From 30a87e90be195dcce555a0904cc5dbd960349271 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Mon, 24 Jan 2022 15:19:43 +0000 Subject: [PATCH] gdb/python: add gdb.history_count function Add a new function gdb.history_count to the Python api, this function returns an integer, the number of items in GDB's value history. This is useful if you want to pull items from the history by their absolute number, for example, if you wanted to show a complete history list. Previously we could figure out how many items are in the history list by trying to fetch the items, and then catching the exception when the item is not available, but having this function seems nicer. --- gdb/NEWS | 3 +++ gdb/doc/python.texi | 5 +++++ gdb/python/py-value.c | 8 ++++++++ gdb/python/python-internal.h | 1 + gdb/python/python.c | 2 ++ gdb/testsuite/gdb.python/py-value.exp | 12 ++++++++++++ gdb/value.c | 8 ++++++++ gdb/value.h | 4 ++++ 8 files changed, 43 insertions(+) diff --git a/gdb/NEWS b/gdb/NEWS index 31dff785d4e..e1900596ca7 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -109,6 +109,9 @@ show debug lin-lwp integer, the index of the new item in the history list, is returned. + ** New function gdb.history_count(), which returns the number of + values in GDB's value history. + ** New gdb.events.gdb_exiting event. This event is called with a gdb.GdbExitingEvent object which has the read-only attribute 'exit_code', which contains the value of the GDB exit code. This diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi index 39bf6e8884d..f1d18272963 100644 --- a/gdb/doc/python.texi +++ b/gdb/doc/python.texi @@ -387,6 +387,11 @@ as its result, then placing the value into the history will allow the user convenient access to those values via CLI history facilities. @end defun +@defun gdb.history_count () +Return an integer indicating the number of values in @value{GDBN}'s +value history (@pxref{Value History}). +@end defun + @findex gdb.convenience_variable @defun gdb.convenience_variable (name) Return the value of the convenience variable (@pxref{Convenience diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c index d6ceb54fed8..6401d96897f 100644 --- a/gdb/python/py-value.c +++ b/gdb/python/py-value.c @@ -2012,6 +2012,14 @@ gdbpy_add_history (PyObject *self, PyObject *args) return nullptr; } +/* Return an integer, the number of items in GDB's history. */ + +PyObject * +gdbpy_history_count (PyObject *self, PyObject *args) +{ + return gdb_py_object_from_ulongest (value_history_count ()).release (); +} + /* Return the value of a convenience variable. */ PyObject * gdbpy_convenience_variable (PyObject *self, PyObject *args) diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h index ccea5c4a9cd..5e15f62f745 100644 --- a/gdb/python/python-internal.h +++ b/gdb/python/python-internal.h @@ -412,6 +412,7 @@ extern enum ext_lang_rc gdbpy_get_matching_xmethod_workers PyObject *gdbpy_history (PyObject *self, PyObject *args); PyObject *gdbpy_add_history (PyObject *self, PyObject *args); +extern PyObject *gdbpy_history_count (PyObject *self, PyObject *args); PyObject *gdbpy_convenience_variable (PyObject *self, PyObject *args); PyObject *gdbpy_set_convenience_variable (PyObject *self, PyObject *args); PyObject *gdbpy_breakpoints (PyObject *, PyObject *); diff --git a/gdb/python/python.c b/gdb/python/python.c index 7ddc170904c..2c8081e1b07 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -2212,6 +2212,8 @@ PyMethodDef python_GdbMethods[] = "Get a value from history" }, { "add_history", gdbpy_add_history, METH_VARARGS, "Add a value to the value history list" }, + { "history_count", gdbpy_history_count, METH_NOARGS, + "Return an integer, the number of values in GDB's value history" }, { "execute", (PyCFunction) execute_gdb_command, METH_VARARGS | METH_KEYWORDS, "execute (command [, from_tty] [, to_string]) -> [String]\n\ Evaluate command, a string, as a gdb CLI command. Optionally returns\n\ diff --git a/gdb/testsuite/gdb.python/py-value.exp b/gdb/testsuite/gdb.python/py-value.exp index 9ee3c5f223d..60039c9373f 100644 --- a/gdb/testsuite/gdb.python/py-value.exp +++ b/gdb/testsuite/gdb.python/py-value.exp @@ -647,6 +647,17 @@ proc test_value_sub_classes {} { "check printing of MyValue when initiaized with a type" } +# Test the history count. This must be the first thing called after +# starting GDB as it depends on there being nothing in the value +# history. +proc test_history_count {} { + for { set i 0 } { $i < 5 } { incr i } { + gdb_test "python print('history count is %d' % gdb.history_count())" \ + "history count is $i" "history count is $i" + gdb_test "print $i" " = $i" + } +} + # Build C version of executable. C++ is built later. if { [build_inferior "${binfile}" "c"] < 0 } { return -1 @@ -658,6 +669,7 @@ clean_restart ${binfile} # Skip all tests if Python scripting is not enabled. if { [skip_python_tests] } { continue } +test_history_count test_value_creation test_value_reinit test_value_numeric_ops diff --git a/gdb/value.c b/gdb/value.c index 37c949f0853..7bd9891b3e9 100644 --- a/gdb/value.c +++ b/gdb/value.c @@ -1909,6 +1909,14 @@ access_value_history (int num) return value_copy (value_history[absnum].get ()); } +/* See value.h. */ + +ULONGEST +value_history_count () +{ + return value_history.size (); +} + static void show_values (const char *num_exp, int from_tty) { diff --git a/gdb/value.h b/gdb/value.h index f91c5a56144..0de4b5f3aef 100644 --- a/gdb/value.h +++ b/gdb/value.h @@ -948,6 +948,10 @@ extern void binop_promote (const struct language_defn *language, extern struct value *access_value_history (int num); +/* Return the number of items in the value history. */ + +extern ULONGEST value_history_count (); + extern struct value *value_of_internalvar (struct gdbarch *gdbarch, struct internalvar *var); -- 2.30.2