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//===- Format.h - Efficient printf-style formatting for streams -*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file implements the format() function, which can be used with other

// LLVM subsystems to provide printf-style formatting.  This gives all the power

// and risk of printf.  This can be used like this (with raw_ostreams as an

// example):

//

//    OS << "mynumber: " << format("%4.5f", 1234.412) << '\n';

//

// Or if you prefer:

//

//  OS << format("mynumber: %4.5f\n", 1234.412);

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_FORMAT_H

#define LLVM_SUPPORT_FORMAT_H

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/DataTypes.h"

#include <cassert>

#include <cstdio>

#include <tuple>

#include <utility>

namespace llvm {

/// This is a helper class used for handling formatted output.  It is the

/// abstract base class of a templated derived class.

class format_object_base {

protected:

  const char *Fmt;

  ~format_object_base() = default; // Disallow polymorphic deletion.

  format_object_base(const format_object_base &) = default;

  virtual void home(); // Out of line virtual method.

  /// Call snprintf() for this object, on the given buffer and size.

  virtual int snprint(char *Buffer, unsigned BufferSize) const = 0;

public:

  format_object_base(const char *fmt) : Fmt(fmt) {}

  /// Format the object into the specified buffer.  On success, this returns

  /// the length of the formatted string.  If the buffer is too small, this

  /// returns a length to retry with, which will be larger than BufferSize.

  unsigned print(char *Buffer, unsigned BufferSize) const {

    assert(BufferSize && "Invalid buffer size!");

    // Print the string, leaving room for the terminating null.

    int N = snprint(Buffer, BufferSize);

    // VC++ and old GlibC return negative on overflow, just double the size.

    if (N < 0)

      return BufferSize * 2;

    // Other implementations yield number of bytes needed, not including the

    // final '\0'.

    if (unsigned(N) >= BufferSize)

      return N + 1;

    // Otherwise N is the length of output (not including the final '\0').

    return N;

  }

};

/// These are templated helper classes used by the format function that

/// capture the object to be formatted and the format string. When actually

/// printed, this synthesizes the string into a temporary buffer provided and

/// returns whether or not it is big enough.

// Helper to validate that format() parameters are scalars or pointers.

template <typename... Args> struct validate_format_parameters;

template <typename Arg, typename... Args>

struct validate_format_parameters<Arg, Args...> {

  static_assert(std::is_scalar_v<Arg>,

                "format can't be used with non fundamental / non pointer type");

  validate_format_parameters() { validate_format_parameters<Args...>(); }

};

template <> struct validate_format_parameters<> {};

template <typename... Ts>

class format_object final : public format_object_base {

  std::tuple<Ts...> Vals;

  template <std::size_t... Is>

  int snprint_tuple(char *Buffer, unsigned BufferSize,

                    std::index_sequence<Is...>) const {

#ifdef _MSC_VER

    return _snprintf(Buffer, BufferSize, Fmt, std::get<Is>(Vals)...);

#else

    return snprintf(Buffer, BufferSize, Fmt, std::get<Is>(Vals)...);

#endif

  }

public:

  format_object(const char *fmt, const Ts &... vals)

      : format_object_base(fmt), Vals(vals...) {

    validate_format_parameters<Ts...>();

  }

  int snprint(char *Buffer, unsigned BufferSize) const override {

    return snprint_tuple(Buffer, BufferSize, std::index_sequence_for<Ts...>());

  }

};

/// These are helper functions used to produce formatted output.  They use

/// template type deduction to construct the appropriate instance of the

/// format_object class to simplify their construction.

///

/// This is typically used like:

/// \code

///   OS << format("%0.4f", myfloat) << '\n';

/// \endcode

template <typename... Ts>

inline format_object<Ts...> format(const char *Fmt, const Ts &... Vals) {

  return format_object<Ts...>(Fmt, Vals...);

}

/// This is a helper class for left_justify, right_justify, and center_justify.

class FormattedString {

public:

  enum Justification { JustifyNone, JustifyLeft, JustifyRight, JustifyCenter };

  FormattedString(StringRef S, unsigned W, Justification J)

      : Str(S), Width(W), Justify(J) {}

private:

  StringRef Str;

  unsigned Width;

  Justification Justify;

  friend class raw_ostream;

};

/// left_justify - append spaces after string so total output is

/// \p Width characters.  If \p Str is larger that \p Width, full string

/// is written with no padding.

inline FormattedString left_justify(StringRef Str, unsigned Width) {

  return FormattedString(Str, Width, FormattedString::JustifyLeft);

}

/// right_justify - add spaces before string so total output is

/// \p Width characters.  If \p Str is larger that \p Width, full string

/// is written with no padding.

inline FormattedString right_justify(StringRef Str, unsigned Width) {

  return FormattedString(Str, Width, FormattedString::JustifyRight);

}

/// center_justify - add spaces before and after string so total output is

/// \p Width characters.  If \p Str is larger that \p Width, full string

/// is written with no padding.

inline FormattedString center_justify(StringRef Str, unsigned Width) {

  return FormattedString(Str, Width, FormattedString::JustifyCenter);

}

/// This is a helper class used for format_hex() and format_decimal().

class FormattedNumber {

  uint64_t HexValue;

  int64_t DecValue;

  unsigned Width;

  bool Hex;

  bool Upper;

  bool HexPrefix;

  friend class raw_ostream;

public:

  FormattedNumber(uint64_t HV, int64_t DV, unsigned W, bool H, bool U,

                  bool Prefix)

      : HexValue(HV), DecValue(DV), Width(W), Hex(H), Upper(U),

        HexPrefix(Prefix) {}

};

/// format_hex - Output \p N as a fixed width hexadecimal. If number will not

/// fit in width, full number is still printed.  Examples:

///   OS << format_hex(255, 4)              => 0xff

///   OS << format_hex(255, 4, true)        => 0xFF

///   OS << format_hex(255, 6)              => 0x00ff

///   OS << format_hex(255, 2)              => 0xff

inline FormattedNumber format_hex(uint64_t N, unsigned Width,

                                  bool Upper = false) {

  assert(Width <= 18 && "hex width must be <= 18");

  return FormattedNumber(N, 0, Width, true, Upper, true);

}

/// format_hex_no_prefix - Output \p N as a fixed width hexadecimal. Does not

/// prepend '0x' to the outputted string.  If number will not fit in width,

/// full number is still printed.  Examples:

///   OS << format_hex_no_prefix(255, 2)              => ff

///   OS << format_hex_no_prefix(255, 2, true)        => FF

///   OS << format_hex_no_prefix(255, 4)              => 00ff

///   OS << format_hex_no_prefix(255, 1)              => ff

inline FormattedNumber format_hex_no_prefix(uint64_t N, unsigned Width,

                                            bool Upper = false) {

  assert(Width <= 16 && "hex width must be <= 16");

  return FormattedNumber(N, 0, Width, true, Upper, false);

}

/// format_decimal - Output \p N as a right justified, fixed-width decimal. If

/// number will not fit in width, full number is still printed.  Examples:

///   OS << format_decimal(0, 5)     => "    0"

///   OS << format_decimal(255, 5)   => "  255"

///   OS << format_decimal(-1, 3)    => " -1"

///   OS << format_decimal(12345, 3) => "12345"

inline FormattedNumber format_decimal(int64_t N, unsigned Width) {

  return FormattedNumber(0, N, Width, false, false, false);

}

class FormattedBytes {

  ArrayRef<uint8_t> Bytes;

  // If not None, display offsets for each line relative to starting value.

  std::optional<uint64_t> FirstByteOffset;

  uint32_t IndentLevel;  // Number of characters to indent each line.

  uint32_t NumPerLine;   // Number of bytes to show per line.

  uint8_t ByteGroupSize; // How many hex bytes are grouped without spaces

  bool Upper;            // Show offset and hex bytes as upper case.

  bool ASCII;            // Show the ASCII bytes for the hex bytes to the right.

  friend class raw_ostream;

public:

  FormattedBytes(ArrayRef<uint8_t> B, uint32_t IL, std::optional<uint64_t> O,

                 uint32_t NPL, uint8_t BGS, bool U, bool A)

      : Bytes(B), FirstByteOffset(O), IndentLevel(IL), NumPerLine(NPL),

        ByteGroupSize(BGS), Upper(U), ASCII(A) {

    if (ByteGroupSize > NumPerLine)

      ByteGroupSize = NumPerLine;

  }

};

inline FormattedBytes

format_bytes(ArrayRef<uint8_t> Bytes,

             std::optional<uint64_t> FirstByteOffset = std::nullopt,

             uint32_t NumPerLine = 16, uint8_t ByteGroupSize = 4,

             uint32_t IndentLevel = 0, bool Upper = false) {

  return FormattedBytes(Bytes, IndentLevel, FirstByteOffset, NumPerLine,

                        ByteGroupSize, Upper, false);

}

inline FormattedBytes

format_bytes_with_ascii(ArrayRef<uint8_t> Bytes,

                        std::optional<uint64_t> FirstByteOffset = std::nullopt,

                        uint32_t NumPerLine = 16, uint8_t ByteGroupSize = 4,

                        uint32_t IndentLevel = 0, bool Upper = false) {

  return FormattedBytes(Bytes, IndentLevel, FirstByteOffset, NumPerLine,

                        ByteGroupSize, Upper, true);

}

} // end namespace llvm

#endif