Subzero: Add necessary PNaCl files for standalone build.

pnacl-llvm/include/llvm/Bitcode/NaCl/NaClBitcodeMungeUtils.h

+//===- NaClBitcodeMungeUtils.h - Munge bitcode records --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines utility class NaClMungedBitcode to edit a base
+// sequence of PNaCl bitcode records. It is intended to be used for
+// both unit testing, and for fuzzing bitcode files.
+//
+// The editing actions are defined in terms of the base sequence of
+// bitcode records, and do not actually modify that base sequence. As
+// such, all edits are defined relative to a record index in the base
+// sequence of bitcode records. Using record indices into the base
+// sequence means that succeeding edits need not modify record indices
+// based on the effects of preceding edits. Rather, the record index
+// remains constant across all editing actions.
+//
+// There are two steps in creating munged bitcode. The first step
+// defines the initial (base) sequence of bitcode records to be
+// edited. The second is to apply editing actions to the base sequence
+// of records.
+//
+// Defining the initial sequence of bitcode records is done by
+// using NaClMungedBitcode's constructor.
+//
+// There are four kinds of editing actions:
+//
+// 1) Add a record before a (base) record index.
+// 2) Add a record after a (base) record index.
+// 3) Remove a record at a (base) record index.
+// 4) Replace a record at a (base) record index.
+//
+// Each of the editing actions are defined by the methods addBefore(),
+// addAfter(), remove(), and replace(). The edited sequence of records
+// is defined by an iterator, and is accessible using methods begin()
+// and end().
+//
+// If multiple records are added before/after a record index, the
+// order of the added records correspond to the order they were added.
+//
+// For unit testing, simple array interfaces are provided. The first
+// interface defines the initial base sequence of bitcode records. The
+// second interface, method munge(), defines a sequence of editing
+// actions to apply to the base sequence of records.
+//
+// These arrays are defined using type uint64_t. A bitcode record is
+// defined as a sequence of values of the form:
+//
+//   AbbrevIndex, RecordCode, Value1, ..., ValueN , Terminator
+//
+// Terminator is a (user-specified) designated constant used to mark
+// the end of bitcode records. A record can contain zero or more
+// values.
+//
+// An editing action is defined as one of the following sequences of
+// values:
+//
+//   RecordIndex, AddBefore, AbbrevIndex, RecordCode, Value, ..., Terminator
+//   RecordIndex, AddAfter, AbbrevIndex, RecordCode, Value, ..., Terminator
+//   RecordIndex, Remove
+//   RecordIndex, Replace, AbbrevIndex, RecordCode, Value, ..., Terminator.
+//
+// RecordIndex defines where the action applies, relative to the base
+// sequence of records. EditAction defines the editing action to
+// apply. The remaining fields define an optional record associated
+// with the editing action.
+//
+// ===---------------------------------------------------------------------===//

[Karl, 2016/05/10 14:49:48]

Is this file really needed?

It is only used in a few unit tests, that probably could be fixed to not use.

[Jim Stichnoth, 2016/05/10 18:11:48]

Done.

+
+#ifndef LLVM_BITCODE_NACL_NACLBITCODEMUNGEUTILS_H
+#define LLVM_BITCODE_NACL_NACLBITCODEMUNGEUTILS_H
+
+#include "llvm/Bitcode/NaCl/NaClBitcodeParser.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+#include <list>
+#include <map>
+
+namespace llvm {
+
+class NaClBitcodeAbbrevRecord; // bitcode record.
+class NaClMungedBitcodeIter;   // iterator over edited bitcode records.
+
+/// \brief Defines a list of bitcode records.
+typedef std::vector<std::unique_ptr<NaClBitcodeAbbrevRecord>>
+    NaClBitcodeRecordList;
+
+// TODO(kschimpf): Modify following two methods to return error_code.
+
+/// \brief Extracts out the records in Records, and puts them into RecordList.
+///
+/// \brief RecordList[in/out] Record list to read into.
+/// \brief Records Array containing data defining records.
+/// \brief RecordsSize The size of array Records.
+/// \brief RecordTerminator The value used to terminate records.
+void readNaClBitcodeRecordList(NaClBitcodeRecordList &RecordList,
+                               const uint64_t Records[],
+                               size_t RecordsSize,
+                               uint64_t RecordTerminator);
+
+/// Read in the list of records from binary bitcode from a memory buffer.
+void readNaClBitcodeRecordList(NaClBitcodeRecordList &RecordList,
+                               std::unique_ptr<MemoryBuffer> InputBuffer);
+
+/// Read in the list of records from textual bitcode from a memory buffer.
+std::error_code readNaClTextBcRecordList(
+    NaClBitcodeRecordList &RecordList,
+    std::unique_ptr<MemoryBuffer> InputBuffer);
+
+/// Read textual bitcode records from Filename, and fill Buffer with
+/// corresponding bitcode. Return error_code describing success of
+/// read.  Verbose (if not nullptr) is used to generate more human
+/// readable error messages than the text in the returned error
+/// message.
+std::error_code readNaClRecordTextAndBuildBitcode(
+    StringRef Filename, SmallVectorImpl<char> &Buffer,
+    raw_ostream *Verbose = nullptr);
+
+/// Write out RecordList (as text) to Buffer. Returns true when
+/// successful. Error message are written to ErrStream.
+bool writeNaClBitcodeRecordList(NaClBitcodeRecordList &RecordList,
+                                SmallVectorImpl<char> &Buffer,
+                                raw_ostream &ErrStream);
+
+/// \brief An edited (i.e. munged) list of bitcode records. Edits are
+/// always relative to the initial list of records.
+class NaClMungedBitcode {
+  friend class NaClMungedBitcodeIter;
+  NaClMungedBitcode() = delete;
+  NaClMungedBitcode(const NaClMungedBitcode &) = delete;
+  NaClMungedBitcode &operator=(const NaClMungedBitcode &) = delete;
+
+public:
+  /// \brief Iterator over edited records.
+  typedef NaClMungedBitcodeIter iterator;
+
+  /// \brief Read in initial list of records from bitcode in a memory buffer.
+  explicit NaClMungedBitcode(std::unique_ptr<MemoryBuffer> InputBuffer,
+                             bool ReadAsText=false)
+      : BaseRecords(new NaClBitcodeRecordList()) {
+    if (ReadAsText)
+      readNaClTextBcRecordList(*BaseRecords, std::move(InputBuffer));
+    else
+      readNaClBitcodeRecordList(*BaseRecords, std::move(InputBuffer));
+  }
+
+  /// \brief Initialize the list of records to be edited.
+  explicit NaClMungedBitcode(std::unique_ptr<NaClBitcodeRecordList> BaseRecords)
+      : BaseRecords(std::move(BaseRecords)) {}
+
+  /// \brief Initialize the list of records to be edited using
+  /// array specification.
+  ///
+  /// \brief Records Array containing data defining records.
+  /// \brief RecordsSize The size of array Records.
+  /// \brief RecordTerminator The value used to terminate records.
+  NaClMungedBitcode(const uint64_t Records[], size_t RecordsSize,
+                    uint64_t RecordTerminator);
+
+  ~NaClMungedBitcode();
+
+  /// \brief Iterator pointing to first record in edited records.
+  NaClMungedBitcodeIter begin() const;
+
+  /// \brief Iterator pointing after last record in edited records.
+  NaClMungedBitcodeIter end() const;
+
+  /// \brief Insert Record immediately before the record at RecordIndex.
+  ///
+  /// \param RecordIndex The index (within BaseRecords) to add before.
+  /// \param Record The record to add.
+  void addBefore(size_t RecordIndex, NaClBitcodeAbbrevRecord &Record);
+
+  /// \brief Insert Record after the record at RecordIndex (and after
+  /// any previously added after records for RecordIndex).
+  ///
+  /// \param RecordIndex The index (within BaseRecords) to add after.
+  /// \param Record The record to add.
+  void addAfter(size_t RecordIndex, NaClBitcodeAbbrevRecord &Record);
+
+  /// \brief Remove the record at RecordIndex. Note that because
+  /// the record index is based on the base records, and those records
+  /// are not modified, this editing action effectively undoes all
+  /// previous remove/replace editing actions for this index.
+  void remove(size_t RecordIndex);
+
+  /// \brief Replace the record at RecordIndex with Record. Note that
+  /// because the record index is based on the base records, and those
+  /// records are not modified, this editing action effectively undoes
+  /// all previous remove/replace editing actions for this index.
+  void replace(size_t RecordIndex, NaClBitcodeAbbrevRecord &Record);
+
+  /// \brief Print out the resulting edited list of records.
+  void print(raw_ostream &Out) const;
+
+  /// Defines set of possible write flags.
+  struct WriteFlags {
+    /// True if error recovery should be applied.
+    bool getTryToRecover() const { return TryToRecover; }
+
+    /// Define that error recovery should be applied when writing.
+    void setTryToRecover(bool NewValue) {
+      TryToRecover = NewValue;
+      assert(!(TryToRecover && WriteBadAbbrevIndex));
+    }
+
+    /// True if a bad abbreviation index should be written (rather than
+    /// trying error recovery) so that bitcode readers can be tested for
+    /// this condition.
+    bool getWriteBadAbbrevIndex() const { return WriteBadAbbrevIndex; }
+
+    /// Define that the first bad abbreviation index should be written,
+    /// and corresponding minimal context added so that the bitcode can
+    /// be used to test reading the erroneous written bitcode.
+    void setWriteBadAbbrevIndex(bool NewValue) {
+      WriteBadAbbrevIndex = NewValue;
+      assert(!(TryToRecover && WriteBadAbbrevIndex));
+    }
+
+    /// Get the stream to print errors while writing bitcode.
+    raw_ostream &getErrStream() const {
+      return ErrStream ? *ErrStream : errs();
+    }
+
+    /// Set the stream to print errors to.
+    void setErrStream(raw_ostream &NewValue) {
+      ErrStream = &NewValue;
+    }
+
+    void reset() {
+      TryToRecover = false;
+      WriteBadAbbrevIndex = false;
+      ErrStream = nullptr;
+    }
+
+  private:
+    bool TryToRecover = false;
+    bool WriteBadAbbrevIndex = false;
+    raw_ostream *ErrStream = nullptr;
+  };
+
+  /// Defines the results associated with writing bitcode.
+  struct WriteResults {
+    /// Number of errors generated.
+    size_t NumErrors = 0;
+    /// Number of repairs (via error recovery) that were applied.
+    size_t NumRepairs = 0;
+    /// True if a bad abbreviation index were written.
+    bool WroteBadAbbrevIndex = false;
+  };
+
+  /// \brief Write out the edited list of bitcode records using
+  /// the given buffer.
+  ///
+  /// \param Buffer The buffer to write into.
+  /// \param AddHeader Add header block when true.
+  /// \param Flags Write flags to use.
+  ///
+  /// \return Returns the results of the write.
+  WriteResults writeMaybeRepair(
+      SmallVectorImpl<char> &Buffer, bool AddHeader,
+      const WriteFlags &Flags) const;
+
+  bool write(SmallVectorImpl<char> &Buffer, bool AddHeader,
+             const WriteFlags &Flags) const {
+    WriteResults Results = writeMaybeRepair(Buffer, AddHeader, Flags);
+    return Results.NumErrors == 0
+        || (Flags.getTryToRecover() && Results.NumErrors == Results.NumRepairs);
+  }
+
+  bool write(SmallVectorImpl<char> &Buffer, bool AddHeader) const {
+    WriteFlags Flags;
+    return write(Buffer, AddHeader, Flags);
+  }
+
+  /// \brief The types of editing actions that can be applied.
+  enum EditAction {
+    AddBefore, // Insert new record before base record at index.
+    AddAfter,  // Insert new record after base record at index.
+    Remove,    // Remove record at index.
+    Replace    // Replace base record at index with new record.
+  };
+
+  /// \brief Apply a set of edits defined in the given array.
+  ///
+  /// Actions are a sequence of values, followed by a (common)
+  /// terminator value. Valid action sequences are:
+  ///
+  /// RecordIndex AddBefore Abbrev Code Values Terminator
+  ///
+  /// RecordIndex AddAfter Abbrev Code Values Terminator
+  ///
+  /// RecordIndex Remove
+  ///
+  /// RecordIndex Replace Abbrev Code Values Terminator
+  ///
+  /// \param Munges The array containing the edits to apply.
+  /// \param MungesSize The size of Munges.
+  /// \param Terminator The value used to terminate records in editing actions.
+  void munge(const uint64_t Munges[], size_t MungesSize, uint64_t Terminator);
+
+  /// \brief Removes all editing actions and resets back to the original
+  /// set of base records.
+  void removeEdits();
+
+  /// Returns the unedited list of bitcode records.
+  const NaClBitcodeRecordList &getBaseRecords() const {
+    return *BaseRecords;
+  }
+
+private:
+  typedef std::list<NaClBitcodeAbbrevRecord *> RecordListType;
+  typedef std::map<size_t, RecordListType *> InsertionsMapType;
+  typedef std::map<size_t, NaClBitcodeAbbrevRecord *> ReplaceMapType;
+
+  /// \brief The list of base records that will be edited.
+  std::unique_ptr<NaClBitcodeRecordList> BaseRecords;
+  // Holds map from record index to list of records added before
+  // the corresponding record in the list of base records.
+  InsertionsMapType BeforeInsertionsMap;
+  // Holds map from record index to the list of records added after
+  // the corresponding record in the list of base records.
+  InsertionsMapType AfterInsertionsMap;
+  // Holds map from record index to the record that replaces the
+  // corresponding record in the list of base records. Note: If the
+  // range is the nullptr, it corresponds to a remove instead of a
+  // replace.
+  ReplaceMapType ReplaceMap;
+
+  // Returns the list of records associated with Index in Map.
+  RecordListType &at(InsertionsMapType &Map, size_t Index) {
+    InsertionsMapType::iterator Pos = Map.find(Index);
+    if (Pos == Map.end()) {
+      RecordListType *List = new RecordListType();
+      Map.emplace(Index, List);
+      return *List;
+    }
+    return *Pos->second;
+  }
+
+  // Creates a (heap allocated) copy of the given record.
+  NaClBitcodeAbbrevRecord *copy(const NaClBitcodeAbbrevRecord &Record);
+
+  // Delete nested objects within insertions map.
+  void destroyInsertionsMap(NaClMungedBitcode::InsertionsMapType &Map);
+};
+
+/// \brief Defines a bitcode record with its associated abbreviation index.
+class NaClBitcodeAbbrevRecord : public NaClBitcodeRecordData {
+  NaClBitcodeAbbrevRecord &operator=(NaClBitcodeAbbrevRecord &) = delete;
+
+public:
+  /// \brief The abbreviation associated with the bitcode record.
+  unsigned Abbrev;
+
+  /// \brief Creates a bitcode record.
+  ///
+  /// \param Abbrev Abbreviation index associated with record.
+  /// \param Code The selector code of the record.
+  /// \param Values The values associated with the selector code.
+  NaClBitcodeAbbrevRecord(unsigned Abbrev, unsigned Code,
+                          const NaClRecordVector &Values)
+      : NaClBitcodeRecordData(Code, Values), Abbrev(Abbrev) {}
+
+  /// \brief Creates a copy of the given abbreviated bitcode record.
+  explicit NaClBitcodeAbbrevRecord(const NaClBitcodeAbbrevRecord &Rcd)
+      : NaClBitcodeRecordData(Rcd), Abbrev(Rcd.Abbrev) {}
+
+  /// \brief Creates a default abbreviated bitcode record.
+  NaClBitcodeAbbrevRecord() : Abbrev(naclbitc::UNABBREV_RECORD) {}
+
+  ~NaClBitcodeAbbrevRecord() {}
+
+  /// \brief Replaces the contents of the abbreviated bitcode record with
+  /// the corresponding contents in the array.
+  ///
+  /// \param Values The array to get values from.
+  /// \param ValuesSize The length of the Values array.
+  /// \param Terminator The value defining the end of the record in Values.
+  /// \param Index The index of the first value to be used in Values.
+  void read(const uint64_t Values[], size_t ValuesSize,
+            const uint64_t Terminator, size_t &Index);
+
+  void print(raw_ostream &out) const;
+};
+
+inline raw_ostream &operator<<(raw_ostream &Out,
+                               const NaClBitcodeAbbrevRecord &Record) {
+  Record.print(Out);
+  return Out;
+}
+
+/// \brief Defines an iterator to walk over elements of an edited
+/// record list.
+class NaClMungedBitcodeIter {
+
+public:
+  /// \brief Returns an iterator pointing to the first record in the
+  /// edited list of records.
+  static NaClMungedBitcodeIter begin(const NaClMungedBitcode &MungedBitcode) {
+    return NaClMungedBitcodeIter(MungedBitcode, 0);
+  }
+
+  /// \brief Returns an iterator pointing past the last record in the
+  /// edited list of records.
+  static NaClMungedBitcodeIter end(const NaClMungedBitcode &MungedBitcode) {
+    return NaClMungedBitcodeIter(MungedBitcode,
+                                 MungedBitcode.BaseRecords->size());
+  }
+
+  bool operator==(const NaClMungedBitcodeIter &Iter) const;
+
+  bool operator!=(const NaClMungedBitcodeIter &Iter) const {
+    return !operator==(Iter);
+  }
+
+  /// \brief Advances the iterator over one record in the list of
+  /// edited records.
+  NaClMungedBitcodeIter &operator++();
+
+  /// \brief Returns the bitcode record the iterator is before.
+  NaClBitcodeAbbrevRecord &operator*();
+
+private:
+  /// \brief Defines position of the iterator, relative to the corresponding
+  /// record index in the base list of records.
+  enum MungedPosition {
+    /// Processing the list of records inserted before the record
+    /// index of the base list of records.
+    InBeforeInsertions,
+    /// Processing the record at the given record index of the base
+    /// list of records.
+    AtIndex,
+    /// Processing the list of records inserted after the record index
+    /// of the base list of records.
+    InAfterInsertions,
+  };
+
+  // The edited list of records to iterate over.
+  const NaClMungedBitcode *MungedBitcode;
+  // The corresponding index, wrt to the edited list of records, that
+  // is being processed.
+  size_t Index;
+  // The position of the iterator wrt to Index.
+  MungedPosition Position;
+  // An iterator defining the current position within a
+  // BeforeInsertions or AfterInsertions list. When the iterator is
+  // not in the corresponding position (i.e. InBeforeInsertions or
+  // InAfterInsertions) this iterator is undefined.
+  NaClMungedBitcode::RecordListType::const_iterator InsertionsIter;
+  // An iterator defining the end position of the corresponding list
+  // of records defined by InsertionsIter. Only defined when
+  // InsertionsIter is defined.
+  NaClMungedBitcode::RecordListType::const_iterator InsertionsIterEnd;
+  // Dummy list to initialize InsertionsIter if no such list exists.
+  NaClMungedBitcode::RecordListType EmptyList;
+
+  // \brief Defines an iterator at the beginning of the
+  // BeforeInsertions list associated with the given Index in
+  // MungedBitcode.
+  NaClMungedBitcodeIter(const NaClMungedBitcode &MungedBitcode, size_t Index)
+      : MungedBitcode(&MungedBitcode), Index(Index),
+        Position(InBeforeInsertions), InsertionsIter(), InsertionsIterEnd() {
+    placeAt(MungedBitcode.BeforeInsertionsMap, 0);
+    updatePosition();
+  }
+
+  // \brief Places the corresponding insertions iterator based on the
+  // list of records defined at Index for the given insertions Map.
+  void placeAt(const NaClMungedBitcode::InsertionsMapType &Map, size_t Index) {
+    NaClMungedBitcode::InsertionsMapType::const_iterator Pos = Map.find(Index);
+    if (Pos == Map.end()) {
+      InsertionsIter = EmptyList.end();
+      InsertionsIterEnd = EmptyList.end();
+    } else {
+      InsertionsIter = Pos->second->begin();
+      InsertionsIterEnd = Pos->second->end();
+    }
+  }
+
+  // \brief Moves the iterator to the position of the next edited
+  // record.
+  void updatePosition();
+};
+
+} // end namespace llvm.
+
+#endif // LLVM_BITCODE_NACL_NACLBITCODEMUNGE_H