path: root/open_issues/binutils.mdwn

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[[!tag stable_URL open_issue_binutils open_issue_gdb]]

Here's what's to be done for maintaining GNU Binutils and GDB.


[[!toc levels=2]]


# General Information


## [[/Binutils]]

As these tools primarily deal with low-level parts of the target architecture
and the object file format (ELF ABI), which are essentially (at least meant to
be) the same, there shouldn't be many differences comparing the binutils
between the GNU/Hurd and GNU/Linux ports, for example.  There are a few,
though, as explained below.


## [[/GDB]]

GDB needs an processor architecture as well as operating system port.


# Configuration

<!--

git checkout reviewed
git diff --patience --stat=$COLUMNS,$COLUMNS --patch --src-prefix=./ --dst-prefix=./ --word-diff --color --find-renames --ignore-space-change ..upstream/master | awk '/^(\x1b\[[0-9]+m)?diff/ { c = " " $0; } /^(\x1b\[[0-9]+m)?@@/ { print c; } { print; }' | less
-i
/^---.*/([^.]*|.*\.texi.*|[^/]*gnu[^/]*)$|hurd|linux|nacl|nptl|glibc|gs:

-->

Last reviewed up to Git commit 03b62bbbce3dc5f15131d9e78f77d035cd1cffb3
(2016-11-23).

  * Globally

      * a.out (such as `ld/emulparams/i386linux.sh`, `ld/emultempl/linux.em`,
        etc.), COFF, PE image support and 64-bit support are not interesting.

      * In the testsuites, `.exp` and `.d` files very likely should not only
        care for `*-*-linux*`, but also `*-*-gnu*`.  (If they need to be
        conditionalized like this at all.)

  * `bfd/`

      * `config.bfd`

          * `i[3-7]86-*-gnu*`

            Comparing to `i[3-7]86-*-linux-*`:

              * `i386linux_vec` -- a.out.

              * `i386pei_vec` -- PE.

              * 64 bit.

      * `configure.host`

        Souldn't need anything.  x86 Linux neither.

      * `configure.in`

        Linux:

          * `COREFILE=trad-core.lo` with `TRAD_HEADER='"hosts/i386linux.h"'`

            We don't have any such core file support configured.  TODO: should
            we?  Where is this core file reading exactly used?  GDB?

          * `i386linux_vec` -- a.out.

          * `i386pei_vec` -- PE.

  * `binutils/`

      * `configure.tgt`

  * `gas/`

      * `config/te-gnu.h`

        C.f. `te-linux.h`; search tree for `TE_LINUX` vs. `TE_GNU` usage.

          * `tc-i386.h`

            Sole `TE_LINUX` usage is for a.out.

      * `configure.tgt`

  * `gdb/`

      * Have a look at config/i386/i386gnu.mh.

      * configure.tgt

          * glibc-tdep et al. also for GNU/Hurd?

      * [[gdb/gdbserver]]

      * In `gdb/gnu-nat.c:gnu_wait`, we don't implement
        `gdb/target/wait.h:TARGET_WNOHANG`.  What is this needed for?

      * Watchpoints

          * Unresolved issues w.r.t. watchpoint usage in context of multiple
            threads, and `fork`/`vfork`.  The Linux port has a bunch of
            special-case code.

          * We don't have anything corresponding to Linux'
            `linux_nat_set_forget_process`, `x86_forget_process`, or Linux'
            whole `linux-fork.c` machinery.  Likewise for
            `linux_nat_set_prepare_to_resume`, `x86_linux_prepare_to_resume`,
            which the Linux port uses to actually set the debug registers.
            Likewise for `linux_nat_set_new_thread`, `x86_linux_new_thread`,
            and `linux_nat_set_new_fork`, `x86_linux_new_fork`.

          * Look into `*_cleanup_dregs`, `*_post_startup_inferior`.  Commits
            53a5351d907ef4eacd463a48a86d35b2b70b9f60,
            52b9821179d84d61852ac2ae2bd16fbb56ffe277,
            9742079a314711c13d269e9e583b7b82dc42f1a6,
            e24d4c64ff2e89327ba84fdcc77cc557791eb3cd,
            fa4ba8da6c28c972dd1b6b9971e29b51aabaafcc,
            9b4f1ba7ede77d776fabb9642cbeef5091e38e1d,
            4de4c07c6b48659ae212352236be9413c853a23c,
            4056d25828218621e7276a3a0c0567cac892ae84,
            10d6c8cd3f92fadf295eb3c91d550626f6080f79,
            4105de343e714e0096723905ada442f1524776a6,
            c5af0dad33ff96dbb404710539f01b011cff0453,
            9bb9e8ade770027f5cced2856574e2d317b15254,
            1ced966e3458bf3db742913f4d0a55549824e298,
            4403d8e9b35649c5b24f65c0ec0decc3839e1164,
            26cb8b7c1a23586ea311d7480f882e2883f6f1f5.

          * [[!message-id "201112051601.59664.pedro@codesourcery.com"]].

          * `I386_WATCHPOINTS_IN_TARGET_VECTOR`

          * `prepare_to_resume`

          * `new_fork`

          * `forget_process`

          * `dr_status_mirror` is not really used anywhere.  Get rid of it; or,
            update it everytime the real value is read from the kernel?

      * TODO

              {+set_gdbarch_vsyscall_range (gdbarch, linux_vsyscall_range);+}
            {+  set_gdbarch_infcall_mmap (gdbarch, linux_infcall_mmap);+}

      * TODO

             diff --git ./gdb/doc/gdb.texinfo ./gdb/doc/gdb.texinfo
            @@ -17340,6 +17433,24 @@ Access to those variables will generate a compiler error which @value{GDBN}
            will print to the console.
            @end table
            
            {+@subsection Compiler search for the @code{compile} command+}
            {+[...]+}
            {+Specifically @code{PATH} is searched for binaries matching regular expression+}
            {+@code{@var{arch}(-[^-]*)?-@var{os}-gcc} [...].  @var{os} is currently supported only for+}
            {+pattern @code{linux(-gnu)?}.+}

      * GDB got support for Linux namespaces: *able to access executable and
        shared library files without a "set sysroot" command when attaching to
        processes running in different mount namespaces from the debugger.
        This makes it possible to attach to processes in containers as simply
        as "gdb -p PID" or "gdbserver --attach PID"*.  Similar support might be
        useful for [[hurd/subhurd]]s?

      * gdbarch `infcall_munmap`

            default_infcall_munmap (CORE_ADDR addr, CORE_ADDR size)
            {
              /* Memory reserved by inferior mmap is kept leaked.  */
            }

      * Support for Intel Processor Trace (--with-intel-pt; libipt)?

      * `supports_get_siginfo_type`

        Has previously been hard-coded in individual tests, now in
        gdb/testsuite/lib/gdb.exp:

            # Return 1 if GDB can get a type for siginfo from the target, otherwise
            # return 0.
            
            proc supports_get_siginfo_type {} {
                if { [istarget "*-*-linux*"] } {
                  return 1
                } else {
                  return 0
                }
            }

      * Check testsuite with check-read1 / READ1=t [./gdb/testsuite/README]

  * `libdecnumber/`

    Should/can probably align to GNU/Linux.

  * `ld/`

     * `configure.host`

         * `*-*-gnu*`

            TODO: resolve `crt0.o` vs. `crt1.o` issue.  [[Testsuite
            failures|binutils#static]].

      * `configure.tgt`

          * `i[3-7]86-*-gnu*`

            Compare to `i[3-7]86-*-linux-*`, but don't need a.out (`i386linux`)
            and 64 bit support.

      * Linuxism

         diff --git ./ld/testsuite/ld-i386/i386.exp ./ld/testsuite/ld-i386/i386.exp
        @@ -263,3 +263,93 @@ run_dump_test "pr12627"
        {+# Must be Linux native with the C compiler+}
        {+if { [isnative]+}
        {+     && [istarget "i?86-*-linux*"]+}
        +[...]

        {+ PASS: ld-i386/pr17935-1+}
        {+ PASS: ld-i386/pr17935-2+}
        {+-PASS: Build plt-lib.so+}
        {+-PASS: Build libplt-main1.a+}
        {+-PASS: Build libplt-main2.a+}
        {+-PASS: Build libplt-main3.a+}
        {+-PASS: Build libplt-main4.a+}
        {+-PASS: Build plt-main+}
        {+-PASS: Build plt-main with PIE+}
        {+-PASS: Run plt-main+}
        {+-PASS: Run plt-main with PIE+}

        diff --git ./ld/testsuite/ld-i386/i386.exp ./ld/testsuite/ld-i386/i386.exp
        {+if { !([istarget "i?86-*-linux*"]+}
        {+       || [istarget "x86_64-*-linux*"]) } {+}
        {+    return+}
        {+}+}
        
        {+# Linux only tests+}
        {+run_dump_test "pltgot-1"+}
        {+run_dump_test "pltgot-2"+}

  * `__ehdr_start symbol`, c84ed8d89d0b8bf5a2968d465f77ac24bcfc40c2 -- can this
    be helpful in the exec server, glibc, or elsewhere?  Used in GDB (BFD)
    commit bdbd9758806ed855af89244870fdc52cf3ff09bc.
    Used in glibc commit 288f7d79fe2dcc8e62c539f57b25d7662a2cd5ff `Use
    __ehdr_start, if available, as fallback for AT_PHDR.`.

  * `Add HOSTING_SCRT0 for PIE test`, 49cc20aa5c416ea4307931cccf6353247368187d
    -- is for GNU/Linux only; but also seems unused.

  * 82763a3d329b0d342d0273941b1521be9ef0c604 »MODIFIED is unknown, pass it as
    true.«

  * Configure so that Debian system's `/usr/lib/debug/[...]` will be loaded
    automatically.

      * [[!message-id "m3ei24vh4l.fsf@fleche.redhat.com"]]

  * [low] c26e9cbb0ce70e8fca32a40c434a0837bf46750a,
    `gdb/gnu-nat.c:set_exceptions_cmd`, `Make this take effect immediately in a
    running process`.

  * [low] b27caf75c311991772b316fe7c0eecfd5788eeaf, ld, `Add HOSTING_SLIBS and
    use it for -pie`.  For us, too?

  * [high] `gdb/remote.c`: `PATH_MAX` usage.  Probably,
    `gdb/gdbserver/remote-utils.c` is the producer, whose `PATH_MAX` might
    differ from the consumer's.

  * [high] In
    96f9814df23564e16909bb5ba00de4a202c63417..9ef9e6a6a0dd8f948708cb67c9afcfd0be40cb0a:

        ../../W._C._Handy/gdb/gnu-nat.c: In function 'set_sig_thread_cmd':
        ../../W._C._Handy/gdb/gnu-nat.c:2973:7: warning: implicit declaration of function 'thread_id_to_pid' [-Wimplicit-function-declaration]
               ptid_t ptid = thread_id_to_pid (atoi (args));
               ^
        ../../W._C._Handy/gdb/gnu-nat.c:2973:7: error: invalid initializer

    Commit 5d5658a1d3c3eb2a09c03f2f0662a1c01963c869
    `Per-inferior/Inferior-qualified thread IDs` renamed `thread_id_to_pid` to
    `global_thread_id_to_ptid`.

  * 9ef9e6a6a0dd8f948708cb67c9afcfd0be40cb0a..a932d108b10518994c873b38a363af9f21bc2e87

        diff --git ./ld/testsuite/lib/ld-lib.exp ./ld/testsuite/lib/ld-lib.exp
        @@ -1796,6 +1797,13 @@ proc check_lto_available { } {
                {+# This test will hide LTO bugs in ld.  Since GCC 4.9 adds+}
        {+      # -ffat-lto-objects, we always run LTO tests on Linux with+}
        {+      # GCC 4.9 or newer.+}
        {+      if { [istarget "*-*-linux*"] && [at_least_gcc_version 4 9] } {+}
        {+          set lto_available_saved 1+}
        {+          return 1+}
        {+      }+}
        
        diff --git ./ld/testsuite/lib/ld-lib.exp ./ld/testsuite/lib/ld-lib.exp
        @@ -1830,6 +1840,13 @@ proc check_lto_fat_available { } {
                {+# This test will hide LTO bugs in ld.  Since GCC 4.9 adds+}
        {+      # -ffat-lto-objects, we always run LTO tests on Linux with+}
        {+      # GCC 4.9 or newer.+}
        {+      if { [istarget "*-*-linux*"] && [at_least_gcc_version 4 9] } {+}
        {+          set lto_fat_available_saved 1+}
        {+          return 1+}
        {+      }+}
        
         diff --git ./ld/testsuite/lib/ld-lib.exp ./ld/testsuite/lib/ld-lib.exp
        @@ -1864,6 +1883,13 @@ proc check_lto_shared_available { } {
                {+# This test will hide LTO bugs in ld.  Since GCC 4.9 adds+}
        {+      # -ffat-lto-objects, we always run LTO tests on Linux with+}
        {+      # GCC 4.9 or newer.+}
        {+      if { [istarget "*-*-linux*"] && [at_least_gcc_version 4 9] } {+}
        {+          set lto_shared_available_saved 1+}
        {+          return 1+}
        {+      }+}


  * a932d108b10518994c873b38a363af9f21bc2e87..f245535cf583ae4ca13b10d47b3c7d3334593ece

    `gas/NEWS`: `Default to --enable-compressed-debug-sections=gas for
    Linux/x86 targets.`

    `gas/configure.tgt`:

        +case ${cpu_type}-${fmt}-${os} in
        +i386-elf-linux*)
        +  # Default to compress DWARF debug sections for Linux/x86.
        +  if test ${ac_default_compressed_debug_sections} = unset; then
        +    ac_default_compressed_debug_sections=yes
        +  fi
        +  ;;
        +esac


    `ld/NEWS`: `Add a configure option --enable-relro to decide whether -z
    relro should be enabled in ELF linker by default.  Default to yes for all
    Linux targets except FRV, HPPA, IA64 and MIPS.`

    `ld/configure.tgt`:

        +case "${target}" in
        +frv-*-* | hppa*-*-* | ia64-*-* | mips*-*-*)
        +  # Don't enable -z relro by default since many relro tests fail on these
        +  # targets:
        +  # FAIL: strip -z relro (relro1)
        +  # FAIL: strip -z relro -shared (relro1)
        +  # FAIL: objcopy -z relro (relro1)
        +  # FAIL: objcopy -z relro -shared (relro1)
        +  # FAIL: objcopy -z relro (tdata1)
        +  # FAIL: objcopy -shared -z relro (tdata1)
        +  # FAIL: objcopy -z relro (tdata2)
        +  # FAIL: objcopy -shared -z relro (tdata2)
        +  # FAIL: objcopy -z relro (tdata3)
        +  # FAIL: objcopy -shared -z relro (tdata3)
        +  # FAIL: objcopy -shared -z relro (tbss1)
        +  # FAIL: objcopy -shared -z relro (tbss2)
        +  # FAIL: objcopy -shared -z relro (tbss3)
        +  ;;
        +*-*-linux*)
        +  if test ${ac_default_ld_z_relro} = unset; then
        +    ac_default_ld_z_relro=1
        +  fi
        +  ;;
        +esac


        --- /dev/null
        +++ ./ld/testsuite/ld-i386/tls.exp
        +# Only on Linux for now.
        +if ![istarget "i?86-*-linux*"] {
        +    return
        +}

        --- /dev/null
        +++ ./ld/testsuite/ld-i386/tlsgd3.dd
        +++ ./ld/testsuite/ld-i386/tlsld2.dd
        +#target: i?86-*-linux*


# Build

Here's a log of a binutils-gdb build run; this is from Git commit
03b62bbbce3dc5f15131d9e78f77d035cd1cffb3 (2016-11-23),
plus `PATH_MAX` hard-coded in `gdb/inferior.c` and `gdb/remote.c`,
and `global_thread_id_to_ptid` used instead of
`thread_id_to_pid` in `gdb/gnu-nat.c`,
and C++ compatibility changes for the x86 GNU/Hurd port, run on kepler.SCHWINGE
and laplace.SCHWINGE.

    $ export LC_ALL=C
    $ ../W._C._Handy/configure --prefix="$PWD".install --enable-gold --enable-plugins --with-sysroot=/ SHELL=/bin/dash CC=gcc-6 CXX=g++-6 --disable-werror 2>&1 | tee log_build
    [...]
    $ make 2>&1 | tee log_build_
    [...]

Different hosts may default to different shells and compiler versions; thus
harmonized.  Debian GCC (which is used in the testsuite) likes to pass
`-plugin [...]` and `--sysroot=/` to `ld`,
so we need to configure with support for plugins and
sysroots.  In the GDB build, there are compiler diagnostics reported in the
MIG-generated stub files; thus no `-Werror` until that is resolved.

This takes up around 1.8 GiB, and runs for [[25 min|performance#measure]] on
kepler.SCHWINGE and [[25 min|performance#measure]] on laplace.SCHWINGE.

<!--

    $ (make && touch .go-install) 2>&1 | tee log_build_ && test -f .go-install && (make install && touch .go-test) 2>&1 | tee log_install && test -f .go-test && sed -e 's%^\([A-Z]\+ = g..-6\)%override \1 -fno-pie -fno-PIE -no-pie%g' -i gold/testsuite/Makefile && make -k check RUNTESTFLAGS=CC_FOR_TARGET='gcc-6\ -fno-pie\ -fno-PIE\ -no-pie'\ CXX_FOR_TARGET='g++-6\ -fno-pie\ -fno-PIE\ -no-pie' CC_FOR_TARGET='gcc-6 -fno-pie -fno-PIE -no-pie' CXX_FOR_TARGET='g++-6 -fno-pie -fno-PIE -no-pie' 2>&1 | tee log_test
    $ (make && touch .go-install) 2>&1 | tee log_build_ && test -f .go-install && (make install && touch .go-test) 2>&1 | tee log_install && test -f .go-test && sed -e 's%^\([A-Z]\+ = g..-6\)%override \1 -fno-pie -fno-PIE -no-pie%g' -i gold/testsuite/Makefile && LD_PRELOAD=$HOME/fopen,unlink-NULL-wrapper.so make -k check RUNTESTFLAGS=CC_FOR_TARGET='gcc-6\ -fno-pie\ -fno-PIE\ -no-pie'\ CXX_FOR_TARGET='g++-6\ -fno-pie\ -fno-PIE\ -no-pie' CC_FOR_TARGET='gcc-6 -fno-pie -fno-PIE -no-pie' CXX_FOR_TARGET='g++-6 -fno-pie -fno-PIE -no-pie' 2>&1 | tee log_test

-->


## Analysis

x86 GNU/Linux' and GNU/Hurd's configurations are slightly different, thus mask
out most of the differences that are due to GNU/Linux supporting more core file
formats, and more emulation vectors.

    $ toolchain/logs/process binutils-gdb build

  * For GDB, why do we specify `-D_GNU_SOURCE`, and GNU/Linux doesn't?

  * GNU/Linux: `gdb/symfile-mem.c` for [[vDSO]].

  * GNU/Linux: `gdb/i386-nat.c` for hardware breakpoints, etc. -- we should
    probably use that, too.  Related to Samuel's Hurd GDB patch?

  * `gdb/gnu-nat.c`

        In file included from ../../W._C._Handy/gdb/defs.h:454:0,
                         from ../../W._C._Handy/gdb/gnu-nat.c:23:
        ../../W._C._Handy/gdb/gnu-nat.c: In function 'proc_trace':
        ./nm.h:35:60: warning: right-hand operand of comma expression has no effect [-Wunused-value]
            ((((struct i386_thread_state *) (state))->efl &= ~0x100), 1)
                                                                    ^
        ../../W._C._Handy/gdb/gnu-nat.c:526:5: note: in expansion of macro 'THREAD_STATE_CLEAR_TRACED'
             THREAD_STATE_CLEAR_TRACED (state);
             ^

    This is no longer seen after the switch to build with C++ instead of C.

  * fe19822761b4635f392875a186e48af446b40f41..7a63e9515491f21eaf07301df87d389def20e317:

    `-Wmissing-prototypes`

    On 2015-10-30 noticed that the following are gone:

        notify_S.c:341:28: warning: no previous prototype for 'notify_server_routine' [-Wmissing-prototypes]
        process_reply_S.c:379:28: warning: no previous prototype for 'process_reply_server_routine' [-Wmissing-prototypes]
        msg_reply_S.c:201:28: warning: no previous prototype for 'msg_reply_server_routine' [-Wmissing-prototypes]
        exc_request_S.c:193:28: warning: no previous prototype for 'exc_server_routine' [-Wmissing-prototypes]

    ... however these still remain:

        notify_S.c:305:24: warning: no previous prototype for 'notify_server' [-Wmissing-prototypes]
        process_reply_S.c:343:24: warning: no previous prototype for 'process_reply_server' [-Wmissing-prototypes]
        msg_reply_S.c:165:24: warning: no previous prototype for 'msg_reply_server' [-Wmissing-prototypes]
        exc_request_S.c:157:24: warning: no previous prototype for 'exc_server' [-Wmissing-prototypes]

    These are no longer seen after the switch to build with C++ instead of C
    (but these files are built with `-x c`?).

  * `O_NOFOLLOW`

    First seen in
    20f498edfd7e57d3297febcf9c7c7d667cc74239..69a5e2b022c7d15ec4c7c49e6f53a8d924d3b72b:

        -checking for working fcntl.h... yes
        +checking for working fcntl.h... no (bad O_NOFOLLOW)

    [[!taglink open_issue_glibc]]?

  * On GNU Hurd, the `checking types of arguments for ptrace...` configure
    check takes a rather long time to determine the result,
    `int,int,long,long`.

  * Something's wrong with Hurd's [[!tag open_issue_glibc]]`rename`?

        -checking whether rename honors trailing slash on destination... yes
        -checking whether rename honors trailing slash on source... yes
        +checking whether rename honors trailing slash on destination... no
        +checking whether rename honors trailing slash on source... no

        -      -e 's|@''REPLACE_RENAME''@|0|g' \
        +      -e 's|@''REPLACE_RENAME''@|1|g' \

  * Some MIG change causes generated code, `gdb/msg_U.c` to change as follows:

                const mach_msg_type_t portType = {
        -               /* msgt_name = */               -1,
        +               /* msgt_name = */               MACH_MSG_TYPE_POLYMORPHIC,

    ... which looks like an improvement indeed.  But given
    `mach/message.h`:`#define MACH_MSG_TYPE_POLYMORPHIC ((mach_msg_type_name_t)
    -1)`, this causes:

        msg_U.c: In function 'msg_set_init_port':
        msg_U.c:777:22: warning: large integer implicitly truncated to unsigned type [-Woverflow]
           /* msgt_name = */  MACH_MSG_TYPE_POLYMORPHIC,
                              ^
        msg_U.c: In function 'msg_set_init_ports':
        msg_U.c:1043:22: warning: large integer implicitly truncated to unsigned type [-Woverflow]
           /* msgtl_name = */ MACH_MSG_TYPE_POLYMORPHIC,
                              ^
        msg_U.c: In function 'msg_set_dtable':
        msg_U.c:1837:22: warning: large integer implicitly truncated to unsigned type [-Woverflow]
           /* msgtl_name = */ MACH_MSG_TYPE_POLYMORPHIC,
                              ^
        msg_U.c: In function 'msg_set_fd':
        msg_U.c:2108:22: warning: large integer implicitly truncated to unsigned type [-Woverflow]
           /* msgt_name = */  MACH_MSG_TYPE_POLYMORPHIC,
                              ^


# Install

    $ make install 2>&1 | tee log_install
    [...]

This takes up around 270 MiB, and runs for [[0 min|performance#measure]] on
kepler.SCHWINGE and [[1 min|performance#measure]] on laplace.SCHWINGE.


## Analysis

    $ toolchain/logs/process binutils-gdb install

  * `libtool: finish`: `ldconfig` is not run for the Hurd.


# Testsuite

At least for GNU/Linux, Debian's GCC 6 is configured with
`--enable-default-pie` -- which the *gdb*, *gold*, and *ld* testsuites don't
like, so we have to cancel that for testing.
`CC_FOR_TARGET` and `CXX_FOR_TARGET` in `RUNTESTFLAGS` is considered by the *gdb* testsuite,
`CC_FOR_TARGET` and `CXX_FOR_TARGET` on the `make` command line by the *ld* testsuite,
`CC` and `CXX` on the `make` command line by the *gold* testsuite
but only when invoked (from the top level) as `make check-gold` and not when run as part of `make check`...
I couldn't figure out a command-line variant for *gold* testsuite,
so instead we apply an ugly hack to `gold/testsuite/Makefile`.

    $ sed -e 's%^\([A-Z]\+ = g..-6\)%override \1 -fno-pie -fno-PIE -no-pie%g' -i gold/testsuite/Makefile
    $ make -k check RUNTESTFLAGS=CC_FOR_TARGET='gcc-6\ -fno-pie\ -fno-PIE\ -no-pie'\ CXX_FOR_TARGET='g++-6\ -fno-pie\ -fno-PIE\ -no-pie' CC_FOR_TARGET='gcc-6 -fno-pie -fno-PIE -no-pie' CXX_FOR_TARGET='g++-6 -fno-pie -fno-PIE -no-pie' 2>&1 | tee log_test
    [...]

This runs for [[25 min|performance#measure]] on kepler.SCHWINGE and [[71
min|performance#measure]] on laplace.SCHWINGE.

When running `make -k check 2>&1 | tee log_test`, at the end of the testsuite
the `tee` process does not terminate if there are still stray leftover
processes that [have their stdout/stderr
open](http://sourceware.org/ml/gdb-patches/2012-10/msg00489.html).  `kill`ing
these (`SIGKILL` may be needed), makes the `tee` process terminate, too.

On laplace.SCHWINGE, running with
`LD_PRELOAD=$HOME/fopen,unlink-NULL-wrapper.so` to get past [[!message-id
"87a907b5f3.fsf@kepler.schwinge.homeip.net"]].

    COLLECT_GCC=gcc-4.9 COLLECT_LTO_WRAPPER=/usr/lib/gcc/i586-linux-gnu/4.9/lto-wrapper COMPILER_PATH=gcctestdir/:/usr/lib/gcc/i586-linux-gnu/4.9/:/usr/lib/gcc/i586-linux-gnu/4.9/:/usr/lib/gcc/i586-linux-gnu/:/usr/lib/gcc/i586-linux-gnu/4.9/:/usr/lib/gcc/i586-linux-gnu/ LIBRARY_PATH=gcctestdir/:/usr/lib/gcc/i586-linux-gnu/4.9/:/usr/lib/gcc/i586-linux-gnu/4.9/../../../i386-linux-gnu/:/usr/lib/gcc/i586-linux-gnu/4.9/../../../../lib/:/lib/i386-linux-gnu/:/lib/../lib/:/usr/lib/i386-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/i586-linux-gnu/4.9/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-Wextra -Wall -Wstrict-prototypes -Wmissing-prototypes -Wshadow -D _LARGEFILE_SOURCE -D _FILE_OFFSET_BITS=64 -fmerge-constants -g -O2 -fno-use-linker-plugin -o incremental_test -B gcctestdir/ -v -mtune=generic -march=i586' gdb -q --args /usr/lib/gcc/i586-linux-gnu/4.9/collect2 --sysroot=/ --build-id --eh-frame-hdr -m elf_i386 --hash-style=gnu -dynamic-linker /lib/ld-linux.so.2 -o incremental_test /usr/lib/gcc/i586-linux-gnu/4.9/../../../i386-linux-gnu/crt1.o /usr/lib/gcc/i586-linux-gnu/4.9/../../../i386-linux-gnu/crti.o /usr/lib/gcc/i586-linux-gnu/4.9/crtbegin.o -Lgcctestdir -L/usr/lib/gcc/i586-linux-gnu/4.9 -L/usr/lib/gcc/i586-linux-gnu/4.9/../../../i386-linux-gnu -L/usr/lib/gcc/i586-linux-gnu/4.9/../../../../lib -L/lib/i386-linux-gnu -L/lib/../lib -L/usr/lib/i386-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/i586-linux-gnu/4.9/../../.. --incremental-full incremental_test_1.o incremental_test_2.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/i586-linux-gnu/4.9/crtend.o /usr/lib/gcc/i586-linux-gnu/4.9/../../../i386-linux-gnu/crtn.o -debug
    break __fopen_internal
    r
    (possibly) c
    Breakpoint 1, __fopen_internal (filename=filename@entry=0x0, mode=mode@entry=0x809b4a7 "r", is32=is32@entry=0) at iofopen.c:65
    65      in iofopen.c
    (gdb) bt
    #0  __fopen_internal (filename=filename@entry=0x0, mode=mode@entry=0x809b4a7 "r", is32=is32@entry=0) at iofopen.c:65
    #1  0xb7e38c1b in _IO_fopen64 (filename=0x0, mode=0x809b4a7 "r") at iofopen64.c:39
    #2  0x0804c289 in ?? ()
    #3  0x0804e670 in ?? ()
    #4  0x0804aa8d in ?? ()
    #5  0xb7deba73 in __libc_start_main (main=0x804a080, argc=38, argv=0xbfffe6a4, init=0x8098f90, fini=0x8099000, rtld_fini=0xb7fedc90 <_dl_fini>,
        stack_end=0xbfffe69c) at libc-start.c:287
    #6  0x0804b3a2 in ?? ()
    (and another one after that)

Goes away if `-debug` is removed.

    commit 9a65bef918dd14d722ef2a1fec90f527158eabe0
    Author: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
    Date:   Tue Jun 11 08:21:22 2013 +0000
    
        2013-06-11  Richard Biener  <rguenther@suse.de>
        
            * collect2.c (main): Do not redirect ld stdout/stderr when
            debugging.
        
        
        git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@199936 138bc75d-0d04-0410-961f-82ee72b054a4
    
    diff --git gcc/collect2.c gcc/collect2.c
    index 99dd41d..d3119b0 100644
    --- gcc/collect2.c
    +++ gcc/collect2.c
    @@ -1189,8 +1189,11 @@ main (int argc, char **argv)
     #ifdef COLLECT_EXPORT_LIST
       export_file = make_temp_file (".x");
     #endif
    -  ldout = make_temp_file (".ld");
    -  lderrout = make_temp_file (".le");
    +  if (!debug)
    +    {
    +      ldout = make_temp_file (".ld");
    +      lderrout = make_temp_file (".le");
    +    }

    id:"alpine.LNX.2.00.1306101358420.26078@zhemvz.fhfr.qr"

Does this also cause:

    [-FAIL:-]{+PASS:+} justsyms


## Analysis

GDB's testsuite uses the system's default `gcc` (and similar) compilers, not
those specified on the `configure` line ([[!taglink open_issue_gdb]]?), see
`find_gcc` (and similar) usage in the testsuite and DejaGnu.  Maybe something
like `gdb/testsuite/boards/cc-with-tweaks.exp` would help, or setting
`CC_FOR_TARGET` (and similar) per `gdb/testsuite/lib/future.exp`?

    $ toolchain/logs/process binutils-gdb test

  * <a name="static"><!-- stable_URL -->`FAIL: static [...]`</a>

    The testsuite isn't prepared for using `crt0.o` instead of `crt1.o`
    depending on whether a static or dynamic executable is created.  Documented
    in `ld/configure.host`.  Perhaps we should finally rewrite this messy code
    in glibc?  Or, something similar to commit
    49cc20aa5c416ea4307931cccf6353247368187d `Add HOSTING_SCRT0 for PIE test`
    or commit b27caf75c311991772b316fe7c0eecfd5788eeaf `Add HOSTING_SLIBS and
    use it for -pie`
    can be used.

    Same issue for `FAIL: Common symbol override ifunc *` ones?

    Same issue for `FAIL: Run pr19579`?

  * <a name="64ksec">`FAIL: ld-elf/64ksec`</a>

    On the idle grubber, this one takes a few minutes wall time to complete
    successfully ([[I/O system
    weakness|performance/io_system/binutils_ld_64ksec]]), so assuming some
    system load variation, the testsuite's timeout may trigger.

  * `FAIL: gas/i386/rept` (intermittently)

    Added in commit 06f1247c54126b9f1e6acb8ff8c7be35aec6f44c (2012-06-07) as
    part of the fix for [[!sourceware_PR 14201]], renamed in commit
    d654e24bbc2f601df4dc43b26049b0339528b93a (2012-06-07):

        WARNING: program timed out.
        FAIL: gas/i386/rept

  * ld IFUNC execution tests

    Missing [[IFUNC]] support on GNU/Hurd.

    Added in commit 82c5587db078581cfe94a4385ed99de1d1fa6657 (2012-09-19):

        FAIL: Common symbol override ifunc test 1a
        FAIL: Common symbol override ifunc test 1b

  * gold GNU/Linux vs. GNU/Hurd

        -FAIL: relro_test.sh
        +PASS: relro_test.sh

        -PASS: ver_matching_test.sh
        +FAIL: ver_matching_test.sh

        -PASS: script_test_3
        +FAIL: script_test_3

        -PASS: tls_phdrs_script_test
        +FAIL: tls_phdrs_script_test

  * `gdb.base/attach-pie-misread.exp`

    Is only run for GNU/Linux; needs [[prelink]].

  * Disabled

      * `gdb.base/attach-wait-input.exp`

      * `gdb.base/interrupt.exp`

             PASS: gdb.base/interrupt.exp: child process is alive
             a
             a
             PASS: gdb.base/interrupt.exp: child process ate our char
             ^C
             Program received signal SIGINT, Interrupt.
            -0x010bf5a2 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
            +0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
             (gdb) PASS: gdb.base/interrupt.exp: send_gdb control C
             p func1 ()
             
             Program received signal SIGTRAP, Trace/breakpoint trap.
            -0x010bf5a2 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
            +0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
             The program being debugged was signaled while in a function called from GDB.
             GDB remains in the frame where the signal was received.
             To change this behavior use "set unwindonsignal on".
             Evaluation of the expression containing the function
             (func1) will be abandoned.
             When the function is done executing, GDB will silently stop.
             (gdb) FAIL: gdb.base/interrupt.exp: call function when asleep (wrong output)
             p func1 ()
             
             Program received signal SIGTRAP, Trace/breakpoint trap.
            -0x010bf5a2 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
            +0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
             The program being debugged was signaled while in a function called from GDB.
             GDB remains in the frame where the signal was received.
             To change this behavior use "set unwindonsignal on".
             Evaluation of the expression containing the function
             (func1) will be abandoned.
             When the function is done executing, GDB will silently stop.
             (gdb) FAIL: gdb.base/interrupt.exp: call function a second time
             continue
             Continuing.
            -PASS: gdb.base/interrupt.exp: continue
            +
            +Program received signal SIGSEGV, Segmentation fault.
            +0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
            +(gdb) FAIL: gdb.base/interrupt.exp: continue
             data
             PASS: gdb.base/interrupt.exp: echo data
             ^C(gdb) Quit
             (gdb) FAIL: gdb.base/interrupt.exp: Send Control-C, second time
             signal SIGINT
             Continuing with signal SIGINT.
             PASS: gdb.base/interrupt.exp: signal SIGINT
             more data
             PASS: gdb.base/interrupt.exp: echo more data
             
             Program received signal SIGSEGV, Segmentation fault.
            -0x010bf6c8 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
            +0x010bdc9d in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
             (gdb) more data
             Undefined command: "more".  Try "help".
             (gdb) FAIL: gdb.base/interrupt.exp: send end of file
            -testcase ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/interrupt.exp completed in 6 seconds
            +[hangs]

             7939 1000  6817  7939  7939  2  144M 8.92M 93.8  5:29.23    10hrs /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/../../gdb/gdb -nw -nx -data-directory /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/../data-directory
             7944 1000  7939  7944  7939  2  146M  744K  0.0  0:00.00  0:00.01 /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/gdb.base/interrupt

            $ gdb -q tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/gdb 7961
            Reading symbols from /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/gdb...done.
            Attaching to program `/media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/gdb', pid 7961
            [New Thread 7961.1]
            [New Thread 7961.2]
            
            warning: Can't modify tracing state for pid 7961: (ipc/rcv) timed out
            Reading symbols [...]
            (gdb) thread apply all bt full
            
            Thread 2 (Thread 7961.2):
            #0  0x014949cc in swtch_pri () at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/swtch_pri.S:2
            No locals.
            #1  0x01496354 in __spin_lock_solid (lock=0x168100c) at spin-solid.c:26
            No locals.
            #2  0x014aa677 in __spin_lock (__lock=<optimized out>) at ../mach/lock-intern.h:54
            No locals.
            #3  _hurd_sigstate_lock (ss=0x1681808) at hurdsig.c:175
            No locals.
            #4  0x014acbfb in post_signal (untraced=untraced@entry=0) at hurdsig.c:680
                    err = <optimized out>
                    handler = <optimized out>
                    blocked = <optimized out>
                    __PRETTY_FUNCTION__ = "post_signal"
                    signo = 11
                    act = 23593696
                    ss = 0x1681808
                    thread_state = {set = 0, basic = {gs = 1, fs = 17840912, es = 23594144, ds = 17840912, edi = 23290621, esi = 21506724, ebp = 23281960, esp = 1, ebx = 3, edx = 27255556, ecx = 23599112, eax = 163840, eip = 23273912, 
                        cs = 29351492, efl = 29351424, uesp = 0, ss = 29351336}, fpu = {fpkind = 17840912, initialized = 29351344, 
                        hw_state = "\364\213\002\000\000\000\000\000\000\000\000\000cfH\001\000\000\000\000\377\377\377\377\000 c\001T\244G\001\020;\020\001\b\030h\001\000\260g\001\370ݿ\001\060\357\277\001p\000\000\000\233\322e\001\220ݿ\001\216\246J\001\000\300b\001\260\341J\001\b\030h\001\000\000\000\000\000\000\000\000\000 c\001\022\000\000\000\000\200\002\000\020;\020\001\030\306b\001", exc_status = 359}}
                    ss_suspended = 0
                    reply = 0x1bfddf4
                    detail = 0x1bfde4c
            #5  0x014ae29e in _hurd_internal_post_signal (ss=ss@entry=0x1681808, signo=11, detail=detail@entry=0x1bfde4c, reply_port=reply_port@entry=0, reply_port_type=reply_port_type@entry=17, untraced=untraced@entry=0) at hurdsig.c:1221
                    reply_rpc = 0x165d200 <__msg_sig_post_reply>
            #6  0x014af98f in _S_catch_exception_raise (port=142, thread=112, task=1, exception=1, code=2, subcode=19137735) at catch-exc.c:88
                    ss = 0x1681808
                    signo = 11
                    d = {exc = 1, exc_code = 2, exc_subcode = 19137735, code = 2, error = EKERN_PROTECTION_FAILURE}
            #7  0x016442c2 in _Xexception_raise (OutHeadP=0x1bfdf20, InHeadP=0x1bfef30) at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/mach/exc_server.c:150
            No locals.
            #8  _Xexception_raise (InHeadP=0x1bfef30, OutHeadP=0x1bfdf20) at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/mach/exc_server.c:41
                    In0P = 0x1bfef30
                    OutP = 0x1bfdf20
            #9  0x01644344 in _S_exc_server (InHeadP=InHeadP@entry=0x1bfef30, OutHeadP=OutHeadP@entry=0x1bfdf20) at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/mach/exc_server.c:189
                    InP = 0x1bfef30
                    OutP = 0x1bfdf20
                    routine = 0x1644220 <_Xexception_raise>
            #10 0x014a58ec in msgport_server (outp=0x1bfdf20, inp=0x1bfef30) at msgportdemux.c:49
            No locals.
            #11 msgport_server (inp=inp@entry=0x1bfef30, outp=outp@entry=0x1bfdf20) at msgportdemux.c:36
                    d = 0x0
            #12 0x01495898 in __mach_msg_server_timeout (demux=demux@entry=0x14a5890 <msgport_server>, max_size=max_size@entry=4096, rcv_name=rcv_name@entry=142, option=option@entry=0, timeout=timeout@entry=0) at msgserver.c:108
                    request = 0x1bfef30
                    reply = 0x1bfdf20
                    mr = <optimized out>
                    __PRETTY_FUNCTION__ = "__mach_msg_server_timeout"
            #13 0x014959cb in __mach_msg_server (demux=demux@entry=0x14a5890 <msgport_server>, max_size=4096, rcv_name=142) at msgserver.c:195
            No locals.
            #14 0x014a597d in _hurd_msgport_receive () at msgportdemux.c:67
            No locals.
            #15 0x010f7956 in entry_point (self=0x8520788, start_routine=0x14a5920 <_hurd_msgport_receive>, arg=0x0) at ./pthread/pt-create.c:61
            No locals.
            #16 0x00000000 in ?? ()
            No symbol table info available.
            
            Thread 1 (Thread 7961.1):
            #0  _hurd_userlink_unlink (link=0x81c2a20 <command_handler+48>) at ../hurd/hurd/userlink.h:123
            No locals.
            #1  __sigreturn (scp=0x81c2950 <handle_sigint>) at ../sysdeps/mach/hurd/i386/sigreturn.c:47
                    link = 0x81c2a20 <command_handler+48>
                    reply_port = <optimized out>
            #2  0x014aef46 in trampoline () from /lib/i386-gnu/libc.so.0.3
            No locals.
            #3  0x081c2950 in ?? () at ../../Ferry_Tagscherer/gdb/event-top.c:869
                    sigtstp_token = 0x860a7c0
                    sighup_token = 0x86089e0
                    more_to_come = 0
                    sigfpe_token = 0x860a7a8
                    sigquit_token = 0x86089c8
                    sigint_token = 0x860a3b0
                    call_readline = 0x81c2ab0 <rl_callback_read_char_wrapper>
                    exec_done_display_p = 0
                    input_handler = 0x81c2c50 <command_line_handler>
                    async_command_editing_p = 1
                    after_char_processing_hook = 0x0
                    async_annotation_suffix = 0x83d8648 "prompt"
                    input_fd = 0
                    readline_input_state = {linebuffer = 0x0, linebuffer_ptr = 0x0}
            Backtrace stopped: previous frame inner to this frame (corrupt stack?)
            (gdb) kill
            Kill the program being debugged? (y or n) y

      * `gdb.base/fileio.exp`

            FAIL: gdb.base/fileio.exp: Stat a NULL pathname returns ENOENT or EFAULT
            FAIL: gdb.base/fileio.exp: Stat an empty pathname returns ENOENT
            FAIL: gdb.base/fileio.exp: Stat a nonexistant file returns ENOENT (the program is no longer running)
            FAIL: gdb.base/fileio.exp: [...] (the program is no longer running)

        Is this actually a correct assumption?

      * `gdb.base/random-signal.exp`

        Several things (suddenly?) seem to go wrong here.  It seems we do hit
        (something similar to?) the issue described in the log of commit
        427cd150eed8c0dd4f0d0a1105448b4ebe36da6d, which adds this test.  The
        `alarm` call in `random-signal.c` doesn't seem to trigger, so
        `random-signal` keeps running (comsuming *system* CPU time) until
        manually terminated.

      * `gdb.base/readline.exp`

        [[term_blocking]] issue.

      * `gdb.base/sigall.exp`

        From `send signal TSTP` on, all FAIL running into timeouts.

      * `gdb.base/watch-vfork.exp`

            Running ../../../W._C._Handy/gdb/testsuite/gdb.base/watch-vfork.exp ...
            PASS: gdb.base/watch-vfork.exp: Watchpoint on global variable (hw)
            FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after vfork (hw)
            PASS: gdb.base/watch-vfork.exp: Watchpoint on global variable (sw)
            FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after vfork (sw) (timeout)
            Running ../../../W._C._Handy/gdb/testsuite/gdb.base/watch_thread_num.exp ...
            PASS: gdb.base/watch_thread_num.exp: successfully compiled posix threads test case
            ERROR: Couldn't load [...]/tschwinge/W._C._Handy.build/gdb/testsuite/gdb.base/watch_thread_num into [...]/tschwinge/W._C._Handy.build/gdb/testsuite/../../gdb/gdb (timeout).
            ERROR: Delete all breakpoints in delete_breakpoints (timeout)

              PID  UID  PPID  PGrp  Sess TH  Vmem   RSS %CPU     User   System Args
            10067 1000     1 10067 10062  2  146M  696K  0.0  0:00.02  0:08.40 /media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/gdb/testsuite/gdb.base/watch-vfork
            10107 1000 22500 10107 10107  2  150M   13M 97.3  0:00.04  3:10.07 /media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/gdb/testsuite/../../gdb/gdb -nw -nx -data-directory /media/erich/home/thomas/tmp/binutils-gdb/tschwin

        Open new screen window.  Prompt is being displayed, but any input not
        shown/reacted on.  Once the watch-vfork process is killed, the input
        shows up.

        Once the busy-looping GDB process is killed, testing proceeds.

      * `gdb.python/py-inferior.exp` (mostly disabled)

            Running ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.exp ...
            [...]
            python print 'result =', i0.was_attached
            result = False
            (gdb) PASS: gdb.python/py-inferior.exp: test Inferior.was_attached
            python print i0.threads ()
            (<gdb.InferiorThread object at 0x61170>, <gdb.InferiorThread object at 0x61160>)
            (gdb) FAIL: gdb.python/py-inferior.exp: test Inferior.threads
            break check_threads
            Breakpoint 2 at 0x8048869: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.c, line 61.
            (gdb) continue
            Continuing.
            [New Thread 25670.6]
            [New Thread 25670.7]
            [New Thread 25670.8]
            [New Thread 25670.9]
            [New Thread 25670.10]
            [New Thread 25670.11]
            [New Thread 25670.12]
            [New Thread 25670.13]
            
            Breakpoint 2, check_threads (barrier=0x15ff144) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.c:61
            61        pthread_barrier_wait (barrier);
            (gdb) PASS: gdb.python/py-inferior.exp: continue to breakpoint: cont to check_threads
            python print len (i0.threads ())
            10
            (gdb) FAIL: gdb.python/py-inferior.exp: test Inferior.threads 2
            break 28
            Breakpoint 3 at 0x80487c2: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.c, line 28.
            (gdb) continue
            Continuing.
            FAIL: gdb.python/py-inferior.exp: continue to breakpoint: cont to Break here. (timeout)
            python addr = gdb.selected_frame ().read_var ('str')
            FAIL: gdb.python/py-inferior.exp: read str address (timeout)
            [All following tests FAIL with timeout.]
            FAIL: gdb.python/py-inferior.exp: Switch to first inferior (timeout)
            remove-inferiors 3
            FAIL: gdb.python/py-inferior.exp: Remove second inferior (timeout)

        At this point, the system hangs; no new processes can be spawned, so
        perhaps an issue with the exec server.

      * `gdb.threads/hand-call-in-threads.exp`

      * `gdb.threads/manythreads.exp`

        [[!taglink open_issue_libpthread]].  Perhaps fails due to pthread
        attributes usage?  Doesn't execute properly:

            $ gdb/testsuite/gdb.threads/manythreads
            manythreads: ../libpthread/sysdeps/mach/pt-thread-halt.c:51: __pthread_thread_halt: Unexpected error: (ipc/rcv) invalid name.
            Killed

      * `gdb.threads/signal-delivered-right-thread.exp`

      * `gdb.threads/step-over-trips-on-watchpoint.exp`

      * `gdb.threads/thread-find.exp`

  * Linux syscall usage, `<asm/unistd.h>`

      * `UNSUPPORTED: gdb.threads/ia64-sigill.exp: Couldn't compile ../../../master/gdb/testsuite/gdb.threads/ia64-sigill.c: unrecognized error`

      * `UNSUPPORTED: gdb.threads/siginfo-threads.exp: Couldn't compile ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/siginfo-threads.c: unrecognized error`

        Also uses `tgkill`.

      * `gdb.threads/sigstep-threads.c`

        Also uses `tgkill`.

      * `UNSUPPORTED: gdb.threads/watchpoint-fork.exp: parent: multithreaded: Couldn't compile ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/watchpoint-fork-mt.c ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/watchpoint-fork-parent.c: unrecognized error`

  * `UNSUPPORTED: gdb.threads/multi-create.exp: Couldn't compile ../../../master/gdb/testsuite/gdb.threads/multi-create.c: unrecognized error`
        ../../../master/gdb/testsuite/gdb.threads/multi-create.c: In function 'create_function':
        ../../../master/gdb/testsuite/gdb.threads/multi-create.c:46:39: error: 'PTHREAD_STACK_MIN' undeclared (first use in this function)
        ../../../master/gdb/testsuite/gdb.threads/multi-create.c:46:39: note: each undeclared identifier is reported only once for each function it appears in
        ../../../master/gdb/testsuite/gdb.threads/multi-create.c: In function 'main':
        ../../../master/gdb/testsuite/gdb.threads/multi-create.c:73:39: error: 'PTHREAD_STACK_MIN' undeclared (first use in this function)

  * `UNSUPPORTED: gdb.threads/staticthreads.exp: Couldn't compile ../../../master/gdb/testsuite/gdb.threads/staticthreads.c: unrecognized error`

        ../../../master/gdb/testsuite/gdb.threads/staticthreads.c: In function 'main':
        ../../../master/gdb/testsuite/gdb.threads/staticthreads.c:52:37: error: 'PTHREAD_STACK_MIN' undeclared (first use in this function)
        ../../../master/gdb/testsuite/gdb.threads/staticthreads.c:52:37: note: each undeclared identifier is reported only once for each function it appears in

  * `UNSUPPORTED: gdb.threads/create-fail.exp: Couldn't compile ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/create-fail.c: unrecognized error`

        [...]/gdb.threads/create-fail.c:77: undefined reference to `pthread_attr_setaffinity_np'
        [...]/gdb.threads/create-fail.c:83: undefined reference to `pthread_create'

  * `UNTESTED: gdb.base/longest-types.exp: longest-types.exp`

        ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/longest-types.c:20:8: error: size of array 'buf' is too large

    Also on GNU/Linux.

  * `FAIL: gdb.base/jit.exp: PIE: one_jit_test-1: Can't run to main`

        (gdb) break main
        Breakpoint 1 at 0xb84: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/jit-main.c, line 128.
        (gdb) run 
        Starting program: /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/gdb.base/jit-main 
        Cannot access memory at address 0x393
        Cannot access memory at address 0x38f
        (gdb) FAIL: gdb.base/jit.exp: PIE: one_jit_test-1: Can't run to main

    [[GCC/PIE]].

    Is the following supposed to terminate in this way?

        (gdb) break main
        Breakpoint 1 at 0x675: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/attach-pie-noexec.c, line 23.
        (gdb) run 
        Starting program: /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/gdb.base/attach-pie-noexec 
        Cannot access memory at address 0x6c626172
        Cannot access memory at address 0x6c62616e
        (gdb) testcase ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/attach-pie-noexec.exp completed in 3 seconds

    IRC, freenode, #hurd, 2013-09-06:

        <gnu_srs1> How to debug a program that works in the shell but Cannot
          access memory at address ... in gdb?
        <tschwinge> Build it without -pie -- but that is just a guess of what
          might be going on.
        * tschwinge clearly has spent enough time with obscure things to be
            able to make such guesses.
        <gnu_srs1> tschwinge: looks like -fPIE is used.
        <gnu_srs1> verified: some (all?) executables compiled with -fPIE, -fpie
          and linked with -pie cannot be debugged in gdb :(

  * `solib-event stop`

        Running ../../../Ferry_Tagscherer/gdb/testsuite/gdb.mi/mi-catch-load.exp ...
        PASS: gdb.mi/mi-catch-load.exp: breakpoint at main
        PASS: gdb.mi/mi-catch-load.exp: mi runto main
        PASS: gdb.mi/mi-catch-load.exp: catch-load: auto-solib-add on
        PASS: gdb.mi/mi-catch-load.exp: catch-load: catch load
        FAIL: gdb.mi/mi-catch-load.exp: catch-load: solib-event stop
        PASS: gdb.mi/mi-catch-load.exp: breakpoint at main
        PASS: gdb.mi/mi-catch-load.exp: mi runto main
        PASS: gdb.mi/mi-catch-load.exp: catch-unload: auto-solib-add on
        PASS: gdb.mi/mi-catch-load.exp: catch-unload: catch unload
        FAIL: gdb.mi/mi-catch-load.exp: catch-unload: solib-event stop

        *stopped,reason="signal-received",signal-name="SIGSEGV",signal-meaning="Segmentation fault",frame={addr="0x00014add",func="??",args=[],from="/lib/ld.so"},thread-id="4",stopped-threads="all"

  * `gdb.base/call-signal-resume.exp`

        $ gdb -q gdb/testsuite/gdb.base/call-signals
        (gdb) break stop_one
        (gdb) r
        (gdb) call gen_signal()
        (gdb) bt
        (gdb) frame [<function called from gdb>]
        (gdb) return
        (gdb) break handle_signal
        (gdb) c
        (gdb) c

    kepler.SCHWINGE:

        Breakpoint 2, handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
        28      }
        (gdb) bt
        #0  handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
        #1  <signal handler called>
        #2  0xb7fde416 in __kernel_vsyscall ()
        #3  0xb7dffd96 in kill () at ../sysdeps/unix/syscall-template.S:81
        #4  0x0804859c in gen_signal () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:35
        #5  0x08048610 in main () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:81

    laplace.SCHWINGE:

        Breakpoint 2, handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
        28      }
        (gdb) bt
        #0  handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
        #1  0x010baac2 in trampoline () from /lib/i386-gnu/libc.so.0.3
        #2  0x00000006 in ?? ()
        #3  0x00000000 in ?? ()

    kepler.SCHWINGE:

        (gdb) c
        Continuing.
        no signal
        [Inferior 1 (process 10401) exited normally]

    laplace.SCHWINGE:

        (gdb) c
        Continuing.
        no signal
        
        Program received signal SIGSEGV, Segmentation fault.
        0x00000000 in ?? ()
        (gdb) bt
        #0  0x00000000 in ?? ()
        #1  0x01116c28 in _IO_acquire_lock_fct (p=<synthetic pointer>) at libioP.h:905
        #2  _IO_puts (str=0x80487e0 "no signal") at ioputs.c:45
        #3  0x080486d8 in gen_signal () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:38
        #4  0x0804873d in main () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:81

    This is apparently new with the glibc 2.17 upgrade.  If not doing the
    manual `gen_signal` call, it works fine.  TODO.

  * `gdb.base/relativedebug.exp`

        (gdb) PASS: gdb.base/relativedebug.exp: continue
        bt
        #0  0x010a1afc in ?? () from /lib/i386-gnu/libc.so.0.3
        #1  0x010a23be in mach_msg () from /lib/i386-gnu/libc.so.0.3
        #2  0x0126cd98 in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
        #3  0x010e2141 in ?? () from /lib/i386-gnu/libc.so.0.3
        #4  0x010e23ed in kill () from /lib/i386-gnu/libc.so.0.3
        #5  0x010e17f4 in raise () from /lib/i386-gnu/libc.so.0.3
        #6  0x010e5b7c in abort () from /lib/i386-gnu/libc.so.0.3
        #7  0x08048607 in handler (signo=14) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/relativedebug.c:25
        #8  0x010bdac2 in ?? () from /lib/i386-gnu/libc.so.0.3
        Backtrace stopped: previous frame inner to this frame (corrupt stack?)
        (gdb) FAIL: gdb.base/relativedebug.exp: pause found in backtrace

    This is apparently new with the glibc 2.17 upgrade.  Previously it said:

        (gdb) PASS: gdb.base/relativedebug.exp: continue
        bt
        #0  0x0107c85c in ?? () from /lib/i386-gnu/libc.so.0.3
        #1  0x0107d069 in mach_msg () from /lib/i386-gnu/libc.so.0.3
        #2  0x01220d4f in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
        #3  0x010bb683 in ?? () from /lib/i386-gnu/libc.so.0.3
        #4  0x010bb8f6 in kill () from /lib/i386-gnu/libc.so.0.3
        #5  0x010bad76 in raise () from /lib/i386-gnu/libc.so.0.3
        #6  0x010bf029 in abort () from /lib/i386-gnu/libc.so.0.3
        #7  0x08048597 in handler (signo=14) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/relativedebug.c:25
        #8  0x01098282 in ?? () from /lib/i386-gnu/libc.so.0.3
        #9  0x010bbe5a in sigsuspend () from /lib/i386-gnu/libc.so.0.3
        #10 0x0112fee1 in pause () from /lib/i386-gnu/libc.so.0.3
        #11 0x080485c5 in main () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/relativedebug.c:32
        (gdb) PASS: gdb.base/relativedebug.exp: pause found in backtrace

    TODO.

  * `gdb.gdb/selftest.exp`

        (gdb) PASS: gdb.gdb/selftest.exp: send SIGINT signal to child process
        backtrace
        #0  0x0146fafc in ?? () from /lib/i386-gnu/libc.so.0.3
        #1  0x014703be in mach_msg () from /lib/i386-gnu/libc.so.0.3
        #2  0x0163bd98 in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
        #3  0x014b0141 in ?? () from /lib/i386-gnu/libc.so.0.3
        #4  0x014b03ed in kill () from /lib/i386-gnu/libc.so.0.3
        #5  0x082cf471 in _rl_handle_signal (sig=2) at ../../Ferry_Tagscherer/readline/signals.c:221
        #6  0x0148bac2 in ?? () from /lib/i386-gnu/libc.so.0.3
        Backtrace stopped: previous frame inner to this frame (corrupt stack?)
        (gdb) FAIL: gdb.gdb/selftest.exp: backtrace through signal handler

    This is apparently new with the glibc 2.17 upgrade.  Previously it said:

        (gdb) PASS: gdb.gdb/selftest.exp: send SIGINT signal to child process
        backtrace
        #0  0x0144885c in ?? () from /lib/i386-gnu/libc.so.0.3
        #1  0x01449069 in mach_msg () from /lib/i386-gnu/libc.so.0.3
        #2  0x015ecd4f in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
        #3  0x01487683 in ?? () from /lib/i386-gnu/libc.so.0.3
        #4  0x014878f6 in kill () from /lib/i386-gnu/libc.so.0.3
        #5  0x082cf401 in _rl_handle_signal (sig=2) at ../../Ferry_Tagscherer/readline/signals.c:221
        #6  0x01464282 in ?? () from /lib/i386-gnu/libc.so.0.3
        #7  0x0144fce3 in ?? () from /lib/i386-gnu/libc.so.0.3
        #8  0x0153975b in poll () from /lib/i386-gnu/libc.so.0.3
        #9  0x081c91c2 in gdb_wait_for_event (block=1) at ../../Ferry_Tagscherer/gdb/event-loop.c:804
        #10 0x081c998f in gdb_do_one_event () at ../../Ferry_Tagscherer/gdb/event-loop.c:402
        #11 0x081c9b07 in start_event_loop () at ../../Ferry_Tagscherer/gdb/event-loop.c:431
        #12 0x081c2f42 in captured_command_loop (data=data@entry=0x0) at ../../Ferry_Tagscherer/gdb/main.c:260
        #13 0x081c0e57 in catch_errors (func=func@entry=0x81c2f30 <captured_command_loop>, func_args=func_args@entry=0x0, errstring=errstring@entry=0x83
        5b81b "", mask=mask@entry=6) at ../../Ferry_Tagscherer/gdb/exceptions.c:546
        #14 0x081c388c in captured_main (data=data@entry=0x19ff150) at ../../Ferry_Tagscherer/gdb/main.c:1055
        #15 0x081c0e57 in catch_errors (func=func@entry=0x81c3130 <captured_main>, func_args=func_args@entry=0x19ff150, errstring=errstring@entry=0x835b
        81b "", mask=mask@entry=6) at ../../Ferry_Tagscherer/gdb/exceptions.c:546
        #16 0x081c43c0 in gdb_main (args=0x19ff150) at ../../Ferry_Tagscherer/gdb/main.c:1064
        #17 0x08099533 in main (argc=5, argv=0x19ff1e8) at ../../Ferry_Tagscherer/gdb/gdb.c:34
        (gdb) PASS: gdb.gdb/selftest.exp: backtrace through signal handler

    TODO.

  * `gdb.base/restore.exp`, `gdb.base/store.exp`

    Several FAILs, starting with GCC 4.8 usage:

        (gdb) PASS: gdb.base/restore.exp: caller3 calls callee1; return callee now
        print l1
        $16 = <optimized out>
        (gdb) FAIL: gdb.base/restore.exp: caller3 calls callee1; return restored l1 to 32492

    [[!GCC_PR 55056]], [[!message-id
    "20130126202645.GA4888@host2.jankratochvil.net"]], and maybe [[!message-id
    "CAO2gOZXvCLdaKE2=ZKpjGVGq8A0wQ94-AUo7eKvvWHWncrU_yg@mail.gmail.com"]] look
    related.

  * `gdb.base/default.exp`

        shell echo Hi dad!
        bash: relocation error: /lib/i386-gnu/libdl.so.2: symbol __libc_lock_self, version GLIBC_PRIVATE not defined in file libc.so.0.3 with link time reference
        (gdb) FAIL: gdb.base/default.exp: shell echo Hi dad!

    TODO.

  * `gdb.base/exitsignal.exp`

        Running ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/exitsignal.exp ...
        PASS: gdb.base/exitsignal.exp: $_exitsignal is void before running
        PASS: gdb.base/exitsignal.exp: $_exitcode is void before running
        PASS: gdb.base/exitsignal.exp: trigger SIGSEGV
        PASS: gdb.base/exitsignal.exp: program terminated with SIGSEGV
        FAIL: gdb.base/exitsignal.exp: $_exitsignal is 11 (SIGSEGV) after SIGSEGV.
        PASS: gdb.base/exitsignal.exp: $_exitcode is still void after SIGSEGV
        PASS: gdb.base/exitsignal.exp: rerun to main
        FAIL: gdb.base/exitsignal.exp: $_exitsignal is 11 (SIGSEGV) after restarting the inferior
        PASS: gdb.base/exitsignal.exp: $_exitcode is still void after restarting the inferior
        PASS: gdb.base/exitsignal.exp: $_exitsignal is void before normal inferior is executed
        PASS: gdb.base/exitsignal.exp: $_exitcode is void before normal inferior is executed
        PASS: gdb.base/exitsignal.exp: continue until exit
        PASS: gdb.base/exitsignal.exp: $_exitcode is zero after normal inferior is executed
        PASS: gdb.base/exitsignal.exp: $_exitsignal is still void after normal inferior is executed

    TODO.

  * `gdb.base/watchpoint-hw-hit-once.exp`

        PASS: gdb.base/watchpoint-hw-hit-once.exp: rwatch watchee
        PASS: gdb.base/watchpoint-hw-hit-once.exp: continue
        FAIL: gdb.base/watchpoint-hw-hit-once.exp: continue to break-at-exit

    The watchpoint does trigger again, wrongly.

  * `gdb.arch/i386-prologue.exp`

    There are several FAILs, where there are unexpected frames showing up in
    backtraces, for example.  Earlier on, these just FAILed on
    laplace.SCHWINGE; since
    9939e1314f970c6ba568956148a518ac710a280a..c2853f3d99797a321c37948297441ca6021f719a
    on kepler.SCHWINGE, too.  Later, FAILs again disappeared on
    kepler.SCHWINGE.

  * [[libgc|boehm_gc]] `GC_find_limit_with_bound` SIGSEGVs

    On laplace.SCHWINGE, in
    9939e1314f970c6ba568956148a518ac710a280a..c2853f3d99797a321c37948297441ca6021f719a
    several PASSes regressed to FAILs:

        Starting program: [...]/gdb/testsuite/gdb.gdb/xgdb -nw -nx -data-directory [...]/gdb/testsuite/../data-directory
        [New Thread 13417.5]
        
        Program received signal SIGSEGV, Segmentation fault.
        0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
        (gdb) FAIL: gdb.gdb/complaints.exp: run until breakpoint at captured_command_loop
        WARNING: Couldn't test self

        Starting program: [...]/gdb/testsuite/gdb.gdb/xgdb -nw -nx -data-directory [...]/gdb/testsuite/../data-directory
        [New Thread 13448.5]
        
        Program received signal SIGSEGV, Segmentation fault.
        0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
        (gdb) FAIL: gdb.gdb/python-interrupts.exp: run until breakpoint at captured_command_loop
        WARNING: Couldn't test self

        Starting program: [...]/gdb/testsuite/gdb.gdb/xgdb -nw -nx -data-directory [...]/gdb/testsuite/../data-directory
        [New Thread 13464.3]
        
        Program received signal SIGSEGV, Segmentation fault.
        0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
        (gdb) FAIL: gdb.gdb/python-selftest.exp: run until breakpoint at captured_command_loop
        WARNING: Couldn't test self

        (gdb) PASS: gdb.gdb/selftest.exp: step into xmalloc call
        continue
        Continuing.
        
        Program received signal SIGSEGV, Segmentation fault.
        0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
        (gdb) FAIL: gdb.gdb/selftest.exp: xgdb is at prompt

    These are all tests where GDB examines itself; being linked against libgc
    (new dependency due to new Guile scripting support; all Guile scripting
    tests PASS).  So, probably some bad interaction between GDB and a debuggee
    that is using libgc; maybe libgc is using SIGSEGV for internal signalling
    purposes; see the `HEURISTIC2` discussion on [[boehm_gc]].

        #0  0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
        #1  0x0126ba2e in GC_find_limit () from /usr/lib/i386-gnu/libgc.so.1
        #2  0x0126bb15 in GC_get_stack_base () from /usr/lib/i386-gnu/libgc.so.1
        #3  0x011be0ec in scm_init_guile () from /usr/lib/libguile-2.0.so.22
        #4  0x081203ba in _initialize_guile () at ../../W._C._Handy/gdb/guile/guile.c:704
        #5  0x082dc94d in initialize_all_files () at init.c:291
        #6  0x082a3c7f in gdb_init (argv0=0x8563e90 "[...]/gdb/testsuite/gdb.gdb/xgdb") at ../../W._C._Handy/gdb/top.c:1822
        #7  0x081da3b8 in captured_main (data=0x1bff164) at ../../W._C._Handy/gdb/main.c:747
        #8  0x081d70e9 in catch_errors (func=func@entry=0x81da110 <captured_main>, func_args=func_args@entry=0x1bff164, errstring=errstring@entry=0x837a0e5 "", mask=mask@entry=RETURN_MASK_ALL) at ../../W._C._Handy/gdb/exceptions.c:524
        #9  0x081db277 in gdb_main (args=0x1bff164) at ../../W._C._Handy/gdb/main.c:1062
        #10 0x0809714b in main (argc=5, argv=0x1bff1f4) at ../../W._C._Handy/gdb/gdb.c:33

    2016-05-25, commit 9ef9e6a6a0dd8f948708cb67c9afcfd0be40cb0a (2016-02-10):
    problem confirmed, when manually running GDB to debug another GDB instance.
    Worked around by `#if 0`ing the bodies of
    `gdb/guile/guile.c:_initialize_guile`, and
    `gdb/guile/guile.c:gdbscm_finish_initialization`.

    TODO.

  * In
    96f9814df23564e16909bb5ba00de4a202c63417..9ef9e6a6a0dd8f948708cb67c9afcfd0be40cb0a:

        Running [...]/gdb/testsuite/gdb.arch/i386-size-overlap.exp ...
        [-PASS:-]{+FAIL:+} gdb.arch/i386-size-overlap.exp: run past main
        PASS: gdb.arch/i386-size-overlap.exp: backtrace shows the outer function

    ..., and:

        Running [...]/gdb/testsuite/gdb.arch/i386-unwind.exp ...
        [-PASS-]{+FAIL:+} gdb.arch/i386-unwind.exp: run past gdb1435
        PASS: gdb.arch/i386-unwind.exp: backtrace past gdb1435

        PASS: gdb.cp/cpexprs.exp: list tclass<int>::do_something
        PASS: gdb.cp/cpexprs.exp: list tclass<long>::do_something
        PASS: gdb.cp/cpexprs.exp: list tclass<short>::do_something
        PASS: gdb.cp/cpexprs.exp: list test_function
        [-PASS:-]{+FAIL: gdb.cp/cpexprs.exp: continue+}
        {+FAIL:+} gdb.cp/cpexprs.exp: continue to {+test_function for+} base1::a_function
        [-PASS:-]{+FAIL: gdb.cp/cpexprs.exp: continue+}
        {+FAIL:+} gdb.cp/cpexprs.exp: continue to {+test_function for+} base1::base1(int)
        [-PASS:-]{+FAIL: gdb.cp/cpexprs.exp: continue+}
        [...]

    From a quick look, the problem appears to be that we print `Thread 4 hit
    Breakpoint 2, test_function [...]`, but the test harness doesn't expect to
    see the `Thread 4 hit` prefix.

    That might also explain the several other `continue` regressions, where
    only the `continue` itself "FAILs", but otherwise the test case still
    works, so the breakpoint has actually been hit as expected.

    System vs new GDB:

        @@ -1,31 +1,27 @@
        $ [-gdb-]{+gdb/gdb+} -q bfd/doc/chew
        Reading symbols from bfd/doc/chew...done.
        (gdb) show version
        GNU gdb [-(Debian 7.10-1+b1) 7.10-]{+(GDB) 7.10.50.20160210-git+}
        [...]
        (gdb) break main
        Breakpoint 1 at 0x8048730: file ../../../W._C._Handy/bfd/doc/chew.c, line 1494.
        (gdb) r
        Starting program: /media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/bfd/doc/chew 
        [New Thread [-6718.3]-]{+6737.5]+}
        
        {+Thread 4 hit+} Breakpoint 1, main (ac=1, av=0x102cda4) at ../../../W._C._Handy/bfd/doc/chew.c:1494
        1494    {
        (gdb) info threads
          Id   Target Id         Frame 
        [-  3    Thread 6718.3     0x0105d4fc in mach_msg_trap () at /build/glibc-2.22/build-tree/hurd-i386-libc/mach/mach_msg_trap.S:2-]
        [-* 2    Thread 6718.2     main (ac=1, av=0x102cda4) at ../../../W._C._Handy/bfd/doc/chew.c:1494-]
          1    bogus thread id 1 Can't fetch registers from thread bogus thread id 1: No such thread
        (gdb) r
        The program being debugged has been started already.
        Start it from the beginning? (y or n) y
        Starting program: /media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/bfd/doc/chew 
        [New Thread [-6719.8]-]{+6738.10]+}
        
        {+Thread 4 hit+} Breakpoint 1, main (ac=1, av=0x102cda4) at ../../../W._C._Handy/bfd/doc/chew.c:1494
        1494    {
        (gdb) info threads 
          Id   Target Id         Frame 
          [-5    Thread 6719.8     0x0105d4fc in mach_msg_trap () at /build/glibc-2.22/build-tree/hurd-i386-libc/mach/mach_msg_trap.S:2-]
        [-* 4    Thread 6719.7     main (ac=1, av=0x102cda4) at ../../../W._C._Handy/bfd/doc/chew.c:1494-]
        [-  3-]{+1+}    bogus thread id 6 Can't fetch registers from thread bogus thread id 6: No such thread

    Commit f303dbd60d9c7984832446eeb9d4e4d89703c615 `Fix PR threads/19422 -
    show which thread caused stop` needs additional changes for Hurd.
    Reverting that one, the `Thread 4 hit` prefix goes away, but `info threads`
    still doesn't work.

    Bisected the `info threads` problem to commit
    7e0aa6aa9983c745aedc203db0cc360a0ad47cac `List inferiors/threads/pspaces in
    ascending order`.  Does that one sort the `bogus thread id 6` first, and
    GDB stops after running into any such bogus thread ID?

    $ gdb/gdb -q --args gdb/gdb -q bfd/doc/chew --batch -ex 'break main' -ex r -ex 'info threads'

    new_thread calls:

        #0  new_thread (ptid=...) at ../../W._C._Handy/gdb/thread.c:234
        #1  0x081dc973 in add_thread_silent (ptid=...) at ../../W._C._Handy/gdb/thread.c:304
        #2  0x080bcc9b in fork_inferior (exec_file_arg=0x877b868 "/media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/bfd/doc/chew", allargs=0x8787d28 "", env=0x87312f0, traceme_fun=0x2804864, init_trace_fun=0x0, pre_trace_fun=0x0, shell_file_arg=0x0, exec_fun=0x0) at ../../W._C._Handy/gdb/fork-child.c:397
        #3  0x080ba574 in gnu_create_inferior (ops=0x868c148, exec_file=0x877b868 "/media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/bfd/doc/chew", allargs=0x8787d28 "", env=0x87312f0, from_tty=0) at ../../W._C._Handy/gdb/gnu-nat.c:2136
        #4  0x081c4687 in run_command_1 (args=<optimized out>, from_tty=0, tbreak_at_main=<optimized out>) at ../../W._C._Handy/gdb/infcmd.c:604
        #5  0x082aa39d in execute_command (p=<optimized out>, from_tty=0) at ../../W._C._Handy/gdb/top.c:475
        #6  0x081e18c8 in catch_command_errors (command=0x82aa160 <execute_command>, arg=0x102d079 "r", from_tty=0) at ../../W._C._Handy/gdb/main.c:368

        #0  new_thread (ptid=...) at ../../W._C._Handy/gdb/thread.c:234
        #1  0x081dc973 in add_thread_silent (ptid=...) at ../../W._C._Handy/gdb/thread.c:304
        #2  0x080b8359 in inf_validate_procs (inf=0x87a31e0) at ../../W._C._Handy/gdb/gnu-nat.c:1104
        #3  0x080b85f1 in inf_update_procs (inf=0x87a31e0) at ../../W._C._Handy/gdb/gnu-nat.c:1123
        #4  0x080b871e in inf_suspend (inf=0x87a31e0) at ../../W._C._Handy/gdb/gnu-nat.c:1179
        #5  0x080b97a7 in gnu_wait (ops=0x868c148, ptid=..., status=0x2804810, options=0) at ../../W._C._Handy/gdb/gnu-nat.c:1530
        #6  0x08204a17 in delegate_wait (self=<optimized out>, arg1=..., arg2=0x2804810, arg3=0) at ../../W._C._Handy/gdb/target-delegates.c:116
        #7  0x08213c18 in target_wait (ptid=..., status=0x2804810, options=0) at ../../W._C._Handy/gdb/target.c:2256
        #8  0x080bce8d in startup_inferior (ntraps=1) at ../../W._C._Handy/gdb/fork-child.c:445
        #9  0x080ba612 in gnu_create_inferior (ops=0x868c148, exec_file=0x877b868 "/media/erich/home/thomas/tmp/binutils-gdb/tschwinge/W._C._Handy.build/bfd/doc/chew", allargs=0x8787d28 "", env=0x87312f0, from_tty=0) at ../../W._C._Handy/gdb/gnu-nat.c:2158
        #10 0x081c4687 in run_command_1 (args=<optimized out>, from_tty=0, tbreak_at_main=<optimized out>) at ../../W._C._Handy/gdb/infcmd.c:604
        #11 0x082aa39d in execute_command (p=<optimized out>, from_tty=0) at ../../W._C._Handy/gdb/top.c:475
        #12 0x081e18c8 in catch_command_errors (command=0x82aa160 <execute_command>, arg=0x102d079 "r", from_tty=0) at ../../W._C._Handy/gdb/main.c:368

        #0  new_thread (ptid=...) at ../../W._C._Handy/gdb/thread.c:234
        #1  0x081dc973 in add_thread_silent (ptid=...) at ../../W._C._Handy/gdb/thread.c:304
        #2  0x081dca36 in add_thread_with_info (ptid=..., priv=0x0) at ../../W._C._Handy/gdb/thread.c:313
        #3  0x081dcaa6 in add_thread (ptid=...) at ../../W._C._Handy/gdb/thread.c:327
        #4  0x080b84b7 in inf_validate_procs (inf=0x87a31e0) at ../../W._C._Handy/gdb/gnu-nat.c:1106
        #5  0x080b85f1 in inf_update_procs (inf=0x87a31e0) at ../../W._C._Handy/gdb/gnu-nat.c:1123
        #6  0x080b871e in inf_suspend (inf=0x87a31e0) at ../../W._C._Handy/gdb/gnu-nat.c:1179
        #7  0x080b97a7 in gnu_wait (ops=0x868c148, ptid=..., status=0x2804828, options=0) at ../../W._C._Handy/gdb/gnu-nat.c:1530
        #8  0x08204a17 in delegate_wait (self=<optimized out>, arg1=..., arg2=0x2804828, arg3=0) at ../../W._C._Handy/gdb/target-delegates.c:116
        #9  0x08213c18 in target_wait (ptid=..., status=0x2804828, options=0) at ../../W._C._Handy/gdb/target.c:2256
        #10 0x081c80fe in do_target_wait (ptid=..., status=0x2804828, options=0) at ../../W._C._Handy/gdb/infrun.c:3642
        #11 0x081d30f5 in fetch_inferior_event (client_data=0x0) at ../../W._C._Handy/gdb/infrun.c:3900
        #12 0x081e8c54 in inferior_event_handler (event_type=INF_REG_EVENT, client_data=0x0) at ../../W._C._Handy/gdb/inf-loop.c:44
        #13 0x081c782c in infrun_async_inferior_event_handler (data=0x0) at ../../W._C._Handy/gdb/infrun.c:9082
        #14 0x081e72ec in check_async_event_handlers () at ../../W._C._Handy/gdb/event-loop.c:1038
        #15 gdb_do_one_event () at ../../W._C._Handy/gdb/event-loop.c:302
        #16 0x082aa126 in wait_sync_command_done () at ../../W._C._Handy/gdb/top.c:373
        #17 0x082aa323 in maybe_wait_sync_command_done (was_sync=0) at ../../W._C._Handy/gdb/top.c:388
        #18 execute_command (p=<optimized out>, from_tty=0) at ../../W._C._Handy/gdb/top.c:477
        #19 0x081e18c8 in catch_command_errors (command=0x82aa160 <execute_command>, arg=0x102d079 "r", from_tty=0) at ../../W._C._Handy/gdb/main.c:368

    ---
    
    Changes `renumber_threads|prune_threads`
    
    +/* Implement the "to_update_thread_list" target_ops method.  */
    +
    +static void
    +fbsd_update_thread_list (struct target_ops *ops)
    +{
    +#ifdef PT_LWP_EVENTS
    +  /* With support for thread events, threads are added/deleted from the
    +     list as events are reported, so just try deleting exited threads.  */
    +  delete_exited_threads ();
    +#else
    +  prune_threads ();
    +
    +  fbsd_add_threads (ptid_get_pid (inferior_ptid));
    +#endif
    +}
    
     static void
     linux_nat_update_thread_list (struct target_ops *ops)
     {
    -  if (linux_supports_traceclone ())
    -    {
    -      /* With support for clone events, we add/delete threads from the
    -        list as clone/exit events are processed, so just try deleting
    -        exited threads still in the thread list.  */
    -      delete_exited_threads ();
    -    }
    -  else
    -    prune_threads ();
    +  /* We add/delete threads from the list as clone/exit events are
    +     processed, so just try deleting exited threads still in the
    +     thread list.  */
    +  delete_exited_threads ();
     }
    
    commit 8a06aea71e0aa9099d0ca593dbb58f6e056af4ff
    Author: Pedro Alves <palves@redhat.com>
    Date:   Tue Apr 7 15:47:22 2015 +0100
    
        update thread list, delete exited threads
        [...]
    
    ... looks very relevant
    
    commit 44ee4a526db6160b302417127e736b73fc00ee87
    Author: Pedro Alves <palves@redhat.com>
    Date:   Wed Oct 15 22:48:35 2014 +0100
    
        DEC threads: Simplify updating the thread list
        [...]
    
    commit ab970af19746364a4f236bebc238ebb036adc898
    Author: Pedro Alves <palves@redhat.com>
    Date:   Wed Oct 15 22:44:00 2014 +0100
    
        remote: get rid of all the T packets when syncing the thread list
        [...]
    
    commit e8032dde10b743253125d7defb5f5503b21c1d26
    Author: Pedro Alves <palves@redhat.com>
    Date:   Wed Oct 15 22:44:00 2014 +0100
    
        Push pruning old threads down to the target
        [...]
    
    commit c82f56d9d760a9b4034eeaac44f2f0fa5779ff69
    Author: Thomas Schwinge <thomas@codesourcery.com>
    Date:   Wed Jan 8 21:42:07 2014 +0100
    
        Hurd: Adjust to startup-with-shell changes.
        [...]
    
    
        If this is not done, GDB will get confused in the following.  For example,
        "info threads" will stop early with "bogus thread id 6 Can't fetch
        registers from thread bogus thread id 6: No such thread".
    
        Calling delete_exited_threads instead of prune_threads does not work.
    
        It's not clear if this really should be called here, or if we fail to
        properly track/report our own threads.  For example, we're not calling
        delete_thread anywhere.
    
        Alternatively, should/could we provide a update_thread_list function, and
        do the pruning there?
    
    TODO.

  * a932d108b10518994c873b38a363af9f21bc2e87..f245535cf583ae4ca13b10d47b3c7d3334593ece

         Running [...]/tschwinge/W._C._Handy/ld/testsuite/ld-i386/i386.exp ...
        +FAIL: Run ifunc-1b
        +Running [...]/tschwinge/W._C._Handy/ld/testsuite/ld-i386/no-plt.exp ...
        +FAIL: No PLT (static 1d)
        +FAIL: No PLT (static 1j)
        +FAIL: Run pr20244-3b
        +FAIL: Run pr20253-1b
        +FAIL: Run pr20253-1g
        +FAIL: Run pr20253-2b
        +FAIL: Run pr20253-2d

    TODO.

TODO.


# Open Issues

## [[tag/open_issue_binutils]]

## [[tag/open_issue_gdb]]

## GDB `info files` SIGSEGV

[[!tag open_issue_gdb]]


### IRC, freenode, #hurd, 2013-09-07

    <rekado> I'm trying to debug pfinet, but I'm not very familiar with gdb.
      Tried to attach to the running pfinet process (built with debug symbols),
      set a breakpoint and ... when I ran "info files" the process segfaulted.
    <teythoon> which process segfaults, pfinet or gdb?
    <rekado> gdb segfaults.