One part of PR cli/19551 is that the mini debug info objfile reuses the
name of the main objfile from which it comes. This can be seen because
gdb claims to be reading symbols from the same file two times, like:
Reading symbols from /bin/gdb...Reading symbols from /bin/gdb...(no debugging symbols found)...done.
I think this would be less confusing if the minidebug objfile were given
a different name. That is what this patch implements. It also arranges
for the minidebug objfile to be marked OBJF_NOT_FILENAME.
After this patch the output looks like:
Reading symbols from /bin/gdb...Reading symbols from .gnu_debugdata for /usr/libexec/gdb...(no debugging symbols found)...done.
Tested by the buildbot.
gdb/ChangeLog
2018-05-16 Tom Tromey <tom@tromey.com>
PR cli/19551:
* symfile-add-flags.h (enum symfile_add_flags)
<SYMFILE_NOT_FILENAME>: New constant.
* symfile.c (read_symbols): Use SYMFILE_NOT_FILENAME. Get
objfile name from BFD.
(symbol_file_add_with_addrs): Check SYMFILE_NOT_FILENAME.
* minidebug.c (find_separate_debug_file_in_section): Put
".gnu_debugdata" into BFD's file name.
This patch if the first patch in a series to add the ability to add constraints
to system registers that an instruction must adhere to in order for the register
to be usable with that instruction.
These constraints can also be used to disambiguate between registers with the
same encoding during disassembly.
This patch adds a new flags entry in the sysreg structures and ensures it is
filled in and read out during assembly/disassembly. It also adds the ability for
the assemble and disassemble functions to be able to gracefully fail and re-use
the existing error reporting infrastructure.
The return type of these functions are changed to a boolean to denote success or
failure and the error structure is passed around to them. This requires
aarch64-gen changes so a lot of the changes here are just mechanical.
gas/
PR binutils/21446
* config/tc-aarch64.c (parse_sys_reg): Return register flags.
(parse_operands): Fill in register flags.
gdb/
PR binutils/21446
* aarch64-tdep.c (aarch64_analyze_prologue,
aarch64_software_single_step, aarch64_displaced_step_copy_insn):
Indicate not interested in errors.
include/
PR binutils/21446
* opcode/aarch64.h (aarch64_opnd_info): Change sysreg to struct.
(aarch64_decode_insn): Accept error struct.
opcodes/
PR binutils/21446
* aarch64-asm.h (aarch64_insert_operand, aarch64_##x): Return boolean
and take error struct.
* aarch64-asm.c (aarch64_ext_regno, aarch64_ins_reglane,
aarch64_ins_reglist, aarch64_ins_ldst_reglist,
aarch64_ins_ldst_reglist_r, aarch64_ins_ldst_elemlist,
aarch64_ins_advsimd_imm_shift, aarch64_ins_imm, aarch64_ins_imm_half,
aarch64_ins_advsimd_imm_modified, aarch64_ins_fpimm,
aarch64_ins_imm_rotate1, aarch64_ins_imm_rotate2, aarch64_ins_fbits,
aarch64_ins_aimm, aarch64_ins_limm_1, aarch64_ins_limm,
aarch64_ins_inv_limm, aarch64_ins_ft, aarch64_ins_addr_simple,
aarch64_ins_addr_regoff, aarch64_ins_addr_offset, aarch64_ins_addr_simm,
aarch64_ins_addr_simm10, aarch64_ins_addr_uimm12,
aarch64_ins_simd_addr_post, aarch64_ins_cond, aarch64_ins_sysreg,
aarch64_ins_pstatefield, aarch64_ins_sysins_op, aarch64_ins_barrier,
aarch64_ins_prfop, aarch64_ins_hint, aarch64_ins_reg_extended,
aarch64_ins_reg_shifted, aarch64_ins_sve_addr_ri_s4xvl,
aarch64_ins_sve_addr_ri_s6xvl, aarch64_ins_sve_addr_ri_s9xvl,
aarch64_ins_sve_addr_ri_s4, aarch64_ins_sve_addr_ri_u6,
aarch64_ins_sve_addr_rr_lsl, aarch64_ins_sve_addr_rz_xtw,
aarch64_ins_sve_addr_zi_u5, aarch64_ext_sve_addr_zz,
aarch64_ins_sve_addr_zz_lsl, aarch64_ins_sve_addr_zz_sxtw,
aarch64_ins_sve_addr_zz_uxtw, aarch64_ins_sve_aimm,
aarch64_ins_sve_asimm, aarch64_ins_sve_index, aarch64_ins_sve_limm_mov,
aarch64_ins_sve_quad_index, aarch64_ins_sve_reglist,
aarch64_ins_sve_scale, aarch64_ins_sve_shlimm, aarch64_ins_sve_shrimm,
aarch64_ins_sve_float_half_one, aarch64_ins_sve_float_half_two,
aarch64_ins_sve_float_zero_one, aarch64_opcode_encode): Likewise.
* aarch64-dis.h (aarch64_extract_operand, aarch64_##x): Likewise.
* aarch64-dis.c (aarch64_ext_regno, aarch64_ext_reglane,
aarch64_ext_reglist, aarch64_ext_ldst_reglist,
aarch64_ext_ldst_reglist_r, aarch64_ext_ldst_elemlist,
aarch64_ext_advsimd_imm_shift, aarch64_ext_imm, aarch64_ext_imm_half,
aarch64_ext_advsimd_imm_modified, aarch64_ext_fpimm,
aarch64_ext_imm_rotate1, aarch64_ext_imm_rotate2, aarch64_ext_fbits,
aarch64_ext_aimm, aarch64_ext_limm_1, aarch64_ext_limm, decode_limm,
aarch64_ext_inv_limm, aarch64_ext_ft, aarch64_ext_addr_simple,
aarch64_ext_addr_regoff, aarch64_ext_addr_offset, aarch64_ext_addr_simm,
aarch64_ext_addr_simm10, aarch64_ext_addr_uimm12,
aarch64_ext_simd_addr_post, aarch64_ext_cond, aarch64_ext_sysreg,
aarch64_ext_pstatefield, aarch64_ext_sysins_op, aarch64_ext_barrier,
aarch64_ext_prfop, aarch64_ext_hint, aarch64_ext_reg_extended,
aarch64_ext_reg_shifted, aarch64_ext_sve_addr_ri_s4xvl,
aarch64_ext_sve_addr_ri_s6xvl, aarch64_ext_sve_addr_ri_s9xvl,
aarch64_ext_sve_addr_ri_s4, aarch64_ext_sve_addr_ri_u6,
aarch64_ext_sve_addr_rr_lsl, aarch64_ext_sve_addr_rz_xtw,
aarch64_ext_sve_addr_zi_u5, aarch64_ext_sve_addr_zz,
aarch64_ext_sve_addr_zz_lsl, aarch64_ext_sve_addr_zz_sxtw,
aarch64_ext_sve_addr_zz_uxtw, aarch64_ext_sve_aimm,
aarch64_ext_sve_asimm, aarch64_ext_sve_index, aarch64_ext_sve_limm_mov,
aarch64_ext_sve_quad_index, aarch64_ext_sve_reglist,
aarch64_ext_sve_scale, aarch64_ext_sve_shlimm, aarch64_ext_sve_shrimm,
aarch64_ext_sve_float_half_one, aarch64_ext_sve_float_half_two,
aarch64_ext_sve_float_zero_one, aarch64_opcode_decode): Likewise.
(determine_disassembling_preference, aarch64_decode_insn,
print_insn_aarch64_word, print_insn_data): Take errors struct.
(print_insn_aarch64): Use errors.
* aarch64-asm-2.c: Regenerate.
* aarch64-dis-2.c: Regenerate.
* aarch64-gen.c (print_operand_inserter): Use errors and change type to
boolean in aarch64_insert_operan.
(print_operand_extractor): Likewise.
* aarch64-opc.c (aarch64_print_operand): Use sysreg struct.
With native MIPS/Linux targets the $zero register is inaccessible, with
its supposed context slot provided by the OS occupied by the $restart
register. The PTRACE_GETREGS path takes care of it by artificially
supplying the hardwired contents of $zero in `mips_supply_gregset' or
`mips64_supply_gregset', as applicable, however the PTRACE_PEEKUSER
fallback does not, making the register unavailable, e.g.:
(gdb) info registers
zero at v0 v1 a0 a1 a2 a3
R0 <unavl> 00000001 00000001 d2f1a9fc 00000000 00000000 00417158 00417150
t0 t1 t2 t3 t4 t5 t6 t7
R8 00000004 00000000 fffffff8 00000000 00000000 00000000 00000001 00000007
s0 s1 s2 s3 s4 s5 s6 s7
R16 00000000 00405e30 00000000 00500000 00000000 0052ec08 00000000 00000000
t8 t9 k0 k1 gp sp s8 ra
R24 00000000 00417008 00000000 00000000 0041e220 7fff4ce0 7fff4ce0 00405d0c
status lo hi badvaddr cause pc
<unavl> 00441cf1 00000017 00417004 00800024 00405d10
fcsr fir restart
00800000 00f30000 00000000
(gdb)
or (under certain circumstances):
(gdb) stepi
Register 0 is not available
(gdb)
This is specifically because `mips_linux_register_addr' and
`mips64_linux_register_addr', both correctly return -1 for
MIPS_ZERO_REGNUM, and therefore `linux_nat_trad_target::fetch_registers'
faithfully marks this register as unavailable.
Supply this register artificially then in the PTRACE_PEEKUSER case as
well, correcting this issue.
gdb/
* mips-linux-nat.c (mips_linux_nat_target::fetch_registers):
Supply the MIPS_ZERO_REGNUM register.
Make the `mask_address_var' variable static, it is not used outside
mips-tdep.c and having no target name embedded within it causes a risk
of a namespace clash.
gdb/
* mips-tdep.c (mask_address_var): Make variable static.
Fix a commit f90183d7e3 ("Get GDBserver pid on remote target") bug and
correctly handle the case where the PID of `gdbserver' could not have
been retrieved. If that happens, $server_pid is unset causing:
FAIL: gdb.server/server-kill.exp: p server_pid
ERROR: tcl error sourcing .../gdb/testsuite/gdb.server/server-kill.exp.
ERROR: can't read "server_pid": no such variable
while executing
"if {$server_pid == "" } {
return -1
}"
(file ".../gdb/testsuite/gdb.server/server-kill.exp" line 49)
invoked from within
"source .../gdb/testsuite/gdb.server/server-kill.exp"
("uplevel" body line 1)
invoked from within
"uplevel #0 source .../gdb/testsuite/gdb.server/server-kill.exp"
invoked from within
"catch "uplevel #0 source $test_file_name""
Verify that the variable exists then rather than trying to access it.
gdb/testsuite/
* gdb.server/server-kill.exp: Verify whether `server_pid' exists
rather then trying to access it in determining whether the PID
of `gdbserver' could have been retrieved.
It turns out that a dwarf2_cu can remain allocated after psymtab
expansion is done, and so it makes sense to clear rust_unions when
done processing it.
Tested on x86-64 Fedora 27.
2018-05-14 Tom Tromey <tom@tromey.com>
* dwarf2read.c (rust_union_quirks): Clear rust_unions.
In commit:
commit 8ee22052f6
Author: Andrew Burgess <andrew.burgess@embecosm.com>
Date: Thu May 3 17:46:14 2018 +0100
gdb/x86: Handle kernels using compact xsave format
in two places FXSAVE_ADDR was used instead of FXSAVE_MXCSR_ADDR to get
the address of the mxcsr register within the xsave buffer. This will
mean we are potentially accessing the wrong location within the xsave
buffer.
There are no tests included with this patch. The first mistake would
only trigger an issue if/when the user tries to manually set the mxcsr
register to a value that matches the random (value off stack) value
that is in the xsave buffer, in this case the change by the user will
go unnoticed by GDB, and the default value of mxcsr will be preserved.
The second mistake only happens on the code path where all x87
registers are being written out of the register cache. I'm not sure
how to trigger that code path.
gdb/ChangeLog:
* i387-tdep.c (i387_collect_xsave): Use FXSAVE_MXCSR_ADDR not
FXSAVE_ADDR for the mxcsr register.
gdb_target definitions were removed from configure.tgt in 2007, before
xtensa port was merged. Remove it from the xtensa target as well.
gdb/
2018-05-11 Max Filippov <jcmvbkbc@gmail.com>
* configure.tgt (xtensa*-*-linux*): Drop gdb_target definition.
This gets rid of the core_ops global, and replaces it with
heap-allocated core_target instances. In practice, there will only be
one such instance, though that will change further ahead as more
pieces of multi-target support are merged.
Notice that this replaces one heap-allocated object for another, the
number of allocations is the same. Specifically, currently we
heap-allocate the 'core_data' object, which holds the core's section
table. With this patch, that object is made a field of the
core_target class, and no longer allocated separately.
Note that this bit:
- /* Looks semi-reasonable. Toss the old core file and work on the
- new. */
-
- unpush_target (&core_ops);
does not need a replacement, because by the time we get here, the
target_preopen call at the top of core_target_open has already
unpushed any previous target.
gdb/ChangeLog:
2018-05-11 Pedro Alves <palves@redhat.com>
* corelow.c (core_target) <core_target>: No longer inline.
Initialize m_core_gdbarch, m_core_vec and build the section table
here.
<~core_target>: New.
<core_gdbarch, get_core_register_section>: New methods.
<m_core_section_table, m_core_vec, m_core_gdbarch>: New fields,
factored out from ...
<core_data, core_vec, core_gdbarch>: ... these deleted globals.
(core_ops): Delete.
(sniff_core_bfd): Add gdbarch parameter.
(core_close): Delete, merged into ...
(core_target::close): ... here. Delete self.
(core_close_cleanup): Delete.
(core_target_open): Allocate a core_target on the heap. Use a
unique_ptr instead of a cleanup. Bits moved into the core_target
ctor. Adjust to use core_target methods instead of globals.
(get_core_register_section): Rename to ...
(core_target::get_core_register_section): ... this and adjust.
(struct get_core_registers_cb_data): New.
(get_core_registers_cb): Use it. Use bool.
(core_target::fetch_registers, core_target::files_info)
(core_target::xfer_partial, core_target::read_description)
(core_target::pid_to, core_target::thread_name): Adjust to
reference class fields instead of globals.
* target.h (struct target_ops_deleter, target_ops_up): New.
(previously called 'core_target', but since renamed because
'core_target' is the name of the target_ops class now.)
This eliminates the "the_core_target" global, as preparation for being
able to have more than one core loaded. When we get there, we will
instantiate one core_target object per core instead.
Essentially, this replaces the reference to the_core_target in
core_file_command by a reference to core_bfd, which is per
program_space.
Currently, core_file_command calls 'the_core_target->detach()' even if
the core target is not open and pushed on the target stack. If it is
indeed not open, then the practical effect is that
core_target::detach() prints "No core file now.". That is preserved
by printing that directly from within core_file_command if not
debugging a core.
gdb/ChangeLog:
2018-05-11 Pedro Alves <palves@redhat.com>
* corefile.c (core_file_command): Move to corelow.c.
* corelow.c (the_core_target): Delete.
(core_file_command): Moved from corefile.c. Check exec_bfd
instead of the_core_target. Use target_detach instead of calling
into the_core_target directly.
(maybe_say_no_core_file_now): New.
(core_target::detach): Use it.
(_initialize_corelow): Remove references to the_core_target.
* gdbcore.h (the_core_target): Delete.
This moves the core_bfd global to be a field of the program space. It
then replaces core_bfd with a macro to avoid a massive patch -- the
same approach taken for various other program space fields.
This is a basic transformation for multi-target work.
2018-05-11 Tom Tromey <tromey@redhat.com>
Pedro Alves <tromey@redhat.com>
* corefile.c (core_bfd): Remove.
* gdbcore.h (core_bfd): Now a macro.
* progspace.h (struct program_space) <cbfd>: New field.
This removes the remaining cleanups from mdebugread.c, replacing them
with gdb::def_vector.
Tested by the buildbot, though I doubt this exercises mdebugread.
gdb/ChangeLog
2018-05-11 Tom Tromey <tom@tromey.com>
* mdebugread.c (parse_partial_symbols, psymtab_to_symtab_1): Use
gdb::def_vector.
The floating point context structure on x86 LynxOS-178 is not
the same as on LynxOS 5.x. As a consequence, trying to print
the return value of a function returning a float, for instance,
yields incorrect results.
This patch fixes the issue by providing an updated definition
for LynxOS-178 (the reason why we cannot access the actual definition
provided by the system still remains true).
gdb/gdbserver/ChangeLog:
* lynx-i386-low.c (LYNXOS_178): New macro.
[LYNXOS_178] (usr_fcontext_t): Provide a definition that matches
the layout on LynxOS-178.
(lynx_i386_fill_fpregset, lynx_i386_store_fpregset): Do not
handle floating point registers that are not supported by
LynxOS-178.
Simon pointed out that gdb would not build with clang, due to the
addition of -Wimplicit-fallthrough. This patch fixes the problem by
using -Wimplicit-fallthrough=3 -- this does not work with clang,
bypassing the issue.
Tested by rebuilding with both gcc and clang; and also by verifying
that -Wimplicit-fallthrough=3 is used in the gcc build.
I will file a follow-up bug to convert the fall-through comments to a
form that can be used by both clang and gcc.
gdb/ChangeLog
2018-05-10 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* warning.m4 (AM_GDB_WARNINGS): Use -Wimplicit-fallthrough=3.
gdb/gdbserver/ChangeLog
2018-05-10 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
On Windows, starting a new process with GDBserver seems to work,
in the sense that the program does get started, and GDBserver
confirms that it is listening for GDB to connect. However, as soon as
GDB establishes the connection with GDBserver, and starts discussing
with it, GDBserver crashes, with a SEGV.
This SEGV occurs in remote-utils.c::prepare_resume_reply...
| regp = current_target_desc ()->expedite_regs;
| [...]
| while (*regp)
... because, in our case, REGP is NULL.
This patches fixes the issues by adding a parameter to init_target_desc,
in order to make sure that we always provide the list of registers when
we initialize a target description.
gdb/ChangeLog:
PR server/23158:
* regformats/regdat.sh: Adjust script, following the addition
of the new expedite_regs parameter to init_target_desc.
gdb/gdbserver/ChangeLog:
PR server/23158:
* tdesc.h (init_target_desc) <expedite_regs>: New parameter.
* tdesc.c (init_target_desc) <expedite_regs>: New parameter.
Use it to set the expedite_regs field in the given tdesc.
* x86-tdesc.h: New file.
* linux-aarch64-tdesc.c (aarch64_linux_read_description):
Adjust following the addition of the new expedite_regs parameter
to init_target_desc.
* linux-tic6x-low.c (tic6x_read_description): Likewise.
* linux-x86-tdesc.c: #include "x86-tdesc.h".
(i386_linux_read_description, amd64_linux_read_description):
Adjust following the addition of the new expedite_regs parameter
to init_target_desc.
* lynx-i386-low.c: #include "x86-tdesc.h".
(lynx_i386_arch_setup): Adjust following the addition of the new
expedite_regs parameter to init_target_desc.
* nto-x86-low.c: #include "x86-tdesc.h".
(nto_x86_arch_setup): Adjust following the addition of the new
expedite_regs parameter to init_target_desc.
* win32-i386-low.c: #include "x86-tdesc.h".
(i386_arch_setup): Adjust following the addition of the new
expedite_regs parameter to init_target_desc.
Trying to start a program with GDBserver on Windows yields
the following error:
$ gdbserver.exe --once :4444 simple_main.exe
Killing process(es): 5008
No program to debug
Exiting
The error itself comes from the following code shortly after
create_inferior gets called (in server.c::main):
/* Wait till we are at first instruction in program. */
create_inferior (program_path.get (), program_args);
[...]
if (last_status.kind == TARGET_WAITKIND_EXITED
|| last_status.kind == TARGET_WAITKIND_SIGNALLED)
was_running = 0;
else
was_running = 1;
if (!was_running && !multi_mode)
error ("No program to debug");
What happens is that the "last_status" global starts initialized
as zeroes, which means last_status.kind == TARGET_WAITKIND_EXITED,
and we expect create_inferior to be waiting for the inferior to
start until reaching the SIGTRAP, and to set the "last_status"
global to match that last event we received.
I suspect this is an unintended side-effect of the following change...
commit 2090129c36
Date: Thu Dec 22 21:11:11 2016 -0500
Subject: Share fork_inferior et al with gdbserver
... which removes some code in server.c that was responsible for
starting the inferior in a functin that was named start_inferior,
and looked like this:
signal_pid = create_inferior (new_argv[0], &new_argv[0]);
[...]
/* Wait till we are at 1st instruction in program, return new pid
(assuming success). */
last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
The code has been transitioned to using fork_inferior, but sadly,
only for the targets that support it. On Windows, the calls to wait
setting "last_status" simply disappeared.
This patch adds it back in the Windows-specific implementation of
create_inferior.
gdb/gdbserver/ChangeLog:
PR server/23158:
* win32-low.c (win32_create_inferior): Add call to my_wait
setting last_status global.
Trying to start GDBserver on Windows currently yields the following
error...
$ gdbserver.exe --once :4444 simple_main.exe
glob could not process pattern '(null)'.
Exiting
... after which GDB terminates with a nonzero status.
This is because create_process in win32-low.c calls gdb_tilde_expand
with the result of a call to get_inferior_cwd without verifying that
the returned directory is not NULL:
| static BOOL
| create_process (const char *program, char *args,
| DWORD flags, PROCESS_INFORMATION *pi)
| {
| const char *inferior_cwd = get_inferior_cwd ();
| std::string expanded_infcwd = gdb_tilde_expand (inferior_cwd);
This patch avoids this by only calling gdb_tilde_expand when
INFERIOR_CWD is not NULL, which is similar to what is done on
GNU/Linux for instance.
gdb/gdbserver/ChangeLog:
PR server/23158:
* win32-low.c (create_process): Only call gdb_tilde_expand if
inferior_cwd is not NULL.
This patch fixes tagged pointer support for AArch64 GDB. Linux kernel
debugging failure was reported after tagged pointer support was committed.
After a discussion around best path forward to manage tagged pointers
on GDB side we are going to disable tagged pointers support for
aarch64-none-elf-gdb because for non-linux applications we cant be
sure if tagged pointers will be used by MMU or not.
Also for aarch64-linux-gdb we are going to sign extend user-space
address after clearing tag bits. This will help debug both kernel
and user-space addresses based on information from linux kernel
documentation given below:
According to AArch64 memory map:
https://www.kernel.org/doc/Documentation/arm64/memory.txt
"User addresses have bits 63:48 set to 0 while the kernel addresses have
the same bits set to 1."
According to AArch64 tagged pointers document:
https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt
The kernel configures the translation tables so that translations made
via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of
the virtual address ignored by the translation hardware. This frees up
this byte for application use.
Running gdb testsuite after applying this patch introduces no regressions
and tagged pointer test cases still pass.
gdb/ChangeLog:
2018-05-10 Omair Javaid <omair.javaid@linaro.org>
PR gdb/23127
* aarch64-linux-tdep.c (aarch64_linux_init_abi): Add call to
set_gdbarch_significant_addr_bit.
* aarch64-tdep.c (aarch64_gdbarch_init): Remove call to
set_gdbarch_significant_addr_bit.
* utils.c (address_significant): Update to sign extend addr.
xtensa GDB may be used with both bare-metal and linux-based
applications. In case of bare-metal application gdbserver is able to
provide information about all CPU registers: both unprivileged and
privileged. In case of linux-based application only a small subset of
privileged state is available. Currently xtensa GDB only expects
unprivileged registers in 'g' packets and it fails to communicate with
server that sends both privileged and unprivileged registers.
Allow bare-metal xtensa GDB to deal with both privileged and
unprivileged registers by initializing tdep->num_regs with the total
number of target CPU registers. Keep linux-based xtensa GDB
functionality as is by copying tdep->num_nopriv_regs to tdep->num_regs.
gdb/
2018-05-09 Max Filippov <jcmvbkbc@gmail.com>
* xtensa-linux-tdep.c (xtensa-tdep.h): New include.
(xtensa_linux_init_abi): Limit tdep->num_regs by
tdep->num_nopriv_regs.
* xtensa-tdep.c (xtensa_derive_tdep): Calculate
tdep->num_nopriv_regs and only copy it to tdep->num_regs if it's
not initialized.
When building with x86_64-w64-mingw32-g++ (to test cross-compiling for
Windows), I get this error:
unittests/string_view-selftests.o: In function `selftests::string_view::inserters_2::test05(unsigned long long)':
/home/emaisin/src/binutils-gdb/gdb/unittests/basic_string_view/inserters/char/2.cc:60: undefined reference to `std::basic_ofstream<char, std::char_traits<char> >::rpl_close()'
This is caused by gnulib redefining "close" as "rpl_close", and
therefore messing up the declaration of basic_ofstream in the libstdc++
header. The solution would be to use gnulib namespaces [1]. Until we
use them across GDB, we can use them locally in files that are
problematic, like this one.
gdb/ChangeLog:
* unittests/string_view-selftests.c: Define GNULIB_NAMESPACE.
For GNU/Linux on x86-64, if the target is using the xsave format for
passing the floating-point information from the inferior then there
currently exists a bug relating to the x87 control registers, and the
mxcsr register.
The xsave format allows different floating-point features to be lazily
enabled, a bit in the xsave format tells GDB which floating-point
features have been enabled, and which have not.
Currently in GDB, when reading the floating point state, we check the
xsave bit flags, if the feature is enabled then we read the feature
from the xsave buffer, and if the feature is not enabled, then we
supply the default value from within GDB.
Within GDB, when writing the floating point state, we first fetch the
xsave state from the target and then, for any feature that is not yet
enabled, we write the default values into the xsave buffer. Next we
compare the regcache value with the value in the xsave buffer, and, if
the value has changed we update the value in the xsave buffer, and
mark the feature enabled in the xsave bit flags.
The problem then, is that the x87 control registers were not following
this pattern. We assumed that these registers were always written out
by the kernel, and we always wrote them out to the xsave buffer (but
didn't enabled the feature). The result of this is that if the kernel
had not yet enabled the x87 feature then within GDB we would see
random values for the x87 floating point control registers, and if the
user tried to modify one of these register, that modification would be
lost.
Finally, the mxcsr register was also broken in the same way as the x87
control registers. The added complexity with this case is that the
mxcsr register is part of both the avx and sse floating point feature
set. When reading or writing this register we need to check that at
least one of these features is enabled.
This bug was present in native GDB, and within gdbserver. Both are
fixed with this commit.
gdb/ChangeLog:
* common/x86-xstate.h (I387_FCTRL_INIT_VAL): New constant.
(I387_MXCSR_INIT_VAL): New constant.
* amd64-tdep.c (amd64_supply_xsave): Only read state from xsave
buffer if it was supplied by the inferior.
* i387-tdep.c (i387_supply_fsave): Use I387_MXCSR_INIT_VAL.
(i387_xsave_get_clear_bv): New function.
(i387_supply_xsave): Only read x87 control registers from the
xsave buffer if the feature is enabled, and the state will have
been written, otherwise, provide a suitable default.
(i387_collect_xsave): Pre-clear all registers in xsave buffer,
including x87 control registers. Update control registers if they
have changed from the default value, and mark features as enabled
as required.
* i387-tdep.h (i387_xsave_get_clear_bv): Declare.
gdb/gdbserver/ChangeLog:
* i387-fp.c (i387_cache_to_xsave): Only write x87 control
registers to the cache if their values have changed.
(i387_xsave_to_cache): Provide default values for x87 control
registers when these features are available, but disabled.
* regcache.c (supply_register_by_name_zeroed): New function.
* regcache.h (supply_register_by_name_zeroed): Declare new
function.
gdb/testsuite/ChangeLog:
* gdb.arch/amd64-init-x87-values.S: New file.
* gdb.arch/amd64-init-x87-values.exp: New file.
The formatting of the output of the "info spu event" command changed, causing
spurious test suite failures. Use phex instead of phex_nz to get back the
expected format, and fix emission of new line characters.
gdb/ChangeLog:
2018-05-08 Ulrich Weigand <uweigand@de.ibm.com>
* spu-tdep.c (info_spu_event_command): Fix output formatting.
This adds -Wduplicated-cond to warnings.m4. This caught one bug.
I tried adding -Wduplicated-branches as well, but it results in some
spurious failures from code like this in cgen.h:
#define CGEN_ATTR_TYPE(n) \
struct { unsigned int bool_; \
CGEN_ATTR_VALUE_TYPE nonbool[(n) ? (n) : 1]; }
This will trigger a warning if passed n==1, which seems like a
perfectly valid thing to do; and there were other issues like this as
well.
ChangeLog
2018-05-07 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* warning.m4 (AM_GDB_WARNINGS): Add -Wduplicated-cond.
gdbserver/ChangeLog
2018-05-07 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
-Wduplicated-cond pointed out that arm_record_vfp_data_proc_insn
checks "opc1 == 0x0b" twice. I filed this a while ago as
PR tdep/20362.
Based on the ARM instruction manual at
https://www.scss.tcd.ie/~waldroj/3d1/arm_arm.pdf, I think the
instruction decoding in this function has two bugs.
First, opc1 is computed as:
opc1 = bits (arm_insn_r->arm_insn, 20, 23);
[...]
opc1 = opc1 & 0x04;
This means that tests like:
else if (opc1 == 0x01)
can never be true.
In the ARM manual, "opc1" corresponds to these bits:
name bit
r 20
q 21
D 22
p 23
... where the D bit is not used for VFP instruction decoding.
So, I believe this code should use ~0x04 instead.
Second, VDIV is recognized by the bits "pqrs" being equal to "1000".
This tranlates to opc1 == 0x08 -- not 0x0b. Note that pqrs==1001 is
an undefined encoding, which is probably why opc2 is not checked here;
this code doesn't seem to really deal with undefined encodings in
general, so I've left that as is.
I don't have an ARM machine or any reasonable way to test this.
ChangeLog
2018-05-07 Tom Tromey <tom@tromey.com>
PR tdep/20362:
* arm-tdep.c (arm_record_vfp_data_proc_insn): Properly mask off D
bit. Use correct value for VDIV.
This adds -Wimplicit-fallthrough to the set of default warnings.
2018-05-04 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* warning.m4 (AM_GDB_WARNINGS): Add -Wimplicit-fallthrough.
gdbserver/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
This adds a "break" at the end of the RECORD_SYS_RECVFROM case in
record_linux_system_call. This seemed correct to me.
2018-05-04 Tom Tromey <tom@tromey.com>
* linux-record.c (record_linux_system_call) <case
RECORD_SYS_RECVFROM>: Add "break".
This adds a "break" to a couple of spots where it was erroneously
omitted. I think these are the two (potential) real bugs caught by
this series.
2018-05-04 Tom Tromey <tom@tromey.com>
* mi/mi-main.c (mi_cmd_trace_frame_collected) <REGISTERS_FORMAT>:
Add missing "break".
* mi/mi-cmd-stack.c (mi_cmd_stack_list_locals) <NO_FRAME_FILTERS>:
Add missing "break".
This adds two fall-through comments in rs6000-tdep.c. I looked at the
PPC instruction manual and convinced myself that this was correct.
And, this isn't a semantic change. However, close review would still
be good.
2018-05-04 Tom Tromey <tom@tromey.com>
* rs6000-tdep.c (ppc_process_record_op4)
(ppc_process_record_op63): Add fall-through comment.
This adds a fall-through comment in i386-tdep.c. I was not sure what
to do here, so I elected to preserve the status quo. In review, John
Baldwin pointed out that: "I believe this is correct based on the diff
that added the special cases for xgetbv and xsetbv as previously ldgt
and lidt were treated the same".
gdb/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* i386-tdep.c (i386_process_record): Add fall-through comment.
This adds a fall-through comment to stabsread.c. I skimmed the stabs
manual a bit and it seems that 'p' and 'P' are similar enough that
this makes sense. Also, stabs is mostly deprecated, and the code has
been this way for a long time, so it seemed safest to keep the status
quo.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* stabsread.c (define_symbol) <case 'p'>: Add fall-through
comment.
This patch fixes the subset of -Wimplicit-fallthrough warnings that I
considered obvious. In most cases it was obvious from context that
falling through was desired; here I added the appropriate comment. In
a couple of cases it seemed clear that a "break" was missing.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* riscv-tdep.c (riscv_isa_xlen): Add fall-through comment.
* utils.c (can_dump_core) <LIMIT_CUR>: Add fall-through comment.
* eval.c (fetch_subexp_value) <MEMORY_ERROR>: Add fall-through
comment.
* d-valprint.c (d_val_print) <TYPE_CODE_STRUCT>: Add fall-through
comment.
* coffread.c (coff_symtab_read) <C_LABEL>: Add fall-through
comment.
This patch adds a missing ATTRIBUTE_NORETURN. This lets
-Wimplicit-fallthrough recognize that a given case does not fall
through.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* dwarf2loc.c (unimplemented): Add ATTRIBUTE_NORETURN.
This changes the Python API so that breakpoint commands can be set by
writing to the "commands" attribute.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR python/22731:
* NEWS: Mention that breakpoint commands are writable.
* python/py-breakpoint.c (bppy_set_commands): New function.
(breakpoint_object_getset) <"commands">: Use it.
doc/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR python/22731:
* python.texi (Breakpoints In Python): Mention that "commands" is
writable.
testsuite/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR python/22731:
* gdb.python/py-breakpoint.exp: Test setting breakpoint commands.
This changes some functions in cli-script.c to use function_view
rather than a function pointer and closure argument. This simplifies
the code a bit and is useful in a subsequent patch.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* tracepoint.c (actions_command): Update.
* mi/mi-cmd-break.c (mi_command_line_array)
(mi_command_line_array_cnt, mi_command_line_array_ptr)
(mi_read_next_line): Remove.
(mi_cmd_break_commands): Update.
* cli/cli-script.h (read_command_lines, read_command_lines_1): Use
function_view.
* cli/cli-script.c (get_command_line): Update.
(process_next_line): Use function_view. Constify.
(recurse_read_control_structure, read_command_lines)
(read_command_lines_1): Change argument types to function_view.
(do_define_command, document_command): Update.
* breakpoint.h (check_tracepoint_command): Don't declare.
* breakpoint.c (check_tracepoint_command): Remove.
(commands_command_1, create_tracepoint_from_upload): Update.
PR gdb/11750 concerns defining a command inside a user commnad, like:
define outer
define inner
echo hi\n
end
end
This patch adds this capability to gdb.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR gdb/11750:
* cli/cli-script.h (enum command_control_type) <define_control>:
New constant.
* cli/cli-script.c (multi_line_command_p): Handle define_control.
(build_command_line, execute_control_command_1)
(process_next_line): Likewise.
(do_define_command): New function, extracted from define_command.
(define_command): Use it.
testsuite/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR gdb/11750:
* gdb.base/define.exp: Test defining a user command inside a user
command.
* gdb.base/commands.exp (define_if_without_arg_test): Test "define".
The prompt argument to read_command_lines can be const. This patch
makes this change, and also removes some fixed-sized buffers in favor
of using string_printf.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* tracepoint.c (actions_command): Update.
* cli/cli-script.h (read_command_lines): Update.
* cli/cli-script.c (read_command_lines): Constify prompt_arg.
(MAX_TMPBUF): Remove define.
(define_command): Use string_printf.
(document_command): Likewise.
* breakpoint.c (commands_command_1): Update.
I noticed some code in execute_control_command_1 that could be
simplified by making print_command_trace a printf-like function. This
patch makes this change.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* top.c (execute_command): Update.
* cli/cli-script.h (print_command_lines): Now varargs.
* cli/cli-script.c (print_command_lines): Now varargs.
(execute_control_command_1) <case while_control, case if_control>:
Update.
Currently command lines are reference counted using shared_ptr only
when attached to breakpoints. This patch changes gdb to use
shared_ptr in commands as well. This allows for the removal of
copy_command_lines.
Note that the change to execute_user_command explicitly makes a new
reference to the command line. This will be used in a later patch.
This simplifies struct command_line based on the observation that a
given command can have at most two child bodies: an "if" can have both
"then" and "else" parts. Perhaps the names I've chosen for the
replacements here are not very good -- your input requested.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* tracepoint.c (all_tracepoint_actions): Rename from
all_tracepoint_actions_and_cleanup. Change return type.
(actions_command, encode_actions_1, encode_actions)
(trace_dump_actions, tdump_command): Update.
* remote.c (remote_download_command_source): Update.
* python/python.c (gdbpy_eval_from_control_command)
(python_command, python_interactive_command): Update.
* mi/mi-cmd-break.c (mi_cmd_break_commands): Update.
* guile/guile.c (guile_command)
(gdbscm_eval_from_control_command, guile_command): Update.
* compile/compile.c (compile_code_command)
(compile_print_command, compile_to_object): Update.
* cli/cli-script.h (struct command_lines_deleter): New.
(counted_command_line): New typedef.
(struct command_line): Add constructor, destructor.
<body_list>: Remove.
<body_list_0, body_list_1>: New members.
(command_line_up): Remove typedef.
(read_command_lines, read_command_lines_1, get_command_line):
Update.
(copy_command_lines): Don't declare.
* cli/cli-script.c (build_command_line): Use "new".
(get_command_line): Return counted_command_line.
(print_command_lines, execute_user_command)
(execute_control_command_1, while_command, if_command): Update.
(realloc_body_list): Remove.
(process_next_line, recurse_read_control_structure): Update.
(read_command_lines, read_command_lines_1): Return counted_command_line.
(free_command_lines): Use "delete".
(copy_command_lines): Remove.
(define_command, document_command, show_user_1): Update.
* cli/cli-decode.h (struct cmd_list_element) <user_commands>: Now
a counted_command_line.
* breakpoint.h (counted_command_line): Remove typedef.
(breakpoint_set_commands): Update.
* breakpoint.c (check_no_tracepoint_commands)
(validate_commands_for_breakpoint): Update.
(breakpoint_set_commands): Change commands to be a
counted_command_line.
(commands_command_1, update_dprintf_command_list)
(create_tracepoint_from_upload): Update.
This adds a constructor and destructor to cmd_list_element and changes
it to be allocated with new. This will be useful in a subsequent
patch.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* cli/cli-decode.h (cmd_list_element): New constructor.
(~cmd_list_element): New destructor.
(struct cmd_list_element): Add initializers.
* cli/cli-decode.c (do_add_cmd): Use "new".
(delete_cmd): Use "delete".
Some unaligned watchpoints were currently missed.
On old kernels as specified in
kernel RFE: aarch64: ptrace: BAS: Support any contiguous range (edit)
https://sourceware.org/bugzilla/show_bug.cgi?id=20207
after this patch some other unaligned watchpoints will get reported as false
positives.
With new kernels all the watchpoints should work exactly.
There may be a regresion that it now less merges watchpoints so that with
multiple overlapping watchpoints it may run out of the 4 hardware watchpoint
registers. But as discussed in the original thread GDB needs some generic
watchpoints merging framework to be used by all the target specific code.
Even current FSF GDB code does not merge it perfectly. Also with the more
precise watchpoints one can technically merge them less. And I do not think
it matters too much to improve mergeability only for old kernels.
Still even on new kernels some better merging logic would make sense.
There remains one issue:
kernel-4.15.14-300.fc27.armv7hl
FAIL: gdb.base/watchpoint-unaligned.exp: continue
FAIL: gdb.base/watchpoint-unaligned.exp: continue
(gdb) continue
Continuing.
Unexpected error setting watchpoint: Invalid argument.
(gdb) FAIL: gdb.base/watchpoint-unaligned.exp: continue
But that looks as a kernel bug to me.
(1) It is not a regression by this patch.
(2) It is unrelated to this patch.
gdb/ChangeLog
2018-05-04 Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <palves@redhat.com>
PR breakpoints/19806 and support for PR external/20207.
* NEWS: Mention Aarch64 watchpoint improvements.
* aarch64-linux-nat.c (aarch64_linux_stopped_data_address): Fix missed
watchpoints and PR external/20207 watchpoints.
* nat/aarch64-linux-hw-point.c
(kernel_supports_any_contiguous_range): New.
(aarch64_watchpoint_offset): New.
(aarch64_watchpoint_length): Support PR external/20207 watchpoints.
(aarch64_point_encode_ctrl_reg): New parameter offset, new asserts.
(aarch64_point_is_aligned): Support PR external/20207 watchpoints.
(aarch64_align_watchpoint): New parameters aligned_offset_p and
next_addr_orig_p. Support PR external/20207 watchpoints.
(aarch64_downgrade_regs): New.
(aarch64_dr_state_insert_one_point): New parameters offset and
addr_orig.
(aarch64_dr_state_remove_one_point): Likewise.
(aarch64_handle_breakpoint): Update caller.
(aarch64_handle_aligned_watchpoint): Likewise.
(aarch64_handle_unaligned_watchpoint): Support addr_orig and
aligned_offset.
(aarch64_linux_set_debug_regs): Remove const from state. Call
aarch64_downgrade_regs.
(aarch64_show_debug_reg_state): Print also dr_addr_orig_wp.
* nat/aarch64-linux-hw-point.h (DR_CONTROL_LENGTH): Rename to ...
(DR_CONTROL_MASK): ... this.
(struct aarch64_debug_reg_state): New field dr_addr_orig_wp.
(unsigned int aarch64_watchpoint_offset): New prototype.
(aarch64_linux_set_debug_regs): Remove const from state.
* utils.c (align_up, align_down): Move to ...
* common/common-utils.c (align_up, align_down): ... here.
* utils.h (align_up, align_down): Move to ...
* common/common-utils.h (align_up, align_down): ... here.
gdb/gdbserver/ChangeLog
2018-05-04 Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <palves@redhat.com>
* linux-aarch64-low.c (aarch64_stopped_data_address):
Likewise.
gdb/testsuite/ChangeLog
2018-05-04 Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <palves@redhat.com>
PR breakpoints/19806 and support for PR external/20207.
* gdb.base/watchpoint-unaligned.c: New file.
* gdb.base/watchpoint-unaligned.exp: New file.
Add prefixes or suffixes to some test names to make them unique.
Replace a send_gdb/gdb_expect with a gdb_test, and make the test name
unique.
Remove test of 'help maint' as this is already covered by a later call
to test_prefix_command_help.
Removed test of 'help maint info' and add a new call to
test_prefix_command_help instead.
gdb/testsuite/ChangeLog:
* gdb.base/maint.exp: Make test names unique, use
test_prefix_command_help to test 'help maint info', and remove
repeated test of 'help maint'.
Consider the code in the gdb.ada/array_return.exp testcase, which
defines a function returning an array of 2 integers:
type Data_Small is array (1 .. 2) of Integer;
function Create_Small return Data_Small;
When doing a "finish" from inside function Create_Small, we expect
GDB to tell us that the return value was "(1, 1)". However, it currently
prints the wrong value:
(gdb) finish
Run till exit from #0 pck.create_small () at /[...]/pck.adb:5
p () at /[...]/p.adb:10
10 Large := Create_Large;
Value returned is $1 = (0, 0)
This is a regression which I traced back to the following commit...
| commit 1933fd8ee0
| Date: Fri May 19 03:06:19 2017 -0700
| Subject: gdb: fix TYPE_CODE_ARRAY handling in sparc targets
... which, despite what the subject says, is not really about
TYPE_CODE_ARRAY handling, which is a bit of an implementation detail,
but about the GNU vectors extension.
The author of the patch equated TYPE_CODE_ARRAY with vectors, which
is not correct. Vectors are TYPE_CODE_ARRAY types with the TYPE_VECTOR
flag set. So at the very minimum, the patch should have been checking
for both TYPE_CODE_ARRAY and TYPE_VECTOR.
But, that's not the only thing that did not seem right to me. When
looking at the ABI, and at the summary of the implementation in GCC
of the calling conventions for that architecture:
size argument return value
small integer <4 int. reg. int. reg.
word 4 int. reg. int. reg.
double word 8 int. reg. int. reg.
_Complex small integer <8 int. reg. int. reg.
_Complex word 8 int. reg. int. reg.
_Complex double word 16 memory int. reg.
vector integer <=8 int. reg. FP reg.
vector integer >8 memory memory
float 4 int. reg. FP reg.
double 8 int. reg. FP reg.
long double 16 memory memory
_Complex float 8 memory FP reg.
_Complex double 16 memory FP reg.
_Complex long double 32 memory FP reg.
vector float any memory memory
aggregate any memory memory
The nice thing about the patch above is that it nicely factorized
the code that determines how arguments are passed/returns. The bad
news is that the implementation, particularly for the handling of
arrays and vectors, doesn't seem to match the summary above. Hence,
the regression we observed.
So what I did was review and re-implement some of the predicate functions
according to the summary above. Because dejagnu crashes all our Solaris
machines real bad, I can't run the dejagnu testsuite there. So what I did
was test the patch with AdaCore's testsuite against leon3-elf, no
regression. I verified that this fixes the regression above while
at the same time still passing gdb.base/gnu_vector.exp (I transposed
that testcase to our testsuite), which is the testcase that was cited
in the commit above as seeing some FAIL->PASS improvements.
This patch also removes one assertion...
gdb_assert (sparc_integral_or_pointer_p (type)
|| (TYPE_CODE (type) == TYPE_CODE_ARRAY && len <= 8));
... because that assertion is really the "negative" of the other conditions
written in the same "if, else if, else [assert]" block in this function.
To me, this assertion forces us to maintain two versions of the same code,
and is an unnecessary burden. In particular, the above is not the
correct condition, and the ABI summary table above shows that we need
a more complex condition to describe the situations where we expect
arguments to be passed by register.
gdb/ChangeLog:
* sparc-tdep.c (sparc_structure_return_p): Re-implement to
match the ABI as summarized in GCC's gcc/config/sparc/sparc.c.
(sparc_arg_by_memory_p): Renamed from sparc_arg_on_registers_p.
Re-implement to match the ABI as summarized in GCC's
gcc/config/sparc/sparc.c. All callers updated.
(sparc32_store_arguments): Remove assertion.
This changes decode_format to use skip_spaces, and changes printcmd.c
not to include tui.h, which apparently is not needed.
2018-05-04 Tom Tromey <tom@tromey.com>
* printcmd.c: Don't include tui.h.
(decode_format): Use skip_spaces.
About the 'x' command, the manual says:
If you use <RET> to repeat the 'x' command, the repeat count N is
used again; the other arguments default as for successive uses of
'x'.
However, PR gdb/22619 points out that this does not work.
This patch fixes the problem.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR gdb/22619:
* printcmd.c (last_count): New global.
(x_command): Use saved count when repeating.
testsuite/ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
PR gdb/22619:
* gdb.base/long_long.exp (gdb_test_long_long): Add test for repeat
behavior.
This removes both copies of do_closedir_cleanup in favor of a new
unique_ptr specialization.
Tested by the buildbot, though I'm not sure that these code paths are
exercised there.
ChangeLog
2018-05-04 Tom Tromey <tom@tromey.com>
* nto-procfs.c (do_closedir_cleanup): Remove.
(procfs_pidlist): Use gdb_dir_up.
* procfs.c (do_closedir_cleanup): Remove.
(proc_update_threads): Use gdb_dir_up.
* common/filestuff.h (struct gdb_dir_deleter): New.
(gdb_dir_up): New typedef.
Tom Tromey
Simon Marchi
Tamar Christina
Maciej W. Rozycki
Andrew Burgess
Max Filippov
Pedro Alves
Tom Tromey
Joel Brobecker
Omair Javaid
Jan Kratochvil
Ulrich Weigand