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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/internal/str_format/arg.cc')
| -rw-r--r-- | third_party/abseil_cpp/absl/strings/internal/str_format/arg.cc | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/strings/internal/str_format/arg.cc b/third_party/abseil_cpp/absl/strings/internal/str_format/arg.cc new file mode 100644 index 0000000000..9feb224879 --- /dev/null +++ b/third_party/abseil_cpp/absl/strings/internal/str_format/arg.cc @@ -0,0 +1,474 @@ +// +// POSIX spec: +// http://pubs.opengroup.org/onlinepubs/009695399/functions/fprintf.html +// +#include "absl/strings/internal/str_format/arg.h" + +#include <cassert> +#include <cerrno> +#include <cstdlib> +#include <string> +#include <type_traits> + +#include "absl/base/port.h" +#include "absl/strings/internal/str_format/float_conversion.h" +#include "absl/strings/numbers.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace str_format_internal { +namespace { + +// Reduce *capacity by s.size(), clipped to a 0 minimum. +void ReducePadding(string_view s, size_t *capacity) { + *capacity = Excess(s.size(), *capacity); +} + +// Reduce *capacity by n, clipped to a 0 minimum. +void ReducePadding(size_t n, size_t *capacity) { + *capacity = Excess(n, *capacity); +} + +template <typename T> +struct MakeUnsigned : std::make_unsigned<T> {}; +template <> +struct MakeUnsigned<absl::int128> { + using type = absl::uint128; +}; +template <> +struct MakeUnsigned<absl::uint128> { + using type = absl::uint128; +}; + +template <typename T> +struct IsSigned : std::is_signed<T> {}; +template <> +struct IsSigned<absl::int128> : std::true_type {}; +template <> +struct IsSigned<absl::uint128> : std::false_type {}; + +// Integral digit printer. +// Call one of the PrintAs* routines after construction once. +// Use with_neg_and_zero/without_neg_or_zero/is_negative to access the results. +class IntDigits { + public: + // Print the unsigned integer as octal. + // Supports unsigned integral types and uint128. + template <typename T> + void PrintAsOct(T v) { + static_assert(!IsSigned<T>::value, ""); + char *p = storage_ + sizeof(storage_); + do { + *--p = static_cast<char>('0' + (static_cast<size_t>(v) & 7)); + v >>= 3; + } while (v); + start_ = p; + size_ = storage_ + sizeof(storage_) - p; + } + + // Print the signed or unsigned integer as decimal. + // Supports all integral types. + template <typename T> + void PrintAsDec(T v) { + static_assert(std::is_integral<T>::value, ""); + start_ = storage_; + size_ = numbers_internal::FastIntToBuffer(v, storage_) - storage_; + } + + void PrintAsDec(int128 v) { + auto u = static_cast<uint128>(v); + bool add_neg = false; + if (v < 0) { + add_neg = true; + u = uint128{} - u; + } + PrintAsDec(u, add_neg); + } + + void PrintAsDec(uint128 v, bool add_neg = false) { + // This function can be sped up if needed. We can call FastIntToBuffer + // twice, or fix FastIntToBuffer to support uint128. + char *p = storage_ + sizeof(storage_); + do { + p -= 2; + numbers_internal::PutTwoDigits(static_cast<size_t>(v % 100), p); + v /= 100; + } while (v); + if (p[0] == '0') { + // We printed one too many hexits. + ++p; + } + if (add_neg) { + *--p = '-'; + } + size_ = storage_ + sizeof(storage_) - p; + start_ = p; + } + + // Print the unsigned integer as hex using lowercase. + // Supports unsigned integral types and uint128. + template <typename T> + void PrintAsHexLower(T v) { + static_assert(!IsSigned<T>::value, ""); + char *p = storage_ + sizeof(storage_); + + do { + p -= 2; + constexpr const char* table = numbers_internal::kHexTable; + std::memcpy(p, table + 2 * (static_cast<size_t>(v) & 0xFF), 2); + if (sizeof(T) == 1) break; + v >>= 8; + } while (v); + if (p[0] == '0') { + // We printed one too many digits. + ++p; + } + start_ = p; + size_ = storage_ + sizeof(storage_) - p; + } + + // Print the unsigned integer as hex using uppercase. + // Supports unsigned integral types and uint128. + template <typename T> + void PrintAsHexUpper(T v) { + static_assert(!IsSigned<T>::value, ""); + char *p = storage_ + sizeof(storage_); + + // kHexTable is only lowercase, so do it manually for uppercase. + do { + *--p = "0123456789ABCDEF"[static_cast<size_t>(v) & 15]; + v >>= 4; + } while (v); + start_ = p; + size_ = storage_ + sizeof(storage_) - p; + } + + // The printed value including the '-' sign if available. + // For inputs of value `0`, this will return "0" + string_view with_neg_and_zero() const { return {start_, size_}; } + + // The printed value not including the '-' sign. + // For inputs of value `0`, this will return "". + string_view without_neg_or_zero() const { + static_assert('-' < '0', "The check below verifies both."); + size_t advance = start_[0] <= '0' ? 1 : 0; + return {start_ + advance, size_ - advance}; + } + + bool is_negative() const { return start_[0] == '-'; } + + private: + const char *start_; + size_t size_; + // Max size: 128 bit value as octal -> 43 digits, plus sign char + char storage_[128 / 3 + 1 + 1]; +}; + +// Note: 'o' conversions do not have a base indicator, it's just that +// the '#' flag is specified to modify the precision for 'o' conversions. +string_view BaseIndicator(const IntDigits &as_digits, + const FormatConversionSpecImpl conv) { + // always show 0x for %p. + bool alt = conv.has_alt_flag() || + conv.conversion_char() == FormatConversionCharInternal::p; + bool hex = (conv.conversion_char() == FormatConversionCharInternal::x || + conv.conversion_char() == FormatConversionCharInternal::X || + conv.conversion_char() == FormatConversionCharInternal::p); + // From the POSIX description of '#' flag: + // "For x or X conversion specifiers, a non-zero result shall have + // 0x (or 0X) prefixed to it." + if (alt && hex && !as_digits.without_neg_or_zero().empty()) { + return conv.conversion_char() == FormatConversionCharInternal::X ? "0X" + : "0x"; + } + return {}; +} + +string_view SignColumn(bool neg, const FormatConversionSpecImpl conv) { + if (conv.conversion_char() == FormatConversionCharInternal::d || + conv.conversion_char() == FormatConversionCharInternal::i) { + if (neg) return "-"; + if (conv.has_show_pos_flag()) return "+"; + if (conv.has_sign_col_flag()) return " "; + } + return {}; +} + +bool ConvertCharImpl(unsigned char v, const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + size_t fill = 0; + if (conv.width() >= 0) fill = conv.width(); + ReducePadding(1, &fill); + if (!conv.has_left_flag()) sink->Append(fill, ' '); + sink->Append(1, v); + if (conv.has_left_flag()) sink->Append(fill, ' '); + return true; +} + +bool ConvertIntImplInnerSlow(const IntDigits &as_digits, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + // Print as a sequence of Substrings: + // [left_spaces][sign][base_indicator][zeroes][formatted][right_spaces] + size_t fill = 0; + if (conv.width() >= 0) fill = conv.width(); + + string_view formatted = as_digits.without_neg_or_zero(); + ReducePadding(formatted, &fill); + + string_view sign = SignColumn(as_digits.is_negative(), conv); + ReducePadding(sign, &fill); + + string_view base_indicator = BaseIndicator(as_digits, conv); + ReducePadding(base_indicator, &fill); + + int precision = conv.precision(); + bool precision_specified = precision >= 0; + if (!precision_specified) + precision = 1; + + if (conv.has_alt_flag() && + conv.conversion_char() == FormatConversionCharInternal::o) { + // From POSIX description of the '#' (alt) flag: + // "For o conversion, it increases the precision (if necessary) to + // force the first digit of the result to be zero." + if (formatted.empty() || *formatted.begin() != '0') { + int needed = static_cast<int>(formatted.size()) + 1; + precision = std::max(precision, needed); + } + } + + size_t num_zeroes = Excess(formatted.size(), precision); + ReducePadding(num_zeroes, &fill); + + size_t num_left_spaces = !conv.has_left_flag() ? fill : 0; + size_t num_right_spaces = conv.has_left_flag() ? fill : 0; + + // From POSIX description of the '0' (zero) flag: + // "For d, i, o, u, x, and X conversion specifiers, if a precision + // is specified, the '0' flag is ignored." + if (!precision_specified && conv.has_zero_flag()) { + num_zeroes += num_left_spaces; + num_left_spaces = 0; + } + + sink->Append(num_left_spaces, ' '); + sink->Append(sign); + sink->Append(base_indicator); + sink->Append(num_zeroes, '0'); + sink->Append(formatted); + sink->Append(num_right_spaces, ' '); + return true; +} + +template <typename T> +bool ConvertIntArg(T v, const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + using U = typename MakeUnsigned<T>::type; + IntDigits as_digits; + + // This odd casting is due to a bug in -Wswitch behavior in gcc49 which causes + // it to complain about a switch/case type mismatch, even though both are + // FormatConverionChar. Likely this is because at this point + // FormatConversionChar is declared, but not defined. + switch (static_cast<uint8_t>(conv.conversion_char())) { + case static_cast<uint8_t>(FormatConversionCharInternal::c): + return ConvertCharImpl(static_cast<unsigned char>(v), conv, sink); + + case static_cast<uint8_t>(FormatConversionCharInternal::o): + as_digits.PrintAsOct(static_cast<U>(v)); + break; + + case static_cast<uint8_t>(FormatConversionCharInternal::x): + as_digits.PrintAsHexLower(static_cast<U>(v)); + break; + case static_cast<uint8_t>(FormatConversionCharInternal::X): + as_digits.PrintAsHexUpper(static_cast<U>(v)); + break; + + case static_cast<uint8_t>(FormatConversionCharInternal::u): + as_digits.PrintAsDec(static_cast<U>(v)); + break; + + case static_cast<uint8_t>(FormatConversionCharInternal::d): + case static_cast<uint8_t>(FormatConversionCharInternal::i): + as_digits.PrintAsDec(v); + break; + + case static_cast<uint8_t>(FormatConversionCharInternal::a): + case static_cast<uint8_t>(FormatConversionCharInternal::e): + case static_cast<uint8_t>(FormatConversionCharInternal::f): + case static_cast<uint8_t>(FormatConversionCharInternal::g): + case static_cast<uint8_t>(FormatConversionCharInternal::A): + case static_cast<uint8_t>(FormatConversionCharInternal::E): + case static_cast<uint8_t>(FormatConversionCharInternal::F): + case static_cast<uint8_t>(FormatConversionCharInternal::G): + return ConvertFloatImpl(static_cast<double>(v), conv, sink); + + default: + ABSL_INTERNAL_ASSUME(false); + } + + if (conv.is_basic()) { + sink->Append(as_digits.with_neg_and_zero()); + return true; + } + return ConvertIntImplInnerSlow(as_digits, conv, sink); +} + +template <typename T> +bool ConvertFloatArg(T v, const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return FormatConversionCharIsFloat(conv.conversion_char()) && + ConvertFloatImpl(v, conv, sink); +} + +inline bool ConvertStringArg(string_view v, const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + if (conv.is_basic()) { + sink->Append(v); + return true; + } + return sink->PutPaddedString(v, conv.width(), conv.precision(), + conv.has_left_flag()); +} + +} // namespace + +// ==================== Strings ==================== +StringConvertResult FormatConvertImpl(const std::string &v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertStringArg(v, conv, sink)}; +} + +StringConvertResult FormatConvertImpl(string_view v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertStringArg(v, conv, sink)}; +} + +ArgConvertResult<FormatConversionCharSetUnion( + FormatConversionCharSetInternal::s, FormatConversionCharSetInternal::p)> +FormatConvertImpl(const char *v, const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + if (conv.conversion_char() == FormatConversionCharInternal::p) + return {FormatConvertImpl(VoidPtr(v), conv, sink).value}; + size_t len; + if (v == nullptr) { + len = 0; + } else if (conv.precision() < 0) { + len = std::strlen(v); + } else { + // If precision is set, we look for the NUL-terminator on the valid range. + len = std::find(v, v + conv.precision(), '\0') - v; + } + return {ConvertStringArg(string_view(v, len), conv, sink)}; +} + +// ==================== Raw pointers ==================== +ArgConvertResult<FormatConversionCharSetInternal::p> FormatConvertImpl( + VoidPtr v, const FormatConversionSpecImpl conv, FormatSinkImpl *sink) { + if (!v.value) { + sink->Append("(nil)"); + return {true}; + } + IntDigits as_digits; + as_digits.PrintAsHexLower(v.value); + return {ConvertIntImplInnerSlow(as_digits, conv, sink)}; +} + +// ==================== Floats ==================== +FloatingConvertResult FormatConvertImpl(float v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertFloatArg(v, conv, sink)}; +} +FloatingConvertResult FormatConvertImpl(double v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertFloatArg(v, conv, sink)}; +} +FloatingConvertResult FormatConvertImpl(long double v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertFloatArg(v, conv, sink)}; +} + +// ==================== Chars ==================== +IntegralConvertResult FormatConvertImpl(char v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(signed char v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(unsigned char v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} + +// ==================== Ints ==================== +IntegralConvertResult FormatConvertImpl(short v, // NOLINT + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(unsigned short v, // NOLINT + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(int v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(unsigned v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(long v, // NOLINT + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(unsigned long v, // NOLINT + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(long long v, // NOLINT + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(unsigned long long v, // NOLINT + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(absl::int128 v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} +IntegralConvertResult FormatConvertImpl(absl::uint128 v, + const FormatConversionSpecImpl conv, + FormatSinkImpl *sink) { + return {ConvertIntArg(v, conv, sink)}; +} + +ABSL_INTERNAL_FORMAT_DISPATCH_OVERLOADS_EXPAND_(); + + + +} // namespace str_format_internal + +ABSL_NAMESPACE_END +} // namespace absl |