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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/internal/str_format/parser.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/strings/internal/str_format/parser.h | 335 |
1 files changed, 0 insertions, 335 deletions
diff --git a/third_party/abseil_cpp/absl/strings/internal/str_format/parser.h b/third_party/abseil_cpp/absl/strings/internal/str_format/parser.h deleted file mode 100644 index fffed04fa0..0000000000 --- a/third_party/abseil_cpp/absl/strings/internal/str_format/parser.h +++ /dev/null @@ -1,335 +0,0 @@ -#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_PARSER_H_ -#define ABSL_STRINGS_INTERNAL_STR_FORMAT_PARSER_H_ - -#include <limits.h> -#include <stddef.h> -#include <stdlib.h> - -#include <cassert> -#include <cstdint> -#include <initializer_list> -#include <iosfwd> -#include <iterator> -#include <memory> -#include <string> -#include <vector> - -#include "absl/strings/internal/str_format/checker.h" -#include "absl/strings/internal/str_format/extension.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace str_format_internal { - -enum class LengthMod : std::uint8_t { h, hh, l, ll, L, j, z, t, q, none }; - -std::string LengthModToString(LengthMod v); - -// The analyzed properties of a single specified conversion. -struct UnboundConversion { - UnboundConversion() - : flags() /* This is required to zero all the fields of flags. */ { - flags.basic = true; - } - - class InputValue { - public: - void set_value(int value) { - assert(value >= 0); - value_ = value; - } - int value() const { return value_; } - - // Marks the value as "from arg". aka the '*' format. - // Requires `value >= 1`. - // When set, is_from_arg() return true and get_from_arg() returns the - // original value. - // `value()`'s return value is unspecfied in this state. - void set_from_arg(int value) { - assert(value > 0); - value_ = -value - 1; - } - bool is_from_arg() const { return value_ < -1; } - int get_from_arg() const { - assert(is_from_arg()); - return -value_ - 1; - } - - private: - int value_ = -1; - }; - - // No need to initialize. It will always be set in the parser. - int arg_position; - - InputValue width; - InputValue precision; - - Flags flags; - LengthMod length_mod = LengthMod::none; - FormatConversionChar conv = FormatConversionCharInternal::kNone; -}; - -// Consume conversion spec prefix (not including '%') of [p, end) if valid. -// Examples of valid specs would be e.g.: "s", "d", "-12.6f". -// If valid, it returns the first character following the conversion spec, -// and the spec part is broken down and returned in 'conv'. -// If invalid, returns nullptr. -const char* ConsumeUnboundConversion(const char* p, const char* end, - UnboundConversion* conv, int* next_arg); - -// Helper tag class for the table below. -// It allows fast `char -> ConversionChar/LengthMod` checking and -// conversions. -class ConvTag { - public: - constexpr ConvTag(FormatConversionChar conversion_char) // NOLINT - : tag_(static_cast<int8_t>(conversion_char)) {} - // We invert the length modifiers to make them negative so that we can easily - // test for them. - constexpr ConvTag(LengthMod length_mod) // NOLINT - : tag_(~static_cast<std::int8_t>(length_mod)) {} - // Everything else is -128, which is negative to make is_conv() simpler. - constexpr ConvTag() : tag_(-128) {} - - bool is_conv() const { return tag_ >= 0; } - bool is_length() const { return tag_ < 0 && tag_ != -128; } - FormatConversionChar as_conv() const { - assert(is_conv()); - return static_cast<FormatConversionChar>(tag_); - } - LengthMod as_length() const { - assert(is_length()); - return static_cast<LengthMod>(~tag_); - } - - private: - std::int8_t tag_; -}; - -extern const ConvTag kTags[256]; -// Keep a single table for all the conversion chars and length modifiers. -inline ConvTag GetTagForChar(char c) { - return kTags[static_cast<unsigned char>(c)]; -} - -// Parse the format string provided in 'src' and pass the identified items into -// 'consumer'. -// Text runs will be passed by calling -// Consumer::Append(string_view); -// ConversionItems will be passed by calling -// Consumer::ConvertOne(UnboundConversion, string_view); -// In the case of ConvertOne, the string_view that is passed is the -// portion of the format string corresponding to the conversion, not including -// the leading %. On success, it returns true. On failure, it stops and returns -// false. -template <typename Consumer> -bool ParseFormatString(string_view src, Consumer consumer) { - int next_arg = 0; - const char* p = src.data(); - const char* const end = p + src.size(); - while (p != end) { - const char* percent = static_cast<const char*>(memchr(p, '%', end - p)); - if (!percent) { - // We found the last substring. - return consumer.Append(string_view(p, end - p)); - } - // We found a percent, so push the text run then process the percent. - if (ABSL_PREDICT_FALSE(!consumer.Append(string_view(p, percent - p)))) { - return false; - } - if (ABSL_PREDICT_FALSE(percent + 1 >= end)) return false; - - auto tag = GetTagForChar(percent[1]); - if (tag.is_conv()) { - if (ABSL_PREDICT_FALSE(next_arg < 0)) { - // This indicates an error in the format string. - // The only way to get `next_arg < 0` here is to have a positional - // argument first which sets next_arg to -1 and then a non-positional - // argument. - return false; - } - p = percent + 2; - - // Keep this case separate from the one below. - // ConvertOne is more efficient when the compiler can see that the `basic` - // flag is set. - UnboundConversion conv; - conv.conv = tag.as_conv(); - conv.arg_position = ++next_arg; - if (ABSL_PREDICT_FALSE( - !consumer.ConvertOne(conv, string_view(percent + 1, 1)))) { - return false; - } - } else if (percent[1] != '%') { - UnboundConversion conv; - p = ConsumeUnboundConversion(percent + 1, end, &conv, &next_arg); - if (ABSL_PREDICT_FALSE(p == nullptr)) return false; - if (ABSL_PREDICT_FALSE(!consumer.ConvertOne( - conv, string_view(percent + 1, p - (percent + 1))))) { - return false; - } - } else { - if (ABSL_PREDICT_FALSE(!consumer.Append("%"))) return false; - p = percent + 2; - continue; - } - } - return true; -} - -// Always returns true, or fails to compile in a constexpr context if s does not -// point to a constexpr char array. -constexpr bool EnsureConstexpr(string_view s) { - return s.empty() || s[0] == s[0]; -} - -class ParsedFormatBase { - public: - explicit ParsedFormatBase( - string_view format, bool allow_ignored, - std::initializer_list<FormatConversionCharSet> convs); - - ParsedFormatBase(const ParsedFormatBase& other) { *this = other; } - - ParsedFormatBase(ParsedFormatBase&& other) { *this = std::move(other); } - - ParsedFormatBase& operator=(const ParsedFormatBase& other) { - if (this == &other) return *this; - has_error_ = other.has_error_; - items_ = other.items_; - size_t text_size = items_.empty() ? 0 : items_.back().text_end; - data_.reset(new char[text_size]); - memcpy(data_.get(), other.data_.get(), text_size); - return *this; - } - - ParsedFormatBase& operator=(ParsedFormatBase&& other) { - if (this == &other) return *this; - has_error_ = other.has_error_; - data_ = std::move(other.data_); - items_ = std::move(other.items_); - // Reset the vector to make sure the invariants hold. - other.items_.clear(); - return *this; - } - - template <typename Consumer> - bool ProcessFormat(Consumer consumer) const { - const char* const base = data_.get(); - string_view text(base, 0); - for (const auto& item : items_) { - const char* const end = text.data() + text.size(); - text = string_view(end, (base + item.text_end) - end); - if (item.is_conversion) { - if (!consumer.ConvertOne(item.conv, text)) return false; - } else { - if (!consumer.Append(text)) return false; - } - } - return !has_error_; - } - - bool has_error() const { return has_error_; } - - private: - // Returns whether the conversions match and if !allow_ignored it verifies - // that all conversions are used by the format. - bool MatchesConversions( - bool allow_ignored, - std::initializer_list<FormatConversionCharSet> convs) const; - - struct ParsedFormatConsumer; - - struct ConversionItem { - bool is_conversion; - // Points to the past-the-end location of this element in the data_ array. - size_t text_end; - UnboundConversion conv; - }; - - bool has_error_; - std::unique_ptr<char[]> data_; - std::vector<ConversionItem> items_; -}; - - -// A value type representing a preparsed format. These can be created, copied -// around, and reused to speed up formatting loops. -// The user must specify through the template arguments the conversion -// characters used in the format. This will be checked at compile time. -// -// This class uses Conv enum values to specify each argument. -// This allows for more flexibility as you can specify multiple possible -// conversion characters for each argument. -// ParsedFormat<char...> is a simplified alias for when the user only -// needs to specify a single conversion character for each argument. -// -// Example: -// // Extended format supports multiple characters per argument: -// using MyFormat = ExtendedParsedFormat<Conv::d | Conv::x>; -// MyFormat GetFormat(bool use_hex) { -// if (use_hex) return MyFormat("foo %x bar"); -// return MyFormat("foo %d bar"); -// } -// // 'format' can be used with any value that supports 'd' and 'x', -// // like `int`. -// auto format = GetFormat(use_hex); -// value = StringF(format, i); -// -// This class also supports runtime format checking with the ::New() and -// ::NewAllowIgnored() factory functions. -// This is the only API that allows the user to pass a runtime specified format -// string. These factory functions will return NULL if the format does not match -// the conversions requested by the user. -template <FormatConversionCharSet... C> -class ExtendedParsedFormat : public str_format_internal::ParsedFormatBase { - public: - explicit ExtendedParsedFormat(string_view format) -#ifdef ABSL_INTERNAL_ENABLE_FORMAT_CHECKER - __attribute__(( - enable_if(str_format_internal::EnsureConstexpr(format), - "Format string is not constexpr."), - enable_if(str_format_internal::ValidFormatImpl<C...>(format), - "Format specified does not match the template arguments."))) -#endif // ABSL_INTERNAL_ENABLE_FORMAT_CHECKER - : ExtendedParsedFormat(format, false) { - } - - // ExtendedParsedFormat factory function. - // The user still has to specify the conversion characters, but they will not - // be checked at compile time. Instead, it will be checked at runtime. - // This delays the checking to runtime, but allows the user to pass - // dynamically sourced formats. - // It returns NULL if the format does not match the conversion characters. - // The user is responsible for checking the return value before using it. - // - // The 'New' variant will check that all the specified arguments are being - // consumed by the format and return NULL if any argument is being ignored. - // The 'NewAllowIgnored' variant will not verify this and will allow formats - // that ignore arguments. - static std::unique_ptr<ExtendedParsedFormat> New(string_view format) { - return New(format, false); - } - static std::unique_ptr<ExtendedParsedFormat> NewAllowIgnored( - string_view format) { - return New(format, true); - } - - private: - static std::unique_ptr<ExtendedParsedFormat> New(string_view format, - bool allow_ignored) { - std::unique_ptr<ExtendedParsedFormat> conv( - new ExtendedParsedFormat(format, allow_ignored)); - if (conv->has_error()) return nullptr; - return conv; - } - - ExtendedParsedFormat(string_view s, bool allow_ignored) - : ParsedFormatBase(s, allow_ignored, {C...}) {} -}; -} // namespace str_format_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_PARSER_H_ |