[PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[Siva Chandra]

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The attached patch wraps PyObject_GetAttrString and
PyObject_HasAttrString in internal functions which have const
qualifier for the second argument. This is required because these
functions were missing the const qualifier in Python-2.4.

ChangeLog
2014-06-09  Siva Chandra Reddy  <sivachandra@google.com>

        * python/python-internal.h (gdb_PyObject_GetAttrString)
        (gdb_PyObject_HasAttrString): New inline function definitions.
        * py-value.c (get_field_flag): Remove the now unnecessary cast to
        (char *) of the second argument to PyObject_GetAttrString.

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diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c
index 54da67a..9821990 100644
--- a/gdb/python/py-value.c
+++ b/gdb/python/py-value.c
@@ -555,7 +555,7 @@ get_field_flag (PyObject *field, const char *flag_name)
 {
   int flag_value;
   /* Python 2.4 did not have a 'const' here.  */
-  PyObject *flag_object = PyObject_GetAttrString (field, (char *) flag_name);
+  PyObject *flag_object = PyObject_GetAttrString (field, flag_name);
 
   if (flag_object == NULL)
     return -1;
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 9c06621..7cf03b5 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -187,6 +187,32 @@ gdb_Py_DECREF (void *op) /* ARI: editCase function */
 #undef Py_DECREF
 #define Py_DECREF(op) gdb_Py_DECREF (op)
 
+/* The second argument to PyObject_GetAttrString was missing the 'const'
+   qualifier.  Hence, we wrap it in a function to avoid errors when compiled
+   with -Werror against Python 2.4.  */
+
+static inline PyObject *
+gdb_PyObject_GetAttrString (PyObject *obj,
+			    const char *attr) /* ARI: editCase function */
+{
+  return PyObject_GetAttrString (obj, (char *) attr);
+}
+
+#define PyObject_GetAttrString(obj, attr) gdb_PyObject_GetAttrString (obj, attr)
+
+/* The second argument to PyObject_HasAttrString was also missing the 'const'
+   qualifier.  Hence, we wrap it also in a function to avoid errors when
+   compiled with -Werror against Python 2.4.  */
+
+static inline int
+gdb_PyObject_HasAttrString (PyObject *obj,
+			    const char *attr)  /* ARI: editCase function */
+{
+  return PyObject_HasAttrString (obj, (char *) attr);
+}
+
+#define PyObject_HasAttrString(obj, attr) gdb_PyObject_HasAttrString (obj, attr)
+
 /* In order to be able to parse symtab_and_line_to_sal_object function
    a real symtab_and_line structure is needed.  */
 #include "symtab.h"

Re: [PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[Pedro Alves]

On 06/09/2014 02:42 PM, Siva Chandra wrote:
> +/* The second argument to PyObject_GetAttrString was missing the 'const'
> +   qualifier.  Hence, we wrap it in a function to avoid errors when compiled
> +   with -Werror against Python 2.4.  */

I'd suggest moving the "in Python 2.4" to the first sentence, like:

/* The second argument to PyObject_GetAttrString was missing the 'const'
   qualifier in Python 2.4.  Hence, we wrap it in a function to avoid errors
   when compiled with -Werror.  */

Otherwise looks great to me.

Thanks!

-- 
Pedro Alves

Re: [PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[Pedro Alves]

On 06/09/2014 02:42 PM, Siva Chandra wrote:
> @@ -555,7 +555,7 @@ get_field_flag (PyObject *field, const char *flag_name)
>  {
>    int flag_value;
>    /* Python 2.4 did not have a 'const' here.  */

Oh, and this comment is stale here now.

> -  PyObject *flag_object = PyObject_GetAttrString (field, (char *) flag_name);
> +  PyObject *flag_object = PyObject_GetAttrString (field, flag_name);

-- 
Pedro Alves

Re: [PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[Siva Chandra]

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On Tue, Jun 10, 2014 at 11:56 AM, Siva Chandra <sivachandra@google.com> wrote:
> Thanks for the quick review. I have pushed the attached patch which
> includes the doc fixes suggested by Pedro.

Ah! The patch is attached now!

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diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c
index 54da67a..8532da6 100644
--- a/gdb/python/py-value.c
+++ b/gdb/python/py-value.c
@@ -554,8 +554,7 @@ static int
 get_field_flag (PyObject *field, const char *flag_name)
 {
   int flag_value;
-  /* Python 2.4 did not have a 'const' here.  */
-  PyObject *flag_object = PyObject_GetAttrString (field, (char *) flag_name);
+  PyObject *flag_object = PyObject_GetAttrString (field, flag_name);
 
   if (flag_object == NULL)
     return -1;
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 9c06621..0198e9d 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -187,6 +187,32 @@ gdb_Py_DECREF (void *op) /* ARI: editCase function */
 #undef Py_DECREF
 #define Py_DECREF(op) gdb_Py_DECREF (op)
 
+/* The second argument to PyObject_GetAttrString was missing the 'const'
+   qualifier in Python-2.4.  Hence, we wrap it in a function to avoid errors
+   when compiled with -Werror.  */
+
+static inline PyObject *
+gdb_PyObject_GetAttrString (PyObject *obj,
+			    const char *attr) /* ARI: editCase function */
+{
+  return PyObject_GetAttrString (obj, (char *) attr);
+}
+
+#define PyObject_GetAttrString(obj, attr) gdb_PyObject_GetAttrString (obj, attr)
+
+/* The second argument to PyObject_HasAttrString was also missing the 'const'
+   qualifier in Python-2.4.  Hence, we wrap it also in a function to avoid
+   errors when compiled with -Werror.  */
+
+static inline int
+gdb_PyObject_HasAttrString (PyObject *obj,
+			    const char *attr)  /* ARI: editCase function */
+{
+  return PyObject_HasAttrString (obj, (char *) attr);
+}
+
+#define PyObject_HasAttrString(obj, attr) gdb_PyObject_HasAttrString (obj, attr)
+
 /* In order to be able to parse symtab_and_line_to_sal_object function
    a real symtab_and_line structure is needed.  */
 #include "symtab.h"

Re: [PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[Siva Chandra]

Thanks for the quick review. I have pushed the attached patch which
includes the doc fixes suggested by Pedro.

Re: [PATCH] Wrap PyObject_Get/HasAttrString in a function with second arg having const qualifier.

[Ulrich Weigand]

Siva Chandra wrote:

> On Tue, Jun 10, 2014 at 11:56 AM, Siva Chandra <sivachandra@google.com> wrote:
> > Thanks for the quick review. I have pushed the attached patch which
> > includes the doc fixes suggested by Pedro.
> 
> Ah! The patch is attached now!

GDB now builds again on my Python-2.4 system.  Thanks for taking care of this!


Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com