktrace supports ELF, PE/COFF, Mach-O, and XCOFF executables with DWARF debugging information. In other words, it supports GNU/Linux, *BSD, macOS, Windows, and AIX. The library is written to make it straightforward to add support for other object file and debugging formats. The library relies on the C++ unwind API defined at https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html This API is provided by GCC and clang.