After #37544 OptimizedRegularExpressionImpl started to be moved, but
StringSearcher is not copyable since it holds pointers that goes out of
scope after move (before Regexps::get() returns std::shared_ptr<Regexp>
but it had been replaced with Regexps::createRegexp() that returns
Regexp object).
<details>
<summary>ASan report</summary>
==48348==ERROR: AddressSanitizer: stack-use-after-scope on address 0x7fff577239a9 at pc 0x00001518209b bp 0x7fff57723820 sp 0x7fff57723818
READ of size 1 at 0x7fff577239a9 thread T0
0 0x1518209a in char8_t const* DB::StringSearcher<true, true>::search<char8_t>(char8_t const*, char8_t const*) const /bld/./src/Common/StringSearcher.h:730:41
1 0x1518dd3f in char8_t const* DB::StringSearcher<true, true>::search<char8_t>(char8_t const*, unsigned long) const /bld/./src/Common/StringSearcher.h:751:16
2 0x1518dd3f in OptimizedRegularExpressionImpl<false>::match(char const*, unsigned long, std::__1::vector<OptimizedRegularExpressionDetails::Match, std::__1::allocator<OptimizedRegularExpressionDetails::Match> >&, unsigned int) const /bld/./src/Common/OptimizedRegularExpression.cpp:463:54
3 0x1811cb42 in DB::ExtractAllImpl::get(char const*&, char const*&) /bld/./src/Functions/FunctionsStringArray.h:588:18
4 0x1811aa62 in DB::FunctionTokens<DB::ExtractAllImpl>::executeImpl(std::__1::vector<DB::ColumnWithTypeAndName, std::__1::allocator<DB::ColumnWithTypeAndName> > const&, std::__1::shared_ptr<DB::IDataType const> const&, unsigned long) const /bld/./src/Functions/FunctionsStringArray.h:704:30
5 0x14fe17b4 in DB::IFunction::executeImplDryRun(std::__1::vector<DB::ColumnWithTypeAndName, std::__1::allocator<DB::ColumnWithTypeAndName> > const&, std::__1::shared_ptr<DB::IDataType const> const&, unsigned long) const /bld/./src/Functions/IFunction.h:409:16
Address 0x7fff577239a9 is located in stack of thread T0 at offset 201 in frame
0 0x1518d98f in OptimizedRegularExpressionImpl<false>::match(char const*, unsigned long, std::__1::vector<OptimizedRegularExpressionDetails::Match, std::__1::allocator<OptimizedRegularExpressionDetails::Match> >&, unsigned int) const /bld/./src/Common/OptimizedRegularExpression.cpp:439
</details>
CI: https://s3.amazonaws.com/clickhouse-test-reports/39342/c6f7698f9ad6ae22199182ebf7c3b2dac77d69d8/fuzzer_astfuzzerasan,actions//report.htmlFixes: #37544 (cc @rschu1ze)
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
The original goal was to get change
const auto & needle = String(
reinterpret_cast<const char *>(cur_needle_data),
cur_needle_length);
in Functions/MatchImpl.h into a std::string_view to save an allocation +
copy. The needle is eventually passed as search pattern into the re2
library. Re2 has an alternative constructor taking a const char * i.e. a
NULL-terminated string. Here, the needle is NULL-terminated but
1. this is only because it is passed inside a ColumnString yet this is
not always the case (e.g. fixed string columns has a dense layout w/o
NULL terminator).
2. assuming NULL termination for users != MatchImpl of the regex code is
too dangerous.
So, for now we'll stay with copying to be on the safe side. One fine day
when re2 has a ptr/size ctor, we can use std::string_view.
Just changing a few other places from std::string to std::string_view
but this will not help with performance.
