Add $_memeq, $_regex, $_streq, $_strlen convenience functions.

* NEWS: Document them.
	* data-directory/Makefile.in (PYTHON_FILES): Add function/__init__.py,
	function/strfns.py.
	* python/py-type.c (typy_array_1): New function.
	(typy_array): Call it.
	(typy_vector): New function.
	(type_object_methods): Add "vector".
	* python/lib/gdb/function/__init__.py: New file.
	* python/lib/gdb/function/strfns.py: New file.

	doc/
	* gdb.texinfo (Convenience Funs): New node.
	(Types In Python): Document Type.vector.

	testsuite/
	* gdb.python/py-strfns.c: New file.
	* gdb.python/py-strfns.exp: New file.
	* gdb.python/py-type.exp (test_fields): Add vector tests.

gdb/python/lib/gdb/function/__init__.py

@@ -0,0 +1,14 @@
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.

gdb/python/lib/gdb/function/strfns.py

@@ -0,0 +1,108 @@
+# Useful gdb string convenience functions.
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""$_memeq, $_strlen, $_streq, $_regex"""
+
+import gdb
+import re
+
+
+class _MemEq(gdb.Function):
+  """$_memeq - compare bytes of memory
+
+Usage:
+  $_memeq(a, b, len)
+
+Returns:
+  True if len bytes at a and b compare equally.
+"""
+  def __init__(self):
+    super(_MemEq, self).__init__("_memeq")
+
+  def invoke(self, a, b, length):
+    if length < 0:
+      raise ValueError("length must be non-negative")
+    if length == 0:
+      return True
+    # The argument(s) to vector are [low_bound,]high_bound.
+    byte_vector = gdb.lookup_type("char").vector(length - 1)
+    ptr_byte_vector = byte_vector.pointer()
+    a_ptr = a.reinterpret_cast(ptr_byte_vector)
+    b_ptr = b.reinterpret_cast(ptr_byte_vector)
+    return a_ptr.dereference() == b_ptr.dereference()
+
+
+class _StrLen(gdb.Function):
+  """$_strlen - compute string length
+
+Usage:
+  $_strlen(a)
+
+Returns:
+  Length of string a, assumed to be a string in the current language.
+"""
+  def __init__(self):
+    super(_StrLen, self).__init__("_strlen")
+
+  def invoke(self, a):
+    s = a.string()
+    return len(s)
+
+
+class _StrEq(gdb.Function):
+  """$_streq - check string equality
+
+Usage:
+  $_streq(a, b)
+
+Returns:
+  True if a and b are identical strings in the current language.
+
+Example (amd64-linux):
+  catch syscall open
+  cond $bpnum $_streq((char*) $rdi, "foo")
+"""
+  def __init__(self):
+    super(_StrEq, self).__init__("_streq")
+
+  def invoke(self, a, b):
+    return a.string() == b.string()
+
+
+class _RegEx(gdb.Function):
+  """$_regex - check if a string matches a regular expression
+
+Usage:
+  $_regex(string, regex)
+
+Returns:
+  True if string str (in the current language) matches the
+  regular expression regex.
+"""
+  def __init__(self):
+    super(_RegEx, self).__init__("_regex")
+
+  def invoke(self, string, regex):
+    s = string.string()
+    r = re.compile(regex.string())
+    return bool(r.match(s))
+
+
+# GDB will import us automagically via gdb/__init__.py.
+_MemEq()
+_StrLen()
+_StrEq()
+_RegEx()

gdb/python/py-type.c

@@ -461,10 +461,10 @@ typy_get_composite (struct type *type)
   return type;
 }
 
-/* Return an array type.  */
+/* Helper for typy_array and typy_vector.  */
 
 static PyObject *
-typy_array (PyObject *self, PyObject *args)
+typy_array_1 (PyObject *self, PyObject *args, int is_vector)
 {
   long n1, n2;
   PyObject *n2_obj = NULL;
@@ -503,12 +503,30 @@ typy_array (PyObject *self, PyObject *args)
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
       array = lookup_array_range_type (type, n1, n2);
+      if (is_vector)
+	make_vector_type (array);
     }
   GDB_PY_HANDLE_EXCEPTION (except);
 
   return type_to_type_object (array);
 }
 
+/* Return an array type.  */
+
+static PyObject *
+typy_array (PyObject *self, PyObject *args)
+{
+  return typy_array_1 (self, args, 0);
+}
+
+/* Return a vector type.  */
+
+static PyObject *
+typy_vector (PyObject *self, PyObject *args)
+{
+  return typy_array_1 (self, args, 1);
+}
+
 /* Return a Type object which represents a pointer to SELF.  */
 static PyObject *
 typy_pointer (PyObject *self, PyObject *args)
@@ -1559,6 +1577,14 @@ static PyMethodDef type_object_methods[] =
 Return a type which represents an array of objects of this type.\n\
 The bounds of the array are [LOW_BOUND, HIGH_BOUND] inclusive.\n\
 If LOW_BOUND is omitted, a value of zero is used." },
+  { "vector", typy_vector, METH_VARARGS,
+    "vector ([LOW_BOUND,] HIGH_BOUND) -> Type\n\
+Return a type which represents a vector of objects of this type.\n\
+The bounds of the array are [LOW_BOUND, HIGH_BOUND] inclusive.\n\
+If LOW_BOUND is omitted, a value of zero is used.\n\
+Vectors differ from arrays in that if the current language has C-style\n\
+arrays, vectors don't decay to a pointer to the first element.\n\
+They are first class values." },
    { "__contains__", typy_has_key, METH_VARARGS,
      "T.__contains__(k) -> True if T has a field named k, else False" },
   { "const", typy_const, METH_NOARGS,