First, consider the RISC-V register $x1. This register has an alias
$ra. When GDB processes an incoming target description we allow the
target to use either register name to describe the target.
However, within GDB's UI we want to use the $ra alias in preference to
the $x1 architecture name.
To achieve this GDB overrides the tdesc_register_name callback with
riscv_register_name. In riscv_register_name we ensure that we always
return the preferred name, so in this case "ra".
To ensure the user can still access the register as $x1 if they want
to, when in riscv_check_tdesc_feature we spot that the target has
supplied the register, we add aliases for every name except the
preferred one, so in this case we add the alias "x1".
This scheme seems to work quite well, the targets have the flexibility
to be architecture focused if they wish (using x0 - x31) while GDB is
still using the ABI names ra, sp, gp, etc.
When this code was originally added there was an attempt made to
include the CSRs in the same scheme. At the time the CSRs only had
two names, one pulled from riscv-opc.h, and one generated in GDB that
had the pattern csr%d.
The idea was that if the remote targets description described the CSRs
as csr%d then GDB would rename these back to the real CSR name. This
code was only included because if followed the same pattern as the
x-regs and f-regs, not because I was actually aware of any target that
did this.
However, recent changes to add additional CSR aliases has made me
rethink the position here.
Lets consider the CSR $dscratch0. This register has an alias
'csr1970' (1970 is 0x7b2, which is the offset of the CSR register into
the CSR address space). However, this register was originally called
just 'dscratch', and so, after recent commits, this register also has
the alias 'dscratch'.
As the riscv-opc.h file calls this register 'dscratch0' GDB's
preferred name for this register is 'dscratch0'.
So, if the remote target description includes the register
'dscratch0', then GDB will add the aliases 'dscratch', and 'csr1970'.
In the UI GDB will describe the register as 'dscratch0', and all it
good.
The problem I see in this case is where the target describes the
register as 'dscratch'. In this case GDB will still spot the register
and add the aliases 'dscratch', and 'csr1970', GDB will then give the
register the preferred name 'dscratch0'.
I don't like this. For the CSRs I think that we should stick with the
naming scheme offered by the remote target description. As the RISC-V
specification evolves and CSR register names evolve, insisting on
referring to registers by the most up to date name makes it harder for
a target to provide a consistent target description for an older
version of the RISC-V architecture spec.
In this precise case the target offers 'dscratch', which is from an
older version of the RISC-V specification, the newer version of the
spec has two registers 'dscratch0' and 'dscratch1'. If we insist on
using 'dscratch0' it is then a little "weird" (or seems so to me) when
'dscratch1' is missing.
This patch makes a distinction between the x and f registers and the
other register sets. For x and f we still make use of the renaming
scheme, forcing GDB to prefer the ABI name. But after this patch the
CSR register group, and also the virtual register group, will always
prefer to use the name given in the target description, adding other
names as aliases, but not making any other name the preferred name.
gdb/ChangeLog:
* riscv-tdep.c (struct riscv_register_feature::register_info): Fix
whitespace error for declaration of names member variable.
(struct riscv_register_feature): Add new prefer_first_name member
variable, and fix whitespace error in declaration of registers.
(riscv_xreg_feature): Initialize prefer_first_name field.
(riscv_freg_feature): Likewise.
(riscv_virtual_feature): Likewise.
(riscv_csr_feature): Likewise.
(riscv_register_name): Expand on comments. Remove register name
modifications for CSR and virtual registers.
gdb/testsuite/ChangeLog:
* gdb.arch/riscv-tdesc-regs.exp: Extend test case.
This commit does two things:
1. Makes use of the DECLARE_CSR_ALIAS definitions in riscv-opc.h to
add additional aliases for CSRs.
2. Only creates aliases for registers that are actually present on
the target (as announced in the target XML description).
This means that the 'csr%d' aliases that exist will only be created
for those CSRs the target actually has, which is a nice improvement,
as accessing one of the CSRs that didn't exist would cause GDB to
crash with this error:
valprint.c:1560: internal-error: bool maybe_negate_by_bytes(const gdb_byte*, unsigned int, bfd_endian, gdb::byte_vector*): Assertion `len > 0' failed.
When we look at the DECLARE_CSR_ALIAS lines in riscv-opc.h, these can
be split into three groups:
DECLARE_CSR_ALIAS(misa, 0xf10, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P9P1)
The 'misa' register used to exist of offset 0xf10, but was moved to
its current offset (0x301) in with privilege spec 1.9.1. We don't
want GDB to create an alias called 'misa' as we will already have a
'misa' register created by the DECLARE_CSR(misa ....) call earlier in
riscv-opc.h
DECLARE_CSR_ALIAS(ubadaddr, CSR_UTVAL, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P10)
DECLARE_CSR_ALIAS(sbadaddr, CSR_STVAL, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P10)
DECLARE_CSR_ALIAS(sptbr, CSR_SATP, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P10)
DECLARE_CSR_ALIAS(mbadaddr, CSR_MTVAL, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P10)
DECLARE_CSR_ALIAS(mucounteren, CSR_MCOUNTINHIBIT, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P10)
These aliases are all CSRs that were removed in privilege spec 1.10,
and whose addresses were reused by new CSRs. The names meaning of the
old names is totally different to the new CSRs that have taken their
place. I don't believe we should add these as aliases into GDB. If
the new CSR exists in the target then that should be enough.
DECLARE_CSR_ALIAS(dscratch, CSR_DSCRATCH0, CSR_CLASS_I, PRIV_SPEC_CLASS_1P9, PRIV_SPEC_CLASS_1P11)
In privilege spec 1.11 the 'dscratch' register was renamed to
'dscratch0', however the meaning of the register didn't change.
Adding the 'dscratch' alias makes sense I think.
Looking then at the final PRIV_SPEC_CLASS_* field for each alias then
we can see that currently we only want to take the alias from
PRIV_SPEC_CLASS_1P11. For now then this is what I'm using to filter
the aliases within GDB.
In the future there's no telling how DECLARE_CSR_ALIAS will be used.
I've heard it said that future RISC-V privilege specs will not reuse
CSR offsets again. But it could happen. We just don't know.
If / when it does we may need to revisit how aliases are created for
GDB, but for now this seems to be OK.
gdb/ChangeLog:
* riscv-tdep.c (riscv_create_csr_aliases): Handle csr aliases from
riscv-opc.h.
(class riscv_pending_register_alias): New class.
(riscv_check_tdesc_feature): Take vector of pending aliases and
populate it as appropriate.
(riscv_setup_register_aliases): Delete.
(riscv_gdbarch_init): Create vector of pending aliases and pass it
to riscv_check_tdesc_feature in all cases. Use the vector to
create the register aliases.
gdb/testsuite/ChangeLog:
* gdb.arch/riscv-tdesc-regs-32.xml: New file.
* gdb.arch/riscv-tdesc-regs-64.xml: New file.
* gdb.arch/riscv-tdesc-regs.c: New file.
* gdb.arch/riscv-tdesc-regs.exp: New file.
gdbarch_static_transform_name is completely Solaris-specific or rather
specific to the Studio compilers. Studio cc has deprecated Stabs support
in the 12.4 release back in 2015, GCC has defaulted to DWARF-2 on Solaris
7+ since 2004 and Stabs themselves are pretty much obsolete, so the whole
code can go.
Tested on sparcv9-sun-solaris2.11 and x86_64-pc-linux-gnu with
--enable-targets=all.
* sol2-tdep.c (sol2_static_transform_name): Remove.
(sol2_init_abi): Don't register it.
* gdbarch.sh (static_transform_name): Remove.
* gdbarch.c, gdbarch.h: Regenerate.
* dbxread.c (read_dbx_symtab) <'S'>: Remove call to
gdbarch_static_transform_name.
* mdebugread.c (parse_partial_symbols) <'S'>: Likewise.
* stabsread.c (define_symbol) <'X'>: Remove.
(define_symbol) <'S'>: Remove gdbarch_static_transform_name
handling.
<'V'>: Likewise.
* xcoffread.c (scan_xcoff_symtab): Remove gdbarch.
<'S'>: Remove call to gdbarch_static_transform_name.
The gdb.mi/mi-exec-run.exp test never completed/timed out on Solaris for
quite some time:
FAIL: gdb.mi/mi-exec-run.exp: inferior-tty=main: mi=main: force-fail=1: run failure detected (timeout)
This is for gdb trying to exec mi-exec-run.nox, a copy of mi-exec-run
with execute permissions removed.
The process tree at this point looks like this:
21254 /vol/gcc/bin/expect -- /vol/gcc/share/dejagnu/runtest.exp GDB_PARALLEL=yes --outdir=outputs/gdb.mi/mi-exec-run-vfork gdb.mi/mi-exec-run.exp
21300 <defunct>
21281 <defunct>
21294 $obj/gdb/testsuite/../../gdb/gdb -nw -nx -data-directory $obj/gdb/testsuite/../data-directory -i=mi
21297 $obj/gdb/testsuite/../../gdb/gdb -nw -nx -data-directory $obj/gdb/testsuite/../data-directory -i=mi
The parent gdb hangs here:
21294: $obj/gdb/testsuite/../../gdb/gdb -nw
------------ lwp# 1 / thread# 1 ---------------
0000000000000000 SYS#0 ()
0000000000daeccd procfs_target::create_inferior(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, char**, int) () + 97 (procfs.c:2853)
0000000000ca63a7 run_command_1(char const*, int, run_how) () + 349 (basic_string.h:187)
0000000000ca6516 start_command(char const*, int) () + 26 (infcmd.c:584)
0000000000b3ca8e do_const_cfunc(cmd_list_element*, char const*, int) () + f (cli-decode.c:96)
0000000000b3ed77 cmd_func(cmd_list_element*, char const*, int) () + 32 (cli-decode.c:2113)
0000000000f2d219 execute_command(char const*, int) () + 455 (top.c:657)
0000000000d4ad77 mi_execute_cli_command(char const*, int, char const*) () + 242 (basic_string.h:187)
0000000000d4ae80 mi_cmd_exec_run(char const*, char**, int) () + ba (mi-main.c:473)
with these process flags
21294: $obj/gdb/testsuite/../../gdb/gdb -nw
data model = _LP64 flags = VFORKP|ORPHAN|MSACCT|MSFORK
sigpend = 0x00004103,0x00000000,0x00000000
/1: flags = 0
sigmask = 0xffbffeff,0xffffffff,0x000000ff
cursig = SIGKILL
/2: flags = DETACH|STOPPED|ASLEEP lwp_park(0x0,0x0,0x0)
why = PR_SUSPENDED
sigmask = 0x000a2002,0x00000000,0x00000000
[...]
while the child sits at
21297: $obj/gdb/testsuite/../../gdb/gdb -nw
00007fffbf078a0b execve (7fffbffff756, 7fffbfffec58, 7fffbfffec90, 0)
00007fffbef84cf6 execvpex () + f6
00007fffbef84f45 execvp () + 15
0000000000d60a44 fork_inferior(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, char**, void (*)(), gdb::function_view<void (int)>, void (*)(), char const*, void (*)(char const*, char* const*, char* const*)) () + 47f (fork-inferior.c:423)
0000000000daeccd procfs_target::create_inferior(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, char**, int) () + 97 (procfs.c:2853)
0000000000ca63a7 run_command_1(char const*, int, run_how) () + 349 (basic_string.h:187)
0000000000ca6516 start_command(char const*, int) () + 26 (infcmd.c:584)
0000000000b3ca8e do_const_cfunc(cmd_list_element*, char const*, int) () + f (cli-decode.c:96)
0000000000b3ed77 cmd_func(cmd_list_element*, char const*, int) () + 32 (cli-decode.c:2113)
0000000000f2d219 execute_command(char const*, int) () + 455 (top.c:657)
0000000000d4ad77 mi_execute_cli_command(char const*, int, char const*) () + 242 (basic_string.h:187)
0000000000d4ae80 mi_cmd_exec_run(char const*, char**, int) () + ba (mi-main.c:473)
with
21297: $obj/gdb/testsuite/../../gdb/gdb -nw
data model = _LP64 flags = MSACCT|MSFORK
exitset = 0x00000000 0x04000000 0x00000000 0x00000000
0x00000000 0x00000000 0x00000000 0x00000000
/1: flags = STOPPED|ISTOP execve(0x7fffbffff756,0x7fffbfffec58,0x7fffbfffec90,0x0)
why = PR_SYSEXIT what = execve
We have a deadlock here: the execve in the child cannot return until the
parent has handled the PR_SYSEXIT while the parent cannot run with a
vfork'ed child as documented in proc(4):
The child of a vfork(2) borrows the parent's address space. When a
vfork(2) is executed by a traced process, all watched areas established
for the parent are suspended until the child terminates or performs an
exec(2). Any watched areas established independently in the child are
cancelled when the parent resumes after the child's termination or
exec(2). PCWATCH fails with EBUSY if applied to the parent of a
vfork(2) before the child has terminated or performed an exec(2). The
PR_VFORKP flag is set in the pstatus structure for such a parent
process.
In that situation, the parent cannot be killed even with SIGKILL (as
runtest will attempt once the timeout occurs; the pending signal can be
seen in the pflags output above), so the whole test hangs until one
manually kills the child process.
Fortunately, there's an easy way out: when using fork instead of vfork,
the problem doesn't occur, and this is what the current patch does: it
calls fork_inferior with a dummy pre_trace_fun arg.
Tested on amd64-pc-solaris2.11 and sparcv9-sun-solaris2.11.
* procfs.c (procfs_pre_trace): New function.
(procfs_target::create_inferior): Pass it to fork_inferior.
Linux/sparc* currently links Solaris-specific files (sparc-sol2-tdep.o,
sparc64-sol2-tdep.o, sol2-tdep.o) for no apparent reason. It has no
business doing so, and none of the functions/variables defined there are
used explicitly. If support for the Solaris OSABI were desired, this
should be done using --enable-targets instead.
Since neither sparc{32,64}_sol2_init_abi currently declared in common
headers (sparc*-tdep.h) are used outside their source files, they are made
static and the declarations removed.
Tested on sparcv9-sun-solaris2.11 and sparc64-unknown-linux-gnu.
* configure.tgt <sparc-*-linux*> (gdb_target_obs): Remove
sparc-sol2-tdep.o, sol2-tdep.o, sparc64-sol2-tdep.o.
<sparc64-*-linux*> (gdb_target_obs): Remove sparc64-sol2-tdep.o,
sol2-tdep.o, sparc-sol2-tdep.o.
* sparc-sol2-tdep.c (sparc32_sol2_init_abi): Make static.
* sparc-tdep.h (sparc32_sol2_init_abi): Remove.
* sparc64-sol2-tdep.c (sparc64_sol2_init_abi): Make static.
* sparc64-tdep.h (sparc64_sol2_init_abi): Remove.
There's some overlap and duplication between 32 and 64-bit Solaris/SPARC
and x86 tdep files, in particular
sol2_core_pid_to_str
*_sol2_sigtramp_p
sol2_skip_solib_resolver
*_sol2_static_transform_name (forgotten on amd64)
set_gdbarch_sofun_address_maybe_missing (likewise)
This patch avoids this by centralizing common code in sol2-tdep.c.
While sparc_sol2_pc_in_sigtramp and sparc_sol2_static_transform_name
were declared in the shared sparc-tdep.h, they were only used in Solaris
files.
Tested on amd64-pc-solaris2.11, i386-pc-solaris2.11,
sparcv9-sun-solaris2.11, and sparc-sun-solaris2.11, and
sparc64-unknown-linux-gnu.
* amd64-sol2-tdep.c (amd64_sol2_sigtramp_p): Remove.
(amd64_sol2_init_abi): Use sol2_sigtramp_p.
Call sol2_init_abi.
Remove calls to set_gdbarch_skip_solib_resolver,
set_gdbarch_core_pid_to_str.
* i386-sol2-tdep.c (i386_sol2_sigtramp_p): Remove.
(i386_sol2_static_transform_name): Remove.
(i386_sol2_init_abi): Call sol2_init_abi.
Remove calls to set_gdbarch_sofun_address_maybe_missing,
set_gdbarch_static_transform_name,
set_gdbarch_skip_solib_resolver, set_gdbarch_core_pid_to_str.
Use sol2_sigtramp_p.
* sol2-tdep.c (sol2_pc_in_sigtramp): New function.
(sol2_sigtramp_p): New function.
(sol2_static_transform_name): New function.
(sol2_skip_solib_resolver, sol2_core_pid_to_str): Make static.
(sol2_init_abi): New function.
* sol2-tdep.h (sol2_sigtramp_p, sol2_init_abi): Declare.
(sol2_skip_solib_resolver, sol2_core_pid_to_str): Remove.
* sparc-sol2-tdep.c (sparc_sol2_pc_in_sigtramp): Remove.
(sparc32_sol2_sigtramp_frame_sniffer): Just call sol2_sigtramp_p.
(sparc_sol2_static_transform_name): Remove.
(sparc32_sol2_init_abi): Call sol2_init_abi.
Remove calls to set_gdbarch_sofun_address_maybe_missing,
set_gdbarch_static_transform_name,
set_gdbarch_skip_solib_resolver,
set_gdbarch_core_pid_to_str.
* sparc-tdep.h (sparc_sol2_pc_in_sigtramp)
(sparc_sol2_static_transform_name): Remove
* sparc64-sol2-tdep.c (sparc64_sol2_sigtramp_frame_sniffer): Just
call sol2_sigtramp_p.
(sparc64_sol2_init_abi): Call sol2_init_abi.
Remove calls to set_gdbarch_sofun_address_maybe_missing,
set_gdbarch_static_transform_name,
set_gdbarch_skip_solib_resolver, set_gdbarch_core_pid_to_str.
As explained in https://sourceware.org/bugzilla/show_bug.cgi?id=25475,
when the currently loaded file has no debug symbol,
symbol_file_add_with_addrs does not ask a confirmation to the user
before loading the new symbol file. The behaviour is not consistent
when symbol_file_add_with_addrs is called due to exec-file-mismatch "ask"
setting.
The PR discusses several solutions/approaches.
The preferred approach (suggested by Joel) is to ensure that GDB always asks
a confirmation when it loads a new symbol file due to exec-file-mismatch,
using a new SYMFILE add-flag.
I tested this manually. If OK, we can remove the bypass introduced by Tom
in 6b9374f1, in order to always answer to the 'load' question.
gdb/ChangeLog
2020-06-24 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* symfile-add-flags.h: New flag SYMFILE_ALWAYS_CONFIRM.
* exec.c (validate_exec_file): If from_tty, set both
SYMFILE_VERBOSE (== from_tty) and SYMFILE_ALWAYS_CONFIRM.
* symfile.c (symbol_file_add_with_addrs): if always_confirm
and from_tty, unconditionally ask a confirmation.
This commit adds a new maintenance command that dumps the current
target description as an XML document. This is a maintenance command
as I currently only see this being useful for GDB developers, or for
people debugging a new remote target.
By default the command will print whatever the current target
description is, whether this was delivered by the remote, loaded by
the user from a file, or if it is a built in target within GDB.
The command can also take an optional filename argument. In this case
GDB loads a target description from the file, and then reprints it.
This could be useful for testing GDB's parsing of target descriptions,
or to check that GDB can successfully parse a particular XML
description.
It is worth noting that the XML description printed will not be an
exact copy of the document fed into GDB. For example this minimal
input file:
<target>
<feature name="abc">
<reg name="r1" bitsize="32"/>
</feature>
</target>
Will produce this output:
(gdb) maint print xml-tdesc path/to/file.xml
<?xml version="1.0"?>
<!DOCTYPE target SYSTEM "gdb-target.dtd">
<target>
<feature name="abc">
<reg name="r1" bitsize="32" type="int" regnum="0"/>
</feature>
</target>
Notice that GDB filled in both the 'type' and 'regnum' fields of the
<reg>. I think this is actually a positive as it means we get to
really understand how GDB processed the document, if GDB made some
assumptions that differ to those the user expected then hopefully this
will bring those issues to the users attention.
To implement this I have tweaked the output produced by the
print_xml_feature which is defined within the gdbsupport/ directory.
The changes I have made to this class are:
1. The <architecture>...</architecture> tags are now not produced if
the architecture name is NULL.
2. The <osabi>...</osabi> tags get a newline at the end.
3. And, the whole XML document is indented using white space in a
nested fashion (as in the example output above).
I think that these changes should be fine, the print_xml_feature class
is used:
1. In gdbserver to generate an XML document to send as the target
description to GDB.
2. In GDB as part of a self-check function, a target_desc is
converted to XML then parsed back into a target_desc. We then check
the before and after target_desc objects are the same.
3. In the new 'maint print xml-tdesc' command.
In all of these use cases adding the extra white space should be fine.
gdbsupport/ChangeLog:
* tdesc.cc (print_xml_feature::visit_pre): Use add_line to add
output content, and call indent as needed in all overloaded
variants.
(print_xml_feature::visit_post): Likewise.
(print_xml_feature::visit): Likewise.
(print_xml_feature::add_line): Two new overloaded functions.
* tdesc.h (print_xml_feature::indent): New member function.
(print_xml_feature::add_line): Two new overloaded member
functions.
(print_xml_feature::m_depth): New member variable.
gdb/ChangeLog:
* target-descriptions.c (tdesc_architecture_name): Protect against
NULL pointer dereference.
(maint_print_xml_tdesc_cmd): New function.
(_initialize_target_descriptions): Register new 'maint print
xml-tdesc' command and give it the filename completer.
* NEWS: Mention new 'maint print xml-tdesc' command.
gdb/testsuite/ChangeLog:
* gdb.xml/tdesc-reload.c: New file.
* gdb.xml/tdesc-reload.exp: New file.
* gdb.xml/maint-xml-dump-01.xml: New file.
* gdb.xml/maint-xml-dump-02.xml: New file.
* gdb.xml/maint-xml-dump.exp: New file.
gdb/doc/ChangeLog:
* gdb.texinfo (Maintenance Commands): Document new 'maint print
xml-desc' command.
The gdbsupport directory contains a helper class print_xml_feature
that is shared between gdb and gdbserver. This class is used for
printing an XML representation of a target_desc object.
Currently this class doesn't have the ability to print the
<compatible> entities that can appear within a target description, I
guess no targets have needed that functionality yet.
The print_xml_feature classes API is based around operating on the
target_desc class, however, the sharing between gdb and gdbserver is
purely textural, we rely on their being a class called target_desc in
both gdb and gdbserver, but there is no shared implementation. We
then have a set of functions declared that operate on an object of
type target_desc, and again these functions have completely separate
implementations.
Currently then the gdb version of target_desc contains a vector of
bfd_arch_info pointers which represents the compatible entries from a
target description. The gdbserver version of target_desc has no such
information. Further, the gdbserver code doesn't seem to include the
bfd headers, and so doesn't know about the bfd types.
I was reluctant to include the bfd headers into gdbserver just so I
can reference the compatible information, which isn't (currently) even
needed in gdbserver.
So, the approach I take in this patch is to wrap the compatible
information into a new helper class. This class is declared in the
gdbsupport library, but implemented separately in both gdb and
gdbserver.
In gdbserver the class is empty. The compatible information within
the gdbserver is an empty list, of empty classes.
In gdb the class contains a pointer to the bfd_arch_info object.
With this in place we can now add support to print_xml_feature for
printing the compatible information if it is present. In the
gdbserver code this will never happen, as the gdbserver never has any
compatible information. But in gdb, this code will trigger when
appropriate.
gdb/ChangeLog:
* target-descriptions.c (class tdesc_compatible_info): New class.
(struct target_desc): Change type of compatible vector.
(tdesc_compatible_p): Update for change in type of
target_desc::compatible.
(tdesc_compatible_info_list): New function.
(tdesc_compatible_info_arch_name): New function.
(tdesc_add_compatible): Update for change in type of
target_desc::compatible.
(print_c_tdesc::visit_pre): Likewise.
gdbserver/ChangeLog:
* tdesc.cc (struct tdesc_compatible_info): New struct.
(tdesc_compatible_info_list): New function.
(tdesc_compatible_info_arch_name): New function.
gdbsupport/ChangeLog:
* tdesc.cc (print_xml_feature::visit_pre): Print compatible
information.
* tdesc.h (struct tdesc_compatible_info): Declare new struct.
(tdesc_compatible_info_up): New typedef.
(tdesc_compatible_info_list): Declare new function.
(tdesc_compatible_info_arch_name): Declare new function.
The maintenance command 'maintenance print c-tdesc' can only print the
target description if it was loaded from a local file, or if the local
filename is passed to the maintenance command as an argument.
Sometimes it would be nice to know what target description GDB was
given by the remote, however, if I connect to a remote target and try
this command I see this:
(gdb) maintenance print c-tdesc
The current target description did not come from an XML file.
(gdb)
Which is not very helpful.
This commit changes things so that if the description came from the
remote end then GDB will use a fake filename 'fetched from target' as
the filename for the description, GDB will then create the C
description of the target as though it came from this file. Example
output would look like this (I snipped the feature creation from the
middle as that hasn't changed):
(gdb) maintenance print c-tdesc
/* THIS FILE IS GENERATED. -*- buffer-read-only: t -*- vi:set ro:
Original: fetched from target */
#include "defs.h"
#include "osabi.h"
#include "target-descriptions.h"
struct target_desc *tdesc_fetched_from_target;
static void
initialize_tdesc_fetched_from_target (void)
{
struct target_desc *result = allocate_target_description ();
struct tdesc_feature *feature;
/* ... features created here ... */
tdesc_fetched_from_target = result;
}
(gdb)
In order to support using 'fetched from target' I had to update the
print_c_tdesc code to handle filenames that include a space. This has
the benefit that we can now print out real files with spaces in the
name, for example the file 'with space.xml':
(gdb) maint print c-tdesc with space.xml
I originally added this functionality so I could inspect the
description passed to GDB by the remote target. After using this for
a while I realised that actually having GDB recreate the XML would be
even better, so a later commit will add that functionality too.
Still, given how small this patch is I thought it might be nice to
include this in GDB anyway.
While I was working on this anyway I've added filename command
completion to this command.
gdb/ChangeLog:
* target-descriptions.c (print_c_tdesc::print_c_tdesc): Change
whitespace to underscore.
(maint_print_c_tdesc_cmd): Use fake filename for target
descriptions that came from the target.
(_initialize_target_descriptions): Add filename command completion
for 'maint print c-tdesc'.
Add some empty lines at places I forgot in the previous patch.
gdb/ChangeLog:
* dwarf2/loc.c (decode_debug_loclists_addresses): Add empty
lines.
Change-Id: I8a9f3766ede1ce750e0703023285dca873bce0da
I always found that some switch statements in this file were a bit too
packed. I think having empty lines between each case helps with
reading. I'm pushing this as obvious, I hope it won't be too
controversial.
gdb/ChangeLog:
* dwarf2/loc.c (decode_debug_loc_dwo_addresses): Add empty
lines.
(dwarf2_find_location_expression): Likewise.
(call_site_parameter_matches): Likewise.
(dwarf2_compile_expr_to_ax): Likewise.
(disassemble_dwarf_expression): Likewise.
(loclist_describe_location): Likewise.
Change-Id: I381366a0468ff1793faa612c46ef48a9d4773192
This commit:
commit 3922b30264
Author: Pedro Alves <palves@redhat.com>
AuthorDate: Thu Jun 18 21:28:37 2020 +0100
Decouple inferior_ptid/inferior_thread(); dup ptids in thread list (PR 25412)
caused a regression for gdb.gdb/unittest.exp when GDB is configured
with --enable-targets=all. The failure is:
gdb/thread.c:95: internal-error: thread_info* inferior_thread(): Assertion `current_thread_ != nullptr' failed.
The problem is in this line in regcache.c:cooked_read_test:
/* Switch to the mock thread. */
scoped_restore restore_inferior_ptid
= make_scoped_restore (&inferior_ptid, mock_ptid);
Both gdbarch-selftest.c and regcache.c set up a similar mock context,
but the series the patch above belongs to only updated the
gdbarch-selftest.c context to not write to inferior_ptid directly, and
missed updating regcache.c's.
Instead of copying the fix over to regcache.c, share the mock context
setup code in a new RAII class, based on gdbarch-selftest.c's version.
Also remove the "target already pushed" error from regcache.c, like it
had been removed from gdbarch-selftest.c in the multi-target series.
That check is unnecessary because each inferior now has its own target
stack, and the unit test pushes a target on a separate (mock)
inferior, not the current inferior on entry.
gdb/ChangeLog:
2020-06-23 Pedro Alves <palves@redhat.com>
* gdbarch-selftests.c: Don't include inferior.h, gdbthread.h or
progspace-and-thread.h. Include scoped-mock-context.h instead.
(register_to_value_test): Use scoped_mock_context.
* regcache.c: Include "scoped-mock-context.h".
(cooked_read_test): Don't error out if a target is already pushed.
Use scoped_mock_context. Adjust.
* scoped-mock-context.h: New file.
This commit changes the language_data::la_is_string_type_p function
pointer member variable into a member function of language_defn.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (ada_language_data): Delete la_is_string_type_p
initializer.
(ada_language::is_string_type_p): New member function.
* c-lang.c (c_language_data): Delete la_is_string_type_p
initializer.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
* f-lang.c (f_is_string_type_p): Delete function, implementation
moved to f_language::is_string_type_p.
(f_language_data): Delete la_is_string_type_p initializer.
(f_language::is_string_type_p): New member function,
implementation from f_is_string_type_p.
* go-lang.c (go_is_string_type_p): Delete function, implementation
moved to go_language::is_string_type_p.
(go_language_data): Delete la_is_string_type_p initializer.
(go_language::is_string_type_p): New member function,
implementation from go_is_string_type_p.
* language.c (language_defn::is_string_type_p): Define new member
function.
(default_is_string_type_p): Make static, add comment copied from
header file.
(unknown_language_data): Delete la_is_string_type_p initializer.
(unknown_language::is_string_type_p): New member function.
(auto_language_data): Delete la_is_string_type_p initializer.
(auto_language::is_string_type_p): New member function.
* language.h (language_data): Delete la_is_string_type_p field.
(language_defn::is_string_type_p): Declare new function.
(default_is_string_type_p): Delete desclaration, move comment to
definition.
* m2-lang.c (m2_is_string_type_p): Delete function, implementation
moved to m2_language::is_string_type_p.
(m2_language_data): Delete la_is_string_type_p initializer.
(m2_language::is_string_type_p): New member function,
implementation from m2_is_string_type_p.
* objc-lang.c (objc_language_data): Delete la_is_string_type_p
initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_is_string_type_p): Delete function,
implementation moved to pascal_language::is_string_type_p.
(pascal_language_data): Delete la_is_string_type_p initializer.
(pascal_language::is_string_type_p): New member function,
implementation from pascal_is_string_type_p.
* rust-lang.c (rust_is_string_type_p): Delete function,
implementation moved to rust_language::is_string_type_p.
(rust_language_data): Delete la_is_string_type_p initializer.
(rust_language::is_string_type_p): New member function,
implementation from rust_is_string_type_p.
* valprint.c (val_print_scalar_or_string_type_p): Update call to
is_string_type_p.
This commit changes the language_data::la_print_typedef function
pointer member variable into a member function of language_defn.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (ada_language_data): Delete la_print_typedef
initializer.
(ada_language::print_typedef): New member function.
* c-lang.c (c_language_data): Delete la_print_typedef initializer.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
* f-lang.c (f_language_data): Likewise.
(f_language::print_typedef): New member function.
* go-lang.c (go_language_data): Delete la_print_typedef
initializer.
* language.c (language_defn::print_typedef): Define member
function.
(unknown_language_data): Delete la_print_typedef initializer.
(unknown_language::print_typedef): New member function.
(auto_language_data): Delete la_print_typedef initializer.
(auto_language::print_typedef): New member function.
* language.h (language_data): Delete la_print_typedef field.
(language_defn::print_typedef): Declare new member function.
(LA_PRINT_TYPEDEF): Update call to print_typedef.
(default_print_typedef): Delete declaration.
* m2-lang.c (m2_language_data): Delete la_print_typedef
initializer.
(m2_language::print_typedef): New member function.
* objc-lang.c (objc_language_data): Delete la_print_typedef
initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_language_data): Likewise.
(pascal_language::print_typedef): New member function.
* rust-lang.c (rust_print_typedef): Delete function,
implementation moved to rust_language::print_typedef.
(rust_language): Delete la_print_typedef initializer.
(rust_language::print_typedef): New member function,
implementation from rust_print_typedef.
* typeprint.c (default_print_typedef): Delete.
This commit changes the language_data::la_printstr function pointer
member variable into a member function of language_defn.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (ada_language_data): Delete la_printstr initializer.
(ada_language::printstr): New member function.
* c-lang.c (c_language_data): Delete la_printstr initializer.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
* f-lang.c (f_printstr): Rename to f_language::printstr.
(f_language_data): Delete la_printstr initializer.
(f_language::printstr): New member function, implementation from
f_printstr.
* go-lang.c (go_language_data): Delete la_printstr initializer.
* language.c (language_defn::printstr): Define new member
function.
(unk_lang_printstr): Delete.
(unknown_language_data): Delete la_printstr initializer.
(unknown_language::printstr): New member function.
(auto_language_data): Delete la_printstr initializer.
(auto_language::printstr): New member function.
* language.h (language_data): Delete la_printstr field.
(language_defn::printstr): Declare new member function.
(LA_PRINT_STRING): Update call to printstr.
* m2-lang.c (m2_printstr): Rename to m2_language::printstr.
(m2_language_data): Delete la_printstr initializer.
(m2_language::printstr): New member function, implementation from
m2_printstr.
* objc-lang.c (objc_language_data): Delete la_printstr
initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_printstr): Rename to pascal_language::printstr.
(pascal_language_data): Delete la_printstr initializer.
(pascal_language::printstr): New member function, implementation
from pascal_printstr.
* p-lang.h (pascal_printstr): Delete declaration.
* rust-lang.c (rust_printstr): Update header comment.
(rust_language_data): Delete la_printstr initializer.
(rust_language::printstr): New member function.
This commit changes the language_data::la_printchar function pointer
member variable into a member function of language_defn.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (ada_language_data): Delete la_printchar initializer.
(ada_language::printchar): New member function.
* c-lang.c (c_language_data): Delete la_printchar initializer.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
* f-lang.c (f_printchar): Rename to f_language::printchar.
(f_language_data): Delete la_printchar initializer.
(f_language::printchar): New member function, implementation from
f_printchar.
* go-lang.c (go_language_data): Delete la_printchar initializer.
* language.c (unk_lang_printchar): Delete.
(language_defn::printchar): Define new member function.
(unknown_language_data): Delete la_printchar initializer.
(unknown_language::printchar): New member function.
(auto_language_data): Delete la_printchar initializer.
(auto_language::printchar): New member function.
* language.h (language_data): Delete la_printchar field.
(language_defn::printchar): Declare new member function.
(LA_PRINT_CHAR): Update call to printchar.
* m2-lang.c (m2_language_data): Delete la_printchar initializer.
(m2_language::printchar): New member function.
* objc-lang.c (objc_language_data): Delete la_printchar
initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_language_data): Delete la_printchar
initializer.
(pascal_language::printchar): New member function.
* rust-lang.c (rust_printchar): Rename to
rust_language::printchar.
(rust_language_data): Delete la_printchar initializer.
(rust_language::printchar): New member function, implementation
from rust_printchar.
This commit changes the language_data::la_emitchar function pointer
member variable into a member function of language_defn.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (emit_char): Renamed to ada_language::emitchar.
(ada_language_data): Delete la_emitchar initializer.
(ada_language::emitchar): New member function, implementation from
emit_char.
* c-lang.c (c_language_data): Delete la_emitchar initializer.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
* f-lang.c (f_emit_char): Rename to f_language::emitchar.
(f_language_data): Delete la_emitchar initializer.
(f_language::emitchar): New member function, implementation from
f_emit_char.
* go-lang.c (go_language_data): Delete la_emitchar initializer.
* language.c (unk_lang_emit_char): Delete.
(language_defn::emitchar): New member function definition.
(unknown_language_data): Delete la_emitchar initializer.
(unknown_language::emitchar): New member function.
(auto_language_data): Delete la_emitchar initializer.
(auto_language::emitchar): New member function.
* language.h (language_data): Delete la_emitchar field.
(language_defn::emitchar): New member field declaration.
(LA_EMIT_CHAR): Update call to emitchar.
* m2-lang.c (m2_emit_char): Rename to m2_language::emitchar.
(m2_language_data): Delete la_emitchar initializer.
(m2_language::emitchar): New member function, implementation from
m2_emit_char.
* objc-lang.c (objc_language_data): Delete la_emitchar
initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_emit_char): Rename to pascal_language::emitchar.
(pascal_language_data): Delete la_emitchar initializer.
(pascal_language::emitchar): New member function, implementation
from pascal_emit_char.
* rust-lang.c (rust_emitchar): Rename to rust_language::emitchar.
(rust_language_data): Delete la_emitchar initializer.
(rust_language::emitchar): New member function, implementation
from rust_emitchar.
This commit changes the language_data::la_parser function pointer
member variable into a member function of language_defn.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (parse): Rename to ada_language::parser.
(ada_language_data): Delete la_parser initializer.
(ada_language::parser): New member function, implementation from
parse.
* c-lang.c (c_language_data): Delete la_parser initializer.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
(d_language::parser): New member function.
* f-lang.c (f_language_data): Delete la_parser initializer.
(f_language::parser): New member function.
* go-lang.c (go_language_data): Delete la_parser initializer.
(go_language::parser): New member function.
* language.c (unk_lang_parser): Delete.
(language_defn::parser): Define new member function.
(unknown_language_data): Delete la_parser initializer.
(unknown_language::parser): New member function.
(auto_language_data): Delete la_parser initializer.
(auto_language::parser): New member function.
* language.h (language_data): Delete la_parser field.
(language_defn::parser): Declare new member function.
* m2-lang.c (m2_language_data): Delete la_parser initializer.
(m2_language::parser): New member function.
* objc-lang.c (objc_language_data): Delete la_parser initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_language_data): Likewise.
(pascal_language::parser): New member function.
* parse.c (parse_exp_in_context): Update call to parser.
* rust-lang.c (rust_language_data): Delete la_parser initializer.
(rust_language::parser): New member function.
Commit:
commit d13c7322fe
Date: Fri Jan 17 00:10:22 2020 +0000
gdb: Allow more control over where to find python libraries
Added a new configuration option --with-python-libdir, but failed to
add this option to the output of 'gdb --configuration'. This commit
fixes this mistake.
gdb/ChangeLog:
* top.c (print_gdb_configuration): Print --with-python-libdir
configuration value.
gdb/ChangeLog
2020-06-22 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* NEWS: Mention change to the alias command.
gdb/doc/ChangeLog
2020-06-22 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.texinfo (Command aliases default args): New node documenting
how to use default args for a command using aliases.
(Aliases): Document the new 'DEFAULT-ARGS...' option.
(Help): Update help aliases text and describe when full alias
definition is provided.
Currently, a user can define an alias, but cannot have default
arguments for this alias.
This patch modifies the 'alias' command so that default args can
be provided.
(gdb) h alias
Define a new command that is an alias of an existing command.
Usage: alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
ALIAS is the name of the alias command to create.
COMMAND is the command being aliased to.
Options:
-a
Specify that ALIAS is an abbreviation of COMMAND.
Abbreviations are not used in command completion..
GDB will automatically prepend the provided DEFAULT-ARGS to the list
of arguments explicitly provided when using ALIAS.
Use "help aliases" to list all user defined aliases and their default args.
Examples:
Make "spe" an alias of "set print elements":
alias spe set print elements
Make "elms" an alias of "elements" in the "set print" command:
alias -a set print elms set print elements
Make "btf" an alias of "backtrace -full -past-entry -past-main" :
alias btf = backtrace -full -past-entry -past-main
Make "wLapPeu" an alias of 2 nested "with":
alias wLapPeu = with language pascal -- with print elements unlimited --
(gdb)
The way 'default-args' is implemented makes it trivial to set default
args also for GDB commands (such as "backtrace") and for GDB pre-defined
aliases (such as "bt"). It was however deemed better to not allow to
define default arguments for pre-defined commands and aliases, to avoid
users believing that e.g. default args for "backtrace" would apply to "bt".
If needed, default-args could be allowed for GDB predefined commands
and aliases by adding a command
'set default-args GDB_COMMAND_OR_PREDEFINED_ALIAS [DEFAULT-ARGS...]'.
* 'alias' command now has a completer that helps to complete:
- ALIAS (if the user defines an alias after a prefix),
- the aliased COMMAND
- the possible options for the aliased COMMAND.
* Help and apropos commands show the definitions of the aliases
that have default arguments, e.g.
(gdb) help backtrace
backtrace, btf, where, bt
alias btf = backtrace -full -past-entry -past-main
Print backtrace of all stack frames, or innermost COUNT frames.
Usage: backtrace [OPTION]... [QUALIFIER]... [COUNT | -COUNT]
Options:
-entry-values no|only|preferred|if-needed|both|compact|default
Set printing of function arguments at function entry.
...
gdb/ChangeLog
2020-06-22 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-cmds.c (lookup_cmd_for_default_args)
(alias_command_completer)
(make_alias_options_def_group): New functions.
(alias_opts, alias_option_defs): New struct and array.
(alias_usage_error): Update usage.
(alias_command): Handles optional DEFAULT-ARGS... arguments.
Use option framework.
(_initialize_cli_cmds): Update alias command help.
Update aliases command help.
(show_user):
Add NULL for new default_args lookup_cmd argument.
(valid_command_p): Rename to validate_aliased_command.
Add NULL for new default_args lookup_cmd argument. Verify that the
aliased_command has no default args.
* cli/cli-decode.c (help_cmd): Show aliases definitions.
(lookup_cmd_1, lookup_cmd): New argument default_args.
(add_alias_cmd):
Add NULL for new default_args lookup_cmd argument.
(print_help_for_command): Show default args under the layout
alias some_alias = some_aliased_cmd some_alias_default_arg.
* cli/cli-decode.h (struct cmd_list_element): New member default_args.
xfree default_args in destructor.
* cli/cli-script.c (process_next_line, do_define_command):
Add NULL for new default_args lookup_cmd argument.
* command.h: Declare new default_args argument in lookup_cmd
and lookup_cmd_1.
* completer.c (complete_line_internal_1):
Add NULL for new default_args lookup_cmd or lookup_cmd_1 argument.
* guile/scm-cmd.c (gdbscm_parse_command_name): Likewise.
* guile/scm-param.c (add_setshow_generic, pascm_parameter_defined_p):
Likewise.
* infcmd.c (_initialize_infcmd): Likewise.
* python/py-auto-load.c (gdbpy_initialize_auto_load): Likewise.
* python/py-cmd.c (gdbpy_parse_command_name): Likewise.
* python/py-param.c (add_setshow_generic): Likewise.
* remote.c (_initialize_remote): Likewise.
* top.c (execute_command): Prepend default_args if command has some.
(set_verbose):
Add NULL for new default_args lookup_cmd or lookup_cmd_1 argument.
* tracepoint.c (validate_actionline, encode_actions_1):
Add NULL for new default_args lookup_cmd or lookup_cmd_1 argument.
This is a minor refactoring that converts the return type of
jit_read_descriptor and jit_breakpoint_re_set_internal functions
from 'int' to 'bool'.
The return value logic of jit_breakpoint_re_set_internal has been
reversed. With this patch it now returns true if the jit breakpoint
has been successfully initialized.
gdb/ChangeLog:
2020-06-22 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* jit.c (jit_read_descriptor): Use bool as the return type.
(jit_breakpoint_re_set_internal): Use bool as the return type.
Invert the return value logic; return true if the jit breakpoint
has been successfully initialized.
(jit_inferior_init): Update the call to
jit_breakpoint_re_set_internal.
Debugging on Solaris is broken, with the procfs target backend failing
with:
procfs: couldn't find pid 0 in procinfo list.
as soon as you start a program.
The problem is procfs_target::wait assuming that inferior_ptid is
meaningful on entry, but, since the multi-target series, inferior_ptid
is null_ptid before we call target_wait, in infrun.c:
static ptid_t
do_target_wait_1 (inferior *inf, ptid_t ptid,
target_waitstatus *status, int options)
{
...
/* We know that we are looking for an event in the target of inferior
INF, but we don't know which thread the event might come from. As
such we want to make sure that INFERIOR_PTID is reset so that none of
the wait code relies on it - doing so is always a mistake. */
switch_to_inferior_no_thread (inf);
This patch tweaks the backend to remove the assumption that
inferior_ptid points at something. sol-thread.c (the thread_stratum
that sits on top of procfs.c) also has the same issue.
Some spots in procfs_target::wait were returning
TARGET_WAITKIND_SPURIOUS+inferior_ptid. This commit replaces those
with waiting again without returning to the core. This fixes the
relying on inferior_ptid, and also should fix the issue discussed
here:
https://sourceware.org/pipermail/gdb/2020-May/048616.htmlhttps://sourceware.org/pipermail/gdb/2020-June/048660.html
gdb/ChangeLog:
2020-06-22 Pedro Alves <palves@redhat.com>
PR gdb/25939
* procfs.c (procfs_target::wait): Don't reference inferior_ptid.
Use the current inferior instead. Don't return
TARGET_WAITKIND_SPURIOUS/inferior_ptid -- instead continue and
wait again.
* sol-thread.c (sol_thread_target::wait): Don't reference
inferior_ptid.
(ps_lgetregs, ps_lsetregs, ps_lgetfpregs, ps_lsetfpregs)
(sol_update_thread_list_callback): Use the current inferior's pid
instead of inferior_ptid.
While reading through procfs.c, I noticed a couple of cleanup
opportunities:
* Some comments and code allowed for portability across different
targets. Since procfs.c is Solaris-only for some time now, those can
go.
* Likewise, there were some references to the old ioctl-based /proc left.
* The code still allowed for SYS_exec. However, it is no longer present
in either Solaris 11.3, 11.4, or Illumos. Checking the OpenSolaris
sources, I found that it had already been removed in 2010 well before
the Solaris 11 release.
* Some blocks of #if 0 code can go:
** References to struct procinfo.{g,fp}regs_dirty which are no longer
defined.
** Code handling the PR_ASLWP flag where <sys/procfs.h> has
#define PR_ASLWP 0x00000040 /* obsolete flag; never set */
Tested on amd64-pc-solaris2.11.
* procfs.c: Cleanup many comments.
(READ_WATCHFLAG, WRITE_WATCHFLAG, EXEC_WATCHFLAG)
(AFTER_WATCHFLAG): Replace by value.
(MAIN_PROC_NAME_FORMAT): Inline ...
(create_procinfo): ... here.
(procfs_debug_inferior): Remove SYS_exec handling.
(syscall_is_exec): Likewise.
(procfs_set_exec_trap): Likewise.
(syscall_is_lwp_exit): Inline in callers.
(syscall_is_exit): Likewise.
(syscall_is_exec): Likewise.
(syscall_is_lwp_create): Likewise.
(invalidate_cache): Remove #if 0 code.
(make_signal_thread_runnable): Remove.
(procfs_target::resume): Remove #if 0 code.
Since the multi-target patch, the run command fails on Solaris with an
assertion failure even for a trivial program:
$ ./gdb -D ./data-directory ./hello
GNU gdb (GDB) 10.0.50.20200106-git
[...]
Reading symbols from ./hello...
(gdb) run
Starting program: /vol/obj/gnu/gdb/gdb/reghunt/no-resync/122448/gdb/hello
/vol/src/gnu/gdb/hg/master/reghunt/gdb/thread.c:336: internal-error:
thread_info::thread_info(inferior*, ptid_t): Assertion `inf_ != NULL'
failed.
Here's the start of the corresponding stack trace:
#0 internal_error (
file=file@entry=0x966150
"/vol/src/gnu/gdb/hg/master/reghunt/gdb/thread.c", line=line@entry=336,
fmt=0x9ddb94 "%s: Assertion `%s' failed.")
at /vol/src/gnu/gdb/hg/master/reghunt/gdb/gdbsupport/errors.c:51
#1 0x0000000000ef81f4 in thread_info::thread_info (this=0x1212020,
inf_=<optimized out>, ptid_=...)
at /vol/src/gnu/gdb/hg/master/reghunt/gdb/thread.c:344
#2 0x0000000000ef82cd in new_thread (inf=inf@entry=0x0, ptid=...)
at /vol/src/gnu/gdb/hg/master/reghunt/gdb/thread.c:239
#3 0x0000000000efac3c in add_thread_silent (
targ=targ@entry=0x11b0940 <the_procfs_target>, ptid=...)
at /vol/src/gnu/gdb/hg/master/reghunt/gdb/thread.c:304
#4 0x0000000000d90692 in procfs_target::create_inferior (
this=0x11b0940 <the_procfs_target>,
exec_file=0x13dbef0
"/vol/obj/gnu/gdb/gdb/reghunt/no-resync/122448/gdb/hello", allargs="",
env=0x13c48f0, from_tty=<optimized out>)
at /vol/src/gnu/gdb/hg/master/reghunt/gdb/gdbsupport/ptid.h:47
#5 0x0000000000c84e64 in run_command_1 (args=<optimized out>, from_tty=1,
run_how=run_how@entry=RUN_NORMAL)
at /vol/gcc-9/include/c++/9.1.0/bits/basic_string.h:263
#6 0x0000000000c85007 in run_command (args=<optimized out>,
from_tty=<optimized out>)
at /vol/src/gnu/gdb/hg/master/reghunt/gdb/infcmd.c:687
Looking closer, I found that in add_thread_silent as called from
procfs.c (procfs_target::create_inferior) find_inferior_ptid returns
NULL. The all_inferiors (targ) iterator comes up empty.
Going from there, I see that in add_thread_silent
m_target_stack = {m_top = file_stratum, m_stack = {0x20190e0
<the_dummy_target>, 0x200b8c0 <exec_ops>, 0x0, 0x0, 0x0, 0x0, 0x0}}}
i.e. the_procfs_target is missing compared to the_amd64_linux_nat_target
on Linux/x86_64.
Moving the push_target call earlier allows debugging to get over the
initial assertion failure. I run instead into
procfs: couldn't find pid 0 in procinfo list.
which is fixed by
https://sourceware.org/pipermail/gdb-patches/2020-June/169674.html
Both patches tested together on amd64-pc-solaris2.11.
PR gdb/25939
* procfs.c (procfs_target::procfs_init_inferior): Move push_target
call ...
(procfs_target::create_inferior): ... here.
Following the implementation of exec-file-mismatch based on build-id,
an attach to a process that runs a modified exec-file was triggering
the exec-file-mismatch handling, giving a warning such as:
warning: Mismatch between current exec-file /bd/home/philippe/gdb/git/build_termours/gdb/testsuite/outputs/gdb.base/attach/attach
and automatically determined exec-file /bd/home/philippe/gdb/git/build_termours/gdb/testsuite/outputs/gdb.base/attach/attach
exec-file-mismatch handling is currently "ask"
as the build-ids differ when an exec-file is recompiled.
This patch ensures that the exec-file-mismatch check is done with an up to date
build-id. With this, exec-file-mismatch check will only trigger when the
PID file really differs from the (build-id refreshed) current exec-file.
Note that the additional check does not (yet) reload the symbols if
the exec-file is changed: this reload will happen later if needed.
gdb/ChangeLog
2020-06-21 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* exec.c (validate_exec_file): Ensure the build-id is up to
date by calling reopen_exec_file (that checks file timestamp
to decide to re-read the file).
gdb/testsuite/ChangeLog
2020-06-21 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/attach.exp: Test priority of 'exec-file' changed
over 'exec-file-mismatch'.
* gdb.base/attach.c: Mark should_exit volatile.
* gdb.base/attach2.c: Likewise. Add a comment explaining
why the sleep cannot be big.
* gdb.base/attach3.c: New file.
In PR 25412, Simon noticed that after the multi-target series, the
tid-reuse.exp testcase manages to create a duplicate thread in the
thread list. Or rather, two threads with the same PTID.
add_thread_silent has code in place to detect the case of a new thread
reusing some older thread's ptid, but it doesn't work correctly
anymore when the old thread is NOT the current thread and it has a
refcount higher than 0. Either condition prevents a thread from being
deleted, but the refcount case wasn't being considered. I think the
reason that case wasn't considered is that that code predates
thread_info refcounting. Back when it was originally written,
delete_thread always deleted the thread.
That add_thread_silent code in question has some now-unnecessary
warts, BTW. For instance, this:
/* Make switch_to_thread not read from the thread. */
new_thr->state = THREAD_EXITED;
... used to be required because switch_to_thread would update
'stop_pc' otherwise. I.e., it would read registers from an exited
thread otherwise. switch_to_thread no longer reads the stop_pc, since:
commit f2ffa92bbc
Author: Pedro Alves <palves@redhat.com>
AuthorDate: Thu Jun 28 20:18:24 2018 +0100
gdb: Eliminate the 'stop_pc' global
Also, if the ptid of the now-gone current thread is reused, we
currently return from add_thread_silent with the current thread
pointing at the _new_ thread. Either pointing at the old thread, or
at no thread selected would be reasonable. But pointing at an
unrelated thread (the new thread that happens to reuse the ptid) is
just broken. Seems like I was the one who wrote it like that but I
have no clue why, FWIW.
Currently, an exited thread kept in the thread list still holds its
original ptid. The idea was that we need the ptid to be able to
temporarily switch to another thread and then switch back to the
original thread, because thread switching is really inferior_ptid
switching. Switching back to the original thread requires a ptid
lookup.
Now, in order to avoid exited threads with the same ptid as a live
thread in the same thread list, one thing I considered (and tried) was
to change an exited thread's ptid to minus_one_ptid. However, with
that, there's a case that we won't handle well, which is if we end up
with more than one exited thread in the list, since then all exited
threads will all have the same ptid. Since inferior_thread() relies
on inferior_ptid, may well return the wrong thread.
My next attempt to address this, was to switch an exited thread's ptid
to a globally unique "exited" ptid, which is a ptid with pid == -1 and
tid == 'the thread's global GDB thread number'. Note that GDB assumes
that the GDB global thread number is monotonically increasing and
doesn't wrap around. (We should probably make GDB thread numbers
64-bit to prevent that happening in practice; they're currently signed
32-bit.) This attempt went a long way, but still ran into a number of
issues. It was a major hack too, obviously.
My next attempt is the one that I'm proposing, which is to bite the
bullet and break the connection between inferior_ptid and
inferior_thread(), aka the current thread. I.e., make the current
thread be a global thread_info pointer that is written to directly by
switch_to_thread, etc., and making inferior_thread() return that
pointer, instead of having inferior_thread() lookup up the
inferior_ptid thread, by ptid_t. You can look at this as a
continuation of the effort of using more thread_info pointers instead
of ptids when possible.
By making the current thread a global thread_info pointer, we can make
switch_to_thread simply write to the global thread pointer, which
makes scoped_restore_current_thread able to restore back to an exited
thread without relying on unrelyable ptid look ups. I.e., this makes
it not a real problem to have more than one thread with the same ptid
in the thread list. There will always be only one live thread with a
given ptid, so code that looks up a live thread by ptid will always be
able to find the right one.
This change required auditing the whole codebase for places where we
were writing to inferior_ptid directly to change the current thread,
and change them to use switch_to_thread instead or one of its
siblings, because otherwise inferior_thread() would return a thread
unrelated to the changed-to inferior_ptid. That was all (hopefully)
done in previous patches.
After this, inferior_ptid is mainly used by target backend code. It
is also relied on by a number of target methods. E.g., the
target_resume interface and the memory reading routines -- we still
need it there because we need to be able to access memory off of
processes for which we don't have a corresponding inferior/thread
object, like when handling forks. Maybe we could pass down a context
explicitly to target_read_memory, etc.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
PR gdb/25412
* gdbthread.h (delete_thread, delete_thread_silent)
(find_thread_ptid): Update comments.
* thread.c (current_thread_): New global.
(is_current_thread): Move higher, and reimplement.
(inferior_thread): Reimplement.
(set_thread_exited): Use bool. Add assertions.
(add_thread_silent): Simplify thread-reuse handling by always
calling delete_thread.
(delete_thread): Remove intro comment.
(find_thread_ptid): Skip exited threads.
(switch_to_thread_no_regs): Write to current_thread_.
(switch_to_no_thread): Check CURRENT_THREAD_ instead of
INFERIOR_PTID. Clear current_thread_.
There are other writes in the file, but they seem more harmless. This
one is changing the current thread permanently.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* aix-thread.c (pd_update): Use switch_to_thread.
Writing to inferior_ptid in
windows_nat_target::get_windows_debug_event is just incorrect and not
necessary. We'll report the event to GDB's core, which then takes
care of switching inferior_ptid / current thread.
Related (see windows_nat_target::get_windows_debug_event), there's
also a "current_windows_thread" global that is just begging to get out
of sync with core GDB's current thread. This patch removes it.
gdbserver already does not have an equivalent global in win32-low.cc.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* nat/windows-nat.c (current_windows_thread): Remove.
* nat/windows-nat.h (current_windows_thread): Remove.
* windows-nat.c (windows_nat_target::stopped_by_sw_breakpoint):
Adjust.
(display_selectors): Adjust to fetch the current
windows_thread_info based on inferior_ptid.
(fake_create_process): No longer write to current_windows_thread.
(windows_nat_target::get_windows_debug_event):
Don't set inferior_ptid or current_windows_thread.
(windows_nat_target::wait): Adjust to not rely on
current_windows_thread.
(do_initial_windows_stuff): Now a method of windows_nat_target.
Switch to the last_ptid thread.
(windows_nat_target::attach): Adjust.
(windows_nat_target::detach): Use switch_to_no_thread instead of
writing to inferior_ptid directly.
(windows_nat_target::create_inferior): Adjust.
The inferior_ptid hack in do_initial_win32_stuff, added back in 2008:
https://sourceware.org/ml/gdb-patches/2008-10/msg00012.html
with:
commit 9f9d052e60
Author: Pierre Muller <muller@sourceware.org>
AuthorDate: Thu Oct 2 14:20:07 2008 +0000
* win32-nat.c (do_initial_win32_stuff): Set inferior_ptid.
is no longer needed. Back then, current_inferior looked like this:
struct inferior*
current_inferior (void)
{
struct inferior *inf = find_inferior_pid (ptid_get_pid (inferior_ptid));
gdb_assert (inf);
return inf;
}
Nowadays, current_inferior() just returns the global current_inferior_
pointer, which didn't exist back then.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* windows-nat.c (do_initial_windows_stuff): No longer set inferior_ptid.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* go32-nat.c (go32_nat_target::create_inferior): Switch to thread
after creating it, instead of writing to inferior_ptid. Don't
write to inferior_ptid.
This is no longer necessary. All targets that call fork_inferior now
also call switch_to_thread as soon as they add the main thread.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* fork-child.c (postfork_hook): Don't write to inferior_ptid.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* bsd-kvm.c (bsd_kvm_target_open): Switch to thread after adding
it, instead of writing to inferior_ptid.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* bsd-kvm.c (bsd_kvm_target::close): Use switch_to_no_thread
instead of writing to inferior_ptid directly.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* corelow.c (core_target::close): Use switch_to_no_thread instead
of writing to inferior_ptid directly.
(add_to_thread_list, core_target_open): Use switch_to_thread
instead of writing to inferior_ptid directly.
Untested.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* darwin-nat.c (darwin_nat_target::decode_message): Don't write to
inferior_ptid.
(darwin_nat_target::stop_inferior, darwin_nat_target::kill): Avoid
inferior_ptid.
(darwin_attach_pid): Use switch_to_no_thread instead of writing to
inferior_ptid directly.
(darwin_nat_target::init_thread_list): Switch to thread, instead
of writing to inferior_ptid.
(darwin_nat_target::attach): Don't write to inferior_ptid.
(darwin_nat_target::get_ada_task_ptid): Avoid inferior_ptid.
Untested.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* gnu-nat.c (gnu_nat_target::create_inferior): Switch to the added
thread.
(gnu_nat_target::attach): Don't write to inferior_ptid directly.
Instead use switch_to_thread.
(gnu_nat_target::detach): Use switch_to_no_thread
instead of writing to inferior_ptid directly. Used passed-in
inferior instead of looking up the inferior by pid.
generic_mourn_inferior already takes care of switching to no thread.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* go32-nat.c (go32_nat_target::create_inferior): Don't write to
inferior_ptid.
A best effort patch, which fixes some bit rot and removes some
inferior_ptid references -- this port clearly hasn't been built in a
long while.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* nto-procfs.c (nto_procfs_target::update_thread_list): Avoid
inferior_ptid.
(nto_procfs_target::attach): Avoid inferior_ptid. Switch to
thread.
(nto_procfs_target::detach): Avoid referencing
inferior_ptid. Use switch_to_no_thread instead of writing to
inferior_ptid directly.
(nto_procfs_target::mourn_inferior): Use switch_to_no_thread
instead of writing to inferior_ptid directly.
(nto_procfs_target::create_inferior): Avoid inferior_ptid. Switch
to thread.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* remote-sim.c (gdbsim_target::create_inferior): Switch to thread
after creating it, instead of writing to inferior_ptid.
(gdbsim_target_open): Use switch_to_no_thread instead of writing
to inferior_ptid directly.
(gdbsim_target::wait): Don't write to inferior_ptid.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* remote.c (remote_target::remote_notice_new_inferior): Use
switch_to_thread instead of writing to inferior_ptid directly.
(remote_target::add_current_inferior_and_thread): Use
switch_to_no_thread instead of writing to inferior_ptid directly.
(extended_remote_target::attach): Use switch_to_inferior_no_thread
and switch_to_thread instead of using set_current_inferior or
writing to inferior_ptid directly.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* tracectf.c (ctf_target_open): Switch to added thread instead of
writing to inferior_ptid directly.
(ctf_target::close): Use switch_to_no_thread instead of writing to
inferior_ptid directly.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* tracefile-tfile.c (tfile_target_open): Don't write to
inferior_ptid directly, instead switch to added thread.
(tfile_target::close): Use switch_to_no_thread instead of writing
to inferior_ptid directly.
The inferior_ptid write in procfs_do_thread_registers should be
unnecessary because the target_fetch_registers method should (and
does) extract the ptid from the regcache.
Not tested.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* procfs.c (procfs_target::attach): Don't write to inferior_ptid.
(procfs_target::detach): Use switch_to_no_thread
instead of writing to inferior_ptid directly.
(do_attach): Change return type to void. Switch to the added
thread.
(procfs_target::create_inferior): Switch to the added thread.
(procfs_do_thread_registers): Don't write to inferior_ptid.
gdb/ChangeLog:
2020-06-18 Pedro Alves <palves@redhat.com>
* infrun.c (generic_mourn_inferior): Use switch_to_thread instead
of writing to inferior_ptid.
(scoped_restore_exited_inferior): Delete.
(handle_vfork_child_exec_or_exit): Simplify using
scoped_restore_current_pspace_and_thread. Use switch_to_thread
instead of writing to inferior_ptid.
(THREAD_STOPPED_BY): Delete.
(thread_stopped_by_watchpoint, thread_stopped_by_sw_breakpoint)
(thread_stopped_by_hw_breakpoint): Delete.
(save_waitstatus): Use
scoped_restore_current_thread+switch_to_thread, and call
target_stopped_by_watchpoint instead of
thread_stopped_by_watchpoint, target_stopped_by_sw_breakpoint
instead of thread_stopped_by_sw_breakpoint, and
target_stopped_by_hw_breakpoint instead of
thread_stopped_by_hw_breakpoint.
(handle_inferior_event)
<TARGET_WAITKIND_EXITED/TARGET_WAITKIND_SIGNALLED>: Don't write to
inferior_ptid directly, nor
set_current_inferior/set_current_program_space. Use
switch_to_thread / switch_to_inferior_no_thread instead.
Andrew Burgess
Rainer Orth
Philippe Waroquiers
Simon Marchi
Pedro Alves
Tankut Baris Aktemur