Alan Modra
a4cd947aca
dwarf2.c code reasonably assumes that debug info is local to a file, an assumption now violated by gcc, resulting in "DWARF error: invalid abstract instance DIE ref" or wrong details when attempting to print linker error messages with file, function and line reported. This is because find_abstract_instance is only prepared to handle DW_FORM_ref_addr when the .debug_info section referenced is in the current file. When that isn't the case, relocations to access another file's .debug_info will typically be against a symbol defined at the start of that .debug_info section, plus an addend. Since the dwarf2.c code only considers the current file's debug info, that symbol will be undefined, resolving to zero. In effect the ref_addr will wrongly resolve to the current file's .debug_info. This patch avoids the problem by treating relocations in debug sections against undefined symbols in a similar manner to the way relocations against symbols defined in discarded sections are resolved. They result in a zero value (except in .debug_ranges) regardless of the addend. PR 23425 * reloc.c (bfd_generic_get_relocated_section_contents): Zero reloc fields in debug sections when reloc is against an undefined symbol and called from bfd_simple_get_relocated_section_contents or similar. * dwarf2.c (find_abstract_instance): Return true for zero offset DW_FORM_ref_addr without returning values.
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.