From c97d123d6701fbf462e96db001cea07ed32e4efa Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 16 Mar 2023 10:57:32 -0600 Subject: [PATCH] Implement gdb.execute_mi This adds a new Python function, gdb.execute_mi, that can be used to invoke an MI command but get the output as a Python object, rather than a string. This is done by implementing a new ui_out subclass that builds a Python object. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=11688 Reviewed-By: Eli Zaretskii --- gdb/Makefile.in | 1 + gdb/NEWS | 3 + gdb/doc/python.texi | 30 +++ gdb/mi/mi-cmds.h | 5 + gdb/mi/mi-main.c | 15 ++ gdb/python/py-mi.c | 298 ++++++++++++++++++++++++ gdb/python/python-internal.h | 3 + gdb/python/python.c | 5 + gdb/testsuite/gdb.python/py-exec-mi.exp | 32 +++ gdb/testsuite/gdb.python/py-mi-cmd.py | 27 +++ 10 files changed, 419 insertions(+) create mode 100644 gdb/python/py-mi.c create mode 100644 gdb/testsuite/gdb.python/py-exec-mi.exp diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 14b5dd0bad6..d909786792c 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -414,6 +414,7 @@ SUBDIR_PYTHON_SRCS = \ python/py-lazy-string.c \ python/py-linetable.c \ python/py-membuf.c \ + python/py-mi.c \ python/py-micmd.c \ python/py-newobjfileevent.c \ python/py-objfile.c \ diff --git a/gdb/NEWS b/gdb/NEWS index b82114d80b0..3ea7237d022 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -192,6 +192,9 @@ info main - Changes are backwards compatible, the older API can still be used to disassemble instructions without styling. + ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a + GDB/MI command and returns the output as a Python dictionary. + *** Changes in GDB 13 * MI version 1 is deprecated, and will be removed in GDB 14. diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi index c93f289746c..d1f9311f0db 100644 --- a/gdb/doc/python.texi +++ b/gdb/doc/python.texi @@ -4584,6 +4584,36 @@ commands have been added: (@value{GDBP}) @end smallexample +Conversely, it is possible to execute @sc{gdb/mi} commands from +Python, with the results being a Python object and not a +specially-formatted string. This is done with the +@code{gdb.execute_mi} function. + +@findex gdb.execute_mi +@defun gdb.execute_mi (command @r{[}, arg @r{]}@dots{}) +Invoke a @sc{gdb/mi} command. @var{command} is the name of the +command, a string. The arguments, @var{arg}, are passed to the +command. Each argument must also be a string. + +This function returns a Python dictionary whose contents reflect the +corresponding @sc{GDB/MI} command's output. Refer to the +documentation for these commands for details. Lists are represented +as Python lists, and tuples are represented as Python dictionaries. + +If the command fails, it will raise a Python exception. +@end defun + +Here is how this works using the commands from the example above: + +@smallexample +(@value{GDBP}) python print(gdb.execute_mi("-echo-dict", "abc", "def", "ghi")) +@{'dict': @{'argv': ['abc', 'def', 'ghi']@}@} +(@value{GDBP}) python print(gdb.execute_mi("-echo-list", "abc", "def", "ghi")) +@{'list': ['abc', 'def', 'ghi']@} +(@value{GDBP}) python print(gdb.execute_mi("-echo-string", "abc", "def", "ghi")) +@{'string': 'abc, def, ghi'@} +@end smallexample + @node Parameters In Python @subsubsection Parameters In Python diff --git a/gdb/mi/mi-cmds.h b/gdb/mi/mi-cmds.h index d867c298df9..c62b134fe3d 100644 --- a/gdb/mi/mi-cmds.h +++ b/gdb/mi/mi-cmds.h @@ -206,6 +206,11 @@ extern mi_command *mi_cmd_lookup (const char *command); extern void mi_execute_command (const char *cmd, int from_tty); +/* Execute an MI command given an already-constructed parse + object. */ + +extern void mi_execute_command (mi_parse *context); + /* Insert COMMAND into the global mi_cmd_table. Return false if COMMAND->name already exists in mi_cmd_table, in which case COMMAND will not have been added to mi_cmd_table. Otherwise, return true, and diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c index b430115daea..f3b7490e089 100644 --- a/gdb/mi/mi-main.c +++ b/gdb/mi/mi-main.c @@ -1965,6 +1965,21 @@ mi_execute_command (const char *cmd, int from_tty) } } +/* See mi-cmds.h. */ + +void +mi_execute_command (mi_parse *context) +{ + if (context->op != MI_COMMAND) + error (_("Command is not an MI command")); + + scoped_restore save_token = make_scoped_restore (¤t_token, + context->token); + scoped_restore save_debug = make_scoped_restore (&mi_debug_p, 0); + + mi_cmd_execute (context); +} + /* Captures the current user selected context state, that is the current thread and frame. Later we can then check if the user selected context has changed at all. */ diff --git a/gdb/python/py-mi.c b/gdb/python/py-mi.c new file mode 100644 index 00000000000..0fcd57844e7 --- /dev/null +++ b/gdb/python/py-mi.c @@ -0,0 +1,298 @@ +/* Python interface to MI commands + + Copyright (C) 2023 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 . */ + +#include "defs.h" +#include "python-internal.h" +#include "ui-out.h" +#include "mi/mi-parse.h" + +/* A ui_out subclass that creates a Python object based on the data + that is passed in. */ + +class py_ui_out : public ui_out +{ +public: + + py_ui_out () + : ui_out (fix_multi_location_breakpoint_output + | fix_breakpoint_script_output) + { + do_begin (ui_out_type_tuple, nullptr); + } + + bool can_emit_style_escape () const override + { return false; } + + bool do_is_mi_like_p () const override + { return true; } + + /* Return the Python object that was created. If a Python error + occurred during the processing, set the Python error and return + nullptr. */ + PyObject *result () + { + if (m_error.has_value ()) + { + m_error->restore (); + return nullptr; + } + return current ().obj.release (); + } + +protected: + + void do_progress_end () override { } + void do_progress_start () override { } + void do_progress_notify (const std::string &, const char *, double, double) + override + { } + + void do_table_begin (int nbrofcols, int nr_rows, const char *tblid) override + { + do_begin (ui_out_type_list, tblid); + } + void do_table_body () override + { } + void do_table_end () override + { + do_end (ui_out_type_list); + } + void do_table_header (int width, ui_align align, + const std::string &col_name, + const std::string &col_hdr) override + { } + + void do_begin (ui_out_type type, const char *id) override; + void do_end (ui_out_type type) override; + + void do_field_signed (int fldno, int width, ui_align align, + const char *fldname, LONGEST value) override; + void do_field_unsigned (int fldno, int width, ui_align align, + const char *fldname, ULONGEST value) override; + + void do_field_skip (int fldno, int width, ui_align align, + const char *fldname) override + { } + + void do_field_string (int fldno, int width, ui_align align, + const char *fldname, const char *string, + const ui_file_style &style) override; + void do_field_fmt (int fldno, int width, ui_align align, + const char *fldname, const ui_file_style &style, + const char *format, va_list args) override + ATTRIBUTE_PRINTF (7, 0); + + void do_spaces (int numspaces) override + { } + + void do_text (const char *string) override + { } + + void do_message (const ui_file_style &style, + const char *format, va_list args) + override ATTRIBUTE_PRINTF (3,0) + { } + + void do_wrap_hint (int indent) override + { } + + void do_flush () override + { } + + void do_redirect (struct ui_file *outstream) override + { } + +private: + + /* When constructing Python objects, this class keeps a stack of + objects being constructed. Each such object has this type. */ + struct object_desc + { + /* Name of the field (or empty for lists) that this object will + eventually become. */ + std::string field_name; + /* The object under construction. */ + gdbpy_ref<> obj; + /* The type of structure being created. Note that tables are + treated as lists here. */ + ui_out_type type; + }; + + /* The stack of objects being created. */ + std::vector m_objects; + + /* If an error occurred, this holds the exception information for + use by the 'release' method. */ + gdb::optional m_error; + + /* Return a reference to the object under construction. */ + object_desc ¤t () + { return m_objects.back (); } + + /* Add a new field to the current object under construction. */ + void add_field (const char *name, const gdbpy_ref<> &obj); +}; + +void +py_ui_out::add_field (const char *name, const gdbpy_ref<> &obj) +{ + if (obj == nullptr) + { + m_error.emplace (); + return; + } + + object_desc &desc = current (); + if (desc.type == ui_out_type_list) + { + if (PyList_Append (desc.obj.get (), obj.get ()) < 0) + m_error.emplace (); + } + else + { + if (PyDict_SetItemString (desc.obj.get (), name, obj.get ()) < 0) + m_error.emplace (); + } +} + +void +py_ui_out::do_begin (ui_out_type type, const char *id) +{ + if (m_error.has_value ()) + return; + + gdbpy_ref<> new_obj (type == ui_out_type_list + ? PyList_New (0) + : PyDict_New ()); + if (new_obj == nullptr) + { + m_error.emplace (); + return; + } + + object_desc new_desc; + if (id != nullptr) + new_desc.field_name = id; + new_desc.obj = std::move (new_obj); + new_desc.type = type; + + m_objects.push_back (std::move (new_desc)); +} + +void +py_ui_out::do_end (ui_out_type type) +{ + if (m_error.has_value ()) + return; + + object_desc new_obj = std::move (current ()); + m_objects.pop_back (); + add_field (new_obj.field_name.c_str (), new_obj.obj); +} + +void +py_ui_out::do_field_signed (int fldno, int width, ui_align align, + const char *fldname, LONGEST value) +{ + if (m_error.has_value ()) + return; + + gdbpy_ref<> val = gdb_py_object_from_longest (value); + add_field (fldname, val); +} + +void +py_ui_out::do_field_unsigned (int fldno, int width, ui_align align, + const char *fldname, ULONGEST value) +{ + if (m_error.has_value ()) + return; + + gdbpy_ref<> val = gdb_py_object_from_ulongest (value); + add_field (fldname, val); +} + +void +py_ui_out::do_field_string (int fldno, int width, ui_align align, + const char *fldname, const char *string, + const ui_file_style &style) +{ + if (m_error.has_value ()) + return; + + gdbpy_ref<> val = host_string_to_python_string (string); + add_field (fldname, val); +} + +void +py_ui_out::do_field_fmt (int fldno, int width, ui_align align, + const char *fldname, const ui_file_style &style, + const char *format, va_list args) +{ + if (m_error.has_value ()) + return; + + std::string str = string_vprintf (format, args); + do_field_string (fldno, width, align, fldname, str.c_str (), style); +} + +/* Implementation of the gdb.execute_mi command. */ + +PyObject * +gdbpy_execute_mi_command (PyObject *self, PyObject *args, PyObject *kw) +{ + gdb::unique_xmalloc_ptr mi_command; + std::vector> arg_strings; + + Py_ssize_t n_args = PyTuple_Size (args); + if (n_args < 0) + return nullptr; + + for (Py_ssize_t i = 0; i < n_args; ++i) + { + /* Note this returns a borrowed reference. */ + PyObject *arg = PyTuple_GetItem (args, i); + if (arg == nullptr) + return nullptr; + gdb::unique_xmalloc_ptr str = python_string_to_host_string (arg); + if (str == nullptr) + return nullptr; + if (i == 0) + mi_command = std::move (str); + else + arg_strings.push_back (std::move (str)); + } + + py_ui_out uiout; + + try + { + scoped_restore save_uiout = make_scoped_restore (¤t_uiout, &uiout); + std::unique_ptr parser + = mi_parse::make (std::move (mi_command), std::move (arg_strings)); + mi_execute_command (parser.get ()); + } + catch (const gdb_exception &except) + { + gdbpy_convert_exception (except); + return nullptr; + } + + return uiout.result (); +} diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h index 1142e0e739d..93217375cc5 100644 --- a/gdb/python/python-internal.h +++ b/gdb/python/python-internal.h @@ -483,6 +483,9 @@ struct symtab_and_line *sal_object_to_symtab_and_line (PyObject *obj); frame_info_ptr frame_object_to_frame_info (PyObject *frame_obj); struct gdbarch *arch_object_to_gdbarch (PyObject *obj); +extern PyObject *gdbpy_execute_mi_command (PyObject *self, PyObject *args, + PyObject *kw); + /* Convert Python object OBJ to a program_space pointer. OBJ must be a gdb.Progspace reference. Return nullptr if the gdb.Progspace is not valid (see gdb.Progspace.is_valid), otherwise return the program_space diff --git a/gdb/python/python.c b/gdb/python/python.c index fd5a920cbdb..9703d6ef900 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -2484,6 +2484,11 @@ PyMethodDef python_GdbMethods[] = Evaluate command, a string, as a gdb CLI command. Optionally returns\n\ a Python String containing the output of the command if to_string is\n\ set to True." }, + { "execute_mi", (PyCFunction) gdbpy_execute_mi_command, + METH_VARARGS | METH_KEYWORDS, + "execute_mi (command, arg...) -> dictionary\n\ +Evaluate command, a string, as a gdb MI command.\n\ +Arguments (also strings) are passed to the command." }, { "parameter", gdbpy_parameter, METH_VARARGS, "Return a gdb parameter's value" }, diff --git a/gdb/testsuite/gdb.python/py-exec-mi.exp b/gdb/testsuite/gdb.python/py-exec-mi.exp new file mode 100644 index 00000000000..09c4877870c --- /dev/null +++ b/gdb/testsuite/gdb.python/py-exec-mi.exp @@ -0,0 +1,32 @@ +# Copyright (C) 2023 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 . + +# Test gdb.execute_mi. + +load_lib gdb-python.exp +require allow_python_tests + +clean_restart + +gdb_test_no_output "source ${srcdir}/${subdir}/py-mi-cmd.py" \ + "load python file" + +gdb_test "python run_execute_mi_tests()" "PASS" + +# Be sure to test a command implemented as CLI command, as those fetch +# the args. +gdb_test_no_output "python gdb.execute_mi('-exec-arguments', 'a', 'b', 'c')" \ + "set arguments" + +gdb_test "show args" ".*\"a b c\"." diff --git a/gdb/testsuite/gdb.python/py-mi-cmd.py b/gdb/testsuite/gdb.python/py-mi-cmd.py index c7bf5b7226f..2c86c909858 100644 --- a/gdb/testsuite/gdb.python/py-mi-cmd.py +++ b/gdb/testsuite/gdb.python/py-mi-cmd.py @@ -118,3 +118,30 @@ def free_invoke(obj, args): # these as a Python function which is then called from the exp script. def run_exception_tests(): print("PASS") + + +# Run some execute_mi tests. This is easier to do from Python. +def run_execute_mi_tests(): + # Install the command. + cmd = pycmd1("-pycmd") + # Pass in a representative subset of the pycmd1 keys, and then + # check that the result via MI is the same as the result via a + # direct Python call. Note that some results won't compare as + # equal -- for example, a Python MI command can return a tuple, + # but that will be translated to a Python list. + for name in ("int", "str", "dct"): + expect = cmd.invoke([name]) + got = gdb.execute_mi("-pycmd", name) + if expect != got: + print("FAIL: saw " + repr(got) + ", but expected " + repr(expect)) + return + ok = False + try: + gdb.execute_mi("-pycmd", "exp") + # Due to the "denaturation" problem, we have to expect a gdb.error + # here and not a gdb.GdbError. + except gdb.error: + ok = True + if not ok: + print("FAIL: did not throw exception") + print("PASS") -- 2.30.2