On Tue, 6 Sept 2022 at 22:25, Philipp Fent <f...@in.tum.de> wrote:
>
> To display (o-,i-)stringstreams in the common case, we just print the
> underlying stringbuf, without the many ios_base members. In the
> unconventional case that the underlying streambuf was redirected, we
> report the redirected target.
>
> Signed-off-by: Philipp Fent <f...@in.tum.de>
> ---
> libstdc++-v3/python/libstdcxx/v6/printers.py | 56 +++++++++++++++++++
> .../libstdc++-prettyprinters/debug.cc | 15 +++++
> .../libstdc++-prettyprinters/simple.cc | 15 +++++
> .../libstdc++-prettyprinters/simple11.cc | 15 +++++
> 4 files changed, 101 insertions(+)
>
> diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py
> b/libstdc++-v3/python/libstdcxx/v6/printers.py
> index d70c8d5d616..bd4289c1c62 100644
> --- a/libstdc++-v3/python/libstdcxx/v6/printers.py
> +++ b/libstdc++-v3/python/libstdcxx/v6/printers.py
> @@ -969,6 +969,57 @@ class StdStringPrinter:
> def display_hint (self):
> return 'string'
>
> +def access_streambuf_ptrs(streambuf):
> + "Access the streambuf put area pointers"
> + pbase = streambuf['_M_out_beg']
> + pptr = streambuf['_M_out_cur']
> + egptr = streambuf['_M_in_end']
> + return pbase, pptr, egptr
> +
> +class StdStringBufPrinter:
> + "Print a std::basic_stringbuf"
> +
> + def __init__(self, _, val):
> + self.val = val
> +
> + def to_string(self):
> + (pbase, pptr, egptr) = access_streambuf_ptrs(self.val)
> + # Logic from basic_stringbuf::_M_high_mark()
> + if pptr:
> + if not egptr or pptr > egptr:
> + return pbase.string(length = pptr - pbase)
> + else:
> + return pbase.string(length = egptr - pbase)
> + return self.val['_M_string']
> +
> + def display_hint(self):
> + return 'string'
> +
> +class StdStringStreamPrinter:
> + "Print a std::basic_stringstream"
> +
> + def __init__(self, typename, val):
> + self.val = val
> + self.typename = typename
> +
> + # Check if the stream was redirected:
> + # This is essentially: val['_M_streambuf'] ==
> val['_M_stringbuf'].address
> + # However, GDB can't resolve the virtual inheritance, so we do that
> manually
Oh yuck, sorry you had to figure that out.
The patch looks good, thanks. I'll get it pushed to trunk.
> + basetype = [f.type for f in val.type.fields() if f.is_base_class][0]
> + gdb.set_convenience_variable('__stream', val.cast(basetype).address)
> + self.streambuf = gdb.parse_and_eval('$__stream->rdbuf()')
> + self.was_redirected = self.streambuf != val['_M_stringbuf'].address
> +
> + def to_string(self):
> + if self.was_redirected:
> + return "%s redirected to %s" % (self.typename,
> self.streambuf.dereference())
> + return self.val['_M_stringbuf']
> +
> + def display_hint(self):
> + if self.was_redirected:
> + return None
> + return 'string'
> +
> class Tr1HashtableIterator(Iterator):
> def __init__ (self, hashtable):
> self.buckets = hashtable['_M_buckets']
> @@ -2232,6 +2283,11 @@ def build_libstdcxx_dictionary ():
> libstdcxx_printer.add_version('std::', 'initializer_list',
> StdInitializerListPrinter)
> libstdcxx_printer.add_version('std::', 'atomic', StdAtomicPrinter)
> + libstdcxx_printer.add_version('std::', 'basic_stringbuf',
> StdStringBufPrinter)
> + libstdcxx_printer.add_version('std::__cxx11::', 'basic_stringbuf',
> StdStringBufPrinter)
> + for sstream in ('istringstream', 'ostringstream', 'stringstream'):
> + libstdcxx_printer.add_version('std::', 'basic_' + sstream,
> StdStringStreamPrinter)
> + libstdcxx_printer.add_version('std::__cxx11::', 'basic_' + sstream,
> StdStringStreamPrinter)
>
> # std::regex components
> libstdcxx_printer.add_version('std::__detail::', '_State',
> diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/debug.cc
> b/libstdc++-v3/testsuite/libstdc++-prettyprinters/debug.cc
> index 98bbc182551..3c6195591c5 100644
> --- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/debug.cc
> +++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/debug.cc
> @@ -29,6 +29,7 @@
> #include <list>
> #include <map>
> #include <set>
> +#include <sstream>
> #include <vector>
> #include <ext/slist>
>
> @@ -110,6 +111,20 @@ main()
> __gnu_cxx::slist<int>::iterator slliter = sll.begin();
> // { dg-final { note-test slliter {47} } }
>
> + std::stringstream sstream;
> + sstream << "abc";
> +// { dg-final { note-test sstream "\"abc\"" } }
> + std::stringstream ssin("input", std::ios::in);
> +// { dg-final { note-test ssin "\"input\"" } }
> + std::istringstream ssin2("input");
> +// { dg-final { note-test ssin2 "\"input\"" } }
> + std::ostringstream ssout;
> + ssout << "out";
> +// { dg-final { note-test ssout "\"out\"" } }
> + std::stringstream redirected("xxx");
> +
> static_cast<std::basic_ios<std::stringstream::char_type>&>(redirected).rdbuf(sstream.rdbuf());
> +// { dg-final { regexp-test redirected {std::.*stringstream redirected to
> .*} } }
> +
> std::cout << "\n";
> return 0; // Mark SPOT
> }
> diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple.cc
> b/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple.cc
> index 1f85775bff0..1609ae2c8db 100644
> --- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple.cc
> +++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple.cc
> @@ -30,6 +30,7 @@
> #include <list>
> #include <map>
> #include <set>
> +#include <sstream>
> #include <vector>
> #include <ext/slist>
>
> @@ -169,6 +170,20 @@ main()
> __gnu_cxx::slist<int>::iterator slliter0;
> // { dg-final { note-test slliter0 {non-dereferenceable iterator for
> __gnu_cxx::slist} } }
>
> + std::stringstream sstream;
> + sstream << "abc";
> +// { dg-final { note-test sstream "\"abc\"" } }
> + std::stringstream ssin("input", std::ios::in);
> +// { dg-final { note-test ssin "\"input\"" } }
> + std::istringstream ssin2("input");
> +// { dg-final { note-test ssin2 "\"input\"" } }
> + std::ostringstream ssout;
> + ssout << "out";
> +// { dg-final { note-test ssout "\"out\"" } }
> + std::stringstream redirected("xxx");
> +
> static_cast<std::basic_ios<std::stringstream::char_type>&>(redirected).rdbuf(sstream.rdbuf());
> +// { dg-final { regexp-test redirected {std::.*stringstream redirected to
> .*} } }
> +
> std::cout << "\n";
> return 0; // Mark SPOT
> }
> diff --git a/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple11.cc
> b/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple11.cc
> index 6f21675cf41..a4b82e30f9c 100644
> --- a/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple11.cc
> +++ b/libstdc++-v3/testsuite/libstdc++-prettyprinters/simple11.cc
> @@ -30,6 +30,7 @@
> #include <list>
> #include <map>
> #include <set>
> +#include <sstream>
> #include <vector>
> #include <ext/slist>
>
> @@ -162,6 +163,20 @@ main()
> __gnu_cxx::slist<int>::iterator slliter0;
> // { dg-final { note-test slliter0 {non-dereferenceable iterator for
> __gnu_cxx::slist} } }
>
> + std::stringstream sstream;
> + sstream << "abc";
> +// { dg-final { note-test sstream "\"abc\"" } }
> + std::stringstream ssin("input", std::ios::in);
> +// { dg-final { note-test ssin "\"input\"" } }
> + std::istringstream ssin2("input");
> +// { dg-final { note-test ssin2 "\"input\"" } }
> + std::ostringstream ssout;
> + ssout << "out";
> +// { dg-final { note-test ssout "\"out\"" } }
> + std::stringstream redirected("xxx");
> +
> static_cast<std::basic_ios<std::stringstream::char_type>&>(redirected).rdbuf(sstream.rdbuf());
> +// { dg-final { regexp-test redirected {std::.*stringstream redirected to
> .*} } }
> +
> std::cout << "\n";
> return 0; // Mark SPOT
> }
> --
> 2.37.3
>
