[PATCH v6 4/8] GDB/Python: Make `None' stand for `unlimited' in setting integer parameters

["Maciej W. Rozycki" <macro@embecosm.com>]

Similarly to booleans and following the fix for PR python/29217 make 
`gdb.parameter' accept `None' for `unlimited' with parameters of the 
PARAM_UINTEGER, PARAM_INTEGER, and PARAM_ZUINTEGER_UNLIMITED types, as 
`None' is already returned by parameters of the two former types, so 
one might expect to be able to feed it back.  It also makes it possible 
to avoid the need to know what the internal integer representation is 
for the special setting of `unlimited'.

Expand the testsuite accordingly.
---
New change in v6.
---
 gdb/python/lib/gdb/__init__.py            |    9 ++++++---
 gdb/python/py-param.c                     |   10 +++++++---
 gdb/testsuite/gdb.python/py-parameter.exp |   21 +++++++++++++++------
 3 files changed, 28 insertions(+), 12 deletions(-)

gdb-python-set-var-xinteger-none.diff
Index: src/gdb/python/lib/gdb/__init__.py
===================================================================
--- src.orig/gdb/python/lib/gdb/__init__.py
+++ src/gdb/python/lib/gdb/__init__.py
@@ -240,9 +240,12 @@ Return the name of the shared library ho
 
 def set_parameter(name, value):
     """Set the GDB parameter NAME to VALUE."""
-    # Handle the specific case of booleans here, because gdb.parameter
-    # can return them, but they can't be passed to 'set' this way.
-    if isinstance(value, bool):
+    # Handle the specific cases of None and booleans here, because
+    # gdb.parameter can return them, but they can't be passed to 'set'
+    # this way.
+    if value is None:
+        value = "unlimited"
+    elif isinstance(value, bool):
         if value:
             value = "on"
         else:
Index: src/gdb/python/py-param.c
===================================================================
--- src.orig/gdb/python/py-param.c
+++ src/gdb/python/py-param.c
@@ -243,14 +243,18 @@ set_parameter_value (parmpy_object *self
 	long l;
 	int ok;
 
-	if (!PyLong_Check (value))
+	if (value == Py_None
+	    && (self->type == var_uinteger || self->type == var_integer))
+	  l = 0;
+	else if (value == Py_None && self->type == var_zuinteger_unlimited)
+	  l = -1;
+	else if (!PyLong_Check (value))
 	  {
 	    PyErr_SetString (PyExc_RuntimeError,
 			     _("The value must be integer."));
 	    return -1;
 	  }
-
-	if (! gdb_py_int_as_long (value, &l))
+	else if (! gdb_py_int_as_long (value, &l))
 	  return -1;
 
 	switch (self->type)
Index: src/gdb/testsuite/gdb.python/py-parameter.exp
===================================================================
--- src.orig/gdb/testsuite/gdb.python/py-parameter.exp
+++ src/gdb/testsuite/gdb.python/py-parameter.exp
@@ -346,18 +346,21 @@ proc_with_prefix test_gdb_parameter { }
 	    "listsize" {
 		set param_get_zero None
 		set param_get_minus_one -1
+		set param_get_none None
 		set param_get_unlimited None
 		set param_set_minus_one ""
 	    }
 	    "print elements" {
 		set param_get_zero None
 		set param_get_minus_one None
+		set param_get_none None
 		set param_get_unlimited None
 		set param_set_minus_one $param_range_error
 	    }
 	    "max-completions" {
 		set param_get_zero 0
 		set param_get_minus_one -1
+		set param_get_none -1
 		set param_get_unlimited -1
 		set param_set_minus_one ""
 	    }
@@ -385,6 +388,12 @@ proc_with_prefix test_gdb_parameter { }
 	gdb_test "python print(gdb.parameter('$param'))" \
 	    $param_get_minus_one "test value of -1"
 
+	gdb_test_no_output "python gdb.set_parameter('$param', None)" \
+	    "test set to None"
+
+	gdb_test "python print(gdb.parameter('$param'))" \
+	    $param_get_none "test value of None"
+
 	gdb_test_no_output "python gdb.set_parameter('$param', 'unlimited')" \
 	    "test set to 'unlimited'"
 
@@ -425,19 +434,19 @@ proc_with_prefix test_integer_parameter
 		set param_get_zero None
 		set param_get_minus_one None
 		set param_get_minus_five 1
-		set param_get_none 5
+		set param_get_none None
 		set param_set_minus_one $param_range_error
 		set param_set_minus_five $param_range_error
-		set param_set_none $param_integer_error
+		set param_set_none ""
 	    }
 	    PARAM_INTEGER {
 		set param_get_zero None
 		set param_get_minus_one -1
 		set param_get_minus_five -5
-		set param_get_none 5
+		set param_get_none None
 		set param_set_minus_one -1
 		set param_set_minus_five -5
-		set param_set_none $param_integer_error
+		set param_set_none ""
 	    }
 	    PARAM_ZINTEGER {
 		set param_get_zero 0
@@ -461,10 +470,10 @@ proc_with_prefix test_integer_parameter
 		set param_get_zero 0
 		set param_get_minus_one -1
 		set param_get_minus_five 1
-		set param_get_none 5
+		set param_get_none -1
 		set param_set_minus_one ""
 		set param_set_minus_five $param_range_error
-		set param_set_none $param_integer_error
+		set param_set_none ""
 	    }
 	    default {
 		error "invalid kind: $kind"