... when trying to execute an undefined GDB/MI command. When trying
to execute a GDB/MI command which does not exist, the current error
result record looks like this:
-unsupported
^error,msg="Undefined MI command: unsupported"
The only indication that the command does not exist is the error
message. It would be a little fragile for a consumer to rely solely
on the contents of the error message in order to determine whether
a command exists or not.
This patch improves the situation by adding concept of error
code, starting with one well-defined error code ("undefined-command")
identifying errors due to a non-existant command. Here is the new
output:
-unsupported
^error,msg="Undefined MI command: unsupported",code="undefined-command"
This error code is only displayed when the corresponding error
condition is met. Otherwise, the error record remains unchanged.
For instance:
-symbol-list-lines foo.adb
^error,msg="-symbol-list-lines: Unknown source file name."
For frontends to be able to know whether they can rely on this
variable, a new entry "undefined-command-error-code" has been
added to the "-list-features" command. Another option would be
to always generate an error="..." variable (for the default case,
we could decide for instance that the error code is the empty string).
But it seems more efficient to provide that info in "-list-features"
and then only add the error code when meaningful.
gdb/ChangeLog:
(from Pedro Alves <palves@redhat.com>)
(from Joel Brobecker <brobecker@adacore.com>)
* exceptions.h (enum_errors) <UNDEFINED_COMMAND_ERROR>: New enum.
* mi/mi-parse.c (mi_parse): Throw UNDEFINED_COMMAND_ERROR instead
of a regular error when the GDB/MI command does not exist.
* mi/mi-main.c (mi_cmd_list_features): Add
"undefined-command-error-code".
(mi_print_exception): Print an "undefined-command"
error code if EXCEPTION.ERROR is UNDEFINED_COMMAND_ERROR.
* NEWS: Add entry documenting the new "code" variable in
"^error" result records.
gdb/doc/ChangeLog:
* gdb.texinfo (GDB/MI Result Records): Fix the syntax of the
"^error" result record concerning the error message. Document
the error code that may also be part of that result record.
(GDB/MI Miscellaneous Commands): Document the
"undefined-command-error-code" element in the output of
the "-list-features" GDB/MI command.
gdb/testsuite/ChangeLog:
* gdb.mi/mi-undefined-cmd.exp: New testcase.
2ea126fa78