[python][rfc] Replace gdb.Frame.addr_in_block withgdb.Frame.function.

[Thiago Jung Bauermann <bauerman at br dot ibm dot com>]

Hi folks,

When posting upstream the patch for the Frames in Python API, this
thought about gdb.Frame.addr_in_block came up:

> The only use I have for this function right now is to obtain an address
> to pass to the function gdb.find_pc_function, which returns a gdb.Symbol
> object for the function containing the given address.
> 
> This usage directly reflects the way things are done in the GDB
> internals. Perhaps I should depart from it, remove gdb.find_pc_function
> and gdb.Frame.address_in_block and directly provide a gdb.Frame.function
> method which returns the gdb.Symbol object for the function
> corresponding to the frame?

This patch implements what's described in the last sentence above. WDYT?

I'm posting as RFC because this patch changes the current Python API.
-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center



gdb/
	* python/lib/gdb/command/backtrace.py: Use gdb.Frame.function
	instead of gdb.Frame.addr_in_block and gdb.find_pc_function.
	* python/python-frame.c (frapy_addr_in_block): Remove.
	(frapy_function): New function.
	(frame_object_methods): Remove entry for `addr_in_block'.
	Add entry for `function'.
	* python/python.c (gdbpy_find_pc_function): Remove.
	(GdbMethods): Remove entry for `find_pc_function'.

gdb/testsuite/
	* gdb.python/python-frame.exp: Remove test for
	gdb.Frame.addr_in_block.  Add test for gdb.function.

gdb/doc/
	* gdb.texinfo (Frames In Python): Remove documentation of
	Frame.addr_in_block.  Add documentation for Frame.function.

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 382f0c1..bdd175e 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -19537,8 +19537,8 @@ Returns the frame's resume address.
 Returns the frame's code block. @c (@pxref{Block,,Code Blocks and Scopes}).
 @end defmethod
 
-@defmethod Frame address_in_block
-Returns an address which falls within the frame's code block.
+@defmethod Frame function
+Returns the symbol for the function corresponding to this frame. @c (@pxref{Symbols In Python}).
 @end defmethod
 
 @defmethod Frame older
diff --git a/gdb/python/lib/gdb/command/backtrace.py b/gdb/python/lib/gdb/command/backtrace.py
index f07696e..17b1c18 100644
--- a/gdb/python/lib/gdb/command/backtrace.py
+++ b/gdb/python/lib/gdb/command/backtrace.py
@@ -92,7 +92,7 @@ class FrameWrapper:
                 stream.write (" 0x%08x in" % pc)
             stream.write (" " + name + " (")
 
-            func = gdb.find_pc_function (self.frame.addr_in_block ())
+            func = self.frame.function ()
             self.print_frame_args (stream, func)
 
             stream.write (")")
diff --git a/gdb/python/python-frame.c b/gdb/python/python-frame.c
index dc3f45e..a2626e4 100644
--- a/gdb/python/python-frame.c
+++ b/gdb/python/python-frame.c
@@ -253,13 +253,13 @@ frapy_block (PyObject *self, PyObject *args)
 }
 
 
-/* Implementation of gdb.Frame.addr_in_block (self) -> Long.
-   Returns an address which falls within the frame's code block.  */
+/* Implementation of gdb.Frame.function (self) -> gdb.Symbol.
+   Returns the symbol for the function corresponding to this frame.  */
 
 static PyObject *
-frapy_addr_in_block (PyObject *self, PyObject *args)
+frapy_function (PyObject *self, PyObject *args)
 {
-  CORE_ADDR pc = 0;	      /* Initialize to appease gcc warning.  */
+  struct symbol *sym = NULL;
   struct frame_info *frame;
   volatile struct gdb_exception except;
 
@@ -267,11 +267,14 @@ frapy_addr_in_block (PyObject *self, PyObject *args)
     {
       FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
 
-      pc = get_frame_address_in_block (frame);
+      sym = find_pc_function (get_frame_address_in_block (frame));
     }
   GDB_PY_HANDLE_EXCEPTION (except);
 
-  return PyLong_FromUnsignedLongLong (pc);
+  if (sym)
+    return symbol_to_symbol_object (sym);
+
+  Py_RETURN_NONE;
 }
 
 /* Convert a frame_info struct to a Python Frame object.
@@ -634,9 +637,9 @@ Return the frame's resume address." },
   { "block", frapy_block, METH_NOARGS,
     "block () -> gdb.Block.\n\
 Return the frame's code block." },
-  { "addr_in_block", frapy_addr_in_block, METH_NOARGS,
-    "addr_in_block () -> Long.\n\
-Return an address which falls within the frame's code block." },
+  { "function", frapy_function, METH_NOARGS,
+    "function () -> gdb.Symbol.\n\
+Returns the symbol for the function corresponding to this frame." },
   { "older", frapy_older, METH_NOARGS,
     "older () -> gdb.Frame.\n\
 Return the frame immediately older (outer) to this frame." },
diff --git a/gdb/python/python.c b/gdb/python/python.c
index c15e718..c94a252 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -312,23 +312,6 @@ gdbpy_solib_address (PyObject *self, PyObject *args)
   return str_obj;
 }
 
-static PyObject *
-gdbpy_find_pc_function (PyObject *self, PyObject *args)
-{
-  unsigned long long pc;
-  struct symbol *sym;
-  PyObject *sym_obj;
-
-  if (!PyArg_ParseTuple (args, "K", &pc))
-    return NULL;
-
-  sym = find_pc_function (pc);
-  if (sym)
-    return symbol_to_symbol_object (sym);
-
-  Py_RETURN_NONE;
-}
-
 /* Adds GDB value V to the pattern buffer in *PATTERN_BUF.  If SIZE is not zero,
    it specifies the number of bytes from V to copy to *PATTERN_BUF.  The
    function increases the size of *PATTERN_BUF as necessary, adjusting
@@ -1897,9 +1880,6 @@ a boolean indicating if name is a field of the current implied argument\n\
     "solib_address (Long) -> String.\n\
 Return the name of the shared library holding a given address, or None." },
 
-  { "find_pc_function", gdbpy_find_pc_function, METH_VARARGS,
-    "Return the function containing the given pc value, or None." },
-
   { "block_for_pc", gdbpy_block_for_pc, METH_VARARGS,
     "Return the block containing the given pc value, or None." },
 
diff --git a/gdb/testsuite/gdb.python/python-frame.exp b/gdb/testsuite/gdb.python/python-frame.exp
index 674c25e..93a3d21 100644
--- a/gdb/testsuite/gdb.python/python-frame.exp
+++ b/gdb/testsuite/gdb.python/python-frame.exp
@@ -78,7 +78,7 @@ gdb_test "python print 'result =', f0.type () == gdb.NORMAL_FRAME" " = True" "te
 gdb_test "python print 'result =', f0.unwind_stop_reason () == gdb.FRAME_UNWIND_NO_REASON" " = True" "test Frame.type"
 gdb_test "python print 'result =', gdb.frame_stop_reason_string (gdb.FRAME_UNWIND_INNER_ID)" " = previous frame inner to this frame \\(corrupt stack\\?\\)" "test gdb.frame_stop_reason_string"
 gdb_test "python print 'result =', f0.pc ()" " = \[0-9\]+" "test Frame.pc"
-gdb_test "python print 'result =', f0.addr_in_block ()" " = \[0-9\]+" "test Frame.addr_in_block"
+gdb_test "python print 'result =', f0.function ()" " = symbol for f2" "test Frame.function"
 gdb_test "python print 'result =', f0.older ().equals (f1)" " = True" "test Frame.older"
 gdb_test "python print 'result =', f1.newer ().equals (f0)" " = True" "test Frame.newer"
 gdb_test "python print 'result =', f0.read_var ('variable_which_surely_doesnt_exist')" \