The function str_to_buf() was too benevolent and did
not perform sufficient error checking on the input
string being parsed. Especially:
- Invalid numbers were silently ignored.
- Out-of-range numbers were silently truncated.
The following commands that use str_to_buf()
were affected:
- reg (when writing a register value)
- set_reg
- jtag drscan
This pull request fixes that by:
- Rewriting str_to_buf() to add the missing checks.
- Adding function command_parse_str_to_buf() which can
be used in command handlers. It parses the input
numbers and provides user-readable error messages
in case of parsing errors.
Examples:
jtag drscan 10 huh10
- Old behavior: The string "huh10" is silently
converted to 10 and the command is then executed.
No warning error or warning is shown to the user.
- New behavior: Error message is shown:
"'huh10' is not a valid number"
reg pc 0x123456789
Assuming the "pc" is 32 bits wide:
- Old behavior: The register value is silently
truncated to 0x23456789 and the command is performed.
- New behavior: Error message is shown to the user:
"Number 0x123456789 exceeds 32 bits"
Change-Id: I079e19cd153aec853a3c2eb66953024b8542d0f4
Signed-off-by: Jan Matyas <jan.matyas@codasip.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8315
Tested-by: jenkins
Reviewed-by: Marek Vrbka <marek.vrbka@codasip.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
clang doesn't support the gnu_printf attribute that OpenOCD uses if
__GNUC__ and __GNUC_MINOR__ indicates gcc >= 4.4.
Most clang builds set __GNUC__/__GNUC_MINOR__ to 4.2 for historical
reasons, so they don't trigger this condition; however, some builds set
it to something much higher to work around code using __GNUC__ to
determine if a feature that does exist in clang (but not gcc 4.2) is
available, causing OpenOCD to use attribute gnu_printf.
The problem can be reproduced without a special clang build by adding
-fgnuc-version=14.1 to CFLAGS.
Change-Id: I3c0832d4201578b116c5214203f95b6153dad30e
Signed-off-by: Bernhard Rosenkränzer <bero@baylibre.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8258
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Some OpenOCD command gets fragment of TCL scripts as command-line
argument, fragments that will be kept and executed later on.
E.g. the command 'configure' gets the body of an OpenOCD event:
$TARGET configure -event halted {TCL code}
These commands store the argument as a Jim_Obj and pass it to the
jimtcl interpreter when the TCL fragment has to be executed.
Using Jim_Obj as storage is relevant to let the jimtcl interpreter
to recover extra info of the TCL fragment, like the file-name and
the line-number that contain the fragment, that will be printed
out in case of run-time errors.
While converting the commands to COMMAND_HANDLER, we should avoid
storing the argument as C strings otherwise we will loose precious
info in case of run-time errors making challenging the debugging
of such TCL fragments.
Extend the struct command_invocation to contain the array that
points to the Jim_Obj of the command arguments.
This will be used while converting commands to COMMAND_HANDLER.
Change-Id: If37c5f20e9a71349f77ba1571baf1e6778e28aa5
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8057
Tested-by: jenkins
The OpenOCD commands produce their TCL text result through the
pair command_print() and command_print_sameline().
The latter is used to concatenate output in a single line.
At the end of a sequence of command_print(), the last LF is taken
as part of the command result, while it is not always needed, and
it is even annoying when the output of two commands needs to be
concatenate in a single line.
Using command_print_sameline() in place of the last call to
command_print() would solve the problem but it's quite expensive
in term of coding to fix all the existing commands.
Drop the last LF, if present.
Commands that would specifically need a LF as last char, can add
an extra LF at the end of the output.
Document this behavior in command.h.
Change-Id: I6757c20fbfce923dd393083146e8d5a1f3b790b4
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7471
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Replace the FSF boilerplate with the SPDX tag.
The SPDX tag on files *.c is incorrect, as it should use the C99
single line comment using '//'. But current checkpatch doesn't
allow C99 comments, so keep using standard C comments, by now.
Change-Id: I7851617e2682f97ccc3927e3941aadef2df63b54
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7068
Tested-by: jenkins
The header files under src/helper/ can currently be included with
either
#include <bits.h>
or
#include <helper/bits.h>
This is because we specify both "src/" and "src/helper/" directories
as include directories. Some files name under "src/helper/", such as
types.h, log.h, and util.h are too generic and could be ambiguous
depending on the search path.
This commit remove "src/helper/" from our include dir and make C files
include explicitly.
Change-Id: I38fc9b96ba01a513d4a72757d40007e21b502f25
Signed-off-by: Yasushi SHOJI <yashi@spacecubics.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6507
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
There are ~900 Yoda conditions to be aligned to the coding style.
For recurrent Yoda conditions it's preferable using a trivial
script in order to minimize the review effort.
E.g. comparison of uppercase macro/enum with lowercase variable:
- ...(ERROR_OK == retval)...
+ ...(retval == ERROR_OK)...
Patch generated automatically with the command:
sed -i \
's/(\([A-Z][A-Z0-9_]*\) \([=!]=\) \([a-z][a-z0-9_]*\))/(\3 \2 \1)/g' \
$(find src/ -type f)
While there, remove the braces {} around a single statement block
to prevent warning from checkpatch.
Change-Id: If585b0a4b4578879c87b2dd74d9e0025e275ec6b
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/6354
Tested-by: jenkins
Reviewed-by: Xiang W <wxjstz@126.com>
Current autocomplete filters-out some command reported by "info
commands". One of the filter rule concerns the command's private
data.
Every command registered by OpenOCD has its 'struct command' as
private data.
By ignoring commands without private data, we loose several TCL
commands registered by jimtcl, e.g. 'foreach', 'llength'.
By assuming that every command with non-NULL private data has
'struct command' as private data, we risk at best to access
inconsistent data, at worst to trigger a segmentation fault.
Export the already available functions:
- to check if a command has been registered by OpenOCD and
- to get the private data.
While there, rename jimcmd_is_ocd_command() as
jimcmd_is_oocd_command().
Don't filter-out jimtcl commands with no private data.
Check the private data only on OpenOCD commands.
Change-Id: Ib5bf8d2bc5c12440c0cfae438f637c38724a79b7
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/6282
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
IPDBG are utilities to debug IP-cores. It uses JTAG for
transport to/from the FPGA. The different UIs use TCP/IP
as transport. The JtagHost makes the bridge between these
two.
Comparable to the bridge between GDB and the in-circuit-
debugging-unit of a micro controller.
Change-Id: Ib1bc10dcbd4ea426e492bb7b2d85c1ed1b7a8d5a
Signed-off-by: Daniel Anselmi <danselmi@gmx.ch>
Reviewed-on: http://openocd.zylin.com/5938
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Now that all commands are executed through the common handler
command_unknown(), the message about command execution is logged
by command_unknown(). There is no need, for "native" commands
(.jim_handler) at root level to log the message (again) by itself.
Remove calls to script_debug() apart from command_unknown().
Make script_debug() static as only used in command.c.
Change-Id: I9b2728b69e7643d6121c4b35a96bc825bcb5488d
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5676
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
There is no need anymore to keep alive the tree of struct command.
Remove it and let jim to free() the command's struct command that
is referenced through command's private data.
Change-Id: I2cd84e0274a969ce200320e3a177ac20c7823da0
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5675
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
While keeping the struct command in place, unregister the jim
commands by scanning the list of jim commands through their
full-name.
Change-Id: I0e903fbc31172858b703d67ccd471809c7949e86
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5674
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
The current implementation of "help" related commands is tightly
connected to the tree of struct command.
The TCL commands 'add_usage_text' and 'add_help_text' have to add
fake commands in the tree of struct command to handle the help of
TCL procs.
Move all the help texts in a list accessible from the struct
command_context and register the commands through their full name.
Keep the list sorted alphabetically by the command name, so the
result of commands 'help' and 'usage' will be sorted too.
Remove the associated help and usage during commands un-register,
but call help_del_all_commands() for the text added through TCL
commands 'add_usage_text' and 'add_help_text'.
The resulting help and usage output is not changed by this patch
(tested on all the help and usage strings in current master
branch).
Change-Id: Ifd37bb5bd374cba1a22cd7aac208505b4ae1e6fc
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5670
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Replace the "struct command *parent" parameter with a string that
contains the command prefix.
This abstracts the openocd code from the knowledge of the tree of
struct command.
This also makes unused the function command_find_in_context(), so
remove it.
Change-Id: I598d60719cfdc1811ee6f6edfff8a116f82c7ed6
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5668
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
In current code the current target is overridden whenever
jim_handler_data is not NULL. This happens not only with target
prefixed commands, but also with cti, dap and swo/tpiu prefixed
commands.
While this is not causing any run-time issue, by now, the
behaviour is tricky and makes the code cryptic.
Add a specific field to struct command for the target override so
the content of jim_handler_data can be restricted to command
specific data only (today only cti, dap and swo/tpiu).
Extend the API register_commands() to specify the presence of
either the command data or the override target.
The new API makes obsolete calling command_set_handler_data() to
set jim_handler_data, so remove it.
Change-Id: Icc323faf754b0546a72208f90abd9e68ff2ef52f
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5667
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
While registering a new command, jim accepts a pointer to command's
private data that will be accessible during the command execution.
Today openocd is not consistent and passes different private data
depending on the command, and then even overwrites it:
- "simple" commands (.handler) are registered with their own
struct command pointer as command private data;
- "native" commands (.jim_handler) at root level are registered
with NULL command private data;
- "native" commands (.jim_handler) not at root level are
registered with the struct command pointer of their root command
as command private data but, when executed, the command private
data is overwritten by the value in field jim_handler_data taken
from their struct command.
Uniform the usage of command private data by always set it to the
struct command pointer while registering the new commands.
Note: for multi-word commands only the root command is registered,
so command private data will be set to the struct command of the
root command. This will change later in this series when the full-
name of the command will be registered.
Don't overwrite the command private data, but let the commands that
needs jim_handler_data to get it directly through struct command.
For sake of uniformity, let function command_set_handler_data() to
set the field jim_handler_data also for "group" commands, even if
such value will not be used.
Now Jim_CmdPrivData() always returns a struct command pointer, so
wrap it in the inline function jim_to_command() to gain compile
time check on the returned type.
While there, uniform the code to use the macro Jim_CmdPrivData()
to access the command's private data pointer.
Change-Id: Idba16242ba1f6769341b4030a49cdf35a5278695
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5664
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
The function command_find_in_parent() is never used in OpenOCD, so
remove it.
The functions command_name() and [un]register_command() are only
used internally in command.c, so make them static.
Change-Id: Ide9842659796f4884fb6c1fcf5979b3b71b67abb
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5663
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Tested-by: jenkins
After commit 0840414f0e ("helper/command: do not replace new
commands with ocd_ prefix"), the command name is present in
argv[0], so there is no need to pass it directly. The current code
causes the command name to be logged twice, once explicitly and
then from the content of argv[0]:
openocd -c 'debug_level 3; echo hello; shutdown'
<snip>
Debug: 13 3 command.c:142 script_debug(): command - echo echo hello
<snip>
Debug: 16 4 command.c:142 script_debug(): command - shutdown shutdown
Remove the command name from the arguments of the function
script_debug().
Change-Id: I57860774f450ff717ee71ef9dc07590549a84319
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5660
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Tested-by: jenkins
The field jim_handler_data in struct command_registration is never
assigned, thus has always value NULL. It was added in commit
17a9dea53a ("add jim_handler to command_registration") on Nov 23
2009, together with the homonym field jim_handler_data in struct
command, but never used since then.
Only the field jim_handler_data in struct command is used.
Remove the field from struct command_registration and use NULL
where it was referenced (or remove the assignment if the recipient
is already zero, e.g. allocated with calloc()).
Removing the field decreases the total size of OpenOCD binary by
only 4944 byte on a 64 bit x86. Not a significant improvement from
this point of view.
Change-Id: I9f1d281e3de6b2eb398e2d883c5e9ff92628aecd
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5225
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Rationale:
1. There's logging output and there're return values;
2. If a function should return something, it should do it explicitly,
same for logging;
3. Interactive interfaces (telnet, Gdb and Tcl RPC) must always return
the result of the evaluation for the given expression. You can
suppress this output by adding ``; after 0'' to the end of your
expression.
4. Some commands "throw an exception" and if you want to be able to
collect both the return value (when it succeeds) and the log output
(when something goes wrong) you can use do like this:
set log_output [capture "catch {reset_config} return_value"]
So what I'm proposing is following:
1. Every jim_handler command should set the return value the standard
JimTcl way, without any tricks. If it needs to print some logging
output, it should use LOG_* functions.
2. The usual commands (COMMANDS) can easily construct their return
value by appending strings with command_print() and
command_print_sameline(). This required changing "struct
command_invocation" and passing a pointer to it to command_print*
functions.
The code is already functional, please test and comment.
TODO items:
1. Modify all jim_handler commands to properly return or log values
(some of them are commented out for now in this patch).
2. Properly document "capture" command and provide a convenience
function to automate log_output + return_value gathering.
3. Add appropriate Doxygen comments.
4. Add Tcl RPC interface description to the manual, all the example
clients in different languages (from the mailing list) to contrib/.
This change is the core part of http://openocd.zylin.com/1815 from
Paul Fertser. It has been extracted and rebased to simplify the
review and provided again as 1815.
Change-Id: I675c91aa9da1e4e7c6f0a8fe6112a00550b9e4db
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/1815
Tested-by: jenkins
To prepare for handling TCL return values consistently, all calls
to command_print/command_print_sameline should switch to CMD as
first parameter.
Change prototype of command_print() and command_print_sameline()
to pass CMD instead of CMD_CTX.
Since the first parameter is currently not used, the change can be
done though scripts without manual coding.
This patch is created using the command:
sed -i PATTERN $(find src/ doc/ -type f)
with all the following patters:
's/\(command_print(cmd\)->ctx,/\1,/'
's/\(command_print(CMD\)_CTX,/\1,/'
's/\(command_print(struct command_\)context \*context,/\1invocation *cmd,/'
's/\(command_print_sameline(cmd\)->ctx,/\1,/'
's/\(command_print_sameline(CMD\)_CTX,/\1,/'
's/\(command_print_sameline(struct command_\)context \*context,/\1invocation *cmd,/'
This change is inspired by http://openocd.zylin.com/1815 from Paul
Fertser but is now done through scripting.
Change-Id: I3386d8f96cdc477e7a2308dd18269de3bed04385
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/5081
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
Accessing the variable "cmd" in a COMMAND_HANDLER is confusing
because the variable definition is not visible in the prototype,
thus "cmd" can be identified by the reader as a global variable
defined somewhere else.
Add the new macro CMD to make more evident it is a part of the
COMMAND_HANDLER.
Change-Id: I8f63da593a931045cc404323f143b88c5c80ab5e
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/5047
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>
This change contains an alternative to Matthias Welwarsky's #4130
(target-prefixed commands) and to #4293 (event handlers).
get_current_target() must retrieve the target associated to the current
command. If no target associated, the current target of the command
context is used as a fallback.
Many Tcl event handlers work with the current target as if it were
the target issuing the event.
current_target in command_context is a number and has to be converted
to a pointer in every get_current_target() call.
The solution:
- Replace current_target in command_context by a target pointer
- Add another target pointer current_target_override
- get_current_target() returns current_target_override if set, otherwise
current_target
- Save, set and restore current_target_override to the current prefix
in run_command()
- Save, set and restore current_target_override to the event invoking
target in target_handle_event()
While on it use calloc when allocating a new command_context.
Change-Id: I9a82102e94dcac063743834a1d28da861b2e74ea
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Suggested-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Reviewed-on: http://openocd.zylin.com/4295
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
Define a target_addr_t type to support 32-bit and 64-bit addresses at
the same time. Also define matching TARGET_PRI*ADDR format macros as
well as a convenient TARGET_ADDR_FMT.
In targets that are 32-bit (avr32, nds32, arm7/9/11, fm4, xmc1000)
be least invasive by leaving the formatting unchanged apart from the
type;
for generic code adopt TARGET_ADDR_FMT as unified address format.
Don't silently change gdb formatting here, leave that to later.
Add COMMAND_PARSE_ADDRESS() macro to abstract the address type.
Implement it using its own parse_target_addr() function, in the hopes
of catching pointer type mismatches better.
Add '--disable-target64' configure option to revert to previous 32-bit
target address behavior.
Change-Id: I2e91d205862ceb14f94b3e72a7e99ee0373a85d5
Signed-off-by: Dongxue Zhang <elta.era@gmail.com>
Signed-off-by: David Ung <david.ung.42@gmail.com>
[AF: Default to enabling (Paul Fertser), rename macros, simplify]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Also make GPL notices consistent according to:
https://www.gnu.org/licenses/gpl-howto.html
Change-Id: I84c9df40a774958a7ed91460c5d931cfab9f45ba
Signed-off-by: Marc Schink <openocd-dev@marcschink.de>
Reviewed-on: http://openocd.zylin.com/3488
Tested-by: jenkins
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
This is a post-release version but hopefully some fixes that went in
are worth it; also the changes here make OpenOCD compatible with stock
0.75 version if a distro maintainer decides to use it.
Change-Id: I7ad1814c7c4868198475cdca4750c3d0ee4f5f8b
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2121
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>
Don't use const on pointers that hold heap allocated data, because that
means functions that free them must cast away the const.
Do use const on pointer parameters or fields that needn't be modified.
Remove pointer casts that are no longer needed after fixing the constness.
Change-Id: I5d206f5019982fd1950bc6d6d07b6062dc24e886
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/1668
Tested-by: jenkins
Reviewed-by: Mathias Küster <kesmtp@freenet.de>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
as well as not being required, as it is already included by jim-nvp.h.
It also makes the doxygen output a bit clearer to read.
Change-Id: Ia2bed7142b4a56b48b1ecf0734e63f860dcd1014
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/859
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>
this header is used in numerous files and adding to config.h
simplifies its use globally.
Change-Id: Id724a9950b90504721233022c7fb5768e9bc5548
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/649
Tested-by: jenkins
Reviewed-by: Xiaofan <xiaofanc@gmail.com>
This issue was caused by uncrustify not correctly converting the doxygen
comments.
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Change-Id: Ie6dc3b057a08603b670cb27312e5f0d989426e6c
Reviewed-on: http://openocd.zylin.com/431
Tested-by: jenkins
Various commands, e.g. "arm mcr xxxx" would fail if invoked upon startup
since it there was no command context defined for the jim interpreter
in that case.
A Jim interpreter is now associated with a command context(telnet,
gdb server's) or the default global command context.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Changes from the flat namespace to heirarchical one. Instead of writing:
#include "types.h"
the following form should be used.
#include <helper/types.h>
The exception is from .c files in the same directory.
Changes from the flat namespace to heirarchical one. Instead of writing:
#include "jim.h"
the following form should be used.
#include <helper/jim.h>
The exception is from .c files in the same directory.
In embedded hosts, the Jim interpreter can come from the
existing context rather than be created by OpenOCD.
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Finish removing references to the 'interp' global variable from the
command module, encapsulating all reference via command_context.
Eliminates use of the global entirely, so it can be removed. Hurrah!