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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/internal/str_format/extension.h')
-rw-r--r-- | third_party/abseil_cpp/absl/strings/internal/str_format/extension.h | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/strings/internal/str_format/extension.h b/third_party/abseil_cpp/absl/strings/internal/str_format/extension.h new file mode 100644 index 000000000000..6c60c6c3a379 --- /dev/null +++ b/third_party/abseil_cpp/absl/strings/internal/str_format/extension.h @@ -0,0 +1,429 @@ +// +// Copyright 2017 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. +// +#ifndef ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_ +#define ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_ + +#include <limits.h> + +#include <cstddef> +#include <cstring> +#include <ostream> + +#include "absl/base/config.h" +#include "absl/base/port.h" +#include "absl/meta/type_traits.h" +#include "absl/strings/internal/str_format/output.h" +#include "absl/strings/string_view.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN + +namespace str_format_internal { + +enum class FormatConversionChar : uint8_t; +enum class FormatConversionCharSet : uint64_t; + +class FormatRawSinkImpl { + public: + // Implicitly convert from any type that provides the hook function as + // described above. + template <typename T, decltype(str_format_internal::InvokeFlush( + std::declval<T*>(), string_view()))* = nullptr> + FormatRawSinkImpl(T* raw) // NOLINT + : sink_(raw), write_(&FormatRawSinkImpl::Flush<T>) {} + + void Write(string_view s) { write_(sink_, s); } + + template <typename T> + static FormatRawSinkImpl Extract(T s) { + return s.sink_; + } + + private: + template <typename T> + static void Flush(void* r, string_view s) { + str_format_internal::InvokeFlush(static_cast<T*>(r), s); + } + + void* sink_; + void (*write_)(void*, string_view); +}; + +// An abstraction to which conversions write their string data. +class FormatSinkImpl { + public: + explicit FormatSinkImpl(FormatRawSinkImpl raw) : raw_(raw) {} + + ~FormatSinkImpl() { Flush(); } + + void Flush() { + raw_.Write(string_view(buf_, pos_ - buf_)); + pos_ = buf_; + } + + void Append(size_t n, char c) { + if (n == 0) return; + size_ += n; + auto raw_append = [&](size_t count) { + memset(pos_, c, count); + pos_ += count; + }; + while (n > Avail()) { + n -= Avail(); + if (Avail() > 0) { + raw_append(Avail()); + } + Flush(); + } + raw_append(n); + } + + void Append(string_view v) { + size_t n = v.size(); + if (n == 0) return; + size_ += n; + if (n >= Avail()) { + Flush(); + raw_.Write(v); + return; + } + memcpy(pos_, v.data(), n); + pos_ += n; + } + + size_t size() const { return size_; } + + // Put 'v' to 'sink' with specified width, precision, and left flag. + bool PutPaddedString(string_view v, int width, int precision, bool left); + + template <typename T> + T Wrap() { + return T(this); + } + + template <typename T> + static FormatSinkImpl* Extract(T* s) { + return s->sink_; + } + + private: + size_t Avail() const { return buf_ + sizeof(buf_) - pos_; } + + FormatRawSinkImpl raw_; + size_t size_ = 0; + char* pos_ = buf_; + char buf_[1024]; +}; + +struct Flags { + bool basic : 1; // fastest conversion: no flags, width, or precision + bool left : 1; // "-" + bool show_pos : 1; // "+" + bool sign_col : 1; // " " + bool alt : 1; // "#" + bool zero : 1; // "0" + std::string ToString() const; + friend std::ostream& operator<<(std::ostream& os, const Flags& v) { + return os << v.ToString(); + } +}; + +// clang-format off +#define ABSL_INTERNAL_CONVERSION_CHARS_EXPAND_(X_VAL, X_SEP) \ + /* text */ \ + X_VAL(c) X_SEP X_VAL(s) X_SEP \ + /* ints */ \ + X_VAL(d) X_SEP X_VAL(i) X_SEP X_VAL(o) X_SEP \ + X_VAL(u) X_SEP X_VAL(x) X_SEP X_VAL(X) X_SEP \ + /* floats */ \ + X_VAL(f) X_SEP X_VAL(F) X_SEP X_VAL(e) X_SEP X_VAL(E) X_SEP \ + X_VAL(g) X_SEP X_VAL(G) X_SEP X_VAL(a) X_SEP X_VAL(A) X_SEP \ + /* misc */ \ + X_VAL(n) X_SEP X_VAL(p) +// clang-format on + +// This type should not be referenced, it exists only to provide labels +// internally that match the values declared in FormatConversionChar in +// str_format.h. This is meant to allow internal libraries to use the same +// declared interface type as the public interface +// (absl::StrFormatConversionChar) while keeping the definition in a public +// header. +// Internal libraries should use the form +// `FormatConversionCharInternal::c`, `FormatConversionCharInternal::kNone` for +// comparisons. Use in switch statements is not recommended due to a bug in how +// gcc 4.9 -Wswitch handles declared but undefined enums. +struct FormatConversionCharInternal { + FormatConversionCharInternal() = delete; + + private: + // clang-format off + enum class Enum : uint8_t { + c, s, // text + d, i, o, u, x, X, // int + f, F, e, E, g, G, a, A, // float + n, p, // misc + kNone + }; + // clang-format on + public: +#define ABSL_INTERNAL_X_VAL(id) \ + static constexpr FormatConversionChar id = \ + static_cast<FormatConversionChar>(Enum::id); + ABSL_INTERNAL_CONVERSION_CHARS_EXPAND_(ABSL_INTERNAL_X_VAL, ) +#undef ABSL_INTERNAL_X_VAL + static constexpr FormatConversionChar kNone = + static_cast<FormatConversionChar>(Enum::kNone); +}; +// clang-format on + +inline FormatConversionChar FormatConversionCharFromChar(char c) { + switch (c) { +#define ABSL_INTERNAL_X_VAL(id) \ + case #id[0]: \ + return FormatConversionCharInternal::id; + ABSL_INTERNAL_CONVERSION_CHARS_EXPAND_(ABSL_INTERNAL_X_VAL, ) +#undef ABSL_INTERNAL_X_VAL + } + return FormatConversionCharInternal::kNone; +} + +inline bool FormatConversionCharIsUpper(FormatConversionChar c) { + if (c == FormatConversionCharInternal::X || + c == FormatConversionCharInternal::F || + c == FormatConversionCharInternal::E || + c == FormatConversionCharInternal::G || + c == FormatConversionCharInternal::A) { + return true; + } else { + return false; + } +} + +inline bool FormatConversionCharIsFloat(FormatConversionChar c) { + if (c == FormatConversionCharInternal::a || + c == FormatConversionCharInternal::e || + c == FormatConversionCharInternal::f || + c == FormatConversionCharInternal::g || + c == FormatConversionCharInternal::A || + c == FormatConversionCharInternal::E || + c == FormatConversionCharInternal::F || + c == FormatConversionCharInternal::G) { + return true; + } else { + return false; + } +} + +inline char FormatConversionCharToChar(FormatConversionChar c) { + if (c == FormatConversionCharInternal::kNone) { + return '\0'; + +#define ABSL_INTERNAL_X_VAL(e) \ + } else if (c == FormatConversionCharInternal::e) { \ + return #e[0]; +#define ABSL_INTERNAL_X_SEP + ABSL_INTERNAL_CONVERSION_CHARS_EXPAND_(ABSL_INTERNAL_X_VAL, + ABSL_INTERNAL_X_SEP) + } else { + return '\0'; + } + +#undef ABSL_INTERNAL_X_VAL +#undef ABSL_INTERNAL_X_SEP +} + +// The associated char. +inline std::ostream& operator<<(std::ostream& os, FormatConversionChar v) { + char c = FormatConversionCharToChar(v); + if (!c) c = '?'; + return os << c; +} + +struct FormatConversionSpecImplFriend; + +class FormatConversionSpecImpl { + public: + // Width and precison are not specified, no flags are set. + bool is_basic() const { return flags_.basic; } + bool has_left_flag() const { return flags_.left; } + bool has_show_pos_flag() const { return flags_.show_pos; } + bool has_sign_col_flag() const { return flags_.sign_col; } + bool has_alt_flag() const { return flags_.alt; } + bool has_zero_flag() const { return flags_.zero; } + + FormatConversionChar conversion_char() const { + // Keep this field first in the struct . It generates better code when + // accessing it when ConversionSpec is passed by value in registers. + static_assert(offsetof(FormatConversionSpecImpl, conv_) == 0, ""); + return conv_; + } + + // Returns the specified width. If width is unspecfied, it returns a negative + // value. + int width() const { return width_; } + // Returns the specified precision. If precision is unspecfied, it returns a + // negative value. + int precision() const { return precision_; } + + template <typename T> + T Wrap() { + return T(*this); + } + + private: + friend struct str_format_internal::FormatConversionSpecImplFriend; + FormatConversionChar conv_ = FormatConversionCharInternal::kNone; + Flags flags_; + int width_; + int precision_; +}; + +struct FormatConversionSpecImplFriend final { + static void SetFlags(Flags f, FormatConversionSpecImpl* conv) { + conv->flags_ = f; + } + static void SetConversionChar(FormatConversionChar c, + FormatConversionSpecImpl* conv) { + conv->conv_ = c; + } + static void SetWidth(int w, FormatConversionSpecImpl* conv) { + conv->width_ = w; + } + static void SetPrecision(int p, FormatConversionSpecImpl* conv) { + conv->precision_ = p; + } + static std::string FlagsToString(const FormatConversionSpecImpl& spec) { + return spec.flags_.ToString(); + } +}; + +// Type safe OR operator. +// We need this for two reasons: +// 1. operator| on enums makes them decay to integers and the result is an +// integer. We need the result to stay as an enum. +// 2. We use "enum class" which would not work even if we accepted the decay. +constexpr FormatConversionCharSet FormatConversionCharSetUnion( + FormatConversionCharSet a) { + return a; +} + +template <typename... CharSet> +constexpr FormatConversionCharSet FormatConversionCharSetUnion( + FormatConversionCharSet a, CharSet... rest) { + return static_cast<FormatConversionCharSet>( + static_cast<uint64_t>(a) | + static_cast<uint64_t>(FormatConversionCharSetUnion(rest...))); +} + +constexpr uint64_t FormatConversionCharToConvInt(FormatConversionChar c) { + return uint64_t{1} << (1 + static_cast<uint8_t>(c)); +} + +constexpr uint64_t FormatConversionCharToConvInt(char conv) { + return +#define ABSL_INTERNAL_CHAR_SET_CASE(c) \ + conv == #c[0] \ + ? FormatConversionCharToConvInt(FormatConversionCharInternal::c) \ + : + ABSL_INTERNAL_CONVERSION_CHARS_EXPAND_(ABSL_INTERNAL_CHAR_SET_CASE, ) +#undef ABSL_INTERNAL_CHAR_SET_CASE + conv == '*' + ? 1 + : 0; +} + +constexpr FormatConversionCharSet FormatConversionCharToConvValue(char conv) { + return static_cast<FormatConversionCharSet>( + FormatConversionCharToConvInt(conv)); +} + +struct FormatConversionCharSetInternal { +#define ABSL_INTERNAL_CHAR_SET_CASE(c) \ + static constexpr FormatConversionCharSet c = \ + FormatConversionCharToConvValue(#c[0]); + ABSL_INTERNAL_CONVERSION_CHARS_EXPAND_(ABSL_INTERNAL_CHAR_SET_CASE, ) +#undef ABSL_INTERNAL_CHAR_SET_CASE + + // Used for width/precision '*' specification. + static constexpr FormatConversionCharSet kStar = + FormatConversionCharToConvValue('*'); + + // Some predefined values (TODO(matthewbr), delete any that are unused). + static constexpr FormatConversionCharSet kIntegral = + FormatConversionCharSetUnion(d, i, u, o, x, X); + static constexpr FormatConversionCharSet kFloating = + FormatConversionCharSetUnion(a, e, f, g, A, E, F, G); + static constexpr FormatConversionCharSet kNumeric = + FormatConversionCharSetUnion(kIntegral, kFloating); + static constexpr FormatConversionCharSet kString = s; + static constexpr FormatConversionCharSet kPointer = p; +}; + +// Type safe OR operator. +// We need this for two reasons: +// 1. operator| on enums makes them decay to integers and the result is an +// integer. We need the result to stay as an enum. +// 2. We use "enum class" which would not work even if we accepted the decay. +constexpr FormatConversionCharSet operator|(FormatConversionCharSet a, + FormatConversionCharSet b) { + return FormatConversionCharSetUnion(a, b); +} + +// Overloaded conversion functions to support absl::ParsedFormat. +// Get a conversion with a single character in it. +constexpr FormatConversionCharSet ToFormatConversionCharSet(char c) { + return static_cast<FormatConversionCharSet>( + FormatConversionCharToConvValue(c)); +} + +// Get a conversion with a single character in it. +constexpr FormatConversionCharSet ToFormatConversionCharSet( + FormatConversionCharSet c) { + return c; +} + +template <typename T> +void ToFormatConversionCharSet(T) = delete; + +// Checks whether `c` exists in `set`. +constexpr bool Contains(FormatConversionCharSet set, char c) { + return (static_cast<uint64_t>(set) & + static_cast<uint64_t>(FormatConversionCharToConvValue(c))) != 0; +} + +// Checks whether all the characters in `c` are contained in `set` +constexpr bool Contains(FormatConversionCharSet set, + FormatConversionCharSet c) { + return (static_cast<uint64_t>(set) & static_cast<uint64_t>(c)) == + static_cast<uint64_t>(c); +} + +// Checks whether all the characters in `c` are contained in `set` +constexpr bool Contains(FormatConversionCharSet set, FormatConversionChar c) { + return (static_cast<uint64_t>(set) & FormatConversionCharToConvInt(c)) != 0; +} + +// Return capacity - used, clipped to a minimum of 0. +inline size_t Excess(size_t used, size_t capacity) { + return used < capacity ? capacity - used : 0; +} + +} // namespace str_format_internal + +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_STRINGS_INTERNAL_STR_FORMAT_EXTENSION_H_ |