2010-01-13 Phil Muldoon <pmuldoon@redhat.com>

	PR python/10705

	* python/python-internal.h: Add lazy_string_object_type
	definition.
	(create_lazy_string_object, gdbpy_initialize_lazy_string)
	(gdbpy_is_lazystring, gdbpy_extract_lazy_string): Define.
	* python/py-value.c (valpy_lazy_string): New function.
	(convert_value_from_python): Add lazy string conversion.
	* python/py-prettyprint.c (pretty_print_one_value): Check if
	return is also a lazy string.
	(print_string_repr): Add lazy string printing branch.
	(print_children): Likewise.
	* python/py-lazy-string.c: New file. Implement lazy strings.
	* python/python.c (_initialize_python): Call
	gdbpy_initialize_lazy_string.
	* varobj.c (value_get_print_value): Add lazy string printing
	branch.  Account for encoding.
	* c-lang.c (c_printstr): Account for new encoding argument.  If
	encoding is NULL, find encoding suited for type, otherwise use
	user encoding.
	* language.h (language_defn): Add encoding argument.
	(LA_PRINT_STRING): Likewise.
	* language.c (unk_lang_printstr): Update to reflect new encoding
	argument to language_defn.
	* ada-lang.h (ada_printstr): Likewise.
	* c-lang.h (c_printstr): Likewise.
	* p-lang.h (pascal_printstr);
	* f-lang.c (f_printstr): Likewise.
	* m2-lang.c (m2_printstr): Likewise.
	* objc-lang.c (objc_printstr): Likewise.
	* p-lang.c (pascal_printstr): Likewise.
	* scm-lang.c (scm_printstr): Likewise.
	* c-valprint.c (c_val_print): Update LA_PRINT_STRING call for
	encoding argument.
	* ada-valprint.c (ada_printstr): Likewise.
	* f-valprint.c (f_val_print): Likewise
	* m2-valprint.c (m2_val_print): Likewise.
	* p-valprint.c (pascal_val_print): Likewise.
	* expprint.c (print_subexp_standard): Likewise.
	* valprint.c (val_print_string): Likewise.
	* Makefile.in (SUBDIR_PYTHON_OBS): Add py-lazy-string.
	(SUBDIR_PYTHON_SRCS): Likewise.
	(py-lazy-string.o): New rule.

2010-01-13  Phil Muldoon  <pmuldoon@redhat.com>

	* gdb.texinfo (Values From Inferior): Document lazy_string value
	method.
	(Python API): Add Lazy strings menu item.
	(Lazy Strings In Python): New node.

2010-01-13  Phil Muldoon  <pmuldoon@redhat.com>

	* gdb.python/py-value.exp (test_lazy_strings): Add lazy string test.
	* gdb.python/py-prettyprint.py (pp_ls): New printer.
	* gdb.python/py-prettyprint.exp (run_lang_tests): Add lazy string
	test.
	* gdb.python/py-prettyprint.c: Define lazystring test structure.
	* gdb.python/py-mi.exp: Add lazy string test.

2 files changed, 87 insertions, 0 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index ae9ce2a..8b5d162 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,10 @@
+2010-01-13  Phil Muldoon  <pmuldoon@redhat.com>
+
+	* gdb.texinfo (Values From Inferior): Document lazy_string value
+	method.
+	(Python API): Add Lazy strings menu item.
+	(Lazy Strings In Python): New node.
+
 2010-01-13  Vladimir Prus  <vladimir@codesourcery.com>
 
 	* gdb.texinfo (GDB/MI Thread Information): New.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 02e2bbd..253e251 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -19420,6 +19420,7 @@ situation, a Python @code{KeyboardInterrupt} exception is thrown.
 * Functions In Python::         Writing new convenience functions.
 * Objfiles In Python::          Object files.
 * Frames In Python::            Acessing inferior stack frames from Python.
+* Lazy Strings In Python::      Python representation of lazy strings.
 @end menu
 
 @node Basic Python
@@ -19694,6 +19695,30 @@ argument to Python's @code{string.decode} method.
 If the optional @var{length} argument is given, the string will be
 fetched and converted to the given length.
 @end defmethod
+
+@defmethod Value lazy_string @r{[}encoding@r{]} @r{[}length@r{]}
+If this @code{gdb.Value} represents a string, then this method
+converts the contents to a @code{gdb.LazyString} (@pxref{Lazy Strings
+In Python}).  Otherwise, this method will throw an exception.
+
+If the optional @var{encoding} argument is given, it must be a string
+naming the encoding of the @code{gdb.LazyString}.  Some examples are:
+@samp{ascii}, @samp{iso-8859-6} or @samp{utf-8}.  If the
+@var{encoding} argument is an encoding that @value{GDBN} does
+recognize, @value{GDBN} will raise an error.
+
+When a lazy string is printed, the @value{GDBN} encoding machinery is
+used to convert the string during printing.  If the optional
+@var{encoding} argument is not provided, or is an empty string,
+@value{GDBN} will automatically select the encoding most suitable for
+the string type.  For further information on encoding in @value{GDBN}
+please see @ref{Character Sets}.
+
+If the optional @var{length} argument is given, the string will be
+fetched and encoded to the length of characters specified.  If
+the @var{length} argument is not provided, the string will be fetched
+and encoded until a null of appropriate width is found.
+@end defmethod
 @end table
 
 @node Types In Python
@@ -20631,6 +20656,61 @@ be a string.
 @end defmethod
 @end table
 
+@node Lazy Strings In Python
+@subsubsection Python representation of lazy strings.
+
+@cindex lazy strings in python
+@tindex gdb.LazyString
+
+A @dfn{lazy string} is a string whose contents is not retrieved or
+encoded until it is needed.
+
+A @code{gdb.LazyString} is represented in @value{GDBN} as an
+@code{address} that points to a region of memory, an @code{encoding}
+that will be used to encode that region of memory, and a @code{length}
+to delimit the region of memory that represents the string.  The
+difference between a @code{gdb.LazyString} and a string wrapped within
+a @code{gdb.Value} is that a @code{gdb.LazyString} will be treated
+differently by @value{GDBN} when printing.  A @code{gdb.LazyString} is
+retrieved and encoded during printing, while a @code{gdb.Value}
+wrapping a string is immediately retrieved and encoded on creation.
+
+A @code{gdb.LazyString} object has the following functions:
+
+@defmethod LazyString value
+Convert the @code{gdb.LazyString} to a @code{gdb.Value}.  This value
+will point to the string in memory, but will lose all the delayed
+retrieval, encoding and handling that @value{GDBN} applies to a
+@code{gdb.LazyString}.
+@end defmethod
+
+@defivar LazyString address
+This attribute holds the address of the string.  This attribute is not
+writable.
+@end defivar
+
+@defivar LazyString length
+This attribute holds the length of the string in characters.  If the
+length is -1, then the string will be fetched and encoded up to the
+first null of appropriate width.  This attribute is not writable.
+@end defivar
+
+@defivar LazyString encoding
+This attribute holds the encoding that will be applied to the string
+when the string is printed by @value{GDBN}.  If the encoding is not
+set, or contains an empty string,  then @value{GDBN} will select the
+most appropriate encoding when the string is printed.  This attribute
+is not writable.
+@end defivar
+
+@defivar LazyString type
+This attribute holds the type that is represented by the lazy string's
+type.  For a lazy string this will always be a pointer type.  To
+resolve this to the lazy string's character type, use the type's
+@code{target} method.  @xref{Types In Python}.  This attribute is not
+writable.
+@end defivar
+
 @node Interpreters
 @chapter Command Interpreters
 @cindex command interpreters