Re: [python][patch] Python rbreak

Phil Muldoon
2017-11-13T19:29:15Z

Ping

On 03/11/17 09:46, Phil Muldoon wrote:
> On 17/10/17 01:24, Simon Marchi wrote:
>> On 2017-10-16 19:01, Phil Muldoon wrote:
>
>
>>>> I can't find a reference, but I think we want test names to start
>>>> with a lower case letter and not end with a dot. I'll see if we
>>>> can add this to the testcase cookbook wiki page.
>>>
>>> As I mentioned on IRC, I've not heard of it but will happily change
>>> the names to comply.
>
> Sorry this took a bit longer to get back out than I would have liked.
> Modified patch follows. I believe I have incorporated yours, Eli's and
> Kevin's comments. ChangeLogs remain the same (other than the new NEWS
> entry which I have added locally.)
>
> Cheers
>
> --
>
> diff --git a/gdb/NEWS b/gdb/NEWS
> index 2bad096a86..1d26ea4af7 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -24,6 +24,10 @@
> gdb.new_thread are emitted. See the manual for further
> description of these.
>
> + ** A new command, "rbreak" has been added to the Python API. This
> + command allows the setting of a large number of breakpoints via a
> + regex pattern in Python. See the manual for further details.
> +
> * New features in the GDB remote stub, GDBserver
>
> ** GDBserver is now able to start inferior processes with a
> diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
> index f661e489bb..f411f60d7e 100644
> --- a/gdb/doc/python.texi
> +++ b/gdb/doc/python.texi
> @@ -243,6 +243,23 @@ were no breakpoints. This peculiarity was subsequently fixed, and now
> @code{gdb.breakpoints} returns an empty sequence in this case.
> @end defun
>
> +@defun gdb.rbreak (regex @r{[}, minsyms @r{[}, throttle, @r{[}, symtabs @r{]]]})
> +Return a Python list holding a collection of newly set
> +@code{gdb.Breakpoint} objects matching function names defined by the
> +@var{regex} pattern. If the @var{minsyms} keyword is @code{True}, all
> +system functions (those not explicitly defined in the inferior) will
> +also be included in the match. The @var{throttle} keyword takes an
> +integer that defines the maximum number of pattern matches for
> +functions matched by the @var{regex} pattern. If the number of
> +matches exceeds the integer value of @var{throttle}, a
> +@code{RuntimeError} will be raised and no breakpoints will be created.
> +If @var{throttle} is not defined then there is no imposed limit on the
> +maximum number of matches and breakpoints to be created. The
> +@var{symtabs} keyword takes a Python iterable that yields a collection
> +of @code{gdb.Symtab} objects and will restrict the search to those
> +functions only contained within the @code{gdb.Symtab} objects.
> +@end defun
> +
> @findex gdb.parameter
> @defun gdb.parameter (parameter)
> Return the value of a @value{GDBN} @var{parameter} given by its name,
> diff --git a/gdb/python/python.c b/gdb/python/python.c
> index b04057ec4a..a044b8ff8b 100644
> --- a/gdb/python/python.c
> +++ b/gdb/python/python.c
> @@ -642,6 +642,190 @@ gdbpy_solib_name (PyObject *self, PyObject *args)
> return str_obj;
> }
>
> +/* Implementation of Python rbreak command. Take a REGEX and
> + optionally a MINSYMS, THROTTLE and SYMTABS keyword and return a
> + Python list that contains newly set breakpoints that match that
> + criteria. REGEX refers to a GDB format standard regex pattern of
> + symbols names to search; MINSYMS is an optional boolean (default
> + False) that indicates if the function should search GDB's minimal
> + symbols; THROTTLE is an optional integer (default unlimited) that
> + indicates the maximum amount of breakpoints allowable before the
> + function exits (note, if the throttle bound is passed, no
> + breakpoints will be set and a runtime error returned); SYMTABS is
> + an optional Python iterable that contains a set of gdb.Symtabs to
> + constrain the search within. */
> +
> +static PyObject *
> +gdbpy_rbreak (PyObject *self, PyObject *args, PyObject *kw)
> +{
> + /* A simple type to ensure clean up of a vector of allocated strings
> + when a C interface demands a const char *array[] type
> + interface. */
> + struct symtab_list_type
> + {
> + ~symtab_list_type ()
> + {
> + for (const char *elem: vec)
> + xfree ((void *) elem);
> + }
> + std::vector<const char *> vec;
> + };
> +
> + char *regex = NULL;
> + std::vector<symbol_search> symbols;
> + unsigned long count = 0;
> + PyObject *symtab_list = NULL;
> + PyObject *minsyms_p_obj = NULL;
> + int minsyms_p = 0;
> + unsigned int throttle = 0;
> + static const char *keywords[] = {"regex","minsyms", "throttle",
> + "symtabs", NULL};
> + symtab_list_type symtab_paths;
> +
> + if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!IO", keywords,
> + &regex, &PyBool_Type,
> + &minsyms_p_obj, &throttle,
> + &symtab_list))
> + return NULL;
> +
> + /* Parse minsyms keyword. */
> + if (minsyms_p_obj != NULL)
> + {
> + int cmp = PyObject_IsTrue (minsyms_p_obj);
> + if (cmp < 0)
> + return NULL;
> + minsyms_p = cmp;
> + }
> +
> + /* The "symtabs" keyword is any Python iterable object that returns
> + a gdb.Symtab on each iteration. If specified, iterate through
> + the provided gdb.Symtabs and extract their full path. As
> + python_string_to_target_string returns a
> + gdb::unique_xmalloc_ptr<char> and a vector containing these types
> + cannot be coerced to a const char **p[] via the vector.data call,
> + release the value from the unique_xmalloc_ptr and place it in a
> + simple type symtab_list_type (which holds the vector and a
> + destructor that frees the contents of the allocated strings. */
> + if (symtab_list != NULL)
> + {
> + gdbpy_ref<> iter (PyObject_GetIter (symtab_list));
> +
> + if (iter == NULL)
> + return NULL;
> +
> + while (true)
> + {
> + gdbpy_ref<> next (PyIter_Next (iter.get ()));
> +
> + if (next == NULL)
> + {
> + if (PyErr_Occurred ())
> + return NULL;
> + break;
> + }
> +
> + gdbpy_ref<> obj_name (PyObject_GetAttrString (next.get (),
> + "filename"));
> +
> + if (obj_name == NULL)
> + return NULL;
> +
> + /* Is the object file still valid? */
> + if (obj_name == Py_None)
> + continue;
> +
> + gdb::unique_xmalloc_ptr<char> filename =
> + python_string_to_target_string (obj_name.get ());
> +
> + if (filename == NULL)
> + return NULL;
> +
> + /* Make sure there is a definite place to store the value of
> + s before it is released. */
> + symtab_paths.vec.push_back (nullptr);
> + symtab_paths.vec.back () = filename.release ();
> + }
> + }
> +
> + if (symtab_list)
> + {
> + const char **files = symtab_paths.vec.data ();
> +
> + symbols = search_symbols (regex, FUNCTIONS_DOMAIN,
> + symtab_paths.vec.size (), files);
> + }
> + else
> + symbols = search_symbols (regex, FUNCTIONS_DOMAIN, 0, NULL);
> +
> + /* Count the number of symbols (both symbols and optionally minimal
> + symbols) so we can correctly check the throttle limit. */
> + for (const symbol_search &p : symbols)
> + {
> + /* Minimal symbols included? */
> + if (minsyms_p)
> + {
> + if (p.msymbol.minsym != NULL)
> + count++;
> + }
> +
> + if (p.symbol != NULL)
> + count++;
> + }
> +
> + /* Check throttle bounds and exit if in excess. */
> + if (throttle != 0 && count > throttle)
> + {
> + PyErr_SetString (PyExc_RuntimeError,
> + _("Number of breakpoints exceeds throttled maximum."));
> + return NULL;
> + }
> +
> + gdbpy_ref<> return_list (PyList_New (0));
> +
> + if (return_list == NULL)
> + return NULL;
> +
> + /* Construct full path names for symbols and call the Python
> + breakpoint constructor on the resulting names. Be tolerant of
> + individual breakpoint failures. */
> + for (const symbol_search &p : symbols)
> + {
> + std::string symbol_name;
> +
> + /* Skipping minimal symbols? */
> + if (minsyms_p == 0)
> + if (p.msymbol.minsym != NULL)
> + continue;
> +
> + if (p.msymbol.minsym == NULL)
> + {
> + struct symtab *symtab = symbol_symtab (p.symbol);
> + const char *fullname = symtab_to_fullname (symtab);
> +
> + symbol_name = fullname;
> + symbol_name += ":";
> + symbol_name += SYMBOL_LINKAGE_NAME (p.symbol);
> + }
> + else
> + symbol_name = MSYMBOL_LINKAGE_NAME (p.msymbol.minsym);
> +
> + gdbpy_ref<> argList (Py_BuildValue("(s)", symbol_name.c_str ()));
> + gdbpy_ref<> obj (PyObject_CallObject ((PyObject *)
> + &breakpoint_object_type,
> + argList.get ()));
> +
> + /* Tolerate individual breakpoint failures. */
> + if (obj == NULL)
> + gdbpy_print_stack ();
> + else
> + {
> + if (PyList_Append (return_list.get (), obj.get ()) == -1)
> + return NULL;
> + }
> + }
> + return return_list.release ();
> +}
> +
> /* A Python function which is a wrapper for decode_line_1. */
>
> static PyObject *
> @@ -1912,7 +2096,9 @@ Return the name of the current target charset." },
> { "target_wide_charset", gdbpy_target_wide_charset, METH_NOARGS,
> "target_wide_charset () -> string.\n\
> Return the name of the current target wide charset." },
> -
> + { "rbreak", (PyCFunction) gdbpy_rbreak, METH_VARARGS | METH_KEYWORDS,
> + "rbreak (Regex) -> List.\n\
> +Return a Tuple containing gdb.Breakpoint objects that match the given Regex." },
> { "string_to_argv", gdbpy_string_to_argv, METH_VARARGS,
> "string_to_argv (String) -> Array.\n\
> Parse String and return an argv-like array.\n\
> diff --git a/gdb/testsuite/gdb.python/py-rbreak-func2.c b/gdb/testsuite/gdb.python/py-rbreak-func2.c
> new file mode 100644
> index 0000000000..2d24b6b557
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-rbreak-func2.c
> @@ -0,0 +1,34 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2017 Free Software Foundation, Inc.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +int
> +efunc1 ()
> +{
> + return 1;
> +}
> +
> +int
> +efunc2 ()
> +{
> + return 2;
> +}
> +
> +int
> +efunc3 ()
> +{
> + return 3;
> +}
> diff --git a/gdb/testsuite/gdb.python/py-rbreak.c b/gdb/testsuite/gdb.python/py-rbreak.c
> new file mode 100644
> index 0000000000..e79d2a34ae
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-rbreak.c
> @@ -0,0 +1,70 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + Copyright 2013-2017 Free Software Foundation, Inc.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +int
> +func1 ()
> +{
> + return 1;
> +}
> +
> +int
> +func2 ()
> +{
> + return 2;
> +}
> +
> +int
> +func3 ()
> +{
> + return 3;
> +}
> +
> +int
> +func4 ()
> +{
> + return 4;
> +}
> +
> +int
> +func5 ()
> +{
> + return 5;
> +}
> +
> +void
> +func6 ()
> +{
> + return;
> +}
> +
> +void
> +outside_scope ()
> +{
> + return;
> +}
> +
> +int
> +main()
> +{
> + func1 (); /* Break func1. */
> + func2 ();
> + func3 ();
> + func4 ();
> + func5 ();
> + func6 ();
> + outside_scope ();
> +}
> diff --git a/gdb/testsuite/gdb.python/py-rbreak.exp b/gdb/testsuite/gdb.python/py-rbreak.exp
> new file mode 100644
> index 0000000000..5aaf2975c9
> --- /dev/null
> +++ b/gdb/testsuite/gdb.python/py-rbreak.exp
> @@ -0,0 +1,61 @@
> +# Copyright (C) 2017 Free Software Foundation, Inc.
> +#
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program. If not, see <http://www.gnu.org/licenses/>.
> +
> +# This file is part of the GDB testsuite. It tests the mechanism
> +# exposing values to Python.
> +
> +load_lib gdb-python.exp
> +
> +standard_testfile py-rbreak.c py-rbreak-func2.c
> +
> +if {[prepare_for_testing "failed to prepare" ${testfile} [list $srcfile $srcfile2]] } {
> + return 1
> +}
> +
> +# Skip all tests if Python scripting is not enabled.
> +if { [skip_python_tests] } { continue }
> +
> +if ![runto_main] then {
> + fail "can't run to main"
> + return 0
> +}
> +
> +gdb_py_test_silent_cmd "py sl = gdb.rbreak(\"\",minsyms=False)" \
> + "get all function breakpoints" 0
> +gdb_test "py print(len(sl))" "11" \
> + "check number of returned breakpoints is 11"
> +gdb_py_test_silent_cmd "py sl = gdb.rbreak(\"main\.\*\",minsyms=False)" \
> + "get main function breakpoint" 0
> +gdb_test "py print(len(sl))" "1" \
> + "check number of returned breakpoints is 1"
> +gdb_py_test_silent_cmd "py sl = gdb.rbreak(\"func\.\*\",minsyms=False,throttle=10)" \
> + "get functions matching func.*" 0
> +gdb_test "py print(len(sl))" "9" \
> + "check number of returned breakpoints is 9"
> +gdb_test "py gdb.rbreak(\"func\.\*\",minsyms=False,throttle=5)" \
> + "Number of breakpoints exceeds throttled maximum.*" \
> + "check throttle errors on too many breakpoints"
> +gdb_py_test_silent_cmd "py sl = gdb.rbreak(\"func1\",minsyms=True)" \
> + "including minimal symbols, get functions matching func.*" 0
> +gdb_test "py print(len(sl))" "2" \
> + "check number of returned breakpoints is 2"
> +gdb_py_test_silent_cmd "python sym = gdb.lookup_symbol(\"efunc1\")" \
> + "find a symbol in objfile" 1
> +gdb_py_test_silent_cmd "python symtab = sym\[0\].symtab" \
> + "get backing symbol table" 1
> +gdb_py_test_silent_cmd "py sl = gdb.rbreak(\"func\.\*\",minsyms=False,throttle=10,symtabs=\[symtab\])" \
> + "get functions matching func.* in one symtab only" 0
> +gdb_test "py print(len(sl))" "3" \
> + "check number of returned breakpoints is 3"
>