Stream.h

Go to the documentation of this file.

//===-- Stream.h ------------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
 
#ifndef LLDB_UTILITY_STREAM_H
#define LLDB_UTILITY_STREAM_H
 
#include "lldb/Utility/Flags.h"
#include "lldb/lldb-defines.h"
#include "lldb/lldb-enumerations.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/raw_ostream.h"
 
#include <cstdarg>
#include <cstddef>
#include <cstdint>
#include <type_traits>
 
namespace lldb_private {
 
/// \class Stream Stream.h "lldb/Utility/Stream.h"
/// A stream class that can stream formatted output to a file.
class Stream {
public:
  /// \a m_flags bit values.
  enum {
    eBinary = (1 << 0) ///< Get and put data as binary instead of as the default
                       /// string mode.
  };
 
  /// Struct to store information for color highlighting in the stream.
  struct HighlightSettings {
    llvm::StringRef pattern; ///< Regex pattern for highlighting.
    llvm::StringRef prefix;  ///< ANSI color code to start colorization.
    llvm::StringRef suffix;  ///< ANSI color code to end colorization.
 
    HighlightSettings(llvm::StringRef p, llvm::StringRef pre,
                      llvm::StringRef suf)
        : pattern(p), prefix(pre), suffix(suf) {}
  };
 
  /// Utility class for counting the bytes that were written to a stream in a
  /// certain time span.
  ///
  /// \example
  ///   ByteDelta delta(*this);
  ///   WriteDataToStream("foo");
  ///   return *delta;
  class ByteDelta {
    Stream *m_stream;
    /// Bytes we have written so far when ByteDelta was created.
    size_t m_start;
 
  public:
    ByteDelta(Stream &s) : m_stream(&s), m_start(s.GetWrittenBytes()) {}
    /// Returns the number of bytes written to the given Stream since this
    /// ByteDelta object was created.
    size_t operator*() const { return m_stream->GetWrittenBytes() - m_start; }
  };
 
  /// Construct with flags and address size and byte order.
  ///
  /// Construct with dump flags \a flags.
  /// \a flags can be any of the above enumeration logical OR'ed together.
  Stream(uint32_t flags, lldb::ByteOrder byte_order, bool colors = false);
 
  /// Construct a default Stream, not binary, host byte order and host addr
  /// size.
  ///
  Stream(bool colors = false);
 
  // FIXME: Streams should not be copyable.
  Stream(const Stream &other) : m_forwarder(*this) { (*this) = other; }
 
  Stream &operator=(const Stream &rhs) {
    m_flags = rhs.m_flags;
    m_byte_order = rhs.m_byte_order;
    m_indent_level = rhs.m_indent_level;
    return *this;
  }
 
  /// Destructor
  virtual ~Stream();
 
  // Subclasses must override these methods
 
  /// Flush the stream.
  ///
  /// Subclasses should flush the stream to make any output appear if the
  /// stream has any buffering.
  virtual void Flush() = 0;
 
  /// Output character bytes to the stream.
  ///
  /// Appends \a src_len characters from the buffer \a src to the stream.
  ///
  /// \param[in] src
  ///     A buffer containing at least \a src_len bytes of data.
  ///
  /// \param[in] src_len
  ///     A number of bytes to append to the stream.
  ///
  /// \return
  ///     The number of bytes that were appended to the stream.
  size_t Write(const void *src, size_t src_len) {
    size_t appended_byte_count = WriteImpl(src, src_len);
    m_bytes_written += appended_byte_count;
    return appended_byte_count;
  }
 
  size_t GetWrittenBytes() const { return m_bytes_written; }
 
  // Member functions
  size_t PutChar(char ch);
 
  /// Set the byte_order value.
  ///
  /// Sets the byte order of the data to extract. Extracted values will be
  /// swapped if necessary when decoding.
  ///
  /// \param[in] byte_order
  ///     The byte order value to use when extracting data.
  ///
  /// \return
  ///     The old byte order value.
  lldb::ByteOrder SetByteOrder(lldb::ByteOrder byte_order);
 
  /// Format a C string from a printf style format and variable arguments and
  /// encode and append the resulting C string as hex bytes.
  ///
  /// \param[in] format
  ///     A printf style format string.
  ///
  /// \param[in] ...
  ///     Any additional arguments needed for the printf format string.
  ///
  /// \return
  ///     The number of bytes that were appended to the stream.
  size_t PrintfAsRawHex8(const char *format, ...)
      __attribute__((__format__(__printf__, 2, 3)));
 
  /// Append an uint8_t value in the hexadecimal format to the stream.
  ///
  /// \param[in] uvalue
  ///     The value to append.
  ///
  /// \return
  ///     The number of bytes that were appended to the stream.
  size_t PutHex8(uint8_t uvalue);
 
  size_t PutNHex8(size_t n, uint8_t uvalue);
 
  size_t PutHex16(uint16_t uvalue,
                  lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
 
  size_t PutHex32(uint32_t uvalue,
                  lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
 
  size_t PutHex64(uint64_t uvalue,
                  lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
 
  size_t PutMaxHex64(uint64_t uvalue, size_t byte_size,
                     lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
  size_t PutFloat(float f,
                  lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
 
  size_t PutDouble(double d,
                   lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
 
  size_t PutLongDouble(long double ld,
                       lldb::ByteOrder byte_order = lldb::eByteOrderInvalid);
 
  size_t PutPointer(void *ptr);
 
  // Append \a src_len bytes from \a src to the stream as hex characters (two
  // ascii characters per byte of input data)
  size_t
  PutBytesAsRawHex8(const void *src, size_t src_len,
                    lldb::ByteOrder src_byte_order = lldb::eByteOrderInvalid,
                    lldb::ByteOrder dst_byte_order = lldb::eByteOrderInvalid);
 
  // Append \a src_len bytes from \a s to the stream as binary data.
  size_t PutRawBytes(const void *s, size_t src_len,
                     lldb::ByteOrder src_byte_order = lldb::eByteOrderInvalid,
                     lldb::ByteOrder dst_byte_order = lldb::eByteOrderInvalid);
 
  size_t PutStringAsRawHex8(llvm::StringRef s);
 
  /// Output a NULL terminated C string \a cstr to the stream \a s.
  ///
  /// \param[in] cstr
  ///     A NULL terminated C string.
  ///
  /// \return
  ///     A reference to this class so multiple things can be streamed
  ///     in one statement.
  Stream &operator<<(const char *cstr);
 
  Stream &operator<<(llvm::StringRef str);
 
  /// Output a pointer value \a p to the stream \a s.
  ///
  /// \param[in] p
  ///     A void pointer.
  ///
  /// \return
  ///     A reference to this class so multiple things can be streamed
  ///     in one statement.
  Stream &operator<<(const void *p);
 
  /// Output a character \a ch to the stream \a s.
  ///
  /// \param[in] ch
  ///     A printable character value.
  ///
  /// \return
  ///     A reference to this class so multiple things can be streamed
  ///     in one statement.
  Stream &operator<<(char ch);
 
  /// Output the result of a formatv expression to the stream.
  ///
  /// \param[in] obj
  ///     A formatv_object_base produced by llvm::formatv().
  ///
  /// \return
  ///     A reference to this class so multiple things can be streamed
  ///     in one statement.
  Stream &operator<<(const llvm::formatv_object_base &obj);
 
  Stream &operator<<(uint8_t uval) = delete;
  Stream &operator<<(uint16_t uval) = delete;
  Stream &operator<<(uint32_t uval) = delete;
  Stream &operator<<(uint64_t uval) = delete;
  Stream &operator<<(int8_t sval) = delete;
  Stream &operator<<(int16_t sval) = delete;
  Stream &operator<<(int32_t sval) = delete;
  Stream &operator<<(int64_t sval) = delete;
 
  /// Output a C string to the stream.
  ///
  /// Print a C string \a cstr to the stream.
  ///
  /// \param[in] cstr
  ///     The string to be output to the stream.
  size_t PutCString(llvm::StringRef cstr);
 
  /// Output a C string to the stream with color highlighting.
  ///
  /// Print a C string \a text to the stream, applying color highlighting to
  /// the portions of the string that match the regex pattern \a pattern. The
  /// pattern is matched as many times as possible throughout the string. If \a
  /// pattern is nullptr, then no highlighting is applied.
  ///
  /// The highlighting is applied by enclosing the matching text in ANSI color
  /// codes. The \a prefix parameter specifies the ANSI code to start the color
  /// (the standard value is assumed to be 'ansi.fg.red', representing red
  /// foreground), and the \a suffix parameter specifies the ANSI code to end
  /// the color (the standard value is assumed to be 'ansi.normal', resetting to
  /// default text style). These constants should be defined appropriately in
  /// your environment.
  ///
  /// \param[in] text
  ///     The string to be output to the stream.
  ///
  /// \param[in] settings
  ///     Optional print hilight settings.
  void PutCStringColorHighlighted(
      llvm::StringRef text,
      std::optional<HighlightSettings> settings = std::nullopt);
 
  /// Output and End of Line character to the stream.
  size_t EOL();
 
  /// The flags accessor.
  ///
  /// \return
  ///     A reference to the Flags member variable.
  Flags &GetFlags();
 
  /// The flags const accessor.
  ///
  /// \return
  ///     A const reference to the Flags member variable.
  const Flags &GetFlags() const;
 
  //// The byte order accessor.
  ////
  //// \return
  ////     The byte order.
  lldb::ByteOrder GetByteOrder() const;
 
  /// Get the current indentation level.
  ///
  /// \return
  ///     The current indentation level.
  unsigned GetIndentLevel() const;
 
  /// Set the current indentation level.
  ///
  /// \param[in] level
  ///     The new indentation level.
  void SetIndentLevel(unsigned level);
 
  /// Indent the current line in the stream.
  ///
  /// Indent the current line using the current indentation level and print an
  /// optional string following the indentation spaces.
  ///
  /// \param[in] s
  ///     A string to print following the indentation.
  size_t Indent(llvm::StringRef s = "");
 
  /// Decrement the current indentation level.
  void IndentLess(unsigned amount = 2);
 
  /// Increment the current indentation level.
  void IndentMore(unsigned amount = 2);
 
  struct IndentScope {
    IndentScope(Stream &stream)
        : m_stream(stream), m_original_indent_level(stream.GetIndentLevel()) {}
    ~IndentScope() { m_stream.SetIndentLevel(m_original_indent_level); }
 
  private:
    Stream &m_stream;
    unsigned m_original_indent_level;
  };
 
  /// Create an indentation scope that restores the original indent level when
  /// the object goes out of scope (RAII).
  IndentScope MakeIndentScope(unsigned indent_amount = 2);
 
  /// Output an offset value.
  ///
  /// Put an offset \a uval out to the stream using the printf format in \a
  /// format.
  ///
  /// \param[in] offset
  ///     The offset value.
  ///
  /// \param[in] format
  ///     The printf style format to use when outputting the offset.
  void Offset(uint32_t offset, const char *format = "0x%8.8x: ");
 
  /// Output printf formatted output to the stream.
  ///
  /// Print some formatted output to the stream.
  ///
  /// \param[in] format
  ///     A printf style format string.
  ///
  /// \param[in] ...
  ///     Variable arguments that are needed for the printf style
  ///     format string \a format.
  size_t Printf(const char *format, ...) __attribute__((format(printf, 2, 3)));
 
  size_t PrintfVarArg(const char *format, va_list args);
 
  /// Forwards the arguments to llvm::formatv and writes to the stream.
  /// FIXME: instead of this API, consider using llvm::formatv directly.
  template <typename... Args> void Format(const char *format, Args &&... args) {
    *this << llvm::formatv(format, std::forward<Args>(args)...);
  }
 
  /// Output a quoted C string value to the stream.
  ///
  /// Print a double quoted NULL terminated C string to the stream using the
  /// printf format in \a format.
  ///
  /// \param[in] cstr
  ///     A NULL terminated C string value.
  ///
  /// \param[in] format
  ///     The optional C string format that can be overridden.
  void QuotedCString(const char *cstr, const char *format = "\"%s\"");
 
  /// Output a SLEB128 number to the stream.
  ///
  /// Put an SLEB128 \a uval out to the stream using the printf format in \a
  /// format.
  ///
  /// \param[in] uval
  ///     A uint64_t value that was extracted as a SLEB128 value.
  size_t PutSLEB128(int64_t uval);
 
  /// Output a ULEB128 number to the stream.
  ///
  /// Put an ULEB128 \a uval out to the stream using the printf format in \a
  /// format.
  ///
  /// \param[in] uval
  ///     A uint64_t value that was extracted as a ULEB128 value.
  size_t PutULEB128(uint64_t uval);
 
  /// Returns a raw_ostream that forwards the data to this Stream object.
  llvm::raw_ostream &AsRawOstream() {
    return m_forwarder;
  }
 
protected:
  // Member variables
  Flags m_flags; ///< Dump flags.
  lldb::ByteOrder
      m_byte_order;   ///< Byte order to use when encoding scalar types.
  unsigned m_indent_level = 0;     ///< Indention level.
  std::size_t m_bytes_written = 0; ///< Number of bytes written so far.
 
  void _PutHex8(uint8_t uvalue, bool add_prefix);
 
  /// Output character bytes to the stream.
  ///
  /// Appends \a src_len characters from the buffer \a src to the stream.
  ///
  /// \param[in] src
  ///     A buffer containing at least \a src_len bytes of data.
  ///
  /// \param[in] src_len
  ///     A number of bytes to append to the stream.
  ///
  /// \return
  ///     The number of bytes that were appended to the stream.
  virtual size_t WriteImpl(const void *src, size_t src_len) = 0;
 
  /// \class RawOstreamForward Stream.h "lldb/Utility/Stream.h"
  /// This is a wrapper class that exposes a raw_ostream interface that just
  /// forwards to an LLDB stream, allowing to reuse LLVM algorithms that take
  /// a raw_ostream within the LLDB code base.
  class RawOstreamForward : public llvm::raw_ostream {
    // Note: This stream must *not* maintain its own buffer, but instead
    // directly write everything to the internal Stream class. Without this,
    // we would run into the problem that the Stream written byte count would
    // differ from the actually written bytes by the size of the internal
    // raw_ostream buffer.
 
    Stream &m_target;
    void write_impl(const char *Ptr, size_t Size) override {
      m_target.Write(Ptr, Size);
    }
 
    uint64_t current_pos() const override {
      return m_target.GetWrittenBytes();
    }
 
  public:
    RawOstreamForward(Stream &target, bool colors = false)
        : llvm::raw_ostream(/*unbuffered*/ true), m_target(target) {
      enable_colors(colors);
    }
  };
  RawOstreamForward m_forwarder;
};
 
/// Output an address value to this stream.
///
/// Put an address \a addr out to the stream with optional \a prefix and \a
/// suffix strings.
///
/// \param[in] s
///     The output stream.
///
/// \param[in] addr
///     An address value.
///
/// \param[in] addr_size
///     Size in bytes of the address, used for formatting.
///
/// \param[in] prefix
///     A prefix C string. If nullptr, no prefix will be output.
///
/// \param[in] suffix
///     A suffix C string. If nullptr, no suffix will be output.
void DumpAddress(llvm::raw_ostream &s, uint64_t addr, uint32_t addr_size,
                 const char *prefix = nullptr, const char *suffix = nullptr);
 
/// Output an address range to this stream.
///
/// Put an address range \a lo_addr - \a hi_addr out to the stream with
/// optional \a prefix and \a suffix strings.
///
/// \param[in] s
///     The output stream.
///
/// \param[in] lo_addr
///     The start address of the address range.
///
/// \param[in] hi_addr
///     The end address of the address range.
///
/// \param[in] addr_size
///     Size in bytes of the address, used for formatting.
///
/// \param[in] prefix
///     A prefix C string. If nullptr, no prefix will be output.
///
/// \param[in] suffix
///     A suffix C string. If nullptr, no suffix will be output.
void DumpAddressRange(llvm::raw_ostream &s, uint64_t lo_addr, uint64_t hi_addr,
                      uint32_t addr_size, const char *prefix = nullptr,
                      const char *suffix = nullptr);
 
} // namespace lldb_private
 
#endif // LLDB_UTILITY_STREAM_H