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Pods/abseil/absl/strings/internal/str_format/parser.cc

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+// Copyright 2020 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/strings/internal/str_format/parser.h"
+
+#include <assert.h>
+#include <string.h>
+#include <wchar.h>
+#include <cctype>
+#include <cstdint>
+
+#include <algorithm>
+#include <initializer_list>
+#include <limits>
+#include <ostream>
+#include <string>
+#include <unordered_set>
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace str_format_internal {
+
+// Define the array for non-constexpr uses.
+constexpr ConvTag ConvTagHolder::value[256];
+
+ABSL_ATTRIBUTE_NOINLINE const char* ConsumeUnboundConversionNoInline(
+    const char* p, const char* end, UnboundConversion* conv, int* next_arg) {
+  return ConsumeUnboundConversion(p, end, conv, next_arg);
+}
+
+std::string LengthModToString(LengthMod v) {
+  switch (v) {
+    case LengthMod::h:
+      return "h";
+    case LengthMod::hh:
+      return "hh";
+    case LengthMod::l:
+      return "l";
+    case LengthMod::ll:
+      return "ll";
+    case LengthMod::L:
+      return "L";
+    case LengthMod::j:
+      return "j";
+    case LengthMod::z:
+      return "z";
+    case LengthMod::t:
+      return "t";
+    case LengthMod::q:
+      return "q";
+    case LengthMod::none:
+      return "";
+  }
+  return "";
+}
+
+struct ParsedFormatBase::ParsedFormatConsumer {
+  explicit ParsedFormatConsumer(ParsedFormatBase *parsedformat)
+      : parsed(parsedformat), data_pos(parsedformat->data_.get()) {}
+
+  bool Append(string_view s) {
+    if (s.empty()) return true;
+
+    size_t text_end = AppendText(s);
+
+    if (!parsed->items_.empty() && !parsed->items_.back().is_conversion) {
+      // Let's extend the existing text run.
+      parsed->items_.back().text_end = text_end;
+    } else {
+      // Let's make a new text run.
+      parsed->items_.push_back({false, text_end, {}});
+    }
+    return true;
+  }
+
+  bool ConvertOne(const UnboundConversion &conv, string_view s) {
+    size_t text_end = AppendText(s);
+    parsed->items_.push_back({true, text_end, conv});
+    return true;
+  }
+
+  size_t AppendText(string_view s) {
+    memcpy(data_pos, s.data(), s.size());
+    data_pos += s.size();
+    return static_cast<size_t>(data_pos - parsed->data_.get());
+  }
+
+  ParsedFormatBase *parsed;
+  char* data_pos;
+};
+
+ParsedFormatBase::ParsedFormatBase(
+    string_view format, bool allow_ignored,
+    std::initializer_list<FormatConversionCharSet> convs)
+    : data_(format.empty() ? nullptr : new char[format.size()]) {
+  has_error_ = !ParseFormatString(format, ParsedFormatConsumer(this)) ||
+               !MatchesConversions(allow_ignored, convs);
+}
+
+bool ParsedFormatBase::MatchesConversions(
+    bool allow_ignored,
+    std::initializer_list<FormatConversionCharSet> convs) const {
+  std::unordered_set<int> used;
+  auto add_if_valid_conv = [&](int pos, char c) {
+    if (static_cast<size_t>(pos) > convs.size() ||
+        !Contains(convs.begin()[pos - 1], c))
+      return false;
+    used.insert(pos);
+    return true;
+  };
+  for (const ConversionItem &item : items_) {
+    if (!item.is_conversion) continue;
+    auto &conv = item.conv;
+    if (conv.precision.is_from_arg() &&
+        !add_if_valid_conv(conv.precision.get_from_arg(), '*'))
+      return false;
+    if (conv.width.is_from_arg() &&
+        !add_if_valid_conv(conv.width.get_from_arg(), '*'))
+      return false;
+    if (!add_if_valid_conv(conv.arg_position,
+                           FormatConversionCharToChar(conv.conv)))
+      return false;
+  }
+  return used.size() == convs.size() || allow_ignored;
+}
+
+}  // namespace str_format_internal
+ABSL_NAMESPACE_END
+}  // namespace absl