[PATCH 4/7] py-symbol: Require a frame for lookup_symbol only when necessary

[jeffm@suse.com]

From: Jeff Mahoney <jeffm@suse.com>

gdbpy_lookup_symbol requires a frame prior to doing the symbol lookup but
a frame isn't necessary for many symbol types.  Calling
symbol_read_needs_frame will tell us if it's necessary but we need to
have already looked up the symbol to use it.  This patch puts the
lookup first and then only resolves the frame if one is required.

This allows us to lookup static symbols directly from python rather
than using gdb.eval_and_parse.
---
 gdb/python/py-symbol.c | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/gdb/python/py-symbol.c b/gdb/python/py-symbol.c
index cbbc9e2..c7f0ff8 100644
--- a/gdb/python/py-symbol.c
+++ b/gdb/python/py-symbol.c
@@ -382,14 +382,28 @@ gdbpy_lookup_symbol (PyObject *self, PyObject *args, PyObject *kw)
 
   if (block_obj)
     block = block_object_to_block (block_obj);
-  else
+
+  TRY
+    {
+      symbol = lookup_symbol (name, block, (domain_enum) domain,
+			      &is_a_field_of_this).symbol;
+    }
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDB_PY_HANDLE_EXCEPTION (except);
+    }
+  END_CATCH
+
+  if (symbol && !block)
     {
       struct frame_info *selected_frame;
 
       TRY
 	{
-	  selected_frame = get_selected_frame (_("No frame selected."));
-	  block = get_frame_block (selected_frame, NULL);
+	  if (symbol_read_needs_frame(symbol)) {
+	    selected_frame = get_selected_frame (_("No frame selected."));
+	    block = get_frame_block (selected_frame, NULL);
+	  }
 	}
       CATCH (except, RETURN_MASK_ALL)
 	{
@@ -398,17 +412,6 @@ gdbpy_lookup_symbol (PyObject *self, PyObject *args, PyObject *kw)
       END_CATCH
     }
 
-  TRY
-    {
-      symbol = lookup_symbol (name, block, (domain_enum) domain,
-			      &is_a_field_of_this).symbol;
-    }
-  CATCH (except, RETURN_MASK_ALL)
-    {
-      GDB_PY_HANDLE_EXCEPTION (except);
-    }
-  END_CATCH
-
   ret_tuple = PyTuple_New (2);
   if (!ret_tuple)
     return NULL;
-- 
2.1.4