From 7371cf6d8db5a0c04550fc95b1acc87857ac348c Mon Sep 17 00:00:00 2001 From: Phil Muldoon Date: Mon, 14 Mar 2011 16:09:55 +0000 Subject: 2011-03-14 Phil Muldoon * gdb.texinfo (Breakpoints In Python): Add description and example of Python stop function operation. 2010-03-14 Phil Muldoon * gdb.python/py-breakpoint.exp: Add Python stop operations tests. 2011-03-14 Phil Muldoon * python/python.h: Declare gdbpy_should_stop and gdbpy_breakpoint_has_py_cond. * python/python.c: Add python.h to includes. Remove python.h from HAVE_PYTHON definition (gdbpy_should_stop): New dummy function. (gdbpy_breakpoint_has_py_cond): New dummy function. * python/py-breakpoint.c (bppy_init): Rewrite to allow sub-classing capabilities. (gdbpy_should_stop): New function. (gdbpy_breakpoint_has_py_cond): New function. (local_setattro): New function. * breakpoint.c (condition_command): Add check for Python 'stop' operation. (bpstat_check_breakpoint_conditions): Execute Python 'stop' operation function as part of stop/continue tests. --- gdb/ChangeLog | 18 ++++ gdb/breakpoint.c | 14 +++ gdb/doc/ChangeLog | 6 ++ gdb/doc/gdb.texinfo | 28 ++++++ gdb/python/py-breakpoint.c | 140 +++++++++++++++++++++++++---- gdb/python/python.c | 18 +++- gdb/python/python.h | 6 ++ gdb/testsuite/ChangeLog | 4 + gdb/testsuite/gdb.python/py-breakpoint.exp | 98 ++++++++++++++++++++ 9 files changed, 312 insertions(+), 20 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 19294a7..4662422 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,21 @@ +2011-03-14 Phil Muldoon + + * python/python.h: Declare gdbpy_should_stop and + gdbpy_breakpoint_has_py_cond. + * python/python.c: Add python.h to includes. Remove python.h from + HAVE_PYTHON definition + (gdbpy_should_stop): New dummy function. + (gdbpy_breakpoint_has_py_cond): New dummy function. + * python/py-breakpoint.c (bppy_init): Rewrite to allow + sub-classing capabilities. + (gdbpy_should_stop): New function. + (gdbpy_breakpoint_has_py_cond): New function. + (local_setattro): New function. + * breakpoint.c (condition_command): Add check for Python 'stop' + operation. + (bpstat_check_breakpoint_conditions): Execute Python 'stop' + operation function as part of stop/continue tests. + 2011-03-14 Tom Tromey PR gdb/12576: diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c index d9e5b1e..c55e5c0 100644 --- a/gdb/breakpoint.c +++ b/gdb/breakpoint.c @@ -72,6 +72,7 @@ #undef savestring #include "mi/mi-common.h" +#include "python/python.h" /* Arguments to pass as context to some catch command handlers. */ #define CATCH_PERMANENT ((void *) (uintptr_t) 0) @@ -643,6 +644,14 @@ condition_command (char *arg, int from_tty) ALL_BREAKPOINTS (b) if (b->number == bnum) { + /* Check if this breakpoint has a Python object assigned to + it, and if it has a definition of the "stop" + method. This method and conditions entered into GDB from + the CLI are mutually exclusive. */ + if (b->py_bp_object + && gdbpy_breakpoint_has_py_cond (b->py_bp_object)) + error (_("Cannot set a condition where a Python 'stop' " + "method has been defined in the breakpoint.")); set_breakpoint_condition (b, p, from_tty); return; } @@ -4070,6 +4079,11 @@ bpstat_check_breakpoint_conditions (bpstat bs, ptid_t ptid) int value_is_zero = 0; struct expression *cond; + /* Evaluate Python breakpoints that have a "stop" + method implemented. */ + if (b->py_bp_object) + bs->stop = gdbpy_should_stop (b->py_bp_object); + if (is_watchpoint (b)) cond = b->cond_exp; else diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 8edb4b7..f0fa2ca 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,9 @@ +2011-03-14 Phil Muldoon + + * gdb.texinfo (Breakpoints In Python): Add description and example + of Python stop function operation. + + 2011-03-10 Phil Muldoon * gdb.texinfo (Parameters In Python): Document get_set_string and diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 4c07af9..01455d1 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -23115,6 +23115,34 @@ argument defines the class of watchpoint to create, if @var{type} is assumed to be a @var{WP_WRITE} class. @end defmethod +@defop Operation {gdb.Breakpoint} stop (self) +The @code{gdb.Breakpoint} class can be sub-classed and, in +particular, you may choose to implement the @code{stop} method. +If this method is defined as a sub-class of @code{gdb.Breakpoint}, +it will be called when the inferior reaches any location of a +breakpoint which instantiates that sub-class. If the method returns +@code{True}, the inferior will be stopped at the location of the +breakpoint, otherwise the inferior will continue. + +If there are multiple breakpoints at the same location with a +@code{stop} method, each one will be called regardless of the +return status of the previous. This ensures that all @code{stop} +methods have a chance to execute at that location. In this scenario +if one of the methods returns @code{True} but the others return +@code{False}, the inferior will still be stopped. + +Example @code{stop} implementation: + +@smallexample +class MyBreakpoint (gdb.Breakpoint): + def stop (self): + inf_val = gdb.parse_and_eval("foo") + if inf_val == 3: + return True + return False +@end smallexample +@end defop + The available watchpoint types represented by constants are defined in the @code{gdb} module: diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c index bfebb1a..0c21bfc 100644 --- a/gdb/python/py-breakpoint.c +++ b/gdb/python/py-breakpoint.c @@ -28,6 +28,8 @@ #include "observer.h" #include "cli/cli-script.h" #include "ada-lang.h" +#include "arch-utils.h" +#include "language.h" static PyTypeObject breakpoint_object_type; @@ -38,6 +40,9 @@ static int bppy_live; constructor and the breakpoint-created hook function. */ static breakpoint_object *bppy_pending_object; +/* Function that is called when a Python condition is evaluated. */ +static char * const stop_func = "stop"; + struct breakpoint_object { PyObject_HEAD @@ -590,10 +595,9 @@ bppy_get_ignore_count (PyObject *self, void *closure) } /* Python function to create a new breakpoint. */ -static PyObject * -bppy_new (PyTypeObject *subtype, PyObject *args, PyObject *kwargs) +static int +bppy_init (PyObject *self, PyObject *args, PyObject *kwargs) { - PyObject *result; static char *keywords[] = { "spec", "type", "wp_class", "internal", NULL }; char *spec; int type = bp_breakpoint; @@ -604,19 +608,16 @@ bppy_new (PyTypeObject *subtype, PyObject *args, PyObject *kwargs) if (! PyArg_ParseTupleAndKeywords (args, kwargs, "s|iiO", keywords, &spec, &type, &access_type, &internal)) - return NULL; + return -1; if (internal) { internal_bp = PyObject_IsTrue (internal); if (internal_bp == -1) - return NULL; + return -1; } - result = subtype->tp_alloc (subtype, 0); - if (! result) - return NULL; - bppy_pending_object = (breakpoint_object *) result; + bppy_pending_object = (breakpoint_object *) self; bppy_pending_object->number = -1; bppy_pending_object->bp = NULL; @@ -653,14 +654,14 @@ bppy_new (PyTypeObject *subtype, PyObject *args, PyObject *kwargs) } if (except.reason < 0) { - subtype->tp_free (result); - return PyErr_Format (except.reason == RETURN_QUIT - ? PyExc_KeyboardInterrupt : PyExc_RuntimeError, - "%s", except.message); + PyErr_Format (except.reason == RETURN_QUIT + ? PyExc_KeyboardInterrupt : PyExc_RuntimeError, + "%s", except.message); + return -1; } - BPPY_REQUIRE_VALID ((breakpoint_object *) result); - return result; + BPPY_SET_REQUIRE_VALID ((breakpoint_object *) self); + return 0; } @@ -711,6 +712,69 @@ gdbpy_breakpoints (PyObject *self, PyObject *args) return PyList_AsTuple (list); } +/* Call the "stop" method (if implemented) in the breakpoint + class. If the method returns True, the inferior will be + stopped at the breakpoint. Otherwise the inferior will be + allowed to continue. */ + +int +gdbpy_should_stop (struct breakpoint_object *bp_obj) +{ + int stop = 1; + + PyObject *py_bp = (PyObject *) bp_obj; + struct breakpoint *b = bp_obj->bp; + struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch (); + struct cleanup *cleanup = ensure_python_env (garch, current_language); + + if (PyObject_HasAttrString (py_bp, stop_func)) + { + PyObject *result = PyObject_CallMethod (py_bp, stop_func, NULL); + + if (result) + { + int evaluate = PyObject_IsTrue (result); + + if (evaluate == -1) + gdbpy_print_stack (); + + /* If the "stop" function returns False that means + the Python breakpoint wants GDB to continue. */ + if (! evaluate) + stop = 0; + + Py_DECREF (result); + } + else + gdbpy_print_stack (); + } + do_cleanups (cleanup); + + return stop; +} + +/* Checks if the "stop" method exists in this breakpoint. + Used by condition_command to ensure mutual exclusion of breakpoint + conditions. */ + +int +gdbpy_breakpoint_has_py_cond (struct breakpoint_object *bp_obj) +{ + int has_func = 0; + PyObject *py_bp = (PyObject *) bp_obj; + struct gdbarch *garch = bp_obj->bp->gdbarch ? bp_obj->bp->gdbarch : + get_current_arch (); + struct cleanup *cleanup = ensure_python_env (garch, current_language); + + if (py_bp == NULL) + return 0; + + has_func = PyObject_HasAttrString (py_bp, stop_func); + do_cleanups (cleanup); + + return has_func; +} + /* Event callback functions. */ @@ -797,7 +861,6 @@ gdbpy_initialize_breakpoints (void) { int i; - breakpoint_object_type.tp_new = bppy_new; if (PyType_Ready (&breakpoint_object_type) < 0) return; @@ -832,6 +895,37 @@ gdbpy_initialize_breakpoints (void) +/* Helper function that overrides this Python object's + PyObject_GenericSetAttr to allow extra validation of the attribute + being set. */ + +static int +local_setattro (PyObject *self, PyObject *name, PyObject *v) +{ + breakpoint_object *obj = (breakpoint_object *) self; + char *attr = python_string_to_host_string (name); + + if (attr == NULL) + return -1; + + /* If the attribute trying to be set is the "stop" method, + but we already have a condition set in the CLI, disallow this + operation. */ + if (strcmp (attr, stop_func) == 0 && obj->bp->cond_string) + { + xfree (attr); + PyErr_SetString (PyExc_RuntimeError, + _("Cannot set 'stop' method. There is an " \ + "existing GDB condition attached to the " \ + "breakpoint.")); + return -1; + } + + xfree (attr); + + return PyObject_GenericSetAttr ((PyObject *)self, name, v); +} + static PyGetSetDef breakpoint_object_getset[] = { { "enabled", bppy_get_enabled, bppy_set_enabled, "Boolean telling whether the breakpoint is enabled.", NULL }, @@ -901,9 +995,9 @@ static PyTypeObject breakpoint_object_type = 0, /*tp_call*/ 0, /*tp_str*/ 0, /*tp_getattro*/ - 0, /*tp_setattro*/ + (setattrofunc)local_setattro, /*tp_setattro */ 0, /*tp_as_buffer*/ - Py_TPFLAGS_DEFAULT, /*tp_flags*/ + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ "GDB breakpoint object", /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ @@ -913,5 +1007,13 @@ static PyTypeObject breakpoint_object_type = 0, /* tp_iternext */ breakpoint_object_methods, /* tp_methods */ 0, /* tp_members */ - breakpoint_object_getset /* tp_getset */ + breakpoint_object_getset, /* tp_getset */ + 0, /* tp_base */ + 0, /* tp_dict */ + 0, /* tp_descr_get */ + 0, /* tp_descr_set */ + 0, /* tp_dictoffset */ + bppy_init, /* tp_init */ + 0, /* tp_alloc */ + PyType_GenericNew /* tp_new */ }; diff --git a/gdb/python/python.c b/gdb/python/python.c index 3b10d8c..2d7213a 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -30,6 +30,7 @@ #include "exceptions.h" #include "event-loop.h" #include "serial.h" +#include "python.h" #include @@ -39,7 +40,6 @@ static int gdbpy_should_print_stack = 1; #ifdef HAVE_PYTHON -#include "python.h" #include "libiberty.h" #include "cli/cli-decode.h" #include "charset.h" @@ -864,6 +864,22 @@ source_python_script (FILE *stream, const char *file) _("Python scripting is not supported in this copy of GDB.")); } +int +gdbpy_should_stop (struct breakpoint_object *bp_obj) +{ + internal_error (__FILE__, __LINE__, + _("gdbpy_should_stop called when Python scripting is " \ + "not supported.")); +} + +int +gdbpy_breakpoint_has_py_cond (struct breakpoint_object *bp_obj) +{ + internal_error (__FILE__, __LINE__, + _("gdbpy_breakpoint_has_py_cond called when Python " \ + "scripting is not supported.")); +} + #endif /* HAVE_PYTHON */ diff --git a/gdb/python/python.h b/gdb/python/python.h index 58d97fc..ce0eb35 100644 --- a/gdb/python/python.h +++ b/gdb/python/python.h @@ -22,6 +22,8 @@ #include "value.h" +struct breakpoint_object; + extern int gdbpy_global_auto_load; extern void finish_python_initialization (void); @@ -41,4 +43,8 @@ void preserve_python_values (struct objfile *objfile, htab_t copied_types); void load_auto_scripts_for_objfile (struct objfile *objfile); +int gdbpy_should_stop (struct breakpoint_object *bp_obj); + +int gdbpy_breakpoint_has_py_cond (struct breakpoint_object *bp_obj); + #endif /* GDB_PYTHON_H */ diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index d56f32a..a99789f 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2010-03-14 Phil Muldoon + + * gdb.python/py-breakpoint.exp: Add Python stop operations tests. + 2011-03-13 Ulrich Weigand * gdb.python/py-section-script.exp: Skip test if no Python support. diff --git a/gdb/testsuite/gdb.python/py-breakpoint.exp b/gdb/testsuite/gdb.python/py-breakpoint.exp index 8f58181..f0a83f1 100644 --- a/gdb/testsuite/gdb.python/py-breakpoint.exp +++ b/gdb/testsuite/gdb.python/py-breakpoint.exp @@ -195,3 +195,101 @@ gdb_py_test_silent_cmd "python wp1 = gdb.Breakpoint (\"result\", type=gdb.BP_WA gdb_test "info breakpoints" "No breakpoints or watchpoints.*" "Check info breakpoints does not show invisible breakpoints" gdb_test "maint info breakpoints" ".*watchpoint.*result.*" "Check maint info breakpoints shows invisible breakpoints" gdb_test "continue" ".*\[Ww\]atchpoint.*result.*Old value = 0.*New value = 25.*" "Test watchpoint write" + +# Breakpoints that have an evaluation function. + +# Start with a fresh gdb. +clean_restart ${testfile} + +if ![runto_main] then { + fail "Cannot run to main." + return 0 +} +delete_breakpoints + +gdb_py_test_multiple "Sub-class a breakpoint" \ + "python" "" \ + "class bp_eval (gdb.Breakpoint):" "" \ + " inf_i = 0" "" \ + " count = 0" "" \ + " def stop (self):" "" \ + " self.count = self.count + 1" "" \ + " self.inf_i = gdb.parse_and_eval(\"i\")" "" \ + " if self.inf_i == 3:" "" \ + " return True" "" \ + " return False" "" \ + "end" "" + +gdb_py_test_multiple "Sub-class a second breakpoint" \ + "python" "" \ + "class bp_also_eval (gdb.Breakpoint):" "" \ + " count = 0" "" \ + " def stop (self):" "" \ + " self.count = self.count + 1" "" \ + " if self.count == 9:" "" \ + " return True" "" \ + " return False" "" \ + "end" "" + +gdb_py_test_multiple "Sub-class a third breakpoint" \ + "python" "" \ + "class basic (gdb.Breakpoint):" "" \ + " count = 0" "" \ + "end" "" + +set bp_location2 [gdb_get_line_number "Break at multiply."] +set end_location [gdb_get_line_number "Break at end."] +gdb_py_test_silent_cmd "python eval_bp1 = bp_eval(\"$bp_location2\")" "Set breakpoint" 0 +gdb_py_test_silent_cmd "python also_eval_bp1 = bp_also_eval(\"$bp_location2\")" "Set breakpoint" 0 +gdb_py_test_silent_cmd "python never_eval_bp1 = bp_also_eval(\"$end_location\")" "Set breakpoint" 0 +gdb_continue_to_breakpoint "Break at multiply." ".*/$srcfile:$bp_location2.*" +gdb_test "print i" "3" "Check inferior value matches python accounting" +gdb_test "python print eval_bp1.inf_i" "3" "Check python accounting matches inferior" +gdb_test "python print also_eval_bp1.count" "4" \ + "Check non firing same-location breakpoint eval function was also called at each stop." +gdb_test "python print eval_bp1.count" "4" \ + "Check non firing same-location breakpoint eval function was also called at each stop." + +delete_breakpoints +set cond_bp [gdb_get_line_number "Break at multiply."] +gdb_py_test_silent_cmd "python eval_bp1 = bp_eval(\"$cond_bp\")" "Set breakpoint" 0 +set test_cond {cond $bpnum} +gdb_test "$test_cond \"foo==3\"" "Cannot set a condition where a Python.*" \ + "Check you cannot add a CLI condition to a Python breakpoint that" \ + "has defined stop" +gdb_py_test_silent_cmd "python eval_bp2 = basic(\"$cond_bp\")" "Set breakpoint" 0 +gdb_py_test_silent_cmd "python eval_bp2.condition = \"1==1\"" "Set a condition" 0 +gdb_py_test_multiple "Construct an eval function" \ + "python" "" \ + "def stop_func ():" "" \ + " return True" "" \ + "end" "" + +gdb_test "python eval_bp2.stop = stop_func" \ + "RuntimeError: Cannot set 'stop' method.*" \ + "Assign stop function to a breakpoint that has a condition" + +delete_breakpoints +gdb_breakpoint [gdb_get_line_number "Break at multiply."] +gdb_py_test_silent_cmd "python check_eval = bp_eval(\"$bp_location2\")" "Set breakpoint" 0 +gdb_test "python print check_eval.count" "0" \ + "Test that evaluate function has not been yet executed (ie count = 0)" +gdb_continue_to_breakpoint "Break at multiply." ".*/$srcfile:$bp_location2.*" +gdb_test "python print check_eval.count" "1" \ + "Test that evaluate function is run when location also has normal bp" + +gdb_py_test_multiple "Sub-class a watchpoint" \ + "python" "" \ + "class wp_eval (gdb.Breakpoint):" "" \ + " def stop (self):" "" \ + " self.result = gdb.parse_and_eval(\"result\")" "" \ + " if self.result == 788:" "" \ + " return True" "" \ + " return False" "" \ + "end" "" + +delete_breakpoints +gdb_py_test_silent_cmd "python wp1 = wp_eval (\"result\", type=gdb.BP_WATCHPOINT, wp_class=gdb.WP_WRITE)" "Set watchpoint" 0 +gdb_test "continue" ".*\[Ww\]atchpoint.*result.*Old value =.*New value = 788.*" "Test watchpoint write" +gdb_test "python print never_eval_bp1.count" "0" \ + "Check that this unrelated breakpoints eval function was never called." -- cgit v1.1