While working on the previous commit to fix PR cli/28665, I noticed
that the 'edit' command would suffer from the same problem. That is,
something like:
(gdb) edit task 123
would cause GDB to break. For a full explanation of what's going on
here, see the commit message for the previous commit.
As with the previous commit, this issue can be prevented by detecting,
and throwing, a junk at the end of the line error earlier, before
calling decode_line_1.
So, that's what this commit does. I've also added some tests for this
issue.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28665
In PR cli/28665, it was reported that GDB would crash when given a
command like:
(gdb) list task 123
The problem here is that in cli/cli-cmd.c:list_command, the string
'task 123' is passed to string_to_event_location in find a location
specification. However, this location parsing understands about
breakpoint conditions, and so, will stop parsing when it sees
something that looks like a condition, in this case, the 'task 123'
looks like a breakpoint condition.
As a result, the location we get back from string_to_event_location
has no actual location specification attached to it. The actual call
path is:
list_command
string_to_event_location
string_to_event_location_basic
new_linespec_location
In new_linespec_location we call linespec_lex_to_end, which looks at
'task 123' and decides that there's nothing there that describes a
location. As such, in new_linespec_location, the spec_string field of
the location is left as nullptr.
Back in list_command we then call decode_line_1, which calls
event_location_to_sals, which calls parse_linespec, which takes the
spec_string we found earlier, and tries to converts this into a list
of sals.
However, parse_linespec is not intended to be passed a nullptr, for
example, calling is_ada_operator will try to access through the
nullptr, causing undefined behaviour. But there are other cases
within parse_linespec which don't expect to see a nullptr.
When looking at how to fix this issue, I first considered having
linespec_lex_to_end detect the problem. That function understands
when the first thing in the linespec is a condition keyword, and so,
could throw an error saying something like: "no linespec before
condition keyword", however, this is not going to work, at least, not
without additional changes to GDB, it is valid to place a breakpoint
like:
(gdb) break task 123
This will place a breakpoint at the current location with the
condition 'task 123', and changing linespec_lex_to_end breaks this
behaviour.
So, next, I considered what would happen if I added a condition to an
otherwise valid list command, this is what I see:
(gdb) list file.c:1 task 123
Junk at end of line specification.
(gdb)
So, then I wondered, could we just pull the "Junk" detection forward,
so that we throw the error earlier, before we call decode_line_1?
It turns out that yes we can. Well, sort of.
It is simpler, I think, to add a separate check into the list_command
function, after calling string_to_event_location, but before calling
decode_line_1. We know when we call string_to_event_location that the
string in question is not empty, so, after calling
string_to_event_location, if non of the string has been consumed, then
the content of the string must be junk - it clearly doesn't look like
a location specification.
I've reused the same "Junk at end of line specification." error for
consistency, and added a few tests to cover this issue.
While the first version of this patch was on the mailing list, a
second bug PR gdb/28797 was raised. This was for a very similar
issue, but this time the problem command was:
(gdb) list ,,
Here the list command understands about the first comma, list can have
two arguments separated by a comma, and the first argument can be
missing. So we end up trying to parse the second command "," as a
linespec.
However, in linespec_lex_to_end, we will stop parsing a linespec at a
comma, so, in the above case we end up with an empty linespec (between
the two commas), and, like above, this results in the spec_string
being nullptr.
As with the previous case, I've resolved this issue by adding an extra
check for junk at the end of the line - after parsing (or failing to
parse) the nothing between the two commas, we still have the "," left
at the end of the list command line - when we see this we can throw
the same "junk at the end of the line" error, and all is good.
I've added tests for this case too.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28665
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28797
I think it only really makes sense to call wrap_here with an argument
consisting solely of spaces. Given this, it seemed better to me that
the argument be an int, rather than a string. This patch is the
result. Much of it was written by a script.
Many otherwise ordinary commands choose to use unfiltered output
rather than filtered. I don't think there's any reason for this, so
this changes many such commands to use filtered output instead.
Note that complete_command is not touched due to a comment there
explaining why unfiltered output is believed to be used.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
This command adds the "exit" command as an alias for the "quit"
command, as requested in PR gdb/28406.
The documentation is also updated to mention this new command.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28406
The motivation is to reduce the number of places where unmanaged
pointers are returned from allocation type routines. All of the
callers are updated.
There should be no user visible changes after this commit.
The 'show user' command (which shows the definition of non-python/scheme
user defined commands) is currently missing a completer. This is
mentioned in PR 16238. Having one can improve the user experience.
In this commit I propose an implementation for such completer as well as
the associated tests.
Tested on x86_64 GNU/Linux.
All feedbacks are welcome.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=16238
There's a common pattern to call add_basic_prefix_cmd and
add_show_prefix_cmd to add matching set and show commands. Add the
add_setshow_prefix_cmd function to factor that out and use it at a few
places.
Change-Id: I6e9e90a30e9efb7b255bf839cac27b85d7069cfd
The bug fixed by this [1] patch was caused by an out-of-bounds access to
a value's content. The code gets the value's content (just a pointer)
and then indexes it with a non-sensical index.
This made me think of changing functions that return value contents to
return array_views instead of a plain pointer. This has the advantage
that when GDB is built with _GLIBCXX_DEBUG, accesses to the array_view
are checked, making bugs more apparent / easier to find.
This patch changes the return types of these functions, and updates
callers to call .data() on the result, meaning it's not changing
anything in practice. Additional work will be needed (which can be done
little by little) to make callers propagate the use of array_view and
reap the benefits.
[1] https://sourceware.org/pipermail/gdb-patches/2021-September/182306.html
Change-Id: I5151f888f169e1c36abe2cbc57620110673816f3
String-like settings (var_string, var_filename, var_optional_filename,
var_string_noescape) currently take a pointer to a `char *` storage
variable (typically global) that holds the setting's value. I'd like to
"mordernize" this by changing them to use an std::string for storage.
An obvious reason is that string operations on std::string are often
easier to write than with C strings. And they avoid having to do any
manual memory management.
Another interesting reason is that, with `char *`, nullptr and an empty
string often both have the same meaning of "no value". String settings
are initially nullptr (unless initialized otherwise). But when doing
"set foo" (where `foo` is a string setting), the setting now points to
an empty string. For example, solib_search_path is nullptr at startup,
but points to an empty string after doing "set solib-search-path". This
leads to some code that needs to check for both to check for "no value".
Or some code that converts back and forth between NULL and "" when
getting or setting the value. I find this very error-prone, because it
is very easy to forget one or the other. With std::string, we at least
know that the variable is not "NULL". There is only one way of
representing an empty string setting, that is with an empty string.
I was wondering whether the distinction between NULL and "" would be
important for some setting, but it doesn't seem so. If that ever
happens, it would be more C++-y and self-descriptive to use
optional<string> anyway.
Actually, there's one spot where this distinction mattered, it's in
init_history, for the test gdb.base/gdbinit-history.exp. init_history
sets the history filename to the default ".gdb_history" if it sees that
the setting was never set - if history_filename is nullptr. If
history_filename is an empty string, it means the setting was explicitly
cleared, so it leaves it as-is. With the change to std::string, this
distinction doesn't exist anymore. This can be fixed by moving the code
that chooses a good default value for history_filename to
_initialize_top. This is ran before -ex commands are processed, so an
-ex command can then clear that value if needed (what
gdb.base/gdbinit-history.exp tests).
Another small improvement, in my opinion is that we can now easily
give string parameters initial values, by simply initializing the global
variables, instead of xstrdup-ing it in the _initialize function.
In Python and Guile, when registering a string-like parameter, we
allocate (with new) an std::string that is owned by the param_smob (in
Guile) and the parmpy_object (in Python) objects.
This patch started by changing all relevant add_setshow_* commands to
take an `std::string *` instead of a `char **` and fixing everything
that failed to build. That includes of course all string setting
variable and their uses.
string_option_def now uses an std::string also, because there's a
connection between options and settings (see
add_setshow_cmds_for_options).
The add_path function in source.c is really complex and twisted, I'd
rather not try to change it to work on an std::string right now.
Instead, I added an overload that copies the std:string to a `char *`
and back. This means more copying, but this is not used in a hot path
at all, so I think it is acceptable.
Change-Id: I92c50a1bdd8307141cdbacb388248e4e4fc08c93
Co-authored-by: Lancelot SIX <lsix@lancelotsix.com>
cmd_list_element can contain a pointer to data that can be set and / or
shown. This is achieved with the void* VAR member which points to the
data that can be accessed, while the VAR_TYPE member (of type enum
var_types) indicates how to interpret the data pointed to.
With this pattern, the user of the cmd_list_element needs to know what
is the storage type associated with a given VAR_TYPES in order to do
the proper casting. No automatic safeguard is available to prevent
miss-use of the pointer. Client code typically looks something like:
switch (c->var_type)
{
case var_zuinteger:
unsigned int v = *(unsigned int*) c->var;
...
break;
case var_boolean:
bool v = *(bool *) c->var;
...
break;
...
}
This patch proposes to add an abstraction around the var_types and void*
pointer pair. The abstraction is meant to prevent the user from having
to handle the cast and verify that the data is read or written as a type
that is coherent with the setting's var_type. This is achieved by
introducing the struct setting which exposes a set of templated get /
set member functions. The template parameter is the type of the
variable that holds the referred variable.
Using those accessors allows runtime checks to be inserted in order to
ensure that the data pointed to has the expected type. For example,
instantiating the member functions with bool will yield something
similar to:
const bool &get<bool> () const
{
gdb_assert (m_var_type == var_boolean);
gdb_assert (m_var != nullptr);
return *static_cast<bool *> (m_var);
}
void set<bool> (const bool &var)
{
gdb_assert (m_var_type == var_boolean);
gdb_assert (m_var != nullptr);
*static_cast<bool *> (m_var) = var;
}
Using the new abstraction, our initial example becomes:
switch (c->var_type)
{
case var_zuinteger:
unsigned int v = c->var->get<unsigned int> ();
...
break;
case var_boolean:
bool v = c->var->get<bool> ();
...
break;
...
}
While the call site is still similar, the introduction of runtime checks
help ensure correct usage of the data.
In order to avoid turning the bulk of add_setshow_cmd_full into a
templated function, and following a suggestion from Pedro Alves, a
setting can be constructed from a pre validated type erased reference to
a variable. This is what setting::erased_args is used for.
Introducing an opaque abstraction to describe a setting will also make
it possible to use callbacks to retrieve or set the value of the setting
on the fly instead of pointing to a static chunk of memory. This will
be done added in a later commit.
Given that a cmd_list_element may or may not reference a setting, the
VAR and VAR_TYPES members of the struct are replaced with a
gdb::optional<setting> named VAR.
Few internal function signatures have been modified to take into account
this new abstraction:
-The functions value_from_setting, str_value_from_setting and
get_setshow_command_value_string used to have a 'cmd_list_element *'
parameter but only used it for the VAR and VAR_TYPE member. They now
take a 'const setting &' parameter instead.
- Similarly, the 'void *' and a 'enum var_types' parameters of
pascm_param_value and gdbpy_parameter_value have been replaced with a
'const setting &' parameter.
No user visible change is expected after this patch.
Tested on GNU/Linux x86_64, with no regression noticed.
Co-authored-by: Simon Marchi <simon.marchi@polymtl.ca>
Change-Id: Ie1d08c3ceb8b30b3d7bf1efe036eb8acffcd2f34
In some situations it is possible that a user might not want GDB to
try and access source code files, for example, the source code might
be stored on a slow to access network file system.
It is almost certainly possible that using some combination of 'set
directories' and/or 'set substitute-path' a user can trick GDB into
being unable to find the source files, but this feels like a rather
crude way to solve the problem.
In this commit a new option is add that stops GDB from opening and
reading the source files. A user can run with source code reading
disabled if this is required, then re-enable later if they decide
that they now want to view the source code.
After browsing the CLI code for quite a while and trying really hard, I
reached the conclusion that I can't give a meaningful explanation of
what "sfunc" and "cfunc" functions are, in cmd_list_element. I don't
see a logic at all. That makes it very difficult to do any kind of
change. Unless somebody can make sense out of all that, I'd like to try
to retro-fit some logic in the cmd_list_element callback function code
so that we can understand what is going on, do some cleanups and add new
features.
The first change is about "cfunc". I can't figure out what the "c" in
cfunc means. It's not const, because there's already "const" in
"cmd_const_cfunc_ftype", and the previous "cmd_cfunc_ftype" had nothing
const.. It's not "cmd" or "command", because there's already "cmd" in
"cmd_const_cfunc_ftype".
The "main" command callback, cmd_list_element::func, has three
parameters, whereas cfunc has two. It is missing the cmd_list_element
parameter. So the only reason I see for cfunc to exist is to be a shim
between the three and two parameter versions. Most commands don't need
to receive the cmd_list_element object, so adding it everywhere would be
long and would just add more unnecessary boilerplate. So since this is
the "simple" version of the callback, compared to the "full", I suggest
renaming cmd_const_cfunc_ftype into cmd_simple_func_ftype, as well as
everything (like the utility functions) that goes with it.
Change-Id: I4e46cacfd77a66bc1cbf683f6a362072504b7868
Same idea as previous patch, but for add_alias_cmd. Remove the overload
that accepts the target command as a string (the target command name),
leaving only the one that takes the cmd_list_element.
gdb/ChangeLog:
* command.h (add_alias_cmd): Accept target as
cmd_list_element. Update callers.
Change-Id: I546311f411e9e7da9302322d6ffad4e6c56df266
The alias creation functions currently accept a name to specify the
target command. They pass this to add_alias_cmd, which needs to lookup
the target command by name.
Given that:
- We don't support creating an alias for a command before that command
exists.
- We always use add_info_alias just after creating that target command,
and therefore have access to the target command's cmd_list_element.
... change add_com_alias to accept the target command as a
cmd_list_element (other functions are done in subsequent patches). This
ensures we don't create the alias before the target command, because you
need to get the cmd_list_element from somewhere when you call the alias
creation function. And it avoids an unecessary command lookup. So it
seems better to me in every aspect.
gdb/ChangeLog:
* command.h (add_com_alias): Accept target as
cmd_list_element. Update callers.
Change-Id: I24bed7da57221cc77606034de3023fedac015150
Same idea as the previous patch, but for prefix instead of alias.
gdb/ChangeLog:
* cli/cli-decode.h (cmd_list_element) <is_prefix>: New, use it.
Change-Id: I76a9d2e82fc8d7429904424674d99ce6f9880e2b
While browsing this code, I found the name "prefixlist" really
confusing. I kept reading it as "list of prefixes". Which it isn't:
it's a list of sub-commands, for a prefix command. I think that
renaming it to "subcommands" would make things clearer.
gdb/ChangeLog:
* Rename "prefixlist" parameters to "subcommands" throughout.
* cli/cli-decode.h (cmd_list_element) <prefixlist>: Rename to...
<subcommands>: ... this.
* cli/cli-decode.c (lookup_cmd_for_prefixlist): Rename to...
(lookup_cmd_with_subcommands): ... this.
Change-Id: I150da10d03052c2420aa5b0dee41f422e2a97928
Previously, the prefixname field of struct cmd_list_element was manually
set for prefix commands. This seems verbose and error prone as it
required every single call to functions adding prefix commands to
specify the prefix name while the same information can be easily
generated.
Historically, this was not possible as the prefix field was null for
many commands, but this was fixed in commit
3f4d92ebdf by Philippe Waroquiers, so
we can rely on the prefix field being set when generating the prefix
name.
This commit also fixes a use after free in this scenario:
* A command gets created via Python (using the gdb.Command class).
The prefix name member is dynamically allocated.
* An alias to the new command is created. The alias's prefixname is set
to point to the prefixname for the original command with a direct
assignment.
* A new command with the same name as the Python command is created.
* The object for the original Python command gets freed and its
prefixname gets freed as well.
* The alias is updated to point to the new command, but its prefixname
is not updated so it keeps pointing to the freed one.
gdb/ChangeLog:
* command.h (add_prefix_cmd): Remove the prefixname argument as
it can now be generated automatically. Update all callers.
(add_basic_prefix_cmd): Ditto.
(add_show_prefix_cmd): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_abbrev_prefix_cmd): Ditto.
* cli/cli-decode.c (add_prefix_cmd): Ditto.
(add_basic_prefix_cmd): Ditto.
(add_show_prefix_cmd): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_prefix_cmd_suppress_notification): Ditto.
(add_abbrev_prefix_cmd): Ditto.
* cli/cli-decode.h (struct cmd_list_element): Replace the
prefixname member variable with a method which generates the
prefix name at runtime. Update all code reading the prefix
name to use the method, and remove all code setting it.
* python/py-cmd.c (cmdpy_destroyer): Remove code to free the
prefixname member as it's now a method.
(cmdpy_function): Determine if the command is a prefix by
looking at prefixlist, not prefixname.
Before this patch:
(gdb) source ~/script.scm
ERROR: In procedure apply-smob/1:
ERROR: In procedure primitive-load-path: Unable to find file "~/script.scm" in load path
Error while executing Scheme code.
(gdb)
This is because the path is not tilde expanded. In contrast, when
sourcing a .py or .gdb script the path is tilde expanded.
This commit fixes this oversight, and allows the above source command
to work as expected.
The tilde expansion is done in the generic GDB code before we call the
sourcer function for any particular extension language.
gdb/ChangeLog:
* cli/cli-cmds.c: Add 'gdbsupport/gdb_tilde_expand.h'
include.
(source_script_with_search): Perform tilde expansion.
gdb/testsuite/ChangeLog:
* gdb.guile/guile.exp: Add an extra test.
Commands "set debug remote" and "set remotetimeout" are defined in
cli/cli-cmds.c, I think it would make more sense for them to be in
remote.c.
gdb/ChangeLog:
* cli/cli-cmds.c (show_remote_debug): Remove.
(show_remote_timeout): Remove.
(_initialize_cli_cmds): Don't register commands.
* remote.c (show_remote_debug): Move here.
(show_remote_timeout): Move here.
(_initialize_remote): Register commands.
Change-Id: Ic4d81888aa4f8dde89d1d29397ef19a08951b80b
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
We currently have two flushing commands 'flushregs' and 'maint
flush-symbol-cache'. I'm planning to add at least one more so I
thought it might be nice if we bundled these together into one place.
And so I created the 'maint flush ' command prefix. Currently there
are two commands:
(gdb) maint flush symbol-cache
(gdb) maint flush register-cache
Unfortunately, even though both of the existing flush commands are
maintenance commands, I don't know how keen we about deleting existing
commands for fear of breaking things in the wild. So, both of the
existing flush commands 'maint flush-symbol-cache' and 'flushregs' are
still around as deprecated aliases to the new commands.
I've updated the testsuite to use the new command syntax, and updated
the documentation too.
gdb/ChangeLog:
* NEWS: Mention new commands, and that the old commands are now
deprecated.
* cli/cli-cmds.c (maintenanceflushlist): Define.
* cli/cli-cmds.h (maintenanceflushlist): Declare.
* maint.c (_initialize_maint_cmds): Initialise
maintenanceflushlist.
* regcache.c: Add 'cli/cli-cmds.h' include.
(reg_flush_command): Add header comment.
(_initialize_regcache): Create new 'maint flush register-cache'
command, make 'flushregs' an alias.
* symtab.c: Add 'cli/cli-cmds.h' include.
(_initialize_symtab): Create new 'maint flush symbol-cache'
command, make old command an alias.
gdb/doc/ChangeLog:
* gdb.texinfo (Symbols): Document 'maint flush symbol-cache'.
(Maintenance Commands): Document 'maint flush register-cache'.
gdb/testsuite/ChangeLog:
* gdb.base/c-linkage-name.exp: Update to use new 'maint flush ...'
commands.
* gdb.base/killed-outside.exp: Likewise.
* gdb.opt/inline-bt.exp: Likewise.
* gdb.perf/gmonster-null-lookup.py: Likewise.
* gdb.perf/gmonster-print-cerr.py: Likewise.
* gdb.perf/gmonster-ptype-string.py: Likewise.
* gdb.python/py-unwind.exp: Likewise.
I noticed a couple of spots where the "disassemble" could style its
output, but currently does not. This patch adds styling to the
function name at the start of the disassembly, and any addresses
printed there.
gdb/ChangeLog
2020-10-08 Tom Tromey <tom@tromey.com>
* cli/cli-cmds.c (print_disassembly): Style function name and
addresses. Add _() wrappers.
gdb/testsuite/ChangeLog
2020-10-08 Tom Tromey <tom@tromey.com>
* gdb.base/style.exp: Check that "main"'s name is styled.
Andrew Burgess pointed out a regression, which he described in
PR symtab/26270:
================
After commit:
commit bcfe6157ca (refs/bisect/bad)
Date: Fri Apr 24 15:35:01 2020 -0600
Use the linkage name if it exists
The disassembler no longer demangles function names in its output. So
we see things like this:
(gdb) disassemble tree_insert
Dump of assembler code for function _Z11tree_insertP4nodei:
....
Instead of this:
(gdb) disassemble tree_insert
Dump of assembler code for function tree_insert(node*, int):
....
This is because find_pc_partial_function now returns the linkage name
rather than the demangled name.
================
This patch fixes the problem by introducing a new "overload" of
find_pc_partial_function, which returns the general_symbol_info rather
than simply the name. This lets the disassemble command choose which
name to show.
Regression tested on x86-64 Fedora 32.
gdb/ChangeLog
2020-07-28 Tom Tromey <tromey@adacore.com>
PR symtab/26270:
* symtab.h (find_pc_partial_function_sym): Declare.
* cli/cli-cmds.c (disassemble_command): Use
find_pc_partial_function_sym. Check asm_demangle.
* blockframe.c (cache_pc_function_sym): New global.
(cache_pc_function_name): Remove.
(clear_pc_function_cache): Update.
(find_pc_partial_function_sym): New function, from
find_pc_partial_function.
(find_pc_partial_function): Rewrite using
find_pc_partial_function_sym.
gdb/testsuite/ChangeLog
2020-07-28 Andrew Burgess <andrew.burgess@embecosm.com>
PR symtab/26270:
* gdb.cp/disasm-func-name.cc: New file.
* gdb.cp/disasm-func-name.exp: New file.
Pedro pointed out that disassemble/m should be documented after
disassemble/s, because /m is deprecated. This patch does so, and adds
a usage line.
Regression tested on x86-64 Fedora 32.
gdb/ChangeLog
2020-07-28 Tom Tromey <tromey@adacore.com>
* cli/cli-cmds.c (_initialize_cli_cmds): Rearrange "disassemble"
help. Add usage.
The cmd_type function only has a single caller, which is in the CLI
implementation code. This patch removes the function, and moves the
cmd_types enum definition from command.h to cli-decode.h, fixing an 18
year old FIXME.
gdb/ChangeLog
2020-06-28 Tom Tromey <tom@tromey.com>
* command.h (cmd_types): Remove.
(cmd_type): Don't declare.
* cli/cli-decode.h (enum cmd_types): Uncomment. No longer a
typedef.
* cli/cli-cmds.c (setting_cmd): Use cmd->type directly.
* cli/cli-decode.c (cmd_type): Remove.
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.
Before this change, "help" was not showing the TUI class.
With this change:
(gdb) help
...
support -- Support facilities.
text-user-interface -- TUI is the GDB text based interface.
tracepoints -- Tracing of program execution without stopping the program.
...
(gdb) help text-user-interface
TUI is the GDB text based interface.
In TUI mode, GDB can display several text windows showing
the source file, the processor registers, the program disassembly, ...
List of commands:
+ -- Scroll window forward.
...
Note that we cannot use "tui" for the fake class command name, as "tui"
is a command.
gdb/ChangeLog
2020-05-26 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* command.h: Add comment giving the name of class_tui.
* cli/cli-cmds.c (_initialize_cli_cmds): If TUI defined,
create the fake command for the help for class_tui.
Currently, help CLASS possibly shows several times the same help,
as it shows it once for the command, and once for each alias.
The final objective of this patch series is to have class_alias used only
for user defined aliases, not anymore for aliases predefined by GDB.
The command 'help aliases' will then only show the user defined aliases.
So, the idea is that GDB predefined aliases will be shown together
with their aliased command.
This commit changes 'help CLASS' so that a command is shown once in the output,
with all its aliases.
This ensures:
* that the user has only to read once the same help text
* and sees the command and all its aliases in a glance, a.o. allowing
the user to choose the preferred way (e.g. the shortest one,
or the most mnemonic one) to type the command.
For example, the old output:
(gdb) help stack
...
List of commands:
backtrace -- Print backtrace of all stack frames, or innermost COUNT frames.
bt -- Print backtrace of all stack frames, or innermost COUNT frames.
...
(note that 'where' is not shown in this output)
becomes
(gdb) help stack
...
List of commands:
backtrace, where, bt -- Print backtrace of all stack frames, or innermost COUNT frames.
...
The output layout chosen is to have the command first, followed by all its
aliases separated by a comma. Note that the command and alias names are
title-styled. For sure, other layouts could be discussed, but this one is IMO
readable and compact.
The function 'help_cmd_list' can be simplified by removing the prefix argument,
as the prefixname of a command can now be retrieved in the GDB command tree
structure.
This also fixes the fact that 'help aliases' wrongly shows a long
list of (non-alias) when defining an alias for a prefix command.
For example, after:
(gdb) alias montre = show
then
(gdb) help aliases
shows hundreds of sub-commands starting with the non aliased command,
such as:
montre -- Generic command for showing things about the debugger.
show ada -- Generic command for showing Ada-specific settings.
show ada print-signatures -- Show whether the output of formal ...
....
'help_cmd_list' is also made static, as it is only used inside cli-decode.c.
Note that the 'help CLASS' is somewhat broken, in the sense that it
sometimes shows too many commands (commands not belonging to CLASS)
and sometimes shows not enough commands (not showing some commands
belonging to CLASS).
For example, 'help breakpoints' shows the command
'disable pretty-printer' and 'disable unwinder', not related to breakpoints.
On the other end, 'help stack' does not show 'disable unwinder'
while 'disable unwinder' is defined in unwinders.py as belonging to class_stack.
Fixing the missing commands is easy to do,
but fixing the excess commands is not straightforward, as many
subcommands have a class 'no_class' or 'all_class'.
Possibly, some of this might be improved/fixed in another patch series.
With this patch series, the 'abbrev flag' has as only remaining purpose
to avoid having the abbreviation alias appearing in the completion list,
so change 'help alias' accordingly.
gdb/ChangeLog
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-decode.h (help_cmd_list): Remove declaration.
* cli/cli-decode.c (help_cmd_list): Declare as static,
remove prefix argument, use bool for recurse arg, rework to show the aliases of
a command together with the command.
(fput_command_name_styled, fput_command_names_styled): New functions.
(print_help_for_command): Remove prefix arg, use bool for recurse arg, use
fput_command_name_styled.
(help_list, help_all): Update callers to remove prefix arg and use bool recurse.
* cli/cli-cmds.c (_initialize_cli_cmds): Update alias_command doc.
gdb/testsuite/ChangeLog
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/alias.exp: Update help output check.
When an alias name starts with the name of another alias,
GDB was accepting to define the aliases in one order (short first, long after),
but refused it the other way around.
So, fix the logic to recognise an already existing alias by using
lookup_cmd_composition.
Also, this revealed a bug in lookup_cmd_composition:
when the searched command is a prefix command, lookup_cmd_composition
was not returning the fact that a command was found even if the
TEXT to parse was fully consumed.
gdb/ChangeLog
YYYY-MM-DD Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-cmds.c (alias_command): Check for an existing alias
using lookup_cmd_composition, as valid_command_p is too strict
and forbids aliases that are the prefix of an existing alias
or command.
* cli/cli-decode.c (lookup_cmd_composition): Ensure a prefix
command is properly recognised as a valid command.
gdb/testsuite/ChangeLog
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/alias.exp: Test aliases starting with a prefix of
another alias.
The next commit introduces a selftest that detects when the GDB
command structure does not define a tree when using the pointers
'next/*prefixlist'. This test detects one such case, fixed
by this commit.
The command 'info set' was defined as a specific prefix command,
but re-using the command list already used for the 'show' command.
This leads to the command tree 'next/*prefixlist' to not be a tree.
This change defines 'info set ' as an alias, thereby fixing the selftest.
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-cmds.c (_initialize_cli_cmds): Define 'info set' as
an alias of 'show'.
Remove TYPE_CODE, changing all the call sites to use type::code
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_CODE): Remove. Change all call sites to use
type::code instead.
As discussed on gdb-patches, this restores info_command and the
breakpoint on info_command in gdb-gdb.gdb. This reverts a tiny part
of 0743fc83c0 ("Replace most calls to help_list and cmd_show_list"),
as well as 652fc23a30 ("Remove gdb-gdb.gdb breakpoint on disappeared
function info_command.").
gdb/ChangeLog
2020-05-11 Tom Tromey <tromey@adacore.com>
* cli/cli-cmds.c (info_command): Restore.
(_initialize_cli_cmds): Use add_prefix_command for "info".
* gdb-gdb.gdb.in: Restore breakpoint on info_command.
Currently there are many prefix commands that do nothing but call
either help_list or cmd_show_list. I happened to notice that one such
call, for "set print type", used the wrong command list parameter,
causing incorrect output.
Rather than fix this bug in isolation, I decided to eliminate this
possibility by adding two new ways to add prefix commands, which
simply route the call to help_list or cmd_show_list, as appropriate.
This makes it impossible for a mismatch to occur.
In some cases, a bit of output was removed; however, I don't think
this output in general was very useful. It seemed redundant with
what's already printed by help_list. A representative example is this
hunk, removed from ada-lang.c:
- printf_unfiltered (_(\
-"\"set ada\" must be followed by the name of a setting.\n"));
This simplified the CLI style set/show commands quite a bit, and
allowed the deletion of a macro.
This also cleans up some unusual code in windows-tdep.c.
Tested on x86-64 Fedora 30. Note that I have no way to build the
go32-nat.c change.
gdb/ChangeLog
2020-04-17 Tom Tromey <tromey@adacore.com>
* auto-load.c (show_auto_load_cmd): Remove.
(auto_load_show_cmdlist_get): Use add_show_prefix_cmd.
* arc-tdep.c (_initialize_arc_tdep): Use add_show_prefix_cmd.
(maintenance_print_arc_command): Remove.
* tui/tui-win.c (tui_command): Remove.
(tui_get_cmd_list): Use add_basic_prefix_cmd.
* tui/tui-layout.c (tui_layout_command): Remove.
(_initialize_tui_layout): Use add_basic_prefix_cmd.
* python/python.c (user_set_python, user_show_python): Remove.
(_initialize_python): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* guile/guile.c (set_guile_command, show_guile_command): Remove.
(install_gdb_commands): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(info_guile_command): Remove.
* dwarf2/read.c (set_dwarf_cmd, show_dwarf_cmd): Remove.
(_initialize_dwarf2_read): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-style.h (class cli_style_option) <add_setshow_commands>:
Remove do_set and do_show parameters.
* cli/cli-style.c (set_style, show_style): Remove.
(_initialize_cli_style): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(cli_style_option::add_setshow_commands): Remove do_set and
do_show parameters.
(cli_style_option::add_setshow_commands): Use
add_basic_prefix_cmd, add_show_prefix_cmd.
(STYLE_ADD_SETSHOW_COMMANDS): Remove macro.
(set_style_name): Remove.
* cli/cli-dump.c (dump_command, append_command): Remove.
(srec_dump_command, ihex_dump_command, verilog_dump_command)
(tekhex_dump_command, binary_dump_command)
(binary_append_command): Remove.
(_initialize_cli_dump): Use add_basic_prefix_cmd.
* windows-tdep.c (w32_prefix_command_valid): Remove global.
(init_w32_command_list): Remove; move into ...
(_initialize_windows_tdep): ... here. Use add_basic_prefix_cmd.
* valprint.c (set_print, show_print, set_print_raw)
(show_print_raw): Remove.
(_initialize_valprint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* typeprint.c (set_print_type, show_print_type): Remove.
(_initialize_typeprint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* record.c (set_record_command, show_record_command): Remove.
(_initialize_record): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-cmds.c (_initialize_cli_cmds): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(info_command, show_command, set_debug, show_debug): Remove.
* top.h (set_history, show_history): Don't declare.
* top.c (set_history, show_history): Remove.
* target-descriptions.c (set_tdesc_cmd, show_tdesc_cmd)
(unset_tdesc_cmd): Remove.
(_initialize_target_descriptions): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* symtab.c (info_module_command): Remove.
(_initialize_symtab): Use add_basic_prefix_cmd.
* symfile.c (overlay_command): Remove.
(_initialize_symfile): Use add_basic_prefix_cmd.
* sparc64-tdep.c (info_adi_command): Remove.
(_initialize_sparc64_adi_tdep): Use add_basic_prefix_cmd.
* sh-tdep.c (show_sh_command, set_sh_command): Remove.
(_initialize_sh_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* serial.c (serial_set_cmd, serial_show_cmd): Remove.
(_initialize_serial): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ser-tcp.c (set_tcp_cmd, show_tcp_cmd): Remove.
(_initialize_ser_tcp): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* rs6000-tdep.c (set_powerpc_command, show_powerpc_command)
(_initialize_rs6000_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* riscv-tdep.c (show_riscv_command, set_riscv_command)
(show_debug_riscv_command, set_debug_riscv_command): Remove.
(_initialize_riscv_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* remote.c (remote_command, set_remote_cmd): Remove.
(_initialize_remote): Use add_basic_prefix_cmd.
* record-full.c (set_record_full_command)
(show_record_full_command): Remove.
(_initialize_record_full): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* record-btrace.c (cmd_set_record_btrace)
(cmd_show_record_btrace, cmd_set_record_btrace_bts)
(cmd_show_record_btrace_bts, cmd_set_record_btrace_pt)
(cmd_show_record_btrace_pt): Remove.
(_initialize_record_btrace): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ravenscar-thread.c (set_ravenscar_command)
(show_ravenscar_command): Remove.
(_initialize_ravenscar): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* mips-tdep.c (show_mips_command, set_mips_command)
(_initialize_mips_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* maint.c (maintenance_command, maintenance_info_command)
(maintenance_check_command, maintenance_print_command)
(maintenance_set_cmd, maintenance_show_cmd): Remove.
(_initialize_maint_cmds): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(show_per_command_cmd): Remove.
* maint-test-settings.c (maintenance_set_test_settings_cmd):
Remove.
(maintenance_show_test_settings_cmd): Remove.
(_initialize_maint_test_settings): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* maint-test-options.c (maintenance_test_options_command):
Remove.
(_initialize_maint_test_options): Use add_basic_prefix_cmd.
* macrocmd.c (macro_command): Remove
(_initialize_macrocmd): Use add_basic_prefix_cmd.
* language.c (set_check, show_check): Remove.
(_initialize_language): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* infcmd.c (unset_command): Remove.
(_initialize_infcmd): Use add_basic_prefix_cmd.
* i386-tdep.c (set_mpx_cmd, show_mpx_cmd): Remove.
(_initialize_i386_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* go32-nat.c (go32_info_dos_command): Remove.
(_initialize_go32_nat): Use add_basic_prefix_cmd.
* cli/cli-decode.c (do_prefix_cmd, add_basic_prefix_cmd)
(do_show_prefix_cmd, add_show_prefix_cmd): New functions.
* frame.c (set_backtrace_cmd, show_backtrace_cmd): Remove.
(_initialize_frame): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* dcache.c (set_dcache_command, show_dcache_command): Remove.
(_initialize_dcache): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cp-support.c (maint_cplus_command): Remove.
(_initialize_cp_support): Use add_basic_prefix_cmd.
* btrace.c (maint_btrace_cmd, maint_btrace_set_cmd)
(maint_btrace_show_cmd, maint_btrace_pt_set_cmd)
(maint_btrace_pt_show_cmd, _initialize_btrace): Use
add_basic_prefix_cmd, add_show_prefix_cmd.
* breakpoint.c (save_command): Remove.
(_initialize_breakpoint): Use add_basic_prefix_cmd.
* arm-tdep.c (set_arm_command, show_arm_command): Remove.
(_initialize_arm_tdep): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* ada-lang.c (maint_set_ada_cmd, maint_show_ada_cmd)
(set_ada_command, show_ada_command): Remove.
(_initialize_ada_language): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* command.h (add_basic_prefix_cmd, add_show_prefix_cmd): Declare.
gdb/testsuite/ChangeLog
2020-04-17 Tom Tromey <tromey@adacore.com>
* gdb.cp/maint.exp (test_help): Simplify multiple_help_body.
Update tests.
* gdb.btrace/cpu.exp: Update tests.
* gdb.base/maint.exp: Update tests.
* gdb.base/default.exp: Update tests.
* gdb.base/completion.exp: Update tests.
When a Windows program is terminated by a fatal exception, its exit
code is the value of that exception, as defined by the various
EXCEPTION_* symbols in the Windows API headers. This commit emulates
WTERMSIG etc. by translating the fatal exception codes to more-or-less
equivalent Posix signals.
gdb/ChangeLog:
2020-01-06 Eli Zaretskii <eliz@gnu.org>
Pedro Alves <palves@redhat.com>
* Makefile.in (COMMON_SFILES): Add gdbsupport/gdb_wait.c.
* windows-tdep.c: New enumeration of WINDOWS_SIG* signals.
(windows_gdb_signal_to_target): New function, uses the above
enumeration to convert GDB internal signal codes to equivalent
Windows codes.
(windows_init_abi): Call set_gdbarch_gdb_signal_to_target.
* windows-nat.c: Include "gdb_wait.h".
(get_windows_debug_event): Extract the fatal exception from the
exit status and convert to the equivalent Posix signal number.
* cli/cli-cmds.c (exit_status_set_internal_vars): Account for the
possibility that WTERMSIG returns GDB_SIGNAL_UNKNOWN.
* gdbsupport/gdb_wait.c: New file, implements
windows_status_to_termsig.
* gdbsupport/gdb_wait.h (WIFEXITED, WIFSIGNALED, WEXITSTATUS)
(WTERMSIG) [__MINGW32__]: Separate definitions for MinGW.
gdb/gdbserver/ChangeLog:
2020-01-06 Eli Zaretskii <eliz@gnu.org>
Pedro Alves <palves@redhat.com>
* win32-low.c (get_child_debug_event): Extract the fatal exception
from the exit status and convert to the equivalent Posix signal
number.
(win32_wait): Allow TARGET_WAITKIND_SIGNALLED status as well.
* Makefile.in (OBS, SFILES): Add gdb_wait.[co].
I noticed that print_disassembly has two #if blocks for TUI code,
where one would do. This patch rearranges the code slightly to remove
a #if.
gdb/ChangeLog
2019-12-27 Tom Tromey <tom@tromey.com>
* cli/cli-cmds.c (print_disassembly): Reorder "if".
Change-Id: I36f3f682f5685b3d9b148da5aed26eb3cc7d598e
I went through most of the spots that include readline.h and, when
appropriate, either removed the include or changed it to include
tilde.h.
Note that remote-sim.c and bsd-kvm.c could probably include tilde.h
instead, but I did not change these. I think I can't build the
latter, and I didn't want to set up a sim build for the former.
Tested by rebuilding.
gdb/ChangeLog
2019-11-06 Tom Tromey <tom@tromey.com>
* tui/tui-interp.c: Don't include readline.h.
* tui/tui-hooks.c: Don't include readline.h.
* symmisc.c: Include tilde.h, not readline.h.
* symfile.c: Include tilde.h, not readline.h.
* source.c: Include tilde.h, not readline.h.
* solib.c: Include tilde.h, not readline.h.
* psymtab.c: Include tilde.h, not readline.h.
* exec.c: Include tilde.h, not readline.h.
* corelow.c: Include tilde.h, not readline.h.
* cli/cli-dump.c: Include tilde.h, not readline.h.
* cli/cli-cmds.c: Don't include readline.h.
Change-Id: I60487a190c43128b800ef77517d1ab42957571d7
The new convenience functions $_gdb_setting and $_gdb_setting_str
provide access to the GDB settings in user-defined commands.
Similarly, $_gdb_maint_setting and $_gdb_maint_setting_str
provide access to the GDB maintenance settings.
The patch was developed following a comment of Eli about the
'set may-call-functions'. Eli said that user-defined functions
should have a way to change their behavior according to this setting.
Rather than have a specialized $_may_call_functions, this patch
implements a general way to access any GDB setting.
Compared to doing such access via Python 'gdb.parameter' and/or
'gdb.execute("set somesetting tosomevalue"):
* The 'with' command is much better than the above python usage:
if the user types C-c or an error happens between the set pagination off
and the python "set pagination on", the above python
does not restore the original setting.
* Effectively, with the "gdb.parameter" python one liner, it is possible to do
simple 'if' conditions, such as set and restore pagination.
But mixing the "python if" within canned
sequence of commands is cumbersome for non trivial combinations.
E.g. if several commands have to be done for a certain condition
accessed from python, I guess something like will be needed:
python if __some_setting: gdb.execute("some command")
python if __some_setting: gdb.execute("some other command")
python if __some_setting: gdb.execute("some different command")
(without speaking about nested "if-s").
With the convenience function:
if $_gdb_setting("some_setting")
some command
some other command
some different command
end
Integer settings (for example print elements) will also be more difficult
to use.
For example, a user defined function that scans and prints a linked list
might want to use the value of "set print elements" to stop printing
the linked list.
Doing that by mixing python expression/if is likely doable, but seems
not easy with the above one liners.
So, in summary, the $_gdb_setting and $_gdb_setting_str avoids to have the
heterogeneous mix of python and GDB commands in one single script
(and of course, it works even if python is not configured, but that
must be an unusual setup I guess).
gdb/ChangeLog
2019-10-31 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-cmds.c (setting_cmd, value_from_setting)
(gdb_setting_internal_fn, gdb_maint_setting_internal_fn)
(str_value_from_setting, gdb_setting_str_internal_fn)
(gdb_maint_setting_str_internal_fn): New functions.
(_initialize_cli_cmds): Define the new convenience functions.
* gdb/cli/cli-setshow.h (get_setshow_command_value_string): Constify.
* gdb/cli/cli-setshow.c (get_setshow_command_value_string): Constify.