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[PATCH 7/7] Allow setting a parameter to raise gdb.GdbError
- From: Tom Tromey <tom at tromey dot com>
- To: gdb-patches at sourceware dot org
- Cc: Tom Tromey <tom at tromey dot com>
- Date: Sat, 15 Sep 2018 01:24:59 -0600
- Subject: [PATCH 7/7] Allow setting a parameter to raise gdb.GdbError
- References: <20180915072459.14934-1-tom@tromey.com>
A convention in the Python layer is that raising a gdb.GdbError will
not print the Python stack -- instead the exception is treated as any
other gdb exception.
PR python/18852 asks that this treatment be extended the the
get_set_value method of gdb.Parameter. This makes sense, because it
lets Python-created parameters act like gdb parameters.
gdb/ChangeLog
2018-09-15 Tom Tromey <tom@tromey.com>
PR python/18852:
* python/py-param.c (get_set_value): Use gdbpy_handle_exception.
gdb/doc/ChangeLog
2018-09-15 Tom Tromey <tom@tromey.com>
PR python/18852:
* python.texi (Parameters In Python): Document exception behavior
of get_set_string.
gdb/testsuite/ChangeLog
2018-09-15 Tom Tromey <tom@tromey.com>
PR python/18852:
* gdb.python/py-parameter.exp: Add test for parameter that throws
on "set".
---
gdb/ChangeLog | 5 +++++
gdb/doc/ChangeLog | 6 ++++++
gdb/doc/python.texi | 24 +++++++++++++++++++++++
gdb/python/py-param.c | 5 +----
gdb/testsuite/ChangeLog | 6 ++++++
gdb/testsuite/gdb.python/py-parameter.exp | 15 ++++++++++++++
6 files changed, 57 insertions(+), 4 deletions(-)
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index aca6ec858cf..0487a6f3bf3 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -3824,6 +3824,30 @@ example, @kbd{set foo off}). The @code{value} attribute has already
been populated with the new value and may be used in output. This
method must return a string. If the returned string is not empty,
@value{GDBN} will present it to the user.
+
+If this method raises @code{gdb.GdbError} (@pxref{Exception
+Handling}), then gdb will print the exception's string and the
+@code{set} command will fail. Note, however, that the @code{value}
+attribute will not be reset in this case. So, if your parameter must
+validate values, it should store the old value internally and reset
+the exposed value, like so:
+
+@smallexample
+class ExampleParam (gdb.Parameter):
+ def __init__ (self, name):
+ super (ExampleParam, self).__init__ (name,
+ gdb.COMMAND_DATA,
+ gdb.PARAM_BOOLEAN)
+ self.value = True
+ self.saved_value = True
+ def validate(self):
+ return False
+ def get_set_string (self):
+ if not self.validate():
+ self.value = self.saved_value
+ raise gdb.GdbError('Failed to validate')
+ self.saved_value = self.value
+@end smallexample
@end defun
@defun Parameter.get_show_string (self, svalue)
diff --git a/gdb/python/py-param.c b/gdb/python/py-param.c
index 0f0214befe0..bff5d60fc26 100644
--- a/gdb/python/py-param.c
+++ b/gdb/python/py-param.c
@@ -396,10 +396,7 @@ get_set_value (const char *args, int from_tty,
{
set_doc_string = call_doc_function (obj, set_doc_func.get (), NULL);
if (! set_doc_string)
- {
- gdbpy_print_stack ();
- return;
- }
+ gdbpy_handle_exception ();
}
const char *str = set_doc_string.get ();
diff --git a/gdb/testsuite/gdb.python/py-parameter.exp b/gdb/testsuite/gdb.python/py-parameter.exp
index 0508544f9d9..9a36e6372de 100644
--- a/gdb/testsuite/gdb.python/py-parameter.exp
+++ b/gdb/testsuite/gdb.python/py-parameter.exp
@@ -203,3 +203,18 @@ foreach kind {PARAM_ZUINTEGER PARAM_ZUINTEGER_UNLIMITED} {
"check that PARAM_ZUINTEGER value is -1 after setting"
}
}
+
+gdb_py_test_multiple "Throwing gdb parameter" \
+ "python" "" \
+ "class TestThrowParam (gdb.Parameter):" "" \
+ " def __init__ (self, name):" "" \
+ " super (TestThrowParam, self).__init__ (name, gdb.COMMAND_DATA, gdb.PARAM_STRING)" "" \
+ " self.value = True" "" \
+ " def get_set_string (self):" "" \
+ " raise gdb.GdbError('Ordinary gdb error')" "" \
+ "test_throw_param = TestThrowParam ('print test-throw-param')" ""\
+ "end"
+
+gdb_test "set print test-throw-param whoops" \
+ "Ordinary gdb error" \
+ "gdb.GdbError does not show Python stack"
--
2.17.1