forked from Imagelibrary/binutils-gdb
a43f3893f6
Recursion detection for static members was broken. The implementation uses a growing (and shrinking) obstack object to simulate a stack of addresses (CORE_ADDR). Pushing addresses is implemented by calling obstack_grow(), while popping is implemented by calling obstack_free(). The latter is problematic because obstack_free() expects a pointer to the base of an object. When popping elements of the stack however, obstack_free() was called with the new top, which potentially is not the same as the base of the stack. This is unintended use and the effect is that obstack->next_free and obstack->object_base members are assigned the value of the new top, which equals an empty stack. Summary: popping elements would always result in an empty stack, which breaks the recursion detection. The fix shrinks the stack using obstack_blank_fast() with a negative value as described at the bottom of this page: https://gcc.gnu.org/onlinedocs/libiberty/Extra-Fast-Growing.html "You can use obstack_blank_fast with a “negative” size argument to make the current object smaller. Just don’t try to shrink it beyond zero length—there’s no telling what will happen if you do that. Earlier versions of obstacks allowed you to use obstack_blank to shrink objects. This will no longer work." The reproducer is added to gdb.cp/classes.exp, which fails without this patch. gdb/ChangeLog: * cp-valprint.c (cp_print_value_fields): Use obstack_blank_fast to rewind obstack. gdb/testsuite/ChangeLog: * gdb.cp/classes.exp (test_static_members): Test printing Outer::instance. * gdb.cp/classes.c (struct Inner, struct Outer): New. (Inner::instance, Outer::instance): New.
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.