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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 for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Holds state from .cv_file and .cv_loc directives for later emission.
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/MC/MCFragment.h"
#include "llvm/MC/MCObjectStreamer.h"
#include <map>
#include <vector>
namespace llvm {
class MCContext;
class MCObjectStreamer;
class MCStreamer;
class CodeViewContext;
/// 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.
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 {
return ParentFuncIdPlusOne - 1;
/// Holds state from .cv_file and .cv_loc directives for later emission.
class 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);
bool isValidCVFileNumber(unsigned FileNumber);
/// 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);
/// 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