Patch: Tweak the libstdc++ std::string pretty-printer to fetch to the string's actual length

[Phil Muldoon <pmuldoon at redhat dot com>]

Over at GDB we've tweaked the pretty-printers and other Python scripting 
code to preserve "embedded nulls" within a string if  string has an 
actual length assigned to it (i.e. a counted string).  To do this we 
also added an optional "length" parameter to the value.string () 
function.  Now that these two patches are in mainline GDB, it allows the 
std::string printer to fetch to the string's actual length, bypassing 
and preserving any embedded nulls that happen to be in the string.

In the old code, the pretty-printed output for:

  std::string barstr ("bar\0string",10);

would be:

barstr = "bar"

But in the new code it would be:

barstr = "bar\000string"

In the scenario below, the output would always be: "foo"

std::string foostr ("foo\0string");

foostr = "foo"

We need to make a few changes to the Python bits of the std::string 
printer to make this work with the new GDB code. What do you think?

Regards

Phil

2009-07-15  Phil Muldoon <pmuldoon@redhat.com>
                     Tom Tromey <tromey@redhat.com>

    * python/libstdcxx/v6/printers.py (StdStringPrinter.to_string):
    Fetch std::string to the given length.

Attachment: printer.py.patch
Description: Text document