mirror of git://gcc.gnu.org/git/gcc.git
4f87bb8d6e
This new implementation has a smaller footprint than the previous implementation, due to replacing std::vector<_Cmpt> with a custom pimpl type that only needs a single pointer. The _M_type enumeration is also combined with the pimpl type, by using a tagged pointer, reducing sizeof(path) further still. Construction and modification of paths is now done more efficiently, by splitting the input into a stack-based buffer of string_view objects instead of a dynamically-allocated vector containing strings. Once the final size is known only a single allocation is needed to reserve space for it. The append and concat operations no longer require constructing temporary path objects, nor re-parsing the entire native pathname. This results in algorithmic improvements to path construction, and working with large paths is much faster. PR libstdc++/71044 * include/bits/fs_path.h (path::path(path&&)): Add noexcept when appropriate. Move _M_cmpts instead of reparsing the native pathname. (path::operator=(const path&)): Do not define as defaulted. (path::operator/=, path::append): Call _M_append. (path::concat): Call _M_concat. (path::path(string_type, _Type): Change type of first parameter to basic_string_view<value_type>. (path::_M_append(basic_string_view<value_type>)): New member function. (path::_M_concat(basic_string_view<value_type>)): New member function. (_S_convert(value_type*, __null_terminated)): Return string view. (_S_convert(const value_type*, __null_terminated)): Return string view. (_S_convert(value_type*, value_type*)) (_S_convert(const value_type*, const value_type*)): Add overloads for pairs of pointers. (_S_convert(_InputIterator, __null_terminated)): Construct string_type explicitly, for cases where _S_convert returns a string view. (path::_S_is_dir_sep): Replace with non-member is_dir_sep. (path::_M_trim, path::_M_add_root_name, path::_M_add_root_dir) (path::_M_add_filename): Remove. (path::_M_type()): New member function to replace _M_type data member. (path::_List): Define new struct type instead of using std::vector. (path::_Cmpt::_Cmpt(string_type, _Type, size_t)): Change type of first parameter to basic_string_view<value_type>. (path::operator+=(const path&)): Do not define inline. (path::operator+=(const string_type&)): Call _M_concat. (path::operator+=(const value_type*)): Likewise. (path::operator+=(value_type)): Likewise. (path::operator+=(basic_string_view<value_type>)): Likewise. (path::operator/=(const path&)): Do not define inline. (path::_M_append(path)): Remove. * python/libstdcxx/v6/printers.py (StdPathPrinter): New printer that understands the new path::_List type. * src/filesystem/std-path.cc (is_dir_sep): New function to replace path::_S_is_dir_sep. (path::_Parser): New helper class to parse strings as paths. (path::_List::_Impl): Define container type for path components. (path::_List): Define members. (path::operator=(const path&)): Define explicitly, to provide the strong exception safety guarantee. (path::operator/=(const path&)): Implement manually by processing each component of the argument, rather than using _M_split_cmpts to parse the entire string again. (path::_M_append(string_type)): Likewise. (path::operator+=(const path&)): Likewise. (path::_M_concat(string_type)): Likewise. (path::remove_filename()): Perform trim directly instead of calling _M_trim(). (path::_M_split_cmpts()): Rewrite in terms of _Parser class. (path::_M_trim, path::_M_add_root_name, path::_M_add_root_dir) (path::_M_add_filename): Remove. * testsuite/27_io/filesystem/path/append/source.cc: Test appending a string view that aliases the path. testsuite/27_io/filesystem/path/concat/strings.cc: Test concatenating a string view that aliases the path. From-SVN: r267106 |
||
|---|---|---|
| .. | ||
| config | ||
| doc | ||
| include | ||
| libsupc++ | ||
| po | ||
| python | ||
| scripts | ||
| src | ||
| testsuite | ||
| ChangeLog | ||
| ChangeLog-1998 | ||
| ChangeLog-1999 | ||
| ChangeLog-2000 | ||
| ChangeLog-2001 | ||
| ChangeLog-2002 | ||
| ChangeLog-2003 | ||
| ChangeLog-2004 | ||
| ChangeLog-2005 | ||
| ChangeLog-2006 | ||
| ChangeLog-2007 | ||
| ChangeLog-2008 | ||
| ChangeLog-2009 | ||
| ChangeLog-2010 | ||
| ChangeLog-2011 | ||
| ChangeLog-2012 | ||
| ChangeLog-2013 | ||
| ChangeLog-2014 | ||
| ChangeLog-2015 | ||
| ChangeLog-2016 | ||
| ChangeLog-2017 | ||
| Makefile.am | ||
| Makefile.in | ||
| README | ||
| acinclude.m4 | ||
| aclocal.m4 | ||
| config.h.in | ||
| configure | ||
| configure.ac | ||
| configure.host | ||
| crossconfig.m4 | ||
| fragment.am | ||
| linkage.m4 | ||
README
file: libstdc++-v3/README New users may wish to point their web browsers to the file index.html in the 'doc/html' subdirectory. It contains brief building instructions and notes on how to configure the library in interesting ways.