Re: [patch] Add solib_address and decode_line Python functionality

Phil Muldoon
2010-08-10T11:17:58Z

On 06/08/10 23:39, Tom Tromey wrote:
>>>>>> "Phil" == Phil Muldoon <pmuldoon@redhat.com> writes:
>
> Phil> I looked at the documentation and PY_LONG_LONG is only available on
> Phil> some platforms (namely, 64 bit platforms). I used unsigned long, and
> Phil> 'k' instead.
>
> Tom> I think PY_LONG_LONG should be available in other situations too -- in
> Tom> particular if the compiler supports "long long", which GCC does.
>
> Tom> It is important to use PY_LONG_LONG if it is available. E.g., consider
> Tom> if gdb is hosted on a 32-bit machine but debugging a 64-bit executable.
> Tom>In this case an address will be 64 bits.
>
> Tom> So, could you make this conditional?

Sure, what do you think of the attached patch?

> Eli> This is okay, but I would suggest to explain what happens without the
> Eli> argument first. Readers shouldn't need to read all the description of
> Eli> how the argument is parsed if they don't want to pass it.

I've used your re-ordering in this patch, too.

OK?

Cheers,

Phil

--
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 867c06c..7dc7137 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -20564,6 +20564,25 @@ Return the name of the current target wide character set
never returned.
@end defun

+@findex gdb.solib_name
+@defun solib_name address
+Return the name of the shared library holding the given @var{address}
+as a string, or @code{None}.
+@end defun
+
+@findex gdb.decode_line
+@defun decode_line @r{[}expression@r{]}
+Return locations of the line specified by @var{expression}, or of the
+current line if no argument was given. This function returns a Python
+tuple containing two elements. The first element contains a string
+holding any unparsed section of @var{expression} (or @code{None} if
+the expression has been fully parsed). The second element contains
+either @code{None} or another tuple that contains all the locations
+that match the expression represented as @code{gdb.Symtab_and_line}
+objects (@pxref{Symbol Tables In Python}). If @var{expression} is
+provided, it is decoded the way that @value{GDBN}'s inbuilt
+@code{break} or @code{edit} commands do (@pxref{Specify Location}).
+
@node Exception Handling
@subsubsection Exception Handling
@cindex python exceptions
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 7346fba..16c3cba 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -42,7 +42,10 @@ static int gdbpy_should_print_stack = 1;
#include "cli/cli-decode.h"
#include "charset.h"
#include "top.h"
+#include "solib.h"
#include "python-internal.h"
+#include "linespec.h"
+#include "source.h"
#include "version.h"
#include "target.h"
#include "gdbthread.h"
@@ -374,6 +377,137 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
Py_RETURN_NONE;
}

+/* Implementation of gdb.solib_name (Long) -> String.
+ Returns the name of the shared library holding a given address, or None. */
+
+static PyObject *
+gdbpy_solib_name (PyObject *self, PyObject *args)
+{
+ char *soname;
+ PyObject *str_obj;
+#ifdef PY_LONG_LONG
+ unsigned PY_LONG_LONG pc;
+ const char *format = "K";
+#else
+ unsigned long pc;
+ const char *format = "k";
+#endif
+
+ if (!PyArg_ParseTuple (args, format, &pc))
+ return NULL;
+
+ soname = solib_name_from_address (current_program_space, pc);
+ if (soname)
+ str_obj = PyString_Decode (soname, strlen (soname), host_charset (), NULL);
+ else
+ {
+ str_obj = Py_None;
+ Py_INCREF (Py_None);
+ }
+
+ return str_obj;
+}
+
+/* A Python function which is a wrapper for decode_line_1. */
+
+static PyObject *
+gdbpy_decode_line (PyObject *self, PyObject *args)
+{
+ struct symtabs_and_lines sals = { NULL, 0 }; /* Initialize to appease gcc. */
+ struct symtab_and_line sal;
+ char *arg = NULL;
+ char *copy = NULL;
+ struct cleanup *cleanups;
+ PyObject *result = NULL;
+ PyObject *return_result = NULL;
+ PyObject *unparsed = NULL;
+ volatile struct gdb_exception except;
+
+ if (! PyArg_ParseTuple (args, "|s", &arg))
+ return NULL;
+
+ cleanups = ensure_python_env (get_current_arch (), current_language);
+
+ TRY_CATCH (except, RETURN_MASK_ALL)
+ {
+ if (arg)
+ {
+ arg = xstrdup (arg);
+ make_cleanup (xfree, arg);
+ copy = arg;
+ sals = decode_line_1 (&copy, 0, 0, 0, 0, 0);
+ make_cleanup (xfree, sals.sals);
+ }
+ else
+ {
+ set_default_source_symtab_and_line ();
+ sal = get_current_source_symtab_and_line ();
+ sals.sals = &sal;
+ sals.nelts = 1;
+ }
+ }
+ if (except.reason < 0)
+ {
+ do_cleanups (cleanups);
+ /* We know this will always throw. */
+ GDB_PY_HANDLE_EXCEPTION (except);
+ }
+
+ if (sals.nelts)
+ {
+ int i;
+
+ result = PyTuple_New (sals.nelts);
+ if (! result)
+ goto error;
+ for (i = 0; i < sals.nelts; ++i)
+ {
+ PyObject *obj;
+ char *str;
+
+ obj = symtab_and_line_to_sal_object (sals.sals[i]);
+ if (! obj)
+ {
+ Py_DECREF (result);
+ goto error;
+ }
+
+ PyTuple_SetItem (result, i, obj);
+ }
+ }
+ else
+ {
+ result = Py_None;
+ Py_INCREF (Py_None);
+ }
+
+ return_result = PyTuple_New (2);
+ if (! return_result)
+ {
+ Py_DECREF (result);
+ goto error;
+ }
+
+ if (copy && strlen (copy) > 0)
+ unparsed = PyString_FromString (copy);
+ else
+ {
+ unparsed = Py_None;
+ Py_INCREF (Py_None);
+ }
+
+ PyTuple_SetItem (return_result, 0, unparsed);
+ PyTuple_SetItem (return_result, 1, result);
+
+ do_cleanups (cleanups);
+
+ return return_result;
+
+ error:
+ do_cleanups (cleanups);
+ return NULL;
+}
+
/* Parse a string and evaluate it as an expression. */
static PyObject *
gdbpy_parse_and_eval (PyObject *self, PyObject *args)
@@ -825,6 +959,16 @@ a boolean indicating if name is a field of the current implied argument\n\
`this' (when the current language is object-oriented)." },
{ "block_for_pc", gdbpy_block_for_pc, METH_VARARGS,
"Return the block containing the given pc value, or None." },
+ { "solib_name", gdbpy_solib_name, METH_VARARGS,
+ "solib_name (Long) -> String.\n\
+Return the name of the shared library holding a given address, or None." },
+ { "decode_line", gdbpy_decode_line, METH_VARARGS,
+ "decode_line (String) -> Tuple. Decode a string argument the way\n\
+that 'break' or 'edit' does. Return a tuple containing two elements.\n\
+The first element contains any unparsed portion of the String parameter\n\
+(or None if the string was fully parsed). The second element contains\n\
+a tuple that contains all the locations that match, represented as\n\
+gdb.Symtab_and_line objects (or None)."},
{ "parse_and_eval", gdbpy_parse_and_eval, METH_VARARGS,
"parse_and_eval (String) -> Value.\n\
Parse String as an expression, evaluate it, and return the result as a Value."
diff --git a/gdb/testsuite/gdb.python/python-sl.c b/gdb/testsuite/gdb.python/python-sl.c
new file mode 100644
index 0000000..579a74e
--- /dev/null
+++ b/gdb/testsuite/gdb.python/python-sl.c
@@ -0,0 +1,26 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2010 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/>. */
+
+void func1 ()
+{
+ return;
+}
+
+int func2 ()
+{
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.python/python.c b/gdb/testsuite/gdb.python/python.c
new file mode 100644
index 0000000..750a90a
--- /dev/null
+++ b/gdb/testsuite/gdb.python/python.c
@@ -0,0 +1,28 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2010 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/>. */
+
+/* Shared library function */
+extern void func1 (void);
+extern int func2 (void);
+
+int
+main (int argc, char *argv[])
+{
+ func1 ();
+ func2 ();
+ return 0; /* Break to end. */
+}
diff --git a/gdb/testsuite/gdb.python/python.exp b/gdb/testsuite/gdb.python/python.exp
index 7aef888..e153ab8 100644
--- a/gdb/testsuite/gdb.python/python.exp
+++ b/gdb/testsuite/gdb.python/python.exp
@@ -20,12 +20,44 @@ if $tracelevel then {
strace $tracelevel
}

-# Start with a fresh gdb.
+set testfile "python"
+set srcfile ${testfile}.c
+set libfile "python-sl"
+set libsrc ${libfile}.c
+set library ${objdir}/${subdir}/${libfile}.sl
+set binfile ${objdir}/${subdir}/${testfile}
+
+if { [gdb_compile_shlib ${srcdir}/${subdir}/${libsrc} ${library} "debug"] != "" } {
+ untested "Could not compile shared library."
+ return -1
+}
+
+set exec_opts [list debug shlib=${library}]
+
+if { [gdb_compile ${srcdir}/${subdir}/${srcfile} ${binfile} executable $exec_opts] != "" } {
+ untested "Could not compile $binfile."
+ return -1
+}

+# Start with a fresh gdb.
gdb_exit
gdb_start
gdb_reinitialize_dir $srcdir/$subdir

+# Skip all tests if Python scripting is not enabled.
+if { [skip_python_tests] } { continue }
+
+# Run a command in GDB, and report a failure if a Python exception is thrown.
+# If report_pass is true, report a pass if no exception is thrown.
+proc gdb_py_test_silent_cmd {cmd name report_pass} {
+ global gdb_prompt
+
+ gdb_test_multiple $cmd $name {
+ -re "Traceback.*$gdb_prompt $" { fail $name }
+ -re "$gdb_prompt $" { if $report_pass { pass $name } }
+ }
+}
+
gdb_test_multiple "python print 23" "verify python support" {
-re "not supported.*$gdb_prompt $" {
unsupported "python support is disabled"
@@ -110,3 +142,50 @@ gdb_test_multiple "python print \"\\n\" * $lines" $test {
}
}
gdb_test "q" "Quit" "verify pagination afterwards: q"
+
+# Start with a fresh gdb.
+clean_restart ${testfile}
+
+# The following tests require execution.
+
+if ![runto_main] then {
+ fail "Can't run to main"
+ return 0
+}
+
+runto [gdb_get_line_number "Break to end."]
+
+# Test gdb.decode_line.
+gdb_test "python gdb.decode_line(\"main.c:43\")" \
+ "RuntimeError: No source file named main.c.*" "test decode_line no source named main"
+
+gdb_py_test_silent_cmd "python symtab = gdb.decode_line()" "test decode_line current location" 1
+gdb_test "python print len(symtab)" "2" "Test decode_line current location"
+gdb_test "python print symtab\[0\]" "None" "Test decode_line expression parse"
+gdb_test "python print len(symtab\[1\])" "1" "Test decode_line current location"
+gdb_test "python print symtab\[1\]\[0\].symtab" "gdb/testsuite/gdb.python/python.c.*" "Test decode_line current locationn filename"
+gdb_test "python print symtab\[1\]\[0\].line" "22" "Test decode_line current location line number"
+
+gdb_py_test_silent_cmd "python symtab = gdb.decode_line(\"python.c:26 if foo\")" "test decode_line python.c:26" 1
+gdb_test "python print len(symtab)" "2" "Test decode_line python.c:26 length"
+gdb_test "python print symtab\[0\]" "if foo" "Test decode_line expression parse"
+gdb_test "python print len(symtab\[1\])" "1" "Test decode_line python.c:26 length"
+gdb_test "python print symtab\[1\]\[0\].symtab" "gdb/testsuite/gdb.python/python.c.*" "Test decode_line python.c:26 filename"
+gdb_test "python print symtab\[1\]\[0\].line" "26" "Test decode_line python.c:26 line number"
+
+gdb_test "python gdb.decode_line(\"randomfunc\")" \
+ "RuntimeError: Function \"randomfunc\" not defined.*" "test decode_line randomfunc"
+gdb_py_test_silent_cmd "python symtab = gdb.decode_line(\"func1\")" "test decode_line func1()" 1
+gdb_test "python print len(symtab)" "2" "Test decode_line func1 length"
+gdb_test "python print len(symtab\[1\])" "1" "Test decode_line func1 length"
+gdb_test "python print symtab\[1\]\[0\].symtab" "gdb/testsuite/gdb.python/python-sl.c.*" "Test decode_line func1 filename"
+gdb_test "python print symtab\[1\]\[0\].line" "19" "Test decode_line func1 line number"
+
+# Test gdb.solib_name
+gdb_test "p &func1" "" "func1 address"
+gdb_py_test_silent_cmd "python func1 = gdb.history(0)" "Aquire func1 address" 1
+gdb_test "python print gdb.solib_name(long(func1))" "gdb/testsuite/gdb.python/python-sl.sl" "test func1 solib location"
+
+gdb_test "p &main" "" "main address"
+gdb_py_test_silent_cmd "python main = gdb.history(0)" "Aquire main address" 1
+gdb_test "python print gdb.solib_name(long(main))" "None" "test main solib location"