clang complains that for some types, we use both the class and struct
keywords in different places. It's not really a problem, so I think we
can safely turn this warning off.
gdb/ChangeLog:
* configure: Re-generate.
* warning.m4 (build_warnings): Add -Wno-mismatched-tags.
gdb/gdbserver/ChangeLog:
* configure: Re-generate.
In warning.m4, we pass all the warning flags one by one to the compiler
to test if they are supported by this particular compiler. If the
compiler exits with an error, we conclude that this warning flag is not
supported and exclude it. This allows us to use warning flags without
having to worry about which versions of which compilers support each
flag.
clang, by default, only emits a warning if an unknown flag is passed:
warning: unknown warning option '-Wfoo' [-Wunknown-warning-option]
The result is that we think that all the warning flags we use are
supported by clang (they are not), and the compilation fails later when
building with -Werror, since the aforementioned warning becomes an
error. The fix is to also pass -Werror when probing for supported
flags, then we'll correctly get an error when using an unknown warning,
and we'll exclude it:
error: unknown warning option '-Wfoo' [-Werror,-Wunknown-warning-option]
I am not sure why there is a change in a random comment in
gdbserver/configure, but I suppose it's a leftfover from a previous
patch, so I included it.
gdb/ChangeLog:
* configure: Re-generate.
* warning.m4: Pass -Werror to compiler when checking for
supported warning flags.
gdb/gdbserver/ChangeLog:
* configure: Re-generate.
Version 2 of libipt adds an event system to instruction flow decoders and
deprecates indicating events via flags in struct pt_insn. Add configuration
checks to determine which version we have.
gdb/
* configure.ac: Check for pt_insn_event, struct pt_insn.enabled,
and struct pt_insn.resynced.
* configure: Regenerated.
* config.in: Regenerated.
Due to my ongoing work to make it possible for gdbserver to start the
inferior using the shell, I had to share the fork_inferior function
under the "nat/" directory. In order to do that, I created a new file
and put the function there; however, this meant that I now had to
update some of the *.mh files (under "gdb/config") and add the new
file as a dependency to be built natively. Bleh...
After talking a bit to Pedro about this, the idea came up to write a
new "gdb/configure.nat" file, a la "gdb/configure.tgt", which would
concentrate all of the native settings for each host/system. I
decided to tackle this issue.
The patch is simple. All of the previous Makefile variables that were
being declared inside the *.mh files are now inside "gdb/Makefile.in",
and "gdb/configure" is responsible for AC_SUBST'ing them. The
definitions of these variables were put inside "gdb/configure.nat", so
now they're shell variables. For excerpts of Makefile code, one must
create a file under "gdb/config/${gdb_cpu_host}" and reference it on
the "nat_extra_makefile_frag" variable.
It should now be easier to update the native dependencies of hosts in
this single file.
This has been tested on x86_64 without regressions.
gdb/ChangeLog:
2017-05-06 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile.in: Remove "@host_makefile_frag@". Add variables
NAT_FILE, NATDEPFILES, NAT_CDEPS, LOADLIBES, MH_CFLAGS, XM_CLIBS,
NAT_GENERATED_FILES, HAVE_NATIVE_GCORE_HOST. Add
"@nat_extra_makefile_frag@".
(Makefile): Remove dependency on "@frags@".
($(GNULIB_BUILDDIR)/Makefile): Likewise.
(data-directory/Makefile): Likewise.
* config/aarch64/linux.mh: Deleted; moved contents to
"gdb/configure.nat".
* config/alpha/alpha-linux.mh: Likewise.
* config/alpha/nbsd.mh: Likewise.
* config/arm/linux.mh: Likewise.
* config/arm/nbsdelf.mh: Likewise.
* config/i386/cygwin.mh: Likewise.
* config/i386/cygwin64.mh: Likewise.
* config/i386/darwin.mh: Likewise.
* config/i386/fbsd.mh: Likewise.
* config/i386/fbsd64.mh: Likewise.
* config/i386/go32.mh: Likewise.
* config/i386/i386gnu.mh: Likewise.
* config/i386/i386sol2.mh: Likewise.
* config/i386/linux.mh: Likewise.
* config/i386/linux64.mh: Likewise.
* config/i386/mingw.mh: Likewise.
* config/i386/mingw64.mh: Likewise.
* config/i386/nbsd64.mh: Likewise.
* config/i386/nbsdelf.mh: Likewise.
* config/i386/nto.mh: Likewise.
* config/i386/obsd.mh: Likewise.
* config/i386/obsd64.mh: Likewise.
* config/i386/sol2-64.mh: Likewise.
* config/ia64/linux.mh: Likewise.
* config/m32r/linux.mh: Likewise.
* config/m68k/linux.mh: Likewise.
* config/m68k/nbsdelf.mh: Likewise.
* config/m68k/obsd.mh: Likewise.
* config/m88k/obsd.mh: Likewise.
* config/mips/fbsd.mh: Likewise.
* config/mips/linux.mh: Likewise.
* config/mips/nbsd.mh: Likewise.
* config/mips/obsd64.mh: Likewise.
* config/pa/linux.mh: Likewise.
* config/pa/nbsd.mh: Likewise.
* config/pa/obsd.mh: Likewise.
* config/powerpc/aix.mh: Likewise.
* config/powerpc/fbsd.mh: Likewise.
* config/powerpc/linux.mh: Likewise.
* config/powerpc/nbsd.mh: Likewise.
* config/powerpc/obsd.mh: Likewise.
* config/powerpc/ppc64-linux.mh: Likewise.
* config/powerpc/spu-linux.mh: Likewise.
* config/s390/linux.mh: Likewise.
* config/sh/nbsd.mh: Likewise.
* config/sparc/fbsd.mh: Likewise.
* config/sparc/linux.mh: Likewise.
* config/sparc/linux64.mh: Likewise.
* config/sparc/nbsd64.mh: Likewise.
* config/sparc/nbsdelf.mh: Likewise.
* config/sparc/obsd64.mh: Likewise.
* config/sparc/sol2.mh: Likewise.
* config/tilegx/linux.mh: Likewise.
* config/vax/nbsdelf.mh: Likewise.
* config/vax/obsd.mh: Likewise.
* config/xtensa/linux.mh: Likewise.
* config/i386/i386gnu.mn: New file, with excerpts from
"config/i386/i386gnu.mh".
* configure: Regenerate.
* configure.ac: Rewrite code to use "gdb/configure.nat" instead of
*.mh files under "gdb/config".
* configure.nat: New file, with contents from the
"gdb/config/*/*.mh" files.
gdb/doc/ChangeLog:
2017-05-06 Sergio Durigan Junior <sergiodj@redhat.com>
* Makefile: Remove "@host_makefile_frag@".
Newer GCCs are triggering false-positive -Wmaybe-uninitialized
warnings around code that uses gdb::optional:
https://sourceware.org/ml/gdb-patches/2017-05/msg00118.html
Using std::optional wouldn't help, it triggers the same warnings:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80635
Initializing the variables to quiet the warning would defeat the
purpose of gdb::optional. Making the optional ctor memset its storage
would be a pessimization. Wrapping gdb::optional's internals with
"#pragma GCC diagnostic push/ignored/pop" doesn't work, we'd have to
wrap uses of gdb::optional instead, which I think would get unwieldy
and ugly as we start using gdb::optional more and more.
The -Wmaybe-uninitialized warning is documented as producing false
positives (unlike -Wuninialized), so until we find a better
workaround, disable -Werror for this warning. You'll still see the
warning when building gdb, but it won't cause a build failure.
Tested by building with gcc 4.8.5, 5.3.1, and gcc trunk (20170428).
gdb/ChangeLog:
2017-05-05 Pedro Alves <palves@redhat.com>
* warning.m4 (build_warnings): Add -Wno-error=maybe-uninitialized.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2017-05-05 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
On commit be628ab814, both
common/common.m4 was modified in order to check for the presence of
'termios.h', 'termio.h' and 'sgtty.h'. However, I forgot to
regenerate both gdb/configure and gdb/gdbserver/configure. This
commit does that.
gdb/ChangeLog:
2017-05-03 Sergio Durigan Junior <sergiodj@redhat.com>
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2017-05-03 Sergio Durigan Junior <sergiodj@redhat.com>
* configure: Regenerate.
AFAIK GDB is now free from -Wwrite-strings warnings. A few warnings may
be left behind in some host-specific code, but those should be few and
easy to fix.
gdb/ChangeLog:
2017-04-05 Pedro Alves <palves@redhat.com>
* warning.m4 (build_warnings): Remove -Wno-write-strings.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2017-04-05 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
This commit adds a new function_view type. This type holds a
non-owning reference to a callable. It is meant to be used as
callback type of functions, instead of using the C-style pair of
function pointer and 'void *data' arguments. function_view allows
passing references to stateful function objects / lambdas with
captures as callbacks efficiently, while function pointer + 'void *'
does not.
See the intro in the new function-view.h header for more.
Unit tests included, put into a new gdb/unittests/ subdir.
gdb/ChangeLog:
2017-02-23 Pedro Alves <palves@redhat.com>
* Makefile.in (SUBDIR_UNITTESTS_SRCS, SUBDIR_UNITTESTS_OBS): New.
(%.o) <unittests/%.c>: New pattern.
* configure.ac ($development): Add $(SUBDIR_UNITTESTS_OBS) to
CONFIG_OBS, and $(SUBDIR_UNITTESTS_SRCS) to CONFIG_SRCS.
* common/function-view.h: New file.
* unittests/function-view-selftests.c: New file.
* configure: Regenerate.
Since GNU make is now required to build GDB, we can remove everything
that checks whether the current make implemention is the GNU one or
not. I simply removed the @GMAKE_TRUE@ prefixes and removed the whole
lines that were prefixed with @GMAKE_FALSE@.
I removed the code in the configure scripts that set those variables.
I also removed the following bits from the configure scripts:
AC_CHECK_PROGS(MAKE, make): GNU make already defines a MAKE variable
internally to be used when invoking Makefiles recursively. I don't see
this variable being used anywhere else (in scripts for example), so I
think it's safe for removal.
AC_PROG_MAKE_SET: This macro defines a SET_MAKE output variable, which
is meant to be used in Makefiles to define the MAKE variable when
using an implementation of make that doesn't already define it.
Since we are now requiring GNU make, we don't need it anymore.
Plus, I don't see SET_MAKE being used anywhere, so I don't think it
was actually doing anything...
gdb/ChangeLog:
* Makefile.in: Remove @GMAKE_TRUE@ prefixes and removes lines
prefixed with @GMAKE_FALSE@. Update comment related to non-GNU
make.
* configure.ac: Remove checks for the make program.
* configure: Re-generate.
gdb/gdbserver/ChangeLog:
* Makefile.in: Remove @GMAKE_TRUE@ prefixes and removes lines
prefixed with @GMAKE_FALSE@. Update comment related to non-GNU
make.
* configure.ac: Remove checks for the make program.
* configure: Re-generate.
gdb/testsuite/ChangeLog:
* Makefile.in: Remove @GMAKE_TRUE@ prefixes and removes lines
prefixed with @GMAKE_FALSE@. Update comment related to non-GNU
make.
* configure.ac: Remove checks for the make program.
* configure: Re-generate.
Use AX_CXX_COMPILE_STDCXX to detect if the compiler supports C++11,
and if -std=xxx switches are necessary to enable C++11.
We need to tweak AX_CXX_COMPILE_STDCXX a bit though. Pristine
upstream AX_CXX_COMPILE_STDCXX appends -std=gnu++11 to CXX directly.
That doesn't work for us, because the top level Makefile passes CXX
down to subdirs, and that overrides whatever gdb/Makefile may set CXX
to. The result would be that a make invocation from the build/gdb/
directory would use "g++ -std=gnu++11" as expected, while a make
invocation at the top level would not.
So instead of having AX_CXX_COMPILE_STDCXX set CXX directly, tweak it
to AC_SUBST a separate variable -- CXX_DIALECT -- and use '$(CXX)
(CXX_DIALECT)' to compile/link.
Confirmed that this enables C++11 starting with gcc 4.8, the first gcc
release with full C++11 support.
Also confirmed that configure errors out gracefully with older GCC
releases:
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features by default... no
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=gnu++11... no
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=gnu++0x... no
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=c++11... no
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -std=c++0x... no
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with +std=c++11... no
checking whether /opt/gcc-4.7/bin/g++ supports C++11 features with -h std=c++11... no
configure: error: *** A compiler with support for C++11 language features is required.
Makefile:9451: recipe for target 'configure-gdb' failed
make[1]: *** [configure-gdb] Error 1
make[1]: Leaving directory '/home/pedro/brno/pedro/gdb/mygit/cxx-convertion/build-gcc-4.7'
If we need to revert back to making C++11 optional, all that's
necessary is to change the "mandatory" to "optional" in configure.ac
and regenerate configure (both gdb and gdbserver).
gdb/ChangeLog:
2016-10-28 Pedro Alves <palves@redhat.com>
* Makefile.in (CXX_DIALECT): Get from configure.
(COMPILE.pre, CC_LD): Append $(CXX_DIALECT).
(FLAGS_TO_PASS): Pass CXX_DIALECT.
* acinclude.m4: Include ax_cxx_compile_stdcxx.m4.
* ax_cxx_compile_stdcxx.m4: Add FSF copyright header. Set and
AC_SUBST CXX_DIALECT instead of changing CXX/CXXCPP.
* configure.ac: Call AX_CXX_COMPILE_STDCXX.
* config.in: Regenerate.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-10-28 Pedro Alves <palves@redhat.com>
* Makefile.in (CXX_DIALECT): Get from configure.
(COMPILE.pre, CC_LD): Append $(CXX_DIALECT).
* acinclude.m4: Include ../ax_cxx_compile_stdcxx.m4.
* configure.ac: Call AX_CXX_COMPILE_STDCXX.
* config.in: Regenerate.
* configure: Regenerate.
This removes all support for building gdb & gdbserver with a C
compiler from gdb & gdbserver's build machinery.
gdb/ChangeLog:
2016-09-05 Pedro Alves <palves@redhat.com>
* NEWS: Mention that a C++ compiler is now required.
* Makefile.in (COMPILER, COMPILER_CFLAGS): Remove.
(COMPILE.pre, CC_LD): Use CXX directly.
(INTERNAL_CFLAGS_BASE): Use CXXFLAGS directly.
* acinclude.m4: Don't include build-with-cxx.m4.
* build-with-cxx.m4: Delete file.
* configure.ac: Remove GDB_AC_BUILD_WITH_CXX call.
* warning.m4: Assume $enable_build_with_cxx is yes.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-09-05 Pedro Alves <palves@redhat.com>
* Makefile.in (COMPILER, COMPILER_CFLAGS): Remove.
(COMPILE.pre, CC_LD): Use CXX directly.
(INTERNAL_CFLAGS_BASE): Use CXXFLAGS directly.
* acinclude.m4: Don't include build-with-cxx.m4.
* configure.ac: Remove GDB_AC_BUILD_WITH_CXX call.
* configure: Regenerate.
gdb's (or gdbserver's) own signal handling should not interfere with
the signal dispositions their spawned children inherit. However, it
currently does. For example, some paths in gdb cause SIGPIPE to be
set to SIG_IGN, and as consequence, the child starts with SIGPIPE to
set to SIG_IGN too, even though gdb was started with SIGPIPE set to
SIG_DFL.
This is because the exec family of functions does not reset the signal
disposition of signals that are set to SIG_IGN:
http://pubs.opengroup.org/onlinepubs/7908799/xsh/execve.html
Signals set to the default action (SIG_DFL) in the calling process
image are set to the default action in the new process
image. Signals set to be ignored (SIG_IGN) by the calling process
image are set to be ignored by the new process image. Signals set to
be caught by the calling process image are set to the default action
in the new process image (see <signal.h>).
And neither does it reset signal masks or flags.
In order to be transparent, when spawning new child processes to debug
(with "run", etc.), reset signal actions and mask back to what was
originally inherited from gdb/gdbserver's parent, just before execing
the target program to debug.
gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* Makefile.in (SFILES): Add
common/signals-state-save-restore.c.
(HFILES_NO_SRCDIR): Add common/signals-state-save-restore.h.
(COMMON_OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* configure: Regenerate.
* fork-child.c: Include "signals-state-save-restore.h".
(fork_inferior): Call restore_original_signals_state.
* main.c: Include "signals-state-save-restore.h".
(captured_main): Call save_original_signals_state.
* common/common.m4: Add sigaction to AC_CHECK_FUNCS checks.
* common/signals-state-save-restore.c: New file.
* common/signals-state-save-restore.h: New file.
gdb/gdbserver/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* Makefile.in (OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* config.in: Regenerate.
* configure: Regenerate.
* linux-low.c: Include "signals-state-save-restore.h".
(linux_create_inferior): Call
restore_original_signals_state.
* server.c: Include "dispositions-save-restore.h".
(captured_main): Call save_original_signals_state.
gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* gdb.base/signals-state-child.c: New file.
* gdb.base/signals-state-child.exp: New file.
* gdb.gdb/selftest.exp (do_steps_and_nexts): Add new pattern.
We build by default with a C++ compiler, but "configure --help" still
says "--enable-build-with-cxx", which hints that it is by default
disabled. Update the --help text.
gdb/ChangeLog:
2016-08-05 Pedro Alves <palves@redhat.com>
* build-with-cxx.m4: Change help string to be in terms of
--disable-build-with-cxx.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-08-05 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
Implement support to add catchpoints for a group of related syscalls
using the syntax:
(gdb) catch syscall group:<group>
or
(gdb) catch syscall g:<group>
Several groups are predefined in the xml files for all architectures
supported by GDB over Linux. They are based on the groups defined by
strace.
gdb/
* xml-syscall.c (get_syscalls_by_group): New.
(get_syscall_group_names): New.
(struct syscall_group_desc): New structure to store group data.
(struct syscalls_info): Include field to store the group list.
(sysinfo_free_syscall_group_desc): New.
(free_syscalls_info): Free group list.
(syscall_group_create_syscall_group_desc): New.
(syscall_group_add_syscall): New.
(syscall_create_syscall_desc): Add syscall to its groups.
(syscall_start_syscall): Load group attribute.
(syscall_group_get_group_by_name): New.
(xml_list_syscalls_by_group): New.
(xml_list_of_groups): New.
* xml-syscall.h (get_syscalls_by_group): Export function
to retrieve a list of syscalls filtered by the group name.
(get_syscall_group_names): Export function to retrieve the list
of syscall groups.
* break-catch-syscall.c (catch_syscall_split_args): Verify if
argument is a syscall group and expand it to a list of syscalls
when creating catchpoints.
(catch_syscall_completer): Add word completion for system call
groups.
* configure.ac: Include dependency for xsltproc when building
in maintainer-mode.
* break-catch-syscall.c (_initialize_breakpoint): Update catch
syscall command documentation.
* NEWS: Include section about catching groups of syscalls.
* configure: Regenerate.
* data-directory/Makefile.in: Generate syscall xml when building
in maintainer mode.
* syscalls/gdb-syscalls.dtd: Include group attribute to the
syscall element.
* syscalls/apply-defaults.xsl: New.
* syscalls/linux-defaults.xml.in: New.
* syscalls/aarch64-linux.xml: Rename to aarch64-linux.xml.in.
* syscalls/amd64-linux.xml: Rename to amd64-linux.xml.in.
* syscalls/arm-linux.xml: Rename to arm-linux.xml.in.
* syscalls/bfin-linux.xml: Rename to bfin-linux.xml.in.
* syscalls/i386-linux.xml: Rename to i386-linux.xml.in.
* syscalls/mips-n32-linux.xml: Rename to mips-n32-linux.xml.in.
* syscalls/mips-n64-linux.xml: Rename to mips-n64-linux.xml.in.
* syscalls/mips-o32-linux.xml: Rename to mips-o32-linux.xml.in.
* syscalls/ppc-linux.xml: Rename to ppc-linux.xml.in.
* syscalls/ppc64-linux.xml: Rename to ppc64-linux.xml.in.
* syscalls/s390-linux.xml: Rename to s390-linux.xml.in.
* syscalls/s390x-linux.xml: Rename to s390x-linux.xml.in.
* syscalls/sparc-linux.xml: Rename to sparc-linux.xml.in.
* syscalls/sparc64-linux.xml: Rename to sparc64-linux.xml.in.
* syscalls/aarch64-linux.xml: Regenerate.
* syscalls/amd64-linux.xml: Regenerate.
* syscalls/arm-linux.xml: Regenerate.
* syscalls/i386-linux.xml: Regenerate.
* syscalls/mips-n32-linux.xml: Regenerate.
* syscalls/mips-n64-linux.xml: Regenerate.
* syscalls/mips-o32-linux.xml: Regenerate.
* syscalls/ppc-linux.xml: Regenerate.
* syscalls/ppc64-linux.xml: Regenerate.
* syscalls/s390-linux.xml: Regenerate.
* syscalls/s390x-linux.xml: Regenerate.
* syscalls/sparc-linux.xml: Regenerate.
* syscalls/sparc64-linux.xml: Regenerate.
gdb/testsuite/
* gdb.base/catch-syscall.exp (do_syscall_tests): Add call
to test_catch_syscall_group.
(test_catch_syscall_group): New.
gdb/doc/
* gdb.texinfo (Set Catchpoints): Add 'group' argument to catch
syscall.
All platforms on FreeBSD use a shared system call table, so use a
single XML file to describe the system calls available on each FreeBSD
platform.
Recent versions of FreeBSD include the identifier of the current
system call when reporting a system call entry or exit event in the
ptrace_lwpinfo structure obtained via PT_LWPINFO in fbsd_wait. As
such, FreeBSD native targets do not use the gdbarch method to fetch
the system call code. In addition, FreeBSD register sets fetched via
ptrace do not include an equivalent of 'orig_rax' (on amd64 for
example), so the system call code cannot be extracted from the
available registers during a system call exit. However, GDB assumes
that system call catch points are not supported if the gdbarch method
is not present. As a workaround, FreeBSD ABIs install a dummy gdbarch
method that throws an internal_error if it is ever invoked.
gdb/ChangeLog:
* configure.ac: Check for support for system call LWP fields on
FreeBSD.
* config.in, configure: Rebuild.
* data-directory/Makefile.in (SYSCALLS_FILES): Add freebsd.xml.
* fbsd-nat.c (fbsd_wait) [HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE]:
Report system call events.
[HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE]
(fbsd_set_syscall_catchpoint): New function.
(fbsd_nat_add_target) [HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE]:
Set "to_set_syscall_catchpoint" to "fbsd_set_syscall_catchpoint".
* fbsd-tdep.c: Include xml-syscall.h
(fbsd_get_syscall_number): New function.
(fbsd_init_abi): Set XML system call file name.
Add "get_syscall_number" gdbarch method.
* syscalls/freebsd.xml: New file.
GDB needs kinfo_getvmmap() on GNU/kFreeBSD systems same as on
pure FreeBSD. However on these systems the FreeBSD version of libutil
is renamed to libutil-freebsd.
2016-05-23 Jon Boden <jon@ubuntubsd.org>
* configure.ac: Search for libutil-freebsd as alternative to libutil.
* configure: Re-generated.
I wanted to unit test the Rust lexer, so I added a simple unit testing
command to gdb.
The intent is that self tests will only be compiled into gdb in
development mode. In release mode they simply won't exist. So, this
exposes $development to C code as GDB_SELF_TEST.
In development mode, test functions are registered with the self test
module. A test function is just a function that does some checks, and
throws an exception on failure.
Then this adds a new "maint selftest" command which invokes the test
functions, and a new dejagnu test case that invokes it.
2016-05-17 Tom Tromey <tom@tromey.com>
* NEWS: Add "maint selftest" entry.
* selftest.h: New file.
* selftest.c: New file.
* maint.c: Include selftest.h.
(maintenance_selftest): New function.
(_initialize_maint_cmds): Add "maint selftest" command.
* configure.ac (GDB_SELF_TEST): Maybe define.
* config.in, configure: Rebuild.
* Makefile.in (SFILES): Add selftest.c.
(COMMON_OBS): Add selftest.o.
2016-05-17 Tom Tromey <tom@tromey.com>
* gdb.texinfo (Maintenance Commands): Document "maint selftest".
2016-05-17 Tom Tromey <tom@tromey.com>
* gdb.gdb/unittest.exp: New file.
GDB's use of --dynamic-list to only export the proc-service symbols is
broken due to Python's "python-config --ldflags" saying we should link
with -export-dynamic, causing us to export _all_ extern symbols
anyway. On Fedora 23:
$ python-config --ldflags
-lpython2.7 -lpthread -ldl -lutil -lm -Xlinker -export-dynamic
$ python3.4-config --ldflags
-L/usr/lib64 -lpython3.4m -lpthread -ldl -lutil -lm -Xlinker -export-dynamic
Having GDB export all its symbols leads to issues such as PR gdb/16818
(GDB crashes when using name for target remote hostname:port), where a
GDB symbol unintentionally preempts a symbol in one of the NSS modules
glibc loads into the process. NSS modules should not define symbols
outside the implementation namespace or the relevant standards, but,
alas, that's a longstanding and hard to fix issue. See libc-alpha
discussion at:
[symbol name space issues with NSS modules]
https://sourceware.org/ml/libc-alpha/2016-04/msg00130.html
Python should instead be either using GCC's symbol visibility feature
or -Wl,--dynamic-list as well, to only export Python API symbols, but,
it doesn't. There are bugs open upstream for that:
[Use -Wl,--dynamic-list=x.list, not -Xlinker -export-dynamic]
http://bugs.python.org/issue10112
[Use GCC visibility attrs in PyAPI_*]
http://bugs.python.org/issue11410
But that's taking a long while to resolve.
I thought of working around this Python issue by making GDB build with
-fvisibility=hidden, as Jan suggests in Python issue 10112, as then
Python's "-Xlinker -export-dynamic" has no effect. However, that
would need to be done in the whole source tree (bfd, libiberty, etc.),
and I think that would break GCC plugins, as I believe those have
access to all of GCCs symbols, by "design". So we'd need a new
configure switch, or have the libraries in the tree detect which of
GCC or GDB is being built, but that doesn't work, because the answer
can be "both" with combined builds...
So this patch instead works around Python's bug, by simply sed'ing
away "-Xlinker -export-dynamic" from the result of python-config.py
--ldflags, making -Wl,--dynamic-list work again as it used to. It's
ugly, but so is the bug...
Note that if -Wl,--dynamic-list doesn't work, we always link with
-rdynamic, so static Python should still work.
Tested on F23 with --python=python (Python 2.7) and
--python=python3.4.
gdb/ChangeLog:y
2016-05-03 Pedro Alves <palves@redhat.com>
* configure.ac (PYTHON_LIBS): Sed away "-Xlinker -export-dynamic".
* configure: Regenerate.
The -Wl,--dynamic-list test is currently broken on Fedora 23, when you
configure with --with-python=python3.4. We see:
configure:13741: checking for the dynamic export flag
configure:13796: gcc -o conftest -g3 -O0 -fno-strict-aliasing -DNDEBUG -fwrapv -Wl,--dynamic-list=/home/pedro/gdb/mygit/src/gdb/proc-service.list conftest.c -ldl -lncurses -lm -ldl -lpthread -ldl -lutil -lm -lpython3.4m -Xlinker -export-dynamic >&5
conftest.c:182:30: fatal error: python3.4/Python.h: No such file or directory
compilation terminated.
configure:13796: $? = 1
The correct -I path is in PYTHON_CPPFLAGS:
PYTHON_CPPFLAGS='-I/usr/include/python3.4m -I/usr/include/python3.4m'
(Other Python-related tests in the file are already doing this.)
gdb/ChangeLog:
2016-05-03 Pedro Alves <palves@redhat.com>
* configure.ac (checking for the dynamic export flag): Add
$PYTHON_CPPFLAGS to CPPFLAGS.
* configure: Regenerate.
In some babeltrace versions before 1.2.0, the header file iterator.h
declares the enum values `BT_SEEK_*' within the struct declaration of
bt_iter_pos. The enum values are supposed to be globally-scoped, which
works for C, but not for C++. Later babeltrace versions declare the
enum outside the struct:
https://lists.lttng.org/pipermail/lttng-dev/2013-September/021411.html
Now that GDB is compiled with C++, the GDB build fails on a system with
an affected babeltrace version: the compiler complains about a missing
declaration of BT_SEEK_BEGIN in ctf.c.
This patch enhances the configure check to recognize such babeltrace
versions as unusable for GDB.
gdb/ChangeLog:
* configure.ac: Enhance configure check for babeltrace to reject
non-C++-enabled versions.
* configure: Regenerate.
This makes --enable-build-with-cxx be "yes" by default.
One must now configure with --enable-build-with-cxx=no in order to
build with a C compiler.
gdb/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* build-with-cxx.m4 (GDB_AC_BUILD_WITH_CXX): Default to yes.
* configure: Renegerate.
gdb/gdbserver/ChangeLog:
2016-04-20 Pedro Alves <palves@redhat.com>
* configure: Renegerate.
The ptrace args/return types detection doesn't work properly in C++
mode, on non-GNU/Linux hosts. For example, on gcc70 (NetBSD 5.1),
where the prototype is:
int ptrace(int, __pid_t, void*, int);
configure misdetects it as:
$ grep PTRACE_TYPE config.h
#define PTRACE_TYPE_ARG1 int
#define PTRACE_TYPE_ARG3 int *
#define PTRACE_TYPE_ARG4 int
/* #undef PTRACE_TYPE_ARG5 */
#define PTRACE_TYPE_RET int
resulting in:
../../src/gdb/amd64bsd-nat.c: In function 'void amd64bsd_fetch_inferior_registers(target_ops*, regcache*, int)':
../../src/gdb/amd64bsd-nat.c:56: warning: dereferencing type-punned pointer will break strict-aliasing rules
../../src/gdb/amd64bsd-nat.c: In function 'void amd64bsd_store_inferior_registers(target_ops*, regcache*, int)':
../../src/gdb/amd64bsd-nat.c:104: warning: dereferencing type-punned pointer will break strict-aliasing rules
../../src/gdb/amd64bsd-nat.c:110: warning: dereferencing type-punned pointer will break strict-aliasing rules
We could address this [1], however despite ptrace.m4's claim:
# Needs to be tested in C++ mode, to detect whether we need to cast
# the first argument to enum __ptrace_request.
it appears that there's actually no need to test in C++ mode. Always
running the ptrace tests in C mode works just the same on GNU/Linux.
I remember experimenting with several different ways to handle the
original issue back then, and maybe that was needed in some other
attempt and then I didn't realize it ended up not really necessary.
Confirmed that this fixes the NetBSD 5.1 C++ build, and confirmed that
C and C++ builds on Fedora 23 are unaffected.
[1] - https://sourceware.org/ml/gdb-patches/2016-04/msg00374.html
gdb/ChangeLog:
2016-04-18 Pedro Alves <palves@redhat.com>
* ptrace.m4 (GDB_AC_PTRACE): Don't run tests in C++ mode.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-04-18 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
Using AC_OUTPUT with arguments has been deprecated for some time in
autoconf, even in version 2.64, which we are using. This change should
not affect functionality.
I also removed the "exit 0"'s, they shouldn't be necessary.
gdb/ChangeLog:
* configure.ac: Use AC_CONFIG_FILES instead of passing arguments
to AC_OUTPUT. Remove "exit 0" at the end.
* configure: Regenerate.
gdb/testsuite/ChangeLog:
* configure.ac: Use AC_CONFIG_FILES instead of passing arguments
to AC_OUTPUT.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
* configure.ac: Use AC_CONFIG_FILES instead of passing arguments
to AC_OUTPUT.
* configure: Regenerate.
Currently, even when built with --enable-build-with-cxx, gdb uses
CFLAGS instead of CXXFLAGS. This commit fixes it.
CXXFLAGS set in the environment when configure was run is now honored
in the generated gdb/Makefile, and you can also override CXXFLAGS in
the command like at make time, with the usual 'make CXXFLAGS="..."'
Objects built with a C compiler (e.g., gnulib) still honor CFLAGS
instead.
gdb/ChangeLog:
2016-01-21 Pedro Alves <palves@redhat.com>
* Makefile.in (COMPILER_CFLAGS): New.
(CXXFLAGS): Get it from configure.
(INTERNAL_CFLAGS_BASE, INTERNAL_LDFLAGS): Use COMPILER_CFLAGS
instead of CFLAGS.
* build-with-cxx.m4 (GDB_AC_BUILD_WITH_CXX): Set and AC_SUBST
COMPILER_CFLAGS.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2016-01-21 Pedro Alves <palves@redhat.com>
* Makefile.in (COMPILER_CFLAGS, CXXFLAGS): New.
(INTERNAL_CFLAGS_BASE): Use COMPILER_CFLAGS instead of CFLAGS.
* configure: Regenerate.
Older versions of FreeBSD supported userland threading via a pure
user-space threading library (N threads scheduled on 1 process) and
a N:M model (N threads scheduled on M LWPs). However, modern FreeBSD
versions only support a M:M threading model where each user thread is
backed by a dedicated LWP. This thread target only supports this
threading model. It also uses ptrace to query and alter LWP state
directly rather than using libthread_db to simplify the implementation.
FreeBSD recently gained support for reporting LWP events (birth and death
of LWPs). GDB will use LWP events when present. For older systems it
fetches the list of LWPs in the to_update_thread_list target op to update
the list of threads on each stop.
This target supports scheduler locking by using ptrace to suspend
individual LWPs as necessary before resuming a process.
gdb/ChangeLog:
* configure.ac: Check for support for LWP names on FreeBSD.
* fbsd-nat.c [PT_LWPINFO] New variable debug_fbsd_lwp.
[TDP_RFPPWAIT || HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME]
(fbsd_fetch_kinfo_proc): Move function earlier.
[PT_LWPINFO] (fbsd_thread_alive): New function.
[PT_LWPINFO] (fbsd_pid_to_str): New function.
[HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME] (fbsd_thread_name): New function.
[PT_LWP_EVENTS] (fbsd_enable_lwp_events): New function.
[PT_LWPINFO] (fbsd_add_threads): New function.
[PT_LWPINFO] (fbsd_update_thread_list): New function.
[PT_LWPINFO] New variable super_resume.
[PT_LWPINFO] (resume_one_thread_cb): New function.
[PT_LWPINFO] (resume_all_threads_cb): New function.
[PT_LWPINFO] (fbsd_resume): New function.
(fbsd_remember_child): Save full ptid instead of plain pid.
(fbsd_is_child_pending): Return ptid of saved child process.
(fbsd_wait): Include lwp in returned ptid and switch to LWP ptid on
first stop.
[PT_LWP_EVENTS] Handle LWP events.
[TDP_RFPPWAIT] Include LWP in child ptid.
(fbsd_post_startup_inferior) [PT_LWP_EVENTS]: Enable LWP events.
(fbsd_post_attach) [PT_LWP_EVENTS]: Enable LWP events.
Add threads for existing processes.
(fbsd_nat_add_target) [PT_LWPINFO]: Set "to_thread_alive" to
"fbsd_thread_alive".
Set "to_pid_to_str" to "fbsd_pid_to_str".
[HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME]: Set "to_thread_name" to
"fbsd_thread_name".
[PT_LWPINFO]: Set "to_update_thread_list" to "fbsd_update_thread_list".
Set "to_has_thread_control" to "tc_schedlock".
Set "to_resume" to "fbsd_resume".
(_initialize_fbsd_nat): New function.
* configure: Regenerate.
* config.in: Regenerate.
gdb/doc/ChangeLog:
* gdb.texinfo (Debugging Output): Document "set/show debug fbsd-lwp".
Include <sys/types.h> as a prerequisite for <machine/reg.h> when checking
for the r_fs and r_gs members in struct reg. Note that the previous test
for <machine/reg.h> already includes <sys/types.h> as a prerequisite.
gdb/ChangeLog:
* configure.ac: Include <sys/types.h when checking for "r_fs" in
"struct reg".
* configure: Regenerate.
The GNU Coding Standards say:
"Please do not include any trademark acknowledgements in GNU
software packages or documentation."
gdb/ChangeLog:
2016-01-12 Pedro Alves <palves@redhat.com>
Remove use of the registered trademark symbol throughout.
gdb/gdbserver/ChangeLog:
2016-01-12 Pedro Alves <palves@redhat.com>
Remove use of the registered trademark symbol throughout.
gdb/doc/ChangeLog:
2016-01-12 Pedro Alves <palves@redhat.com>
Remove use of the registered trademark symbol throughout.
Multitarget builds currently fail when:
(1) simulator support is enabled (the main --target supports target sim)
(2) powerpc is included in the --enable-targets list
(3) powerpc is not the main/default target (--target)
This is because the powerpc sim provides a non-standard API function
sim_spr_register_name which gdb/rs6000-tdep.c utilizes. Since the sim
does not yet support multitarget, only the sim (if one exists) for the
main target is built. When that target isn't powerpc, this function
is not available leading to linking errors:
rs6000-tdep.c:(.text+0x1e34d): undefined reference to
`sim_spr_register_name'
Fix this by only using that API if the sim linked in is the powerpc
sim.
gdb/ChangeLog:
2016-01-05 Pedro Alves <palves@redhat.com>
PR sim/13418
* configure.ac: Define WITH_PPC_SIM when linking in the sim and
the target is powerpc*.
* configure: Regenerate.
* config.in: Regenerate.
Since we now rely on PTRACE_EVENT_CLONE being available (added in
Linux 2.5.46), we're relying on NPTL.
This commit removes the support for older LinuxThreads, as well as the
workarounds for vendor 2.4 kernels with NPTL backported.
- Rely on tkill being available.
- Assume gdb doesn't get cancel signals.
- Remove code that checks the LinuxThreads restart and cancel signals
in the inferior.
- Assume that __WALL is available.
- Assume that non-leader threads report WIFEXITED.
- Thus, no longer need to send signal 0 to check whether threads are
still alive.
- Update comments throughout.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/ChangeLog:
* configure.ac: Remove tkill checks.
* configure, config.in: Regenerate.
* linux-nat.c: Remove HAVE_TKILL_SYSCALL check. Update top level
comments.
(linux_nat_post_attach_wait): Remove 'cloned' parameter. Use
__WALL.
(attach_proc_task_lwp_callback): Don't set the cloned flag.
(linux_nat_attach): Adjust.
(kill_lwp): Remove HAVE_TKILL_SYSCALL check. No longer fall back
to 'kill'.
(linux_handle_extended_wait): Use __WALL. Don't set the cloned
flag.
(wait_lwp): Use __WALL. Update comments.
(running_callback, stop_and_resume_callback): Delete.
(linux_nat_filter_event): Don't stop and resume all lwps. Don't
check if the event LWP has previously exited.
(check_zombie_leaders): Update comments.
(linux_nat_wait_1): Use __WALL.
(kill_wait_callback): Don't handle clone processes separately.
Use __WALL instead.
(linux_thread_alive): Delete.
(linux_nat_thread_alive): Return true as long as the LWP is in the
LWP list.
(linux_nat_update_thread_list): Assume the kernel supports
PTRACE_EVENT_CLONE.
(get_signo): Delete.
(lin_thread_get_thread_signals): Remove LinuxThreads references.
No longer check __pthread_sig_restart / __pthread_sig_cancel in
the inferior.
* linux-nat.h (struct lwp_info) <cloned>: Delete field.
* linux-thread-db.c: Update comments.
(_initialize_thread_db): Remove LinuxThreads references.
* nat/linux-waitpid.c (my_waitpid): No longer emulate __WALL.
Pass down flags unmodified.
* linux-waitpid.h (my_waitpid): Update documentation.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_kill_one_lwp): Remove references to
LinuxThreads.
(kill_lwp): Remove HAVE_TKILL_SYSCALL check. No longer fall back
to 'kill'.
(linux_init_signals): Delete.
(initialize_low): Adjust.
* thread-db.c (thread_db_init): Remove LinuxThreads reference.
Ref: https://sourceware.org/ml/gdb/2015-12/msg00024.html
We have code in configure.ac that tries to detect whether the compiler
supports each warning and suppress it if not, but that doesn't work
with "-Wno-" options, because gcc doesn't error out for
-Wno-unknown-warning unless other diagnostics are being produced.
See https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html.
Handle this by checking whether -Wfoo works when we actually want
-Wno-foo.
gdb/ChangeLog:
2015-12-16 Pedro Alves <palves@redhat.com>
* configure.ac (compiler warning flags): When testing a
-Wno-foo option, check whether -Wfoo works instead.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2015-12-16 Pedro Alves <palves@redhat.com>
* configure.ac (compiler warning flags): When testing a
-Wno-foo option, check whether -Wfoo works instead.
* configure: Regenerate.
Both x86_64 GNU/Linux and x86_64 mingw-w64 build cleanly with
--enable-targets=all. This enables -Werror by default in C++ mode
too, in order to let the buildbot catch C++ build regressions for us.
gdb/ChangeLog:
2015-11-19 Pedro Alves <palves@redhat.com>
* configure.ac (ERROR_ON_WARNING): Don't check whether in C++
mode.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2015-11-19 Pedro Alves <palves@redhat.com>
* configure.ac (ERROR_ON_WARNING): Don't check whether in C++
mode.
* configure: Regenerate.
Both x86_64 GNU/Linux and x86_64 mingw-w64 build cleanly with
--enable-targets=all. Let's drop the -fpermissive hack, in order to
let the buildbot catch C++ build regressions for us.
gdb/ChangeLog:
2015-11-19 Pedro Alves <palves@redhat.com>
* build-with-cxx.m4 (GDB_AC_BUILD_WITH_CXX): Remove -fpermissive.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2015-11-19 Pedro Alves <palves@redhat.com>
* configure: Regenerate.
Since we're using sighandler_t, nothing else refers to RETSIGTYPE in
gdb.
(Actually, given gdb/remote.c has been assuming signal handlers return
void for a long time, we could have gotten get rid of this even
without gnulib's sighandler_t.)
gdb/ChangeLog:
2015-08-27 Pedro Alves <palves@redhat.com>
* configure.ac: Remove AC_TYPE_SIGNAL call.
* configure, config.in: Regenerate.
Intel(R) Processor Trace support requires a recent linux/perf_event.h header.
When GDB is built on an older system, Intel(R) Processor Trace will not be
available and there is no indication in the configure and build log as to
what went wrong.
Check for a compatible linux/perf_event.h at configure-time.
gdb/
* configure.ac: Check for PERF_ATTR_SIZE_VER5 in linux/perf_event.h
* configure: Regenerate.
Building in C++ mode issues ~40 warnings like this:
../../src/gdb/linux-nat.c: In function ‘int linux_handle_extended_wait(lwp_info*, int, int)’:
../../src/gdb/linux-nat.c:2016:51: warning: invalid conversion from ‘int’ to ‘__ptrace_request’ [-fpermissive]
ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid);
The issue is that in glibc, ptrace's first parameter is an enum.
That's not a problem if we pick the PTRACE_XXX requests from
sys/ptrace.h, as those will be values of the corresponding enum.
However, we have fallback definitions for PTRACE_XXX symbols when the
system headers miss them (such as PTRACE_GETEVENTMSG above), and those
are plain integer constants. E.g., nat/linux-ptrace.h:
#define PTRACE_GETEVENTMSG 0x4201
One idea would be to fix this by defining those fallbacks like:
-#define PTRACE_GETEVENTMSG 0x4201
+#define PTRACE_GETEVENTMSG ((enum __ptrace_request) 0x4201)
However, while glibc's ptrace uses enum __ptrace_request for first
parameter:
extern long int ptrace (enum __ptrace_request __request, ...) __THROW;
other libc's, like e.g., Android's bionic do not -- in that case, the
first parameter is int:
long ptrace(int request, pid_t pid, void * addr, void * data);
So the fix I came up is to make configure/ptrace.m4 also detect the
type of the ptrace's first parameter and defin PTRACE_TYPE_ARG1, as
already does the for parameters 3-4, and then simply wrap ptrace with
a macro that casts the first argument to the detected type. (I'm
leaving adding a nicer wrapper for when we drop building in C).
While this adds the wrapper, GNU/Linux files won't use it until the
next patch, which makes all native GNU/Linux files include
gdb_ptrace.h.
gdb/ChangeLog:
2015-07-24 Pedro Alves <palves@redhat.com>
* ptrace.m4 (ptrace tests): Test in C++ mode. Try with 'enum
__ptrace_request as first parameter type instead of int.
(PTRACE_TYPE_ARG1): Define.
* nat/gdb_ptrace.h [!PTRACE_TYPE_ARG5] (ptrace): Define as wrapper
that casts first argument to PTRACE_TYPE_ARG1.
* config.in: Regenerate.
* configure: Regenerate.
gdb/gdbserver/ChangeLog:
2015-07-24 Pedro Alves <palves@redhat.com>
* config.in: Regenerate.
* configure: Regenerate.
Later patches need regex support also in gdbserver.
gdb/ChangeLog
2015-07-15 Jan Kratochvil <jan.kratochvil@redhat.com>
* Makefile.in (HFILES_NO_SRCDIR): Change gdb_regex.h to
common/gdb_regex.h.
(COMMON_OBS): Add gdb_regex.o.
(gdb_regex.o): New.
* common/common.m4 (GDB_AC_COMMON): Add gdb_use_included_regex,
--without-included-regex and USE_INCLUDED_REGEX.
* common/gdb_regex.c: New file from utils.c functions.
* common/gdb_regex.h: Move it here from gdb_regex.h, update include
file wrapping define name.
* configure: Rebuilt.
* configure.ac (gdb_use_included_regex, --without-included-regex)
(USE_INCLUDED_REGEX): Move them to common/common.m4.
* gdb_regex.h: Move it to common/gdb_regex.h.
* utils.c: Remove include gdb_regex.h.
(do_regfree_cleanup, make_regfree_cleanup, get_regcomp_error)
(compile_rx_or_error): Move them to common/gdb_regex.c.
gdb/gdbserver/ChangeLog
2015-07-15 Jan Kratochvil <jan.kratochvil@redhat.com>
* Makefile.in (OBS): Add gdb_regex.o.
(gdb_regex.o): New.
* config.in: Rebuilt.
* configure: Rebuilt.
Check for libipt, an Intel(R) Processor Trace decoder library. The sources
can be found on github at:
https://github.com/01org/processor-trace
gdb/
* configure.ac: Check for libipt
* configure: Regenerate.
* config.in: Regenerate.
* Makefile.in (LIBIPT): New.
(CLIBS): Add $LIBIPT.
* NEWS: document new configure options
Currently building gdb is impossible without an installed termcap or
curses library. But, GDB already has a very minimal termcap in the
tree to handle this situation for Windows -- gdb/stub-termcap.c. This
patch makes that the fallback for all hosts.
Testing this on GNU/Linux (by simply hacking away the termcap/curses
detection in gdb/configure.ac), we trip on:
../readline/libreadline.a(terminal.o): In function `_rl_init_terminal_io':
/home/pedro/gdb/mygit/src/readline/terminal.c:527: undefined reference to `PC'
/home/pedro/gdb/mygit/src/readline/terminal.c:528: undefined reference to `BC'
/home/pedro/gdb/mygit/src/readline/terminal.c:529: undefined reference to `UP'
/home/pedro/gdb/mygit/src/readline/terminal.c:538: undefined reference to `PC'
/home/pedro/gdb/mygit/src/readline/terminal.c:539: undefined reference to `BC'
/home/pedro/gdb/mygit/src/readline/terminal.c:540: undefined reference to `UP'
These are globals that are normally defined by termcap (or ncurses'
termcap emulation).
Now, we could just define replacements in stub-termcap.c, but
readline/terminal.c (at least the copy in our tree) has this:
#if !defined (__linux__) && !defined (NCURSES_VERSION)
# if defined (__EMX__) || defined (NEED_EXTERN_PC)
extern
# endif /* __EMX__ || NEED_EXTERN_PC */
char PC, *BC, *UP;
#endif /* !__linux__ && !NCURSES_VERSION */
which can result in readline defining the globals too. That will
usually work out in C, given that "-fcommon" is usually the default
for C compilers, but that won't work for C++, or C with -fno-common
(link fails with "multiple definition" errors)...
Mirroring those #ifdef conditions in the stub termcap screams
"brittle" to me -- I can see them changing in latter readline
versions.
Work around that by simply using __attribute__((weak)).
Windows/PE/COFF's do support weak, but not on gcc 3.4 based toolchains
(4.8.x does work). Given the file never needed the variables while it
was Windows-only, just continue not defining them there. All other
supported hosts should support this.
gdb/ChangeLog:
2015-04-06 Pedro Alves <palves@redhat.com>
Bernd Edlinger <bernd.edlinger@hotmail.de>
* configure.ac: Remove the mingw32-specific stub-termcap.o
fallback, and instead fallback to the stub termcap on all hosts.
* configure: Regenerate.
* stub-termcap.c [!__MINGW32__] (PC, BC, UP): Define as weak
symbols.
Simon Marchi
Markus Metzger
Pedro Alves
Sergio Durigan Junior
Ambrogino Modigliani
Simon Marchi
Maciej W. Rozycki
Gabriel Krisman Bertazi
Tom Tromey
Jan Kratochvil
John Baldwin
Jon Boden
Andreas Arnez
Mike Frysinger
DJ Delorie
Gary Benson
H.J. Lu