Rebased PNaCl localmods in LLVM to 223109

include/llvm/Bitcode/NaCl/NaClObjDumpStream.h

+//===- NaClObjDumpStream.h --------------------------------------*- C++ -*-===//
+//     Models an objdump stream (bitcode records/assembly code).
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BITCODE_NACL_NACLOBJDUMPSTREAM_H
+#define LLVM_BITCODE_NACL_NACLOBJDUMPSTREAM_H
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Bitcode/NaCl/NaClBitcodeParser.h"
+#include "llvm/Support/raw_ostream.h"
+#include <vector>
+#include <algorithm>
+
+namespace llvm {
+namespace naclbitc {
+
+// The default string assumed for a tab.
+static const char *DefaultTab = "        ";
+
+/// Class that implements text indenting for pretty printing text.
+class TextIndenter {
+public:
+  /// Creates a text indenter that indents using the given tab.
+  TextIndenter(const char* Tab = DefaultTab)
+    : Indent(""),
+      Tab(Tab),
+      TabSize(strlen(Tab)),
+      NumTabs(0) {
+    Values.push_back(Indent);
+  }
+
+  virtual ~TextIndenter() {}
+
+  /// Returns the current indentation to use.
+  const std::string &GetIndent() const {
+    return Indent;
+  }
+
+  /// Returns the indent with the given number of tabs.
+  const std::string &GetIndent(unsigned Count) {
+    if (Count >= Values.size()) {
+      // Indents not yet generated, fill in cache to size needed.
+      std::string Results;
+      if (Values.size() > 0) Results = Values.back();
+      for (size_t i = Values.size(); i <= Count; ++i) {
+        Results += Tab;
+        Values.push_back(Results);
+      }
+    }
+    return Values[Count];
+  }
+
+  /// Increments the current indentation by one tab.
+  void Inc() {
+    ++NumTabs;
+    if (NumTabs < Values.size()) {
+      Indent = Values[NumTabs];
+    } else {
+      Indent += Tab;
+      Values.push_back(Indent);
+    }
+  }
+
+  /// Decrements the current indentation by one tab.
+  void Dec() {
+    // Be sure not to underflow!
+    if (NumTabs) {
+      --NumTabs;
+      Indent = Values[NumTabs];
+    }
+  }
+
+  /// Returns the current number of tabs in the current indentation.
+  unsigned GetNumTabs() const {
+    return NumTabs;
+  }
+
+  const char *GetTab() const {
+    return Tab;
+  }
+
+  size_t GetTabSize() const {
+    return TabSize;
+  }
+
+private:
+  // The current indentation to use.
+  std::string Indent;
+  // The set of (previously computed) identations, based on the number
+  // of tabs.
+  std::vector<std::string> Values;
+  // The text defining a tab.
+  const char *Tab;
+  // The size of the tab.
+  size_t TabSize;
+  // The number of tabs currently being used.
+  unsigned NumTabs;
+};
+
+class TextFormatter;
+
+/// This template class maintains a simply pool of directives for
+/// a text formatter. Assumes that all elements in pool are associated
+/// with the same formatter.
+template<class Directive>
+class DirectiveMemoryPool {
+public:
+  DirectiveMemoryPool() {}
+
+  ~DirectiveMemoryPool() {
+    DeleteContainerPointers(FreeList);
+  }
+
+  Directive *Allocate(TextFormatter *Fmtr) {
+    if (FreeList.empty()) return new Directive(Fmtr);
+    Directive *Element = FreeList.back();
+    assert(&Element->GetFormatter() == Fmtr
+           && "Directive memory pool formatter mismatch");
+    FreeList.pop_back();
+    return Element;
+  }
+
+  void Free(Directive *Dir) {
+    FreeList.push_back(Dir);
+  }
+
+private:
+  std::vector<Directive*> FreeList;
+};
+
+/// This class defines a simple formatter for a stream that consists
+/// of a sequence of instructions. In general, this class assumes that
+/// instructions are a single line. In addition, some instructions
+/// define a block around a sequence of instructions. Each block of
+/// instructions is indented to clarify the block structure over that
+/// set of instructions.
+///
+/// To handle line indentation of blocks, this class inherits class
+/// TextIndenter.  The TextIndenter controls how blocks of lines are
+/// indented. At the beginning of a block, the user should call method
+/// Inc.  It should then write out the sequence of instructions to be
+/// indented.  Then, after the last indented instruction of the block
+/// is printed, the user should call method Dec. Nested blocks are
+/// handled by nesting methods Inc and Dec appropriately.
+///
+/// This class mainly focuses on the tools needed to format an
+/// instruction, given a specified viewing width. The issue is that
+/// while instructions should be on a single line, some instructions
+/// are too wide to fit into the viewing width. Hence, we need a way
+/// to deal with line overflow.
+///
+/// The way this class handles the line overflow problem is to
+/// basically force the user to break up the output into a sequence of
+/// tokens. This is done using two streams. The text stream is used to
+/// buffer tokens.  The base stream is the stream to write tokens to
+/// once they have been identified and positioned.  The goal of the
+/// formatter is to decide where the instruction text should be cut
+/// (i.e. between tokens), so that the instruction does not overflow
+/// the viewing width. It also handles the automatic insertion of line
+/// indentation into the base stream when needed.
+///
+/// To make it easy to print tokens to the text stream, we use text
+/// directives.  Whenever a text directive is written to the text
+/// stream, it is assumed that all text written to the text stream
+/// (since the last directive) is an (indivisible) token. The first
+/// thing directives do is move the token from the text stream (if
+/// present) to the base stream.
+///
+/// In addition to defining tokens, text directives can also be
+/// defined to query the formatter state and apply an appropriate
+/// action. An example of this is the space text directive. It only
+/// adds a space if the formatter isn't at the beginning of a new line
+/// (since a newline can act as whitespace).
+///
+/// The text formatter also has a notion of clustering
+/// tokens. Clustering forces a consecutive sequence of tokens to
+/// be treated as a single token, when deciding where to wrap long
+/// lines. In particular, clustered tokens will not be broken up
+/// unless there is no other way to print them, because the cluster is
+/// larger than what can fit in a line.
+///
+/// Clustering is implemented using two passes. In the first pass, the
+/// sequence of tokens/directives are collected to find the clustered
+/// text.  They are also applied to collect any text internal to the
+/// directives. Actions that can change (intraline) indenting are
+/// turned off.
+///
+/// Once the first pass is done, the second pass starts. It begins
+/// with a check to see if the clustered text can fit on the current
+/// line, and adds a newline if necessary. Then it replays the
+/// directives to put the tokens of the cluster into the base stream.
+/// The replay also changes (intraline) indenting as necessary.
+///
+/// Clusters can be nested. In such cases, they are stripped one layer
+/// per pass. Nested clusters are replayed after line wrapping of
+/// outer clusters have been resolved.
+class TextFormatter : public TextIndenter {
+public:
+
+  /// Creates a text formatter to print instructions onto the given
+  /// Base Stream. The viewing width is defined by LineWidth. The
+  /// given tab is the assumed value for tab characters and line
+  /// indents.
+  explicit TextFormatter(raw_ostream &BaseStream,
+                         unsigned LineWidth = 80,
+                         const char *Tab = DefaultTab);
+
+  ~TextFormatter() override;
+
+  /// Returns the user-level text stream of the formatter that tokens
+  /// should be written to.
+  raw_ostream &Tokens() {
+    return TextStream;
+  }
+
+  /// Changes the line width to the given value.
+  void SetLineWidth(unsigned NewLineWidth) {
+    LineWidth = NewLineWidth;
+    if (MinLineWidth > LineWidth) MinLineWidth = LineWidth;
+  }
+
+  // Changes the (default) line-wrap, continuation indent.
+  void SetContinuationIndent(const std::string &Indent) {
+    ContinuationIndent = Indent;
+  }
+
+  /// Base class for all directives. The basic functionality is that it
+  /// has a reference to the text formatter, and is applied by calling
+  /// method apply. This method apply is encorporated into the
+  /// stream operator<<, so that they can be used as part of the
+  /// streamed output.
+  ///
+  /// Method apply extracts any tokens in the text stream.  Moves them
+  /// into the base stream. Finally, it calls virtual method MyApply
+  /// to do the actions of the directive.
+  class Directive {
+    Directive(const Directive&) LLVM_DELETED_FUNCTION;
+    void operator=(const Directive&) LLVM_DELETED_FUNCTION;
+  public:
+    /// Creates a directive for the given stream.
+    explicit Directive(TextFormatter *Formatter)
+        : Formatter(Formatter) {}
+
+    virtual ~Directive() {}
+
+    /// Returns the formatter associated with the directive.
+    TextFormatter &GetFormatter() const {
+      return *Formatter;
+    }
+
+    /// Does action of directive.
+    void Apply() const {
+      // Start by writing token if Tokens() buffer (if non-empty).
+      Formatter->WriteToken();
+      // Apply the directive.
+      MyApply(false);
+      // Save the directive for replay if we are clustering.
+      MaybeSaveForReplay();
+    }
+
+   protected:
+    // The formatter associated with the directive.
+    TextFormatter *Formatter;
+
+    // Like Apply, but called instead of Apply whey doing a replay.
+    void Reapply() const;
+
+    // Does directive specific action. Replay is true only if the
+    // directive was in a cluster, and it is being called to replay
+    // the directive a second time.
+    virtual void MyApply(bool Replay) const = 0;
+
+    // Adds the directive to the clustered directives if appropriate
+    // (i.e. inside a cluster).
+    virtual void MaybeSaveForReplay() const {
+      if (IsClustering()) AppendForReplay(this);
+    }
+
+    // ***********************************************************
+    // Note: The following have been added so that derived classes
+    // have public access to protected text formatter methods.
+    // (Otherwise, you get a compiler error that they are protected
+    //  in derived classes).
+    // ***********************************************************
+
+    bool IsClustering() const {
+      return Formatter->IsClustering();
+    }
+
+    unsigned GetClusteringLevel() const {
+      return Formatter->GetClusteringLevel();
+    }
+
+    void AppendForReplay(const Directive *D) const {
+      Formatter->AppendForReplay(D);
+    }
+
+    raw_ostream &Tokens() const {
+      return Formatter->Tokens();
+    }
+
+    void WriteToken(const std::string &Token) const {
+      Formatter->WriteToken(Token);
+    }
+
+    void WriteEndline() const {
+      Formatter->WriteEndline();
+    }
+
+    void PopIndent() const {
+      Formatter->PopIndent();
+    }
+
+    void PushIndent() const {
+      Formatter->PushIndent();
+    }
+
+    bool AddLineWrapIfNeeded(unsigned TextSize) const {
+      return Formatter->AddLineWrapIfNeeded(TextSize);
+    }
+
+    void StartClustering() const {
+      Formatter->StartClustering();
+    }
+
+    void FinishClustering() const {
+      Formatter->FinishClustering();
+    }
+  };
+
+protected:
+  // The base stream to send formatted text to.
+  raw_ostream &BaseStream;
+  // Buffer that holds token text.
+  std::string TextBuffer;
+  // The user-level stream for (token) text and directives.
+  raw_string_ostream TextStream;
+  // The buffered token waiting to be flushed to the base stream.
+  // std::string BufferedToken;
+  // The expected line width the formatter should try and match.
+  unsigned LineWidth;
+  // The current position (i.e. column of previous character on line)
+  // associated with the current line in the base stream.
+  unsigned LinePosition;
+  // The stack of (intraline) indents added by PushIndent.
+  std::vector<unsigned> IntralineIndents;
+  // The current intraline indent to use.
+  unsigned CurrentIndent;
+  // The minimum line width. Used to limit indents so that there
+  // will always be at least this amount of space on the line.
+  unsigned MinLineWidth;
+  // True if no characters have moved to the base stream for the
+  // instruction being printed.  Note: This is different than
+  // LinePosition == 0. The latter can be true, when
+  // AtInstructionBeginning is false, if the current line is a
+  // continuation line caused by line overflow.
+  bool AtInstructionBeginning;
+  // The indent string to use for indenting each line of the instruction.
+  std::string LineIndent;
+  // The indent to add on continuation (i.e. overflow) lines for an
+  // instruction.
+  std::string ContinuationIndent;
+  // Counts how nested we are within clustering directives.
+  unsigned ClusteringLevel;
+  // Contains the number of columns needed to hold the generated text,
+  // while clustering. Computed so that we can test if it fits on the
+  // current line.
+  unsigned ClusteredTextSize;
+  // Contains the sequence of directives (including tokens) during
+  // clustering, so that it can be replayed after we determine if a
+  // new line needs to be added.
+  std::vector<const Directive*> ClusteredDirectives;
+
+  // Returns if we are currently inside a cluster.
+  bool IsClustering() const {
+    return ClusteringLevel > 0;
+  }
+
+  // Returns the clustering level of the formatter.
+  unsigned GetClusteringLevel() const {
+    return ClusteringLevel;
+  }
+
+  // Appends the given directive to the list of directives to
+  // replay, if clustering.
+  void AppendForReplay(const Directive *D) {
+    ClusteredDirectives.push_back(D);
+  }
+
+  /// Writes out the token in the text stream. If necessary, moves to
+  // a new line first.
+  void WriteToken() {
+    WriteToken(GetToken());
+  }
+
+  /// Writes out the given token. If necessary, moves to a new line first.
+  void WriteToken(const std::string &Token) {
+    if (Token.empty()) return;
+    AddLineWrapIfNeeded(Token.size());
+    Write(Token);
+  }
+
+  // Extracts the text that has been added to the text stream, and
+  // returns it.
+  std::string GetToken();
+
+  /// Writes out a non-newline character to the base stream.
+  void Write(char ch);
+
+  /// Writes out a string.
+  void Write(const std::string &Text);
+
+  /// Starts a new cluster of tokens.
+  /// Note: We do not allow nested clusterings.
+  void StartClustering();
+
+  /// Ends the existing cluster of tokens.
+  void FinishClustering();
+
+  /// Adds a newline that ends the current instruction being printed.
+  void WriteEndline();
+
+  /// Called just before the first character on a line is printed, to
+  /// add indentation text for the line.
+  virtual void WriteLineIndents();
+
+  /// Analyzes the formatter state to determine if a token of the
+  /// given TextSize can fit on the current line. If it can't fit,
+  /// it wraps the input line. Returns true only if line wrap was
+  /// added by this method.
+  bool AddLineWrapIfNeeded(unsigned TextSize) {
+    if (IsClustering()) {
+      // Don't consider line wrapping until all text is clustered. That
+      // way we have full information on what we should do.
+      return false;
+    } else {
+      // If the text fits on the current line, there is nothing to do.
+      // Otherwise, we should add a newline, unless we are already
+      // at the new line. If we are already at the newline, we can't
+      // split up the token, so just allow line overflow.
+      if (LinePosition + TextSize <= LineWidth
+          || LinePosition == 0)
+        return false;
+      // If reached, it must not fit, so add a line wrap.
+      Write('\n');
+      return true;
+    }
+  }
+
+  /// Pops the current (intraline) indentation and restores it to the
+  /// previous indentation. Used to restore the indentation of
+  /// parenthesized subexpressions, where this should be called on the
+  /// close parenthesis.
+  void PopIndent() {
+    // Be pragmatic. If there is underflow, assume that it was due to
+    // the fact that the caller of this text formatter used a close
+    // directive for a pair of matching parenthesis that crossed
+    // multiple (i.e. instruction) lines.
+    if (IsClustering() || IntralineIndents.empty()) return;
+    CurrentIndent = IntralineIndents.back();
+    IntralineIndents.pop_back();
+  }
+
+  /// Pushes the current (intraline) indentation to match the current
+  /// position within the line. Used to indent parenthesized
+  /// subexpressions, where this should be called on the open
+  /// parenthesis.
+  void PushIndent() {
+    if (IsClustering()) return;
+    IntralineIndents.push_back(CurrentIndent);
+    CurrentIndent = FixIndentValue(LinePosition);
+  }
+
+  /// Fixes the given position, to the appropriate value for setting
+  /// CurrentIndent. That is, it makes sure there is always MinLineWidth
+  /// printable characters on a line.
+  unsigned FixIndentValue(unsigned Position) {
+    return std::min(Position, LineWidth - MinLineWidth);
+  }
+
+private:
+  /// Directive that generates temporary instances to hold tokens from
+  /// the Tokens() stream. Generated when GetToken() is called. Used
+  /// during clustering to regenerate the corresponding extracted
+  /// tokens during a replay.
+  class GetTokenDirective : public Directive {
+    friend class DirectiveMemoryPool<GetTokenDirective>;
+    GetTokenDirective(TextFormatter *Formatter)
+        : Directive(Formatter) {}
+
+  public:
+    ~GetTokenDirective() override {}
+
+    /// Allocates an instance of a GetTokenDirective.
+    /// Note: Will be reclaimed when MyApply is called.
+    static Directive *Allocate(TextFormatter *Formatter,
+                               const std::string &Text);
+
+  protected:
+    void MyApply(bool Replay) const override {
+      WriteToken(Text);
+      if (!IsClustering())
+        Formatter->GetTokenFreeList.Free(const_cast<GetTokenDirective*>(this));
+    }
+
+  private:
+    // The token text.
+    std::string Text;
+  };
+
+  // The set of freed GetTokenDirectives, that can be reused.
+  DirectiveMemoryPool<GetTokenDirective> GetTokenFreeList;
+};
+
+inline raw_ostream &operator<<(raw_ostream &Stream,
+                               const TextFormatter::Directive &Directive) {
+  // Be sure that the directive is defined for the given stream,
+  // before applying the directive, since directives may have
+  // different meanings on different text streams.
+  assert(&Stream == &Directive.GetFormatter().Tokens());
+  Directive.Apply();
+  return Stream;
+}
+
+/// Defines a directive that only tokenizes the text in the Tokens()
+/// stream.
+class TokenizeTextDirective : public TextFormatter::Directive {
+public:
+  explicit TokenizeTextDirective(TextFormatter *Formatter)
+      : TextFormatter::Directive(Formatter) {}
+
+  ~TokenizeTextDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {}
+};
+
+/// Defines a token which doesn't need whitespace on either side of
+/// the token to be a valid token (such as punctuation).
+class TokenTextDirective : public TextFormatter::Directive {
+public:
+  TokenTextDirective(TextFormatter *Formatter, const std::string &Str)
+      : TextFormatter::Directive(Formatter), Text(Str) {
+  }
+
+  ~TokenTextDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    WriteToken(Text);
+  }
+
+private:
+  std::string Text;
+};
+
+/// Writes out the current token. Then adds a space if the base
+/// stream is not at the beginning of a continuation line.
+class SpaceTextDirective : public TextFormatter::Directive {
+public:
+  SpaceTextDirective(TextFormatter *Formatter, const std::string &Space)
+      : TextFormatter::Directive(Formatter), Space(Space) {}
+
+  explicit SpaceTextDirective(TextFormatter *Formatter)
+      : TextFormatter::Directive(Formatter), Space(" ") {}
+
+  ~SpaceTextDirective() {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    if (!AddLineWrapIfNeeded(Space.size()))
+      WriteToken(Space);
+  }
+private:
+  std::string Space;
+};
+
+/// Adds a newline that ends the current instruction being printed.
+class EndlineTextDirective : public TextFormatter::Directive {
+public:
+  explicit EndlineTextDirective(TextFormatter *Formatter)
+      : TextFormatter::Directive(Formatter) {}
+
+  ~EndlineTextDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    WriteEndline();
+  }
+};
+
+/// Inserts a token and then pushes the current indent to the position
+/// after the token. Used to model a open parenthesis.
+class OpenTextDirective : public TokenTextDirective {
+public:
+
+  // Creates an open using the given indent.
+  OpenTextDirective(TextFormatter *Formatter, const std::string &Text)
+      : TokenTextDirective(Formatter, Text) {}
+
+  ~OpenTextDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    TokenTextDirective::MyApply(Replay);
+    PushIndent();
+  }
+};
+
+/// Inserts a token and then pops current indent.  Used to model a
+/// close parenthesis.
+class CloseTextDirective : public TokenTextDirective {
+public:
+  CloseTextDirective(TextFormatter *Formatter, const std::string &Text)
+      : TokenTextDirective(Formatter, Text) {}
+
+  ~CloseTextDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    TokenTextDirective::MyApply(Replay);
+    PopIndent();
+  }
+};
+
+/// Defines the beginning of a token cluster, which should be put on the
+/// same line if possible.
+class StartClusteringDirective : public TextFormatter::Directive {
+public:
+  explicit StartClusteringDirective(TextFormatter *Formatter)
+      : TextFormatter::Directive(Formatter) {}
+
+  ~StartClusteringDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    StartClustering();
+  }
+
+  void MaybeSaveForReplay() const override {
+    if (GetClusteringLevel() > 1) AppendForReplay(this);
+  }
+};
+
+class FinishClusteringDirective : public TextFormatter::Directive {
+public:
+  explicit FinishClusteringDirective(TextFormatter *Formatter)
+      : TextFormatter::Directive(Formatter) {}
+
+  ~FinishClusteringDirective() override {}
+
+protected:
+  void MyApply(bool Replay) const override {
+    FinishClustering();
+  }
+};
+
+class ObjDumpStream;
+
+/// Models that an abbreviation index is not specified when dumping a
+/// bitcode record.
+static int32_t ABBREV_INDEX_NOT_SPECIFIED = -1;
+
+/// The formatter used for dumping records in ObjDumpStream.
+class RecordTextFormatter : public TextFormatter {
+public:
+  /// The address write width used to print the number of
+  /// bytes in the record bit address, when printing records.
+  static const unsigned AddressWriteWidth = 8;
+
+  explicit RecordTextFormatter(ObjDumpStream *ObjDump);
+
+  ~RecordTextFormatter() override {}
+
+  /// Writes out the given record of values as an instruction.
+  void WriteValues(uint64_t Bit,
+                   const llvm::NaClBitcodeValues &Values,
+                   int32_t AbbrevIndex = ABBREV_INDEX_NOT_SPECIFIED);
+
+  /// Returns text corresponding to an empty label column.
+  std::string GetEmptyLabelColumn();
+
+  // Converts the given start bit to the corresponding address to
+  // print. That is, generate "Bit/8:Bit%8" value.
+  static std::string RecordAddress(uint64_t Bit, unsigned MinByteWidth);
+
+  // Returns the record address (when printing records) associated with
+  // the given bit.
+  static std::string RecordAddress(uint64_t Bit) {
+    return RecordAddress(Bit, AddressWriteWidth);
+  }
+
+protected:
+  void WriteLineIndents() override;
+
+private:
+  // The object dumper this formatter is associated with.
+  ObjDumpStream *ObjDump;
+  // The address label associated with the current line.
+  std::string Label;
+  // The open brace '<' for a record.
+  OpenTextDirective OpenBrace;
+  // The close brace '>' for a record.
+  CloseTextDirective CloseBrace;
+  // A comma between elements in a record.
+  TokenTextDirective Comma;
+  // A space inside a record.
+  SpaceTextDirective Space;
+  // End the line.
+  EndlineTextDirective Endline;
+  // Start clustering tokens.
+  StartClusteringDirective StartCluster;
+  // End clustering tokens.
+  FinishClusteringDirective FinishCluster;
+};
+
+/// Implements a stream to print out bitcode records, assembly code,
+/// comments, and errors. The general format is to print records and
+/// assembly side by side. Comments and errors (associated with the
+/// record and/or assembly code) follow each printed record.
+///
+/// Alignment of records, assembly, comments, and errors is done by
+/// buffering assembly, comments, and errors until a write or flush
+/// occurs.  Then, the various streams are stitched together to
+/// produce the corresponding output text. There are two buffers: one
+/// holds the assembly, and the other holds comments and errors.
+///
+/// There are exactly two methods that can cause text to be added to
+/// the objdump stream. Method Flush just flushes out the assembly and
+/// comments/errors buffer without printing a record. If there is no
+/// buffered assembly/comments/errors, nothing is done. Method Write
+/// prints the given record, and also flushes out the assembly and
+/// comments/errors buffer. Hence, in general, comments and errors
+/// follow the record/assembly. However, if you want them to appear
+/// before, use method Flush.
+///
+/// The constructor is defined with two flags: DumpRecords and
+/// DumpAssembly.  Comments and errors are flushed on every write,
+/// independent of these flags.  Records are printed out only if
+/// DumpRecords is true. Assembly is flushed only if DumpAssembly is
+/// true.
+///
+/// To buffer assembly, call method Assembly to get a (string) stream
+/// to buffer the assembly code. To buffer comments, call method
+/// Comments() to get a (string) stream to buffer the comments.
+///
+/// To buffer an error, call method Error. This method will increment
+/// the error count, and return the comments stream after writing
+/// "Error(byte:bit): ".
+///
+/// If a single line of text is buffered into the assembly stream, no
+/// new line is needed. The corresponding call to Write will
+/// automatically insert the newline for you, if you did not add
+/// it. If multiple lines are to be buffered into the assembly stream,
+/// each line must be separated with a newline character.  It is
+/// always safe to end all assembly lines with a newline character.
+///
+/// Also note that this class takes care of formatting records to fit
+/// into a calculated record width (based on value set to
+/// RecordWidth).  On the other hand, we assume that the assembly is
+/// formatted by the caller (i.e. owner of this object).
+class ObjDumpStream {
+  ObjDumpStream(const ObjDumpStream&) LLVM_DELETED_FUNCTION;
+  void operator=(const ObjDumpStream&) LLVM_DELETED_FUNCTION;
+public:
+  /// The default number of error messages that will be printed before
+  /// execution is stopped due to too many errors.
+  static unsigned DefaultMaxErrors;
+
+  /// The default value for the column that separates records and
+  /// assembly, when DumpRecords and DumpAssembly is true.
+  static unsigned ComboObjDumpSeparatorColumn;
+
+  /// The default value for line width when DumpRecords is true,
+  /// and DumpAssembly is false. This value is typically larger
+  /// than ComboObjDumpSeparatorColumn, since the entire line
+  /// can be used to print records.
+  static unsigned RecordObjectDumpLength;
+
+  /// Creates an objdump stream which will dump records, assembly,
+  /// comments and errors into a single (user proved Stream).  When
+  /// DumpRecords is true, the contents of records will be
+  /// dumped. When DumpAssembly is true, the corresponding assembly
+  /// will be printed. When both are true, the records and assembly
+  /// will be printed side by side. When both are false, only comments
+  /// and errors will be printed.
+  ObjDumpStream(raw_ostream &Stream, bool DumpRecords, bool DumpAssembly);
+
+  ~ObjDumpStream() { Flush(); }
+
+  /// Returns stream to buffer assembly that will be printed during the
+  /// next write call.
+  raw_ostream &Assembly() {
+    return AssemblyStream;
+  }
+
+  /// Returns stream to buffer records that will be printed during the
+  /// next write call.
+  raw_ostream &Records() {
+    return RecordStream;
+  }
+
+  /// Returns stream to buffer messages that will be printed during the
+  // next write call.
+  raw_ostream &Comments() {
+    return MessageStream;
+  }
+
+  /// Prints "Warning(Bit/8:Bit%8): " onto the comments stream, and
+  /// then returns the comments stream. In general, warnings will be
+  /// printed after the next record, unless a call to Flush is made.
+  raw_ostream &Warning() {
+    return Warning(LastKnownBit);
+  }
+
+  /// Prints "Warning(Bit/8:Bit%8): " onto the comments stream, and
+  /// then returns the comments stream. In general, warnings will be
+  /// printed after the next record, unless a call to Flush is made.
+  raw_ostream &Warning(uint64_t Bit) {
+    LastKnownBit = Bit;
+    return PrintMessagePrefix("Warning", Bit);
+  }
+
+  /// Prints "Error(Bit/8:Bit%8): " onto the comments stream, records
+  /// that an error has occurred, and then returns the comments
+  /// stream. In general errors will be printed after the next record,
+  /// unless a call to Flush is made.
+  raw_ostream &Error() {
+    return Error(LastKnownBit);
+  }
+
+  /// Prints "Error(Bit/8:Bit%8): " onto the comments stream, records
+  /// that an error has occurred, and then returns the comments
+  /// stream. In general errors will be printed after the next record,
+  /// unless a call to Flush is made.
+  raw_ostream &Error(uint64_t Bit);
+
+  /// Write a fatal error message to the dump stream, and then
+  /// stop the executable. If any assembly, comments, or errors have
+  /// been buffered, they will be printed first.
+  void Fatal(const std::string &Message) {
+    Fatal(LastKnownBit, Message);
+  }
+
+  /// Write a fatal error message to the dump stream, and then
+  /// stop the executable. If any assembly, comments, or errors have
+  /// been buffered, they will be printed first. Associates fatal error
+  /// Message with the given Bit.
+  void Fatal(uint64_t Bit, const std::string &Message);
+
+  /// Write a fatal error message to the dump stream, and then
+  /// stop the executable. If any assembly, comments, or errors have
+  /// been buffered, they will be printed first, along with the given record.
+  void Fatal(uint64_t Bit,
+             const llvm::NaClBitcodeRecordData &Record,
+             const std::string &Message);
+
+  /// Dumps a record (at the given bit), along with all buffered assembly,
+  /// comments, and errors, into the objdump stream.
+  void Write(uint64_t Bit,
+             const llvm::NaClBitcodeRecordData &Record,
+             int32_t AbbrevIndex = ABBREV_INDEX_NOT_SPECIFIED) {
+    LastKnownBit = Bit;
+    NaClBitcodeValues Values(Record);
+    RecordFormatter.WriteValues(Bit, Values, AbbrevIndex);
+    Flush();
+  }
+
+  /// Dumps the buffered assembly, comments, and errors, without any
+  /// corresponding record, into the objdump stream.
+  void Flush();
+
+  /// Increments the record indent by one.
+  void IncRecordIndent() {
+    RecordFormatter.Inc();
+  }
+
+  /// Decrements the record indent by one.
+  void DecRecordIndent() {
+    RecordFormatter.Dec();
+  }
+
+  /// Returns the record indenter being used by the objdump stream, for
+  /// the purposes of querying state.
+  const TextIndenter &GetRecordIndenter() {
+    return RecordFormatter;
+  }
+
+  /// Returns the number of errors reported to the dump stream.
+  unsigned GetNumErrors() const {
+    return NumErrors;
+  }
+
+  // Returns true if dumping record.
+  bool GetDumpRecords() const {
+    return DumpRecords;
+  }
+
+  // Returns true if dumping assembly.
+  bool GetDumpAssembly() const {
+    return DumpAssembly;
+  }
+
+  /// Changes the default assumption that bit addresses start
+  /// at index 0.
+  void SetStartOffset(uint64_t Offset) {
+    StartOffset = Offset;
+  }
+
+  /// Changes the maximum number of errors allowed.
+  void SetMaxErrors(unsigned NewMax) {
+    MaxErrors = NewMax;
+  }
+
+  /// Changes the width allowed for records (from the default).
+  void SetRecordWidth(unsigned Width) {
+    RecordWidth = Width;
+  }
+
+  unsigned GetRecordWidth() const {
+    return RecordWidth;
+  }
+
+  /// Changes the column separator character to the given value.
+  void SetColumnSeparator(char Separator) {
+    ColumnSeparator = Separator;
+  }
+
+  /// Changes the internal state, to assume one is processing a record
+  /// at the given bit. Used by Error() and Fatal(Message) to fill in
+  /// the corresponding bit to associate with the error message.
+  void SetRecordBitAddress(uint64_t Bit) {
+    LastKnownBit = Bit;
+  }
+
+  // Converts the given start bit to the corresponding address to
+  // print. That is, generate "Bit/8:Bit%8" value.
+  std::string ObjDumpAddress(uint64_t Bit, unsigned MinByteWidth=1) {
+    return RecordFormatter.RecordAddress(Bit + StartOffset, MinByteWidth);
+  }
+
+  // Returns the record address (when printing records) associated with
+  // the given bit.
+  std::string RecordAddress(uint64_t Bit) {
+    return RecordFormatter.RecordAddress(Bit + StartOffset);
+  }
+
+private:
+  // The stream to dump to.
+  raw_ostream &Stream;
+  // True if records should be dumped to the dump stream.
+  bool DumpRecords;
+  // True if assembly text should be dumped to the dump stream.
+  bool DumpAssembly;
+  // The number of errors reported.
+  unsigned NumErrors;
+  // The maximum number of errors before quitting.
+  unsigned MaxErrors;
+  // The number of columns available to print bitcode records.
+  unsigned RecordWidth;
+  // The number of bits to add to the record bit address, to correct
+  // the record bit address passed to the write routines.
+  uint64_t StartOffset;
+  // The buffer for assembly to be printed during the next write.
+  std::string AssemblyBuffer;
+  // The stream to buffer assembly into the assembly buffer.
+  raw_string_ostream AssemblyStream;
+  // The buffer for comments and errors.
+  std::string MessageBuffer;
+  // The stream to buffer comments and errors into the message.
+  raw_string_ostream MessageStream;
+  // The character used to separate records from assembly.
+  char ColumnSeparator;
+  // The last known bit passed to the objdump object. Used as default
+  // for automatically generated errors.
+  uint64_t LastKnownBit;
+  /// The buffer for records to be printed to during the next write.
+  std::string RecordBuffer;
+  /// The stream to buffer recordds into the record buffer.
+  raw_string_ostream RecordStream;
+  /// The text formatter for generating records.
+  RecordTextFormatter RecordFormatter;
+
+  // Resets assembly and buffers.
+  void ResetBuffers() {
+    RecordBuffer.clear();
+    AssemblyBuffer.clear();
+    MessageBuffer.clear();
+  }
+
+  // Returns the message stream with 'Label(Bit/8:Bit%8): '.
+  raw_ostream &PrintMessagePrefix(const char *Label, uint64_t Bit) {
+    return Comments() << Label << "(" << ObjDumpAddress(Bit) << "): ";
+  }
+};
+
+}
+}
+
+#endif