[k2] refactor pcre2 functions (#1501)

Author: Shamzik

runtime-light/coroutine/await-set.h

@@ -48,7 +48,7 @@ class await_set {
   }
 
   auto next() noexcept {
-    return detail::await_set::await_set_awaitable<return_type>{*m_await_broker.get()};
+    return detail::await_set::await_set_awaitable<return_type>{*m_await_broker};
   }
 
   bool empty() const noexcept {

runtime-light/stdlib/string/pcre2-functions.h

@@ -0,0 +1,372 @@
+// Compiler for PHP (aka KPHP)
+// Copyright (c) 2025 LLC «V Kontakte»
+// Distributed under the GPL v3 License, see LICENSE.notice.txt
+
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+#include <expected>
+#include <format>
+#include <iterator>
+#include <optional>
+#include <span>
+#include <string_view>
+
+#include "runtime-light/stdlib/diagnostics/logs.h"
+// correctly include PCRE2 lib
+#include "runtime-light/stdlib/string/regex-include.h"
+
+namespace kphp::pcre2 {
+
+namespace details {
+
+namespace offset_pair {
+
+inline constexpr size_t START{0};
+inline constexpr size_t END{1};
+inline constexpr size_t SIZE{2};
+
+} // namespace offset_pair
+
+inline int64_t skip_utf8_subsequent_bytes(size_t offset, const std::string_view subject) noexcept {
+  // all multibyte utf8 runes consist of subsequent bytes,
+  // these subsequent bytes start with 10 bit pattern
+  // 0xc0 selects the two most significant bits, then we compare it to 0x80 (0b10000000)
+  while (offset < subject.size() && ((static_cast<unsigned char>(subject[offset])) & 0xc0) == 0x80) {
+    offset++;
+  }
+  return offset;
+}
+
+} // namespace details
+
+using general_context = std::unique_ptr<pcre2_general_context_8, decltype(std::addressof(pcre2_general_context_free_8))>;
+using compile_context = std::unique_ptr<pcre2_compile_context_8, decltype(std::addressof(pcre2_compile_context_free_8))>;
+using match_context = std::unique_ptr<pcre2_match_context_8, decltype(std::addressof(pcre2_match_context_free_8))>;
+using match_data = std::unique_ptr<pcre2_match_data_8, decltype(std::addressof(pcre2_match_data_free_8))>;
+using code = std::unique_ptr<pcre2_code_8, decltype(std::addressof(pcre2_code_free_8))>;
+
+struct error {
+  int32_t code{};
+};
+
+struct compile_error : kphp::pcre2::error {
+  size_t offset{};
+};
+
+struct group_name {
+  std::string_view name;
+  size_t index{};
+};
+
+class regex {
+  kphp::pcre2::code m_code;
+
+  class group_name_iterator {
+    const PCRE2_UCHAR8* m_ptr{nullptr};
+    const size_t m_entry_size{};
+
+  public:
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = kphp::pcre2::group_name;
+    using difference_type = std::ptrdiff_t;
+    using pointer = kphp::pcre2::group_name*;
+    using reference = kphp::pcre2::group_name;
+
+    group_name_iterator() = delete;
+    group_name_iterator(const PCRE2_UCHAR8* current_entry, size_t entry_size) noexcept
+        : m_ptr{current_entry},
+          m_entry_size{entry_size} {
+      kphp::log::assertion(current_entry != nullptr);
+    }
+
+    kphp::pcre2::group_name operator*() const noexcept {
+      static constexpr size_t UPPER = 0;
+      static constexpr size_t LOWER = 1;
+
+      const auto index{static_cast<size_t>(m_ptr[UPPER] << 8 | m_ptr[LOWER])};
+      const auto* name_ptr{reinterpret_cast<const char*>(std::next(m_ptr, 2 * sizeof(PCRE2_UCHAR8)))};
+      return {.name = std::string_view{name_ptr}, .index = index};
+    }
+
+    group_name_iterator& operator++() noexcept {
+      std::advance(m_ptr, m_entry_size);
+      return *this;
+    }
+
+    group_name_iterator operator++(int) noexcept { // NOLINT
+      group_name_iterator tmp{*this};
+      ++*this;
+      return tmp;
+    }
+
+    bool operator==(const group_name_iterator& other) const noexcept {
+      return m_ptr == other.m_ptr;
+    }
+  };
+
+public:
+  friend class match_view;
+  friend class matcher;
+
+  static std::expected<regex, kphp::pcre2::compile_error> compile(std::string_view pattern, kphp::pcre2::compile_context& ctx, uint32_t options = 0) noexcept {
+    int32_t errorcode{};
+    PCRE2_SIZE erroroffset{};
+
+    kphp::pcre2::code re{pcre2_compile_8(reinterpret_cast<PCRE2_SPTR>(pattern.data()), pattern.length(), options, std::addressof(errorcode),
+                                         std::addressof(erroroffset), ctx.get()),
+                         pcre2_code_free_8};
+
+    if (!re) {
+      return std::unexpected{kphp::pcre2::compile_error{{.code = errorcode}, erroroffset}};
+    }
+    return kphp::pcre2::regex{std::move(re)};
+  }
+
+  struct group_name_range {
+    group_name_iterator b;
+    group_name_iterator e;
+
+    group_name_iterator begin() const noexcept {
+      return b;
+    }
+    group_name_iterator end() const noexcept {
+      return e;
+    }
+
+    bool empty() const noexcept {
+      return b == e;
+    }
+  };
+
+  group_name_range group_names() const noexcept {
+    uint32_t count{};
+    uint32_t entry_size{};
+    PCRE2_SPTR8 table{};
+
+    kphp::log::assertion(pcre2_pattern_info_8(m_code.get(), PCRE2_INFO_NAMECOUNT, std::addressof(count)) == 0);
+
+    if (count == 0) {
+      return {.b = group_name_iterator{nullptr, 0}, .e = group_name_iterator{nullptr, 0}};
+    }
+
+    kphp::log::assertion(pcre2_pattern_info_8(m_code.get(), PCRE2_INFO_NAMEENTRYSIZE, std::addressof(entry_size)) == 0 &&
+                         pcre2_pattern_info_8(m_code.get(), PCRE2_INFO_NAMETABLE, std::addressof(table)) == 0);
+
+    return {.b = group_name_iterator{table, entry_size}, .e = group_name_iterator{std::next(table, static_cast<size_t>(count) * entry_size), entry_size}};
+  }
+
+  uint32_t capture_count() const noexcept {
+    uint32_t count{};
+    kphp::log::assertion(pcre2_pattern_info_8(m_code.get(), PCRE2_INFO_CAPTURECOUNT, std::addressof(count)) == 0);
+    return count;
+  }
+
+  uint32_t name_count() const noexcept {
+    uint32_t count{};
+    kphp::log::assertion(pcre2_pattern_info_8(m_code.get(), PCRE2_INFO_NAMECOUNT, std::addressof(count)) == 0);
+    return count;
+  }
+
+  bool is_utf() const noexcept {
+    uint32_t compile_options{};
+    kphp::log::assertion(pcre2_pattern_info_8(m_code.get(), PCRE2_INFO_ARGOPTIONS, std::addressof(compile_options)) == 0);
+    return (compile_options & PCRE2_UTF) != 0;
+  }
+
+private:
+  explicit regex(kphp::pcre2::code&& code) noexcept
+      : m_code{std::move(code)} {}
+};
+
+class match_view {
+  const kphp::pcre2::regex& m_re;
+  std::string_view m_subject;
+  kphp::pcre2::match_data& m_match_data;
+  uint32_t m_match_options{};
+  size_t m_num_groups{};
+
+public:
+  match_view(const regex& re, std::string_view subject, kphp::pcre2::match_data& match_data, uint32_t match_options, size_t num_groups) noexcept
+      : m_re{re},
+        m_subject{subject},
+        m_match_data{match_data},
+        m_match_options{match_options},
+        m_num_groups{num_groups} {}
+
+  int32_t size() const noexcept {
+    return m_num_groups;
+  }
+
+  struct offset_range {
+    size_t start{};
+    size_t end{};
+  };
+
+  std::optional<std::string_view> get_group(size_t i) const noexcept {
+    if (auto range{get_range(i)}; range.has_value()) {
+      return m_subject.substr(range->start, range->end - range->start);
+    }
+    return std::nullopt;
+  }
+
+  struct group_content {
+    std::string_view text;
+    size_t offset{};
+  };
+
+  std::optional<group_content> get_group_content(size_t i) const noexcept {
+    if (auto range{get_range(i)}; range.has_value()) {
+      return group_content{.text = m_subject.substr(range->start, range->end - range->start), .offset = range->start};
+    }
+    return std::nullopt;
+  }
+
+  size_t match_start() const noexcept {
+    return pcre2_get_ovector_pointer_8(m_match_data.get())[kphp::pcre2::details::offset_pair::START];
+  }
+  size_t match_end() const noexcept {
+    return pcre2_get_ovector_pointer_8(m_match_data.get())[kphp::pcre2::details::offset_pair::END];
+  }
+
+  std::expected<size_t, std::pair<size_t, kphp::pcre2::error>> substitute(std::string_view replacement, std::span<char> buffer,
+                                                                          kphp::pcre2::match_context& ctx) const noexcept {
+    kphp::log::assertion(buffer.data() != nullptr);
+
+    uint32_t substitute_options{PCRE2_SUBSTITUTE_UNKNOWN_UNSET | PCRE2_SUBSTITUTE_UNSET_EMPTY | PCRE2_SUBSTITUTE_MATCHED | PCRE2_SUBSTITUTE_OVERFLOW_LENGTH |
+                                PCRE2_SUBSTITUTE_REPLACEMENT_ONLY | m_match_options};
+
+    auto buffer_len{buffer.size()};
+    auto ret_code{pcre2_substitute_8(m_re.m_code.get(), reinterpret_cast<PCRE2_SPTR8>(m_subject.data()), m_subject.length(), 0, substitute_options,
+                                     m_match_data.get(), ctx.get(), reinterpret_cast<PCRE2_SPTR8>(replacement.data()), replacement.length(),
+                                     reinterpret_cast<PCRE2_UCHAR8*>(buffer.data()), std::addressof(buffer_len))};
+
+    if (ret_code < 0) {
+      return std::unexpected<std::pair<size_t, kphp::pcre2::error>>{{buffer_len, {.code = ret_code}}};
+    }
+
+    return buffer_len;
+  }
+
+private:
+  std::optional<offset_range> get_range(size_t i) const noexcept {
+    if (i >= m_num_groups) {
+      return std::nullopt;
+    }
+
+    const auto* ovector_ptr{pcre2_get_ovector_pointer_8(m_match_data.get())};
+    // ovector is an array of offset pairs
+    PCRE2_SIZE start{ovector_ptr[(kphp::pcre2::details::offset_pair::SIZE * i) + kphp::pcre2::details::offset_pair::START]};
+    PCRE2_SIZE end{ovector_ptr[(kphp::pcre2::details::offset_pair::SIZE * i) + kphp::pcre2::details::offset_pair::END]};
+
+    if (start == PCRE2_UNSET) {
+      return std::nullopt;
+    }
+    return offset_range{.start = start, .end = end};
+  }
+};
+
+class matcher {
+  const kphp::pcre2::regex& m_re;
+  std::string_view m_subject;
+  kphp::pcre2::match_context& m_ctx;
+  PCRE2_SIZE m_current_offset{};
+  kphp::pcre2::match_data& m_match_data;
+  uint32_t m_user_options{};
+  uint32_t m_match_options{};
+  bool m_is_utf{false};
+
+public:
+  matcher(const kphp::pcre2::regex& re, std::string_view subject, size_t match_from, kphp::pcre2::match_context& ctx, kphp::pcre2::match_data& data,
+          uint32_t options = 0) noexcept
+      : m_re{re},
+        m_subject{subject},
+        m_ctx{ctx},
+        m_current_offset{match_from},
+        m_match_data{data},
+        m_user_options{options},
+        m_is_utf{re.is_utf()} {}
+
+  std::expected<std::optional<kphp::pcre2::match_view>, kphp::pcre2::error> next() noexcept {
+    while (m_current_offset <= m_subject.length()) {
+      uint32_t current_attempt_options{m_user_options | m_match_options};
+
+      auto ret_code{pcre2_match_8(m_re.m_code.get(), reinterpret_cast<PCRE2_SPTR8>(m_subject.data()), m_subject.length(), m_current_offset,
+                                  current_attempt_options, m_match_data.get(), m_ctx.get())};
+
+      if (ret_code == PCRE2_ERROR_NOMATCH) {
+        if (m_match_options != 0) {
+          // If the anchored non-empty match failed, advance 1 unit and try again
+          m_match_options = 0;
+          m_current_offset++;
+          if (m_is_utf) {
+            m_current_offset = kphp::pcre2::details::skip_utf8_subsequent_bytes(m_current_offset, m_subject);
+          }
+          continue;
+        }
+        return std::nullopt;
+      }
+
+      // From https://www.pcre.org/current/doc/html/pcre2_match.html
+      // The return from pcre2_match() is one more than the highest numbered capturing pair that has been set
+      // (for example, 1 if there are no captures), zero if the vector of offsets is too small, or a negative error code for no match and other errors.
+      if (ret_code < 0) [[unlikely]] {
+        return std::unexpected{error{.code = ret_code}};
+      }
+
+      size_t matched_groups_count{};
+      if (ret_code == 0) {
+        matched_groups_count = pcre2_get_ovector_count_8(m_match_data.get());
+      } else {
+        matched_groups_count = static_cast<size_t>(ret_code);
+      }
+
+      const PCRE2_SIZE* ovector{pcre2_get_ovector_pointer_8(m_match_data.get())};
+
+      size_t start{ovector[kphp::pcre2::details::offset_pair::START]};
+      size_t end{ovector[kphp::pcre2::details::offset_pair::END]};
+
+      if (start == end) {
+        // Found an empty match; set flags to try finding a non-empty match at same position
+        m_match_options = PCRE2_NOTEMPTY_ATSTART | PCRE2_ANCHORED;
+      } else {
+        m_match_options = 0;
+      }
+      m_current_offset = end;
+
+      return kphp::pcre2::match_view{m_re, m_subject, m_match_data, current_attempt_options, matched_groups_count};
+    }
+
+    return std::nullopt;
+  }
+};
+
+} // namespace kphp::pcre2
+
+template<>
+struct std::formatter<kphp::pcre2::error> {
+  template<typename ParseContext>
+  constexpr auto parse(ParseContext& ctx) const noexcept {
+    return ctx.begin();
+  }
+
+  template<typename FmtContext>
+  auto format(kphp::pcre2::error error, FmtContext& ctx) const noexcept {
+    static constexpr size_t ERROR_BUFFER_LENGTH{256};
+
+    std::array<char, ERROR_BUFFER_LENGTH> buffer; // NOLINT
+    auto ret_code{pcre2_get_error_message_8(error.code, reinterpret_cast<PCRE2_UCHAR8*>(buffer.data()), buffer.size())};
+    if (ret_code < 0) [[unlikely]] {
+      switch (ret_code) {
+      case PCRE2_ERROR_BADDATA:
+        return format_to(ctx.out(), "unknown error ({})", error.code);
+      case PCRE2_ERROR_NOMEMORY:
+        return format_to(ctx.out(), "[truncated] {}", buffer.data());
+      default:
+        kphp::log::error("unsupported regex error code: {}", ret_code);
+      }
+    }
+    return format_to(ctx.out(), "{}", buffer.data());
+  }
+};