We had a few times the need for a data structure that does essentially
what C++17's std::string_view does, which is to give an std::string-like
interface (only the read-only operations) to an arbitrary character
buffer.
This patch adapts the files copied from libstdc++ by the previous patch
to integrate them with GDB. Here's a summary of the changes:
* Remove things related to wstring_view, u16string_view and
u32string_view (I don't think we need them, but we can always add them
later).
* Remove usages of _GLIBCXX_BEGIN_NAMESPACE_VERSION and
_GLIBCXX_END_NAMESPACE_VERSION.
* Put the code in the gdb namespace. I had to add a few "std::" in
front of std type usages.
* Change __throw_out_of_range_fmt() for error().
* Make gdb::string_view an alias of std::string_view when building
with >= c++17.
* Remove a bunch of constexpr, because they are not valid in c++11
(e.g. they are not a single return line).
* Use std::common_type<_Tp>::type instead of std::common_type_t<_Tp>,
because c++11 doesn't have the later.
* Remove the #pragma GCC system_header, since that silences some
warnings that we might want to have if we're doing something not
correctly.
* Remove operator ""sv. It would need a lot of work to make all
supported compilers happy, and we can easily live without it.
* Remove operator<<. It is implemented using __ostream_insert (a
libstdc++ internal). Bringing it in might be possible, but I don't
think that would be worth the effort, since we don't really use
streams at the moment.
* Replace internal libstdc++ asserts ( __glibcxx_assert and
__glibcxx_requires_string_len) with gdb_assert.
* Remove hash helpers, because they use libstdc++ internal functions.
If we need them we always import them later.
The string_view class in cli/cli-script.c is removed and its usage
replaced with the new gdb::string_view.
gdb/ChangeLog:
* common/gdb_string_view.h: Remove libstdc++ implementation
details, adjust to gdb reality.
* common/gdb_string_view.tcc: Likewise.
* cli/cli-script.c (struct string_view): Remove.
(user_args) <m_args>: Change element type to gdb::string_view.
(user_args::insert_args): Adjust.
8345c4a267