[gcc r12-2698] libstdc++: Reduce header dependencies in <regex>
Jonathan Wakely
redi@gcc.gnu.org
Tue Aug 3 15:33:46 GMT 2021
https://gcc.gnu.org/g:e9f64fff64d83f5fcaa9ff17f1688490f75bdcb7
commit r12-2698-ge9f64fff64d83f5fcaa9ff17f1688490f75bdcb7
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Aug 2 18:34:19 2021 +0100
libstdc++: Reduce header dependencies in <regex>
This reduces the size of <regex> a little. This is one of the largest
and slowest headers in the library.
By using <bits/stl_algobase.h> and <bits/stl_algo.h> instead of
<algorithm> we don't need to parse all the parallel algorithms and
std::ranges:: algorithms that are not needed by <regex>. Similarly, by
using <bits/stl_tree.h> and <bits/stl_map.h> instead of <map> we don't
need to parse the definition of std::multimap.
The _State_info type is not movable or copyable, so doesn't need to use
std::unique_ptr<bool[]> to manage a bitset, we can just delete it in the
destructor. It would use a lot less space if we used a bitset instead,
but that would be an ABI break. We could do it for the versioned
namespace, but this patch doesn't do so. For future reference, using
vector<bool> would work, but would increase sizeof(_State_info) by two
pointers, because it's three times as large as unique_ptr<bool[]>. We
can't use std::bitset because the length isn't constant. We want a
bitset with a non-constant but fixed length.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/regex_executor.h (_State_info): Replace
unique_ptr<bool[]> with array of bool.
* include/bits/regex_executor.tcc: Likewise.
* include/bits/regex_scanner.tcc: Replace std::strchr with
__builtin_strchr.
* include/std/regex: Replace standard headers with smaller
internal ones.
* testsuite/28_regex/traits/char/lookup_classname.cc: Include
<string.h> for strlen.
* testsuite/28_regex/traits/char/lookup_collatename.cc:
Likewise.
Diff:
---
libstdc++-v3/include/bits/regex_executor.h | 7 ++++++-
libstdc++-v3/include/bits/regex_executor.tcc | 2 +-
libstdc++-v3/include/bits/regex_scanner.tcc | 4 ++--
libstdc++-v3/include/std/regex | 18 +++++++++---------
.../testsuite/28_regex/traits/char/lookup_classname.cc | 1 +
.../28_regex/traits/char/lookup_collatename.cc | 1 +
6 files changed, 20 insertions(+), 13 deletions(-)
diff --git a/libstdc++-v3/include/bits/regex_executor.h b/libstdc++-v3/include/bits/regex_executor.h
index 4a641eeee6c..014b4e83064 100644
--- a/libstdc++-v3/include/bits/regex_executor.h
+++ b/libstdc++-v3/include/bits/regex_executor.h
@@ -195,6 +195,11 @@ namespace __detail
: _M_visited_states(new bool[__n]()), _M_start(__start)
{ }
+ ~_State_info() { delete[] _M_visited_states; }
+
+ _State_info(const _State_info&) = delete;
+ _State_info& operator=(const _State_info&) = delete;
+
bool _M_visited(_StateIdT __i)
{
if (_M_visited_states[__i])
@@ -212,7 +217,7 @@ namespace __detail
// Saves states that need to be considered for the next character.
vector<pair<_StateIdT, _ResultsVec>> _M_match_queue;
// Indicates which states are already visited.
- unique_ptr<bool[]> _M_visited_states;
+ bool* _M_visited_states;
// To record current solution.
_StateIdT _M_start;
};
diff --git a/libstdc++-v3/include/bits/regex_executor.tcc b/libstdc++-v3/include/bits/regex_executor.tcc
index 405d1c4d0d1..3cefeda48a3 100644
--- a/libstdc++-v3/include/bits/regex_executor.tcc
+++ b/libstdc++-v3/include/bits/regex_executor.tcc
@@ -122,7 +122,7 @@ namespace __detail
_M_has_sol = false;
if (_M_states._M_match_queue.empty())
break;
- std::fill_n(_M_states._M_visited_states.get(), _M_nfa.size(), false);
+ std::fill_n(_M_states._M_visited_states, _M_nfa.size(), false);
auto __old_queue = std::move(_M_states._M_match_queue);
for (auto& __task : __old_queue)
{
diff --git a/libstdc++-v3/include/bits/regex_scanner.tcc b/libstdc++-v3/include/bits/regex_scanner.tcc
index a3512083f0e..a9d6a613648 100644
--- a/libstdc++-v3/include/bits/regex_scanner.tcc
+++ b/libstdc++-v3/include/bits/regex_scanner.tcc
@@ -98,7 +98,7 @@ namespace __detail
{
auto __c = *_M_current++;
- if (std::strchr(_M_spec_char, _M_ctype.narrow(__c, ' ')) == nullptr)
+ if (__builtin_strchr(_M_spec_char, _M_ctype.narrow(__c, ' ')) == nullptr)
{
_M_token = _S_token_ord_char;
_M_value.assign(1, __c);
@@ -394,7 +394,7 @@ namespace __detail
"Unexpected end of regex when escaping.");
auto __c = *_M_current;
- auto __pos = std::strchr(_M_spec_char, _M_ctype.narrow(__c, '\0'));
+ auto __pos = __builtin_strchr(_M_spec_char, _M_ctype.narrow(__c, '\0'));
if (__pos != nullptr && *__pos != '\0')
{
diff --git a/libstdc++-v3/include/std/regex b/libstdc++-v3/include/std/regex
index e623a6ed498..04fb8b2d971 100644
--- a/libstdc++-v3/include/std/regex
+++ b/libstdc++-v3/include/std/regex
@@ -35,26 +35,26 @@
# include <bits/c++0x_warning.h>
#else
-#include <algorithm>
#include <bitset>
-#ifdef _GLIBCXX_DEBUG
-# include <iosfwd>
-#endif
-#include <iterator>
#include <locale>
-#include <memory>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <string>
-#include <vector>
-#include <map>
-#include <cstring>
#include <ext/aligned_buffer.h>
#include <ext/numeric_traits.h>
+#include <bits/shared_ptr.h>
#include <bits/std_function.h>
+#include <bits/stl_algobase.h> // std::copy, std::fill_n
+#include <bits/stl_algo.h> // std::sort, std::unique
+#include <bits/stl_iterator_base_types.h> // std::iterator_traits
#include <bits/stl_pair.h>
+#include <bits/stl_tree.h>
+#include <bits/stl_map.h>
+#include <bits/stl_vector.h>
+#include <bits/stl_bvector.h>
+#include <bits/vector.tcc>
#include <bits/regex_constants.h>
#include <bits/regex_error.h>
#include <bits/regex_automaton.h>
diff --git a/libstdc++-v3/testsuite/28_regex/traits/char/lookup_classname.cc b/libstdc++-v3/testsuite/28_regex/traits/char/lookup_classname.cc
index ffaed97e2a7..6c2baf21b56 100644
--- a/libstdc++-v3/testsuite/28_regex/traits/char/lookup_classname.cc
+++ b/libstdc++-v3/testsuite/28_regex/traits/char/lookup_classname.cc
@@ -27,6 +27,7 @@
#include <regex>
#include <forward_list>
+#include <string.h>
#include <testsuite_hooks.h>
void
diff --git a/libstdc++-v3/testsuite/28_regex/traits/char/lookup_collatename.cc b/libstdc++-v3/testsuite/28_regex/traits/char/lookup_collatename.cc
index 3780c40729d..35447d49f7c 100644
--- a/libstdc++-v3/testsuite/28_regex/traits/char/lookup_collatename.cc
+++ b/libstdc++-v3/testsuite/28_regex/traits/char/lookup_collatename.cc
@@ -27,6 +27,7 @@
#include <regex>
#include <forward_list>
+#include <string.h>
#include <testsuite_hooks.h>
void
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