File 0006-py-symbol-Allow-gdb_lookup_symbol-to-accep... of Package gdb

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File 0006-py-symbol-Allow-gdb_lookup_symbol-to-accept-block-No.patch of Package gdb

From 2dc2a55c66df9f718ec35b44e02a8fa6c295b603 Mon Sep 17 00:00:00 2001
From: Jeff Mahoney <jeffm@suse.com>
Date: Wed, 18 Mar 2020 10:57:31 -0400
Subject: [PATCH 06/17] py-symbol: Allow gdb_lookup_symbol to accept block=None

gdbpy_lookup_symbol refuses to perform a lookup without a valid block.  If
no block is passed, we look up the block using the selected frame.  If there
is no selected frame, we return an error.  Since a frame isn't required
to lookup objects like static functions and variables, we should be
able to complete the lookup without a block.  This patch allows us to
accept block=None to proceed with the lookup without a block.

This allows us to lookup static symbols directly from python rather
than using gdb.eval_and_parse.
---
 gdb/doc/python.texi                    |  5 ++--
 gdb/python/py-symbol.c                 | 39 +++++++++++++++++---------
 gdb/testsuite/gdb.python/py-symbol.c   |  7 +++++
 gdb/testsuite/gdb.python/py-symbol.exp |  7 +++++
 4 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index 918418b08c9..a5012b0ca0d 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -5308,8 +5308,9 @@ arguments.
 @var{name} is the name of the symbol.  It must be a string.  The
 optional @var{block} argument restricts the search to symbols visible
 in that @var{block}.  The @var{block} argument must be a
-@code{gdb.Block} object.  If omitted, the block for the current frame
-is used.  The optional @var{domain} argument restricts
+@code{gdb.Block} object or @code{None}.  If omitted, the block for the
+current frame is used.  If @code{None}, no block will be used to resolve
+the symbol.  The optional @var{domain} argument restricts
 the search to the domain type.  The @var{domain} argument must be a
 domain constant defined in the @code{gdb} module and described later
 in this chapter.
diff --git a/gdb/python/py-symbol.c b/gdb/python/py-symbol.c
index 8c6d205eb42..93e75ea8ca2 100644
--- a/gdb/python/py-symbol.c
+++ b/gdb/python/py-symbol.c
@@ -376,25 +376,36 @@ gdbpy_lookup_symbol (PyObject *self, PyObject *args, PyObject *kw)
   PyObject *block_obj = NULL, *sym_obj, *bool_obj;
   const struct block *block = NULL;
 
-  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!i", keywords, &name,
-					&block_object_type, &block_obj,
-					&domain))
+  if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|Oi", keywords, &name,
+				        &block_obj, &domain))
     return NULL;
 
-  if (block_obj)
-    block = block_object_to_block (block_obj);
-  else
+  if (block_obj && block_obj != Py_None &&
+      !PyObject_TypeCheck (block_obj, &block_object_type))
     {
-      struct frame_info *selected_frame;
+      PyErr_Format (PyExc_TypeError,
+		    "argument 2 must be gdb.Block or None, not %s",
+		    block_obj->ob_type->tp_name);
+      return NULL;
+    }
 
-      try
-	{
-	  selected_frame = get_selected_frame (_("No frame selected."));
-	  block = get_frame_block (selected_frame, NULL);
-	}
-      catch (const gdb_exception &except)
+  if (block_obj != Py_None)
+    {
+      if (block_obj)
+	block = block_object_to_block (block_obj);
+      else
 	{
-	  GDB_PY_HANDLE_EXCEPTION (except);
+	  struct frame_info *selected_frame;
+
+	  try
+	    {
+	      selected_frame = get_selected_frame (_("No frame selected."));
+	      block = get_frame_block (selected_frame, NULL);
+	    }
+	  catch (const gdb_exception &except)
+	    {
+	      GDB_PY_HANDLE_EXCEPTION (except);
+	    }
 	}
     }
 
diff --git a/gdb/testsuite/gdb.python/py-symbol.c b/gdb/testsuite/gdb.python/py-symbol.c
index 61b2c61b51b..872ddc6313f 100644
--- a/gdb/testsuite/gdb.python/py-symbol.c
+++ b/gdb/testsuite/gdb.python/py-symbol.c
@@ -52,6 +52,11 @@ int func (int arg)
   return arg;
 }
 
+static int staticfunc (int arg)
+{
+  return 0;
+}
+
 struct simple_struct
 {
   int a;
@@ -70,6 +75,8 @@ int main (int argc, char *argv[])
 
   result = func (42);
 
+  result = staticfunc (42);
+
 #ifdef __cplusplus
   sclass.seti (42);
   sclass.valueofi ();
diff --git a/gdb/testsuite/gdb.python/py-symbol.exp b/gdb/testsuite/gdb.python/py-symbol.exp
index ef4f86d005d..19b7dce522b 100644
--- a/gdb/testsuite/gdb.python/py-symbol.exp
+++ b/gdb/testsuite/gdb.python/py-symbol.exp
@@ -104,6 +104,13 @@ gdb_test "python print (gdb.lookup_static_symbol ('nonexistent') is None)" \
 gdb_test "python print (gdb.lookup_static_symbol ('qq') is None)" \
     "True" "lookup_static_symbol for global var"
 
+# Test looking up a static symbol that doesn't require a frame
+gdb_test_no_output "python staticfunc = gdb.lookup_symbol(\"staticfunc\", None)" ""
+gdb_test "python print staticfunc\[0\]" "staticfunc" "Test staticfunc lookup"
+
+gdb_test_no_output "python staticfunc = gdb.lookup_symbol(\"does_not_exist\", None)" ""
+gdb_test "python print staticfunc\[0\]" "None" "Test missing symbol lookup"
+
 if ![runto_main] then {
     return 0
 }
-- 
2.37.2

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