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//===- MCCodeView.h - Machine Code CodeView support -------------*- 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

//

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

//

// Holds state from .cv_file and .cv_loc directives for later emission.

//

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

#ifndef LLVM_MC_MCCODEVIEW_H

#define LLVM_MC_MCCODEVIEW_H

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/DenseMap.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include <map>

#include <vector>

namespace llvm {

class MCAsmLayout;

class MCCVDefRangeFragment;

class MCCVInlineLineTableFragment;

class MCDataFragment;

class MCFragment;

class MCSection;

class MCSymbol;

class MCContext;

class MCObjectStreamer;

class MCStreamer;

/// Instances of this class represent the information from a

/// .cv_loc directive.

class MCCVLoc {

  const MCSymbol *Label = nullptr;

  uint32_t FunctionId;

  uint32_t FileNum;

  uint32_t Line;

  uint16_t Column;

  uint16_t PrologueEnd : 1;

  uint16_t IsStmt : 1;

private: // CodeViewContext manages these

  friend class CodeViewContext;

  MCCVLoc(const MCSymbol *Label, unsigned functionid, unsigned fileNum,

          unsigned line, unsigned column, bool prologueend, bool isstmt)

      : Label(Label), FunctionId(functionid), FileNum(fileNum), Line(line),

        Column(column), PrologueEnd(prologueend), IsStmt(isstmt) {}

  // Allow the default copy constructor and assignment operator to be used

  // for an MCCVLoc object.

public:

  const MCSymbol *getLabel() const { return Label; }

  unsigned getFunctionId() const { return FunctionId; }

  /// Get the FileNum of this MCCVLoc.

  unsigned getFileNum() const { return FileNum; }

  /// Get the Line of this MCCVLoc.

  unsigned getLine() const { return Line; }

  /// Get the Column of this MCCVLoc.

  unsigned getColumn() const { return Column; }

  bool isPrologueEnd() const { return PrologueEnd; }

  bool isStmt() const { return IsStmt; }

  void setLabel(const MCSymbol *L) { Label = L; }

  void setFunctionId(unsigned FID) { FunctionId = FID; }

  /// Set the FileNum of this MCCVLoc.

  void setFileNum(unsigned fileNum) { FileNum = fileNum; }

  /// Set the Line of this MCCVLoc.

  void setLine(unsigned line) { Line = line; }

  /// Set the Column of this MCCVLoc.

  void setColumn(unsigned column) {

    assert(column <= UINT16_MAX);

    Column = column;

  }

  void setPrologueEnd(bool PE) { PrologueEnd = PE; }

  void setIsStmt(bool IS) { IsStmt = IS; }

};

/// Information describing a function or inlined call site introduced by

/// .cv_func_id or .cv_inline_site_id. Accumulates information from .cv_loc

/// directives used with this function's id or the id of an inlined call site

/// within this function or inlined call site.

struct MCCVFunctionInfo {

  /// If this represents an inlined call site, then ParentFuncIdPlusOne will be

  /// the parent function id plus one. If this represents a normal function,

  /// then there is no parent, and ParentFuncIdPlusOne will be FunctionSentinel.

  /// If this struct is an unallocated slot in the function info vector, then

  /// ParentFuncIdPlusOne will be zero.

  unsigned ParentFuncIdPlusOne = 0;

  enum : unsigned { FunctionSentinel = ~0U };

  struct LineInfo {

    unsigned File;

    unsigned Line;

    unsigned Col;

  };

  LineInfo InlinedAt;

  /// The section of the first .cv_loc directive used for this function, or null

  /// if none has been seen yet.

  MCSection *Section = nullptr;

  /// Map from inlined call site id to the inlined at location to use for that

  /// call site. Call chains are collapsed, so for the call chain 'f -> g -> h',

  /// the InlinedAtMap of 'f' will contain entries for 'g' and 'h' that both

  /// list the line info for the 'g' call site.

  DenseMap<unsigned, LineInfo> InlinedAtMap;

  /// Returns true if this is function info has not yet been used in a

  /// .cv_func_id or .cv_inline_site_id directive.

  bool isUnallocatedFunctionInfo() const { return ParentFuncIdPlusOne == 0; }

  /// Returns true if this represents an inlined call site, meaning

  /// ParentFuncIdPlusOne is neither zero nor ~0U.

  bool isInlinedCallSite() const {

    return !isUnallocatedFunctionInfo() &&

           ParentFuncIdPlusOne != FunctionSentinel;

  }

  unsigned getParentFuncId() const {

    assert(isInlinedCallSite());

    return ParentFuncIdPlusOne - 1;

  }

};

/// Holds state from .cv_file and .cv_loc directives for later emission.

class CodeViewContext {

public:

  CodeViewContext();

  ~CodeViewContext();

  bool isValidFileNumber(unsigned FileNumber) const;

  bool addFile(MCStreamer &OS, unsigned FileNumber, StringRef Filename,

               ArrayRef<uint8_t> ChecksumBytes, uint8_t ChecksumKind);

  /// Records the function id of a normal function. Returns false if the

  /// function id has already been used, and true otherwise.

  bool recordFunctionId(unsigned FuncId);

  /// Records the function id of an inlined call site. Records the "inlined at"

  /// location info of the call site, including what function or inlined call

  /// site it was inlined into. Returns false if the function id has already

  /// been used, and true otherwise.

  bool recordInlinedCallSiteId(unsigned FuncId, unsigned IAFunc,

                               unsigned IAFile, unsigned IALine,

                               unsigned IACol);

  /// Retreive the function info if this is a valid function id, or nullptr.

  MCCVFunctionInfo *getCVFunctionInfo(unsigned FuncId);

  /// Saves the information from the currently parsed .cv_loc directive

  /// and sets CVLocSeen.  When the next instruction is assembled an entry

  /// in the line number table with this information and the address of the

  /// instruction will be created.

  void recordCVLoc(MCContext &Ctx, const MCSymbol *Label, unsigned FunctionId,

                   unsigned FileNo, unsigned Line, unsigned Column,

                   bool PrologueEnd, bool IsStmt);

  /// Add a line entry.

  void addLineEntry(const MCCVLoc &LineEntry);

  std::vector<MCCVLoc> getFunctionLineEntries(unsigned FuncId);

  std::pair<size_t, size_t> getLineExtent(unsigned FuncId);

  ArrayRef<MCCVLoc> getLinesForExtent(size_t L, size_t R);

  /// Emits a line table substream.

  void emitLineTableForFunction(MCObjectStreamer &OS, unsigned FuncId,

                                const MCSymbol *FuncBegin,

                                const MCSymbol *FuncEnd);

  void emitInlineLineTableForFunction(MCObjectStreamer &OS,

                                      unsigned PrimaryFunctionId,

                                      unsigned SourceFileId,

                                      unsigned SourceLineNum,

                                      const MCSymbol *FnStartSym,

                                      const MCSymbol *FnEndSym);

  /// Encodes the binary annotations once we have a layout.

  void encodeInlineLineTable(MCAsmLayout &Layout,

                             MCCVInlineLineTableFragment &F);

  MCFragment *

  emitDefRange(MCObjectStreamer &OS,

               ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,

               StringRef FixedSizePortion);

  void encodeDefRange(MCAsmLayout &Layout, MCCVDefRangeFragment &F);

  /// Emits the string table substream.

  void emitStringTable(MCObjectStreamer &OS);

  /// Emits the file checksum substream.

  void emitFileChecksums(MCObjectStreamer &OS);

  /// Emits the offset into the checksum table of the given file number.

  void emitFileChecksumOffset(MCObjectStreamer &OS, unsigned FileNo);

  /// Add something to the string table.  Returns the final string as well as

  /// offset into the string table.

  std::pair<StringRef, unsigned> addToStringTable(StringRef S);

private:

  /// Map from string to string table offset.

  StringMap<unsigned> StringTable;

  /// The fragment that ultimately holds our strings.

  MCDataFragment *StrTabFragment = nullptr;

  bool InsertedStrTabFragment = false;

  MCDataFragment *getStringTableFragment();

  /// Get a string table offset.

  unsigned getStringTableOffset(StringRef S);

  struct FileInfo {

    unsigned StringTableOffset;

    // Indicates if this FileInfo corresponds to an actual file, or hasn't been

    // set yet.

    bool Assigned = false;

    uint8_t ChecksumKind;

    ArrayRef<uint8_t> Checksum;

    // Checksum offset stored as a symbol because it might be requested

    // before it has been calculated, so a fixup may be needed.

    MCSymbol *ChecksumTableOffset;

  };

  /// Array storing added file information.

  SmallVector<FileInfo, 4> Files;

  /// The offset of the first and last .cv_loc directive for a given function

  /// id.

  std::map<unsigned, std::pair<size_t, size_t>> MCCVLineStartStop;

  /// A collection of MCCVLoc for each section.

  std::vector<MCCVLoc> MCCVLines;

  /// All known functions and inlined call sites, indexed by function id.

  std::vector<MCCVFunctionInfo> Functions;

  /// Indicate whether we have already laid out the checksum table addresses or

  /// not.

  bool ChecksumOffsetsAssigned = false;

};

} // end namespace llvm

#endif