[RFC - Python Scripting] New method gdb.Architecture.disassemble
Siva Chandra
sivachandra@google.com
Wed Feb 13 14:37:00 GMT 2013
I have addressed all of Tom's comments and added docs and tests in the
attached patch. I did not add a NEWS entry as an entry already exists
for the new gdb.Architecture class.
2013-02-13 Siva Chandra Reddy <sivachandra@google.com>
Add a new method 'disassemble' to gdb.Architecture class.
* python/py-arch.c (archpy_disassmble): Implementation of the
new method gdb.Architecture.disassemble.
(arch_object_methods): Add entry for the new method.
doc/
* gdb.texinfo (Architectures In Python): Add description about
the new method gdb.Architecture.disassemble.
testsuite/
* gdb.python/py-arch.c: New test case
* gdb.python/py-arch.exp: New tests to test
gdb.Architecture.disassemble
* gdb.python/Makefile.in: Add py-arch to the list of
EXECUTABLES.
I have a couple of questions for my knowledge:
1. docs.python.org says that PyList_Append sets an exception when it
fails. It does not say so for PyList_New() and PyDict_New(). However,
Tom commented that even these functions set exception on failure. In
general, how do we know if a certain Python C API function sets an
exception or not?
2. One of Tom's suggestion was to use something like this:
asm_code == NULL ? unknown_str : asm_code
I have modified my code accordingly, but the concern I have is that
asm_code is of type 'char *', while unknown_str if of type 'const char
*'. This means that the type of result of the above expression is
dynamic! Though the code compiles with GCC, it that standard?
Thanks,
Siva Chandra
-------------- next part --------------
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index e3f336e..b18c409 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -26040,6 +26040,36 @@ A @code{gdb.Architecture} class has the following methods:
Return the name (string value) of the architecture.
@end defun
+@defun Architecture.disassemble (@var{low}, @var{high})
+Return a list of disassembled instructions in the memory address range
+@var{low} to @var{high}. Each element of the list is a Python
+@code{dict} with the following string keys:
+
+@table @asis
+
+@item @code{`addr'}
+The value corresponding to this key is a Python long integer capturing
+the memory address of the instruction.
+
+@item @code{`asm'}
+The value corresponding to this key is a string value capturing the
+assembly language code of the instruction.
+
+@item @code{`func'}
+The value corresponding to this key is the name of the function (string
+value) the instruction belongs to.
+
+@item @code{`length'}
+The value correspoding to this key is the length (integer value) of the
+instruction in bytes.
+
+@item @code{`offset'}
+The value corresponding to this key is the byte offset (integer value)
+of the instruction within the function it belongs to.
+
+@end table
+@end defun
+
@node Python Auto-loading
@subsection Python Auto-loading
@cindex Python auto-loading
diff --git a/gdb/python/py-arch.c b/gdb/python/py-arch.c
index edd508f..1837bf3 100644
--- a/gdb/python/py-arch.c
+++ b/gdb/python/py-arch.c
@@ -20,6 +20,7 @@
#include "defs.h"
#include "gdbarch.h"
#include "arch-utils.h"
+#include "disasm.h"
#include "python-internal.h"
typedef struct arch_object_type_object {
@@ -86,6 +87,104 @@ archpy_name (PyObject *self, PyObject *args)
return py_name;
}
+/* Implementation of gdb.Architecture.disassemble (self, low, high) -> List.
+ Returns a list of instructions in a memory address range. Each instruction
+ in the list is a Python dict object.
+*/
+
+static PyObject *
+archpy_disassemble (PyObject *self, PyObject *args, PyObject *kw)
+{
+ static char *keywords[] = { "low", "high", NULL };
+ CORE_ADDR low, high;
+ CORE_ADDR pc;
+ PyObject *result_list;
+ struct gdbarch *gdbarch = arch_object_to_gdbarch (self);
+
+ if (!PyArg_ParseTupleAndKeywords (args, kw, GDB_PY_LLU_ARG GDB_PY_LLU_ARG,
+ keywords, &low, &high))
+ return NULL;
+
+ result_list = PyList_New (0);
+ if (!result_list)
+ return NULL;
+
+ for (pc = low; pc <= high;)
+ {
+ int line = -1, unmapped, offset = -1, insn_len = 0;
+ char *filename = NULL, *fn = NULL, *as = NULL;
+ struct ui_file *memfile = mem_fileopen ();
+ PyObject *insn_dict = PyDict_New ();
+ volatile struct gdb_exception except;
+
+ if (!insn_dict)
+ {
+ Py_DECREF (result_list);
+ ui_file_delete (memfile);
+
+ return NULL;
+ }
+ if (PyList_Append (result_list, insn_dict))
+ {
+ Py_DECREF (result_list);
+ Py_DECREF (insn_dict);
+ ui_file_delete (memfile);
+
+ return NULL; /* PyList_Append Sets the exception. */
+ }
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ insn_len = gdb_print_insn (gdbarch, pc, memfile, NULL);
+ /* Even though filename, line and unmapped are passed as arguments,
+ they do not give us any meaningful values currently. */
+ build_address_symbolic (gdbarch, pc, 0, &fn, &offset, &filename,
+ &line, &unmapped);
+ }
+ if (except.reason < 0)
+ {
+ Py_DECREF (result_list);
+ ui_file_delete (memfile);
+ xfree (fn);
+ xfree (filename);
+
+ return gdbpy_convert_exception (except);
+ }
+
+ as = ui_file_xstrdup (memfile, NULL);
+ if (PyDict_SetItemString (insn_dict, "addr",
+ gdb_py_long_from_ulongest (pc))
+ || PyDict_SetItemString (insn_dict, "asm",
+ PyString_FromString (as ? as : "<unknown>"))
+ || PyDict_SetItemString (insn_dict, "func",
+ PyString_FromString (fn ? fn : "<unknown>"))
+ || PyDict_SetItemString (insn_dict, "length",
+ PyInt_FromLong (insn_len))
+ || PyDict_SetItemString (insn_dict, "offset",
+ PyInt_FromLong (offset)))
+ {
+ Py_DECREF (result_list);
+ PyErr_SetString (PyExc_MemoryError,
+ _("Unable to add fields to instruction dict."));
+
+ ui_file_delete (memfile);
+ xfree (as);
+ xfree (fn);
+ xfree (filename);
+
+ return NULL;
+ }
+
+ pc += insn_len;
+ ui_file_delete (memfile);
+ xfree (as);
+ xfree (fn);
+ xfree (filename);
+ }
+
+ return result_list;
+}
+
/* Initializes the Architecture class in the gdb module. */
void
@@ -105,6 +204,10 @@ static PyMethodDef arch_object_methods [] = {
{ "name", archpy_name, METH_NOARGS,
"name () -> String.\n\
Return the name of the architecture as a string value." },
+ { "disassemble", (PyCFunction) archpy_disassemble,
+ METH_VARARGS | METH_KEYWORDS,
+ "disassemble (low, high) -> List.\n\
+Return the list of disassembled instructions from LOW to HIGH." },
{NULL} /* Sentinel */
};
diff --git a/gdb/testsuite/gdb.python/Makefile.in b/gdb/testsuite/gdb.python/Makefile.in
index 4e286b5..0b81507 100644
--- a/gdb/testsuite/gdb.python/Makefile.in
+++ b/gdb/testsuite/gdb.python/Makefile.in
@@ -6,7 +6,7 @@ EXECUTABLES = py-type py-value py-prettyprint py-template py-block \
py-shared python lib-types py-events py-evthreads py-frame \
py-mi py-pp-maint py-progspace py-section-script py-objfile \
py-finish-breakpoint py-finish-breakpoint2 py-value-cc py-explore \
- py-explore-cc
+ py-explore-cc py-arch
MISCELLANEOUS = py-shared-sl.sl py-events-shlib.so py-events-shlib-nodebug.so
diff --git a/gdb/testsuite/gdb.python/py-arch.c b/gdb/testsuite/gdb.python/py-arch.c
new file mode 100644
index 0000000..e2fe55c
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-arch.c
@@ -0,0 +1,23 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2013 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
+main (void)
+{
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.python/py-arch.exp b/gdb/testsuite/gdb.python/py-arch.exp
new file mode 100644
index 0000000..5104619
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-arch.exp
@@ -0,0 +1,45 @@
+# Copyright 2013 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/>.
+
+standard_testfile
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+ return -1
+}
+
+# Skip all tests if Python scripting is not enabled.
+if { [skip_python_tests] } { continue }
+
+if ![runto_main] {
+ return -1
+}
+
+gdb_py_test_silent_cmd "python frame = gdb.selected_frame()" "get frame" 0
+gdb_py_test_silent_cmd "python arch = frame.architecture()" "get arch" 0
+gdb_py_test_silent_cmd "python pc = frame.pc()" "get pc" 0
+gdb_py_test_silent_cmd "python insn_list = arch.disassemble(pc, pc)" "disassemble" 0
+
+gdb_test "python print len(insn_list)" "1" "test number of instructions"
+
+gdb_py_test_silent_cmd "python insn = insn_list\[0\]" "get instruction" 0
+
+gdb_test "python print \"addr\" in insn" "True" "test key addr"
+gdb_test "python print \"asm\" in insn" "True" "test key asm"
+gdb_test "python print \"func\" in insn" "True" "test key func"
+gdb_test "python print \"length\" in insn" "True" "test key length"
+gdb_test "python print \"offset\" in insn" "True" "test key offset"
+
+# Negative test
+gdb_test "python arch.disassemble(0, 0)" ".*gdb\.MemoryError.*" "test exception"
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