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Pedro Alves b58a68fe57 Fix "info break" + "catch catch" + -static-{libstdc++,libgcc}
If you debug current GDB, set a "catch catch/throw/rethrow"
catchpoint, and then do "info breakpoints", the top GDB hits an
internal error:

 (top-gdb) catch catch
 Catchpoint 1 (catch)
 (top-gdb) info breakpoints
 Num     Type           Disp Enb Address            What
 1       breakpoint     keep y   src/gdb/breakpoint.c:6040: internal-error: void print_one_breakpoint_location(breakpoint*, bp_location*, int, bp_location**, int): Assertion `b->loc == NULL || b->loc->next == NULL' failed.
 A problem internal to GDB has been detected,
 further debugging may prove unreliable.
 Quit this debugging session? (y or n)

The assertion in question is asserting that a breakpoint with a
print_one method only has one location, and it fails because this
catchpoint ends up with two locations.

Internally, "catch catch" sets a breakpoint at __cxa_begin_catch.  If
we do that manually, we see the locations:

  (top-gdb) b -qualified __cxa_begin_catch
  Breakpoint 2 at 0xb122b0 (2 locations)
  (top-gdb) info breakpoints
  Num     Type           Disp Enb Address            What
  2       breakpoint     keep y   <MULTIPLE>
  2.1                         y   0x0000000000b122b0 <__cxa_begin_catch>
  2.2                         y   0x00007ffff2f4ddb0 in __cxxabiv1::__cxa_begin_catch(void*) at ../../../../libstdc++-v3/libsupc++/eh_catch.cc:41

Note that I had used -qualified.  It seems strange that we get a
location for a namespaced symbol, but that happens because the minimal
symbol for that address is indeed called __cxa_begin_catch.

The real issue is that gdb is linked with
-static-libgcc/-static-libstdc++.  And then, it _also_ ends up with
shared libstc++ loaded:

  (top-gdb) info sharedlibrary stdc++
  From                To                  Syms Read   Shared Object Library
  0x00007ffff2f4b380  0x00007ffff2ffc018  Yes         /lib64/libstdc++.so.6

Location 2.2 is set within libstdc++.so.6's range:

  (top-gdb) p 0x00007ffff2f4b380 <= 0x00007ffff2f4ddb0 && 0x00007ffff2f4ddb0 < 0x00007ffff2ffc018
  $1 = true

So due to -static-lib*, we end up with _two_ copies of the
__cxa_begin_catch code:

  (top-gdb) disassemble 0x0000000000b122b0
  Dump of assembler code for function __cxa_begin_catch:
     0x0000000000b122b0 <+0>:     push   %rbx
     0x0000000000b122b1 <+1>:     mov    %rdi,%rbx
     0x0000000000b122b4 <+4>:     callq  0xb11a80 <__cxa_get_globals>
     0x0000000000b122b9 <+9>:     movabs $0xb8b1aabcbcd4d500,%rdx
  ...

  (top-gdb) disassemble 0x00007ffff2f4ddb0
  Dump of assembler code for function __cxxabiv1::__cxa_begin_catch(void*):
     0x00007ffff2f4ddb0 <+0>:     push   %rbx
     0x00007ffff2f4ddb1 <+1>:     mov    %rdi,%rbx
     0x00007ffff2f4ddb4 <+4>:     callq  0x7ffff2f4a090 <__cxa_get_globals@plt>
     0x00007ffff2f4ddb9 <+9>:     movabs $0xb8b1aabcbcd4d500,%rdx
  ...

I think we end up with libstdc++.so.6 loaded because
libsource-highlight.so depends on it.

Irrespective of whether it's a good idea to use
-static-libgcc/-static-libstdc++, GDB should not crash.  Since there
are two copies of the code, it seems right to have more than one
location.  So the fix is just to remove the assertion.

A testcase is included, which mimics the scenerio described above,
with binary linked with -static-lib{stdc++,gcc} and a shared library
that is linked normally, along with other combinations for good
measure.

gdb/ChangeLog:
2019-07-09  Pedro Alves  <palves@redhat.com>

	PR c++/15468
	* breakpoint.c (print_one_breakpoint_location): Remove
	single-location assert.

gdb/testsuite/ChangeLog:
2019-07-09  Pedro Alves  <palves@redhat.com>

	PR c++/15468
	* gdb.cp/except-multi-location-lib.cc: New.
	* gdb.cp/except-multi-location-main.cc: New.
	* gdb.cp/except-multi-location.exp: New.
2019-07-09 19:26:15 +01:00
bfd Automatic date update in version.in 2019-07-09 00:00:12 +00:00
binutils Prevent attempts to allocate excessive amounts of memory when parsing corrupt ELF files. 2019-06-28 15:30:43 +01:00
config Add markers for 2.32 branch to NEWS and ChangeLog files. 2019-01-19 15:55:50 +00:00
contrib
cpu cpu/or1k: Update fpu compare symbols to imply set flag 2019-06-13 06:16:19 +09:00
elfcpp [GOLD] R_PPC64_REL16_HIGH relocs 2019-06-28 10:17:08 +09:30
etc Update year range in copyright notice of binutils files 2019-01-01 22:06:53 +10:30
gas Re: gas/ELF: don't accumulate .type settings 2019-07-09 14:30:00 +09:30
gdb Fix "info break" + "catch catch" + -static-{libstdc++,libgcc} 2019-07-09 19:26:15 +01:00
gnulib Fix gnulib/update-gnulib.sh 2019-06-21 13:23:59 +01:00
gold [GOLD] PowerPC tweak relnum tests 2019-06-28 10:18:03 +09:30
gprof Correct the alpha sorting of the short options in the usage description of the gprof program. 2019-05-20 17:17:24 +01:00
include [gas][aarch64][SVE2] Fix pmull{t,b} requirement on SVE2-AES 2019-07-01 15:17:22 +01:00
intl Change version to 2.32.51 and regenerate configure and pot files. 2019-01-19 16:51:42 +00:00
ld Re: PowerPC notoc call stub tests 2019-07-08 15:24:14 +09:30
libctf libctf: fix spurious error when rolling back to the first snapshot 2019-07-01 11:05:59 +01:00
libdecnumber Merge config/ changes from GCC. 2018-10-31 17:16:41 +00:00
libiberty Pull in patch for libiberty that fixes a stack exhaustion bug when demangling a pathalogically constructed mangled name. 2019-04-10 15:49:36 +01:00
opcodes Kito's 5-part patch set to improve .insn support. 2019-07-05 15:19:11 +08:00
readline config.guess,config.sub: synchronize with config project master sources 2019-05-23 18:19:56 +02:00
sim sim/testsuite/or1k: Add tests for unordered compares 2019-06-13 21:27:10 +09:00
texinfo
zlib Merge config/ changes from GCC. 2018-10-31 17:16:41 +00:00
.cvsignore
.gitattributes
.gitignore
ar-lib
ChangeLog Add gnulib to gdb release tarball 2019-06-21 15:20:34 +02:00
compile
config-ml.in
config.guess config.guess,config.sub: synchronize with config project master sources 2019-05-23 18:19:56 +02:00
config.rpath
config.sub config.guess,config.sub: synchronize with config project master sources 2019-05-23 18:19:56 +02:00
configure Move gnulib to top level 2019-06-14 12:40:02 -06:00
configure.ac Move gnulib to top level 2019-06-14 12:40:02 -06:00
COPYING
COPYING3
COPYING3.LIB
COPYING.LIB
COPYING.LIBGLOSS
COPYING.NEWLIB
depcomp
djunpack.bat
install-sh
libtool.m4
lt~obsolete.m4
ltgcc.m4
ltmain.sh
ltoptions.m4
ltsugar.m4
ltversion.m4
MAINTAINERS Move gnulib to top level 2019-06-14 12:40:02 -06:00
Makefile.def Move gnulib to top level 2019-06-14 12:40:02 -06:00
Makefile.in Move gnulib to top level 2019-06-14 12:40:02 -06:00
Makefile.tpl Revert "Sync top level files with versions from gcc." 2019-05-30 11:17:19 +01:00
makefile.vms
missing
mkdep
mkinstalldirs
move-if-change
multilib.am
README
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setup.com
src-release.sh Add gnulib to gdb release tarball 2019-06-21 15:20:34 +02:00
symlink-tree
test-driver
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		   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.