Patchwork [3/6] framefilter quit: Code cleanup: Avoid gotos

login
register
mail settings
Submitter Jan Kratochvil
Date Feb. 7, 2015, 2:45 p.m.
Message ID <20150207144523.14897.52407.stgit@host1.jankratochvil.net>
Download mbox | patch
Permalink /patch/4956/
State New
Headers show

Comments

Jan Kratochvil - Feb. 7, 2015, 2:45 p.m.
Hi,

goto error patters are sometimes AFAIK used in C for the cases like:
	int retval=-1;
	if (!(a=malloc())) goto error;
	if (!(b=malloc())) goto error_a;
	if (!(c=malloc())) goto error_b;
	retval=0;
	error_c: free(c);
	error_b: free(b);
	error_a: free(a);
	error: return retval;

But here there is single error label with one do_cleanups() which I do not find
it worth the goto complication.  Without goto one can then furher merge code in
the exit paths in the next patches and ... after all it is all the same, just
without a goto.


Jan


gdb/ChangeLog
2015-02-06  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* python/py-framefilter.c (py_print_frame): Substitute goto error.
	Remove the error label.
---
 gdb/python/py-framefilter.c |  103 +++++++++++++++++++++++++++++++------------
 1 file changed, 74 insertions(+), 29 deletions(-)
Jan Kratochvil - Feb. 11, 2015, 1:43 p.m.
On Sat, 07 Feb 2015 15:45:24 +0100, Jan Kratochvil wrote:
> gdb/ChangeLog
> 2015-02-06  Jan Kratochvil  <jan.kratochvil@redhat.com>
> 
> 	* python/py-framefilter.c (py_print_frame): Substitute goto error.
> 	Remove the error label.

800eb1cebe736f6867d13e5df40a2c463a4b23ad master
46d020960241fcafd7d0ab483746a206829620ea 7.9


Jan

Patch

diff --git a/gdb/python/py-framefilter.c b/gdb/python/py-framefilter.c
index 896e2a8..ba1b237 100644
--- a/gdb/python/py-framefilter.c
+++ b/gdb/python/py-framefilter.c
@@ -1033,14 +1033,20 @@  py_print_frame (PyObject *filter, int flags,
   read them if they returned filter object requires us to do so.  */
   py_inf_frame = PyObject_CallMethod (filter, "inferior_frame", NULL);
   if (py_inf_frame == NULL)
-    goto error;
+    {
+      do_cleanups (cleanup_stack);
+      return EXT_LANG_BT_ERROR;
+    }
 
   frame = frame_object_to_frame_info (py_inf_frame);;
 
   Py_DECREF (py_inf_frame);
 
   if (frame == NULL)
-    goto error;
+    {
+      do_cleanups (cleanup_stack);
+      return EXT_LANG_BT_ERROR;
+    }
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
@@ -1049,7 +1055,8 @@  py_print_frame (PyObject *filter, int flags,
   if (except.reason < 0)
     {
       gdbpy_convert_exception (except);
-      goto error;
+      do_cleanups (cleanup_stack);
+      return EXT_LANG_BT_ERROR;
     }
 
   /* stack-list-variables.  */
@@ -1057,7 +1064,10 @@  py_print_frame (PyObject *filter, int flags,
     {
       if (py_mi_print_variables (filter, out, &opts,
 				 args_type, frame) == EXT_LANG_BT_ERROR)
-	goto error;
+	{
+	  do_cleanups (cleanup_stack);
+	  return EXT_LANG_BT_ERROR;
+	}
       do_cleanups (cleanup_stack);
       return EXT_LANG_BT_COMPLETED;
     }
@@ -1080,7 +1090,8 @@  py_print_frame (PyObject *filter, int flags,
 	  if (except.reason < 0)
 	    {
 	      gdbpy_convert_exception (except);
-	      goto error;
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
 	    }
 	}
 
@@ -1091,7 +1102,10 @@  py_print_frame (PyObject *filter, int flags,
 	  PyObject *paddr = PyObject_CallMethod (filter, "address", NULL);
 
 	  if (paddr == NULL)
-	    goto error;
+	    {
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
+	    }
 
 	  if (paddr != Py_None)
 	    {
@@ -1135,7 +1149,8 @@  py_print_frame (PyObject *filter, int flags,
       if (except.reason < 0)
 	{
 	  gdbpy_convert_exception (except);
-	  goto error;
+	  do_cleanups (cleanup_stack);
+	  return EXT_LANG_BT_ERROR;
 	}
     }
 
@@ -1155,7 +1170,8 @@  py_print_frame (PyObject *filter, int flags,
 	  if (except.reason < 0)
 	    {
 	      gdbpy_convert_exception (except);
-	      goto error;
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
 	    }
 	}
 
@@ -1166,7 +1182,10 @@  py_print_frame (PyObject *filter, int flags,
 	  const char *function = NULL;
 
 	  if (py_func == NULL)
-	    goto error;
+	    {
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
+	    }
 
 	  if (gdbpy_is_string (py_func))
 	    {
@@ -1178,7 +1197,8 @@  py_print_frame (PyObject *filter, int flags,
 	      if (function == NULL)
 		{
 		  Py_DECREF (py_func);
-		  goto error;
+		  do_cleanups (cleanup_stack);
+		  return EXT_LANG_BT_ERROR;
 		}
 	      make_cleanup (xfree, function_to_free);
 	    }
@@ -1188,7 +1208,10 @@  py_print_frame (PyObject *filter, int flags,
 	      struct bound_minimal_symbol msymbol;
 
 	      if (PyErr_Occurred ())
-		goto error;
+		{
+		  do_cleanups (cleanup_stack);
+		  return EXT_LANG_BT_ERROR;
+		}
 
 	      msymbol = lookup_minimal_symbol_by_pc (addr);
 	      if (msymbol.minsym != NULL)
@@ -1200,7 +1223,8 @@  py_print_frame (PyObject *filter, int flags,
 			       _("FrameDecorator.function: expecting a " \
 				 "String, integer or None."));
 	      Py_DECREF (py_func);
-	      goto error;
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
 	    }
 
 	  TRY_CATCH (except, RETURN_MASK_ALL)
@@ -1215,7 +1239,8 @@  py_print_frame (PyObject *filter, int flags,
 	    {
 	      Py_DECREF (py_func);
 	      gdbpy_convert_exception (except);
-	      goto error;
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
 	    }
 	  Py_DECREF (py_func);
 	}
@@ -1227,7 +1252,10 @@  py_print_frame (PyObject *filter, int flags,
   if (print_args)
     {
       if (py_print_args (filter, out, args_type, frame) == EXT_LANG_BT_ERROR)
-	goto error;
+	{
+	  do_cleanups (cleanup_stack);
+	  return EXT_LANG_BT_ERROR;
+	}
     }
 
   /* File name/source/line number information.  */
@@ -1240,7 +1268,8 @@  py_print_frame (PyObject *filter, int flags,
       if (except.reason < 0)
 	{
 	  gdbpy_convert_exception (except);
-	  goto error;
+	  do_cleanups (cleanup_stack);
+	  return EXT_LANG_BT_ERROR;
 	}
 
       if (PyObject_HasAttrString (filter, "filename"))
@@ -1248,7 +1277,10 @@  py_print_frame (PyObject *filter, int flags,
 	  PyObject *py_fn = PyObject_CallMethod (filter, "filename", NULL);
 
 	  if (py_fn == NULL)
-	    goto error;
+	    {
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
+	    }
 
 	  if (py_fn != Py_None)
 	    {
@@ -1257,7 +1289,8 @@  py_print_frame (PyObject *filter, int flags,
 	      if (filename == NULL)
 		{
 		  Py_DECREF (py_fn);
-		  goto error;
+		  do_cleanups (cleanup_stack);
+		  return EXT_LANG_BT_ERROR;
 		}
 
 	      make_cleanup (xfree, filename);
@@ -1273,7 +1306,8 @@  py_print_frame (PyObject *filter, int flags,
 		{
 		  Py_DECREF (py_fn);
 		  gdbpy_convert_exception (except);
-		  goto error;
+		  do_cleanups (cleanup_stack);
+		  return EXT_LANG_BT_ERROR;
 		}
 	    }
 	  Py_DECREF (py_fn);
@@ -1285,7 +1319,10 @@  py_print_frame (PyObject *filter, int flags,
 	  int line;
 
 	  if (py_line == NULL)
-	    goto error;
+	    {
+	      do_cleanups (cleanup_stack);
+	      return EXT_LANG_BT_ERROR;
+	    }
 
 	  if (py_line != Py_None)
 	    {
@@ -1300,7 +1337,8 @@  py_print_frame (PyObject *filter, int flags,
 		{
 		  Py_DECREF (py_line);
 		  gdbpy_convert_exception (except);
-		  goto error;
+		  do_cleanups (cleanup_stack);
+		  return EXT_LANG_BT_ERROR;
 		}
 	    }
 	  Py_DECREF (py_line);
@@ -1319,7 +1357,8 @@  py_print_frame (PyObject *filter, int flags,
       if (except.reason < 0)
 	{
 	  gdbpy_convert_exception (except);
-	  goto error;
+	  do_cleanups (cleanup_stack);
+	  return EXT_LANG_BT_ERROR;
 	}
     }
 
@@ -1327,7 +1366,10 @@  py_print_frame (PyObject *filter, int flags,
     {
       if (py_print_locals (filter, out, args_type, indent,
 			   frame) == EXT_LANG_BT_ERROR)
-	goto error;
+	{
+	  do_cleanups (cleanup_stack);
+	  return EXT_LANG_BT_ERROR;
+	}
     }
 
   {
@@ -1336,7 +1378,10 @@  py_print_frame (PyObject *filter, int flags,
     /* Finally recursively print elided frames, if any.  */
     elided = get_py_iter_from_func (filter, "elided");
     if (elided == NULL)
-      goto error;
+      {
+	do_cleanups (cleanup_stack);
+	return EXT_LANG_BT_ERROR;
+      }
 
     make_cleanup_py_decref (elided);
     if (elided != Py_None)
@@ -1358,23 +1403,23 @@  py_print_frame (PyObject *filter, int flags,
 	    if (success == EXT_LANG_BT_ERROR)
 	      {
 		Py_DECREF (item);
-		goto error;
+		do_cleanups (cleanup_stack);
+		return EXT_LANG_BT_ERROR;
 	      }
 
 	    Py_DECREF (item);
 	  }
 	if (item == NULL && PyErr_Occurred ())
-	  goto error;
+	  {
+	    do_cleanups (cleanup_stack);
+	    return EXT_LANG_BT_ERROR;
+	  }
       }
     }
 
 
   do_cleanups (cleanup_stack);
   return EXT_LANG_BT_COMPLETED;
-
- error:
-  do_cleanups (cleanup_stack);
-  return EXT_LANG_BT_ERROR;
 }
 
 /* Helper function to initiate frame filter invocation at starting