On 16/03/21 21:55 +0100, François Dumont via Libstdc++ wrote:
Following:
https://gcc.gnu.org/pipermail/libstdc++/2021-March/052158.html
Here is the patch to complete __gnu_debug::basic_string support.
Contrarily to what I thought code in std::basic_string to generate a
basic_string_view works just fine for __gnu_debug::basic_string.
libstdc++: [_GLIBCXX_DEBUG] Add __gnu_debug
u8string/u16string/u32string
Complete __gnu_debug::basic_string support so that it can be used as a
transparent replacement of std::basic_string.
libstdc++-v3/ChangeLog:
* include/debug/string
(basic_string(const _CharT*, const _Allocator&)): Remove
assign call.
(basic_string<>::insert(const_iterator, _InputIte,
_InputIte)): Try to
remove iterator debug layer even if !_GLIBCXX_USE_CXX11_ABI.
[_GLIBCXX_USE_CHAR8_T] (__gnu_debug::u8string): New.
(__gnu_debug::u16string, __gnu_debug::u32string): New.
[!_GLIBCXX_COMPATIBILITY_CXX0X](std::hash<__gnu_debug::string>): New.
[!_GLIBCXX_COMPATIBILITY_CXX0X][_GLIBCXX_USE_WCHAR_T](std::hash<__gnu_debug::wstring>):
New.
[_GLIBCXX_USE_CHAR8_T](std::hash<__gnu_debug::u8string>): New.
(std::hash<__gnu_debug::u16string>): New.
(std::hash<__gnu_debug::u32string>): New.
* testsuite/21_strings/basic_string/hash/hash_char8_t.cc:
Adapt for
__gnu_debug basic_string.
Tested under Linux x86_64.
Ok to commit ?
François
diff --git a/libstdc++-v3/include/debug/string
b/libstdc++-v3/include/debug/string
index d6eb5280ade..dec23f6277b 100644
--- a/libstdc++-v3/include/debug/string
+++ b/libstdc++-v3/include/debug/string
@@ -41,6 +41,14 @@
__gnu_debug::_Error_formatter::_S_at(_File, _Line, _Func) \
._M_message(#_Cond)._M_error()
+#if _GLIBCXX_USE_CXX11_ABI && __cplusplus >= 201103
+# define _GLIBCXX_CPP11_AND_CXX11_ABI 1
+# define _GLIBCXX_CPP11_AND_CXX11_ABI_ONLY(Statement) Statement
This takes an expression, not a statement.
I think it would be better to use more descriptive names for these:
# define _GLIBCXX_INSERT_RETURNS_ITERATOR 1
# define _GLIBCXX_INSERT_RETURNS_ITERATOR_ONLY(expr) expr
(And don't forget to change the #undef lines too).
+#if __cplusplus >= 201103L
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ // DR 1182.
+
+#ifndef _GLIBCXX_COMPATIBILITY_CXX0X
+ /// std::hash specialization for string.
+ template<>
+ struct hash<__gnu_debug::string>
+ : public __hash_base<size_t, __gnu_debug::string>
I think we could just define on partial specialization that works for
all cases:
template<typename _CharT>
struct hash<__gnu_debug::basic_string<_CharT>>
: public hash<std::basic_string<_CharT>>
{ };
If we're being pedantic, this isn't strictly-conforming because it
will inherit the argument_type member from the base class, which will
be the non-debug string rather than the debug one. I don't think I
care about that.
If we cared, we'd need to do something like:
template<typename _CharT, typename = void>
struct __debug_str_hash
{ };
template<typename _CharT>
struct __debug_str_hash<_CharT,
__void_t<typename
hash<std::basic_string<_CharT>>::argument_type>>
: hash<std::basic_string<_CharT>>
{
using argument_type = __gnu_debug::basic_string<_CharT>;
size_t operator()(const argument_type& __s) const noexcept
{ return hash<std::basic_string<_CharT>>()(__s); }
};
template<typename _CharT>
struct hash<__gnu_debug::basic_string<_CharT>>
: public __debug_str_hash<_CharT>
{ };
I don't think we should care.
+ {
+ size_t
+ operator()(const __gnu_debug::string& __s) const noexcept
+ { return std::hash<std::string>()(__s); }
+ };
+
+ template<>
+ struct __is_fast_hash<hash<__gnu_debug::string>> : std::false_type
+ { };
And:
template<typename _CharT>
struct __is_fast_hash<hash<__gnu_debug::basic_string<_CharT>>>
: __is_fast_hash<hash<std::basic_string<_CharT>>>
{ };
diff --git
a/libstdc++-v3/testsuite/21_strings/basic_string/hash/hash_char8_t.cc
b/libstdc++-v3/testsuite/21_strings/basic_string/hash/hash_char8_t.cc
index c0e8975ce4a..7f8792bbd76 100644
--- a/libstdc++-v3/testsuite/21_strings/basic_string/hash/hash_char8_t.cc
+++ b/libstdc++-v3/testsuite/21_strings/basic_string/hash/hash_char8_t.cc
Why only make this change for the char8_t version? Why not test
hash<__gnu_debug::string> as well?
@@ -18,10 +18,19 @@
// { dg-options "-std=gnu++2a" }
// { dg-do run { target c++2a } }
-#include <string>
#include <memory_resource>
#include <testsuite_hooks.h>
+#ifdef _GLIBCXX_DEBUG
+# include <debug/string>
+
+using namespace __gnu_debug;
This means we no longer test the hash<std::u8string> specialization in
debug mode.
Please leave this test unchanged and add a separate file (e.g.
21_strings/basic_string/hash/debug.cc) which tests all the
hash<__gnu_debug::*string> specializations.
It's stage 4, but this only affects a type that is not used anywhere
by default, not even when Debug Mode is active, so I think this can
still potentially go in for GCC 11.
