1 files changed, 374 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
new file mode 100644
index 000000000000..46c52a1faf4b
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -0,0 +1,374 @@
+//===-- llvm/CodeGen/DwarfUnit.h - Dwarf Compile Unit ---*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing dwarf compile unit.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFUNIT_H
+
+#include "DwarfDebug.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/DIE.h"
+#include "llvm/IR/DIBuilder.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/MC/MCDwarf.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCSection.h"
+
+namespace llvm {
+
+class MachineLocation;
+class MachineOperand;
+class ConstantInt;
+class ConstantFP;
+class DbgVariable;
+class DwarfCompileUnit;
+
+//===----------------------------------------------------------------------===//
+/// This dwarf writer support class manages information associated with a
+/// source file.
+class DwarfUnit : public DIEUnit {
+protected:
+  /// MDNode for the compile unit.
+  const DICompileUnit *CUNode;
+
+  // All DIEValues are allocated through this allocator.
+  BumpPtrAllocator DIEValueAllocator;
+
+  /// Target of Dwarf emission.
+  AsmPrinter *Asm;
+
+  /// Emitted at the end of the CU and used to compute the CU Length field.
+  MCSymbol *EndLabel = nullptr;
+
+  // Holders for some common dwarf information.
+  DwarfDebug *DD;
+  DwarfFile *DU;
+
+  /// An anonymous type for index type.  Owned by DIEUnit.
+  DIE *IndexTyDie;
+
+  /// Tracks the mapping of unit level debug information variables to debug
+  /// information entries.
+  DenseMap<const MDNode *, DIE *> MDNodeToDieMap;
+
+  /// A list of all the DIEBlocks in use.
+  std::vector<DIEBlock *> DIEBlocks;
+
+  /// A list of all the DIELocs in use.
+  std::vector<DIELoc *> DIELocs;
+
+  /// This map is used to keep track of subprogram DIEs that need
+  /// DW_AT_containing_type attribute. This attribute points to a DIE that
+  /// corresponds to the MDNode mapped with the subprogram DIE.
+  DenseMap<DIE *, const DINode *> ContainingTypeMap;
+
+  DwarfUnit(dwarf::Tag, const DICompileUnit *Node, AsmPrinter *A, DwarfDebug *DW,
+            DwarfFile *DWU);
+
+  bool applySubprogramDefinitionAttributes(const DISubprogram *SP, DIE &SPDie);
+
+  bool shareAcrossDWOCUs() const;
+  bool isShareableAcrossCUs(const DINode *D) const;
+
+public:
+  // Accessors.
+  AsmPrinter* getAsmPrinter() const { return Asm; }
+  MCSymbol *getEndLabel() const { return EndLabel; }
+  uint16_t getLanguage() const { return CUNode->getSourceLanguage(); }
+  const DICompileUnit *getCUNode() const { return CUNode; }
+
+  uint16_t getDwarfVersion() const { return DD->getDwarfVersion(); }
+
+  /// Return true if this compile unit has something to write out.
+  bool hasContent() const { return getUnitDie().hasChildren(); }
+
+  /// Get string containing language specific context for a global name.
+  ///
+  /// Walks the metadata parent chain in a language specific manner (using the
+  /// compile unit language) and returns it as a string. This is done at the
+  /// metadata level because DIEs may not currently have been added to the
+  /// parent context and walking the DIEs looking for names is more expensive
+  /// than walking the metadata.
+  std::string getParentContextString(const DIScope *Context) const;
+
+  /// Add a new global name to the compile unit.
+  virtual void addGlobalName(StringRef Name, const DIE &Die,
+                             const DIScope *Context) = 0;
+
+  /// Add a new global type to the compile unit.
+  virtual void addGlobalType(const DIType *Ty, const DIE &Die,
+                             const DIScope *Context) = 0;
+
+  /// Returns the DIE map slot for the specified debug variable.
+  ///
+  /// We delegate the request to DwarfDebug when the MDNode can be part of the
+  /// type system, since DIEs for the type system can be shared across CUs and
+  /// the mappings are kept in DwarfDebug.
+  DIE *getDIE(const DINode *D) const;
+
+  /// Returns a fresh newly allocated DIELoc.
+  DIELoc *getDIELoc() { return new (DIEValueAllocator) DIELoc; }
+
+  /// Insert DIE into the map.
+  ///
+  /// We delegate the request to DwarfDebug when the MDNode can be part of the
+  /// type system, since DIEs for the type system can be shared across CUs and
+  /// the mappings are kept in DwarfDebug.
+  void insertDIE(const DINode *Desc, DIE *D);
+
+  void insertDIE(DIE *D);
+
+  /// Add a flag that is true to the DIE.
+  void addFlag(DIE &Die, dwarf::Attribute Attribute);
+
+  /// Add an unsigned integer attribute data and value.
+  void addUInt(DIEValueList &Die, dwarf::Attribute Attribute,
+               Optional<dwarf::Form> Form, uint64_t Integer);
+
+  void addUInt(DIEValueList &Block, dwarf::Form Form, uint64_t Integer);
+
+  /// Add an signed integer attribute data and value.
+  void addSInt(DIEValueList &Die, dwarf::Attribute Attribute,
+               Optional<dwarf::Form> Form, int64_t Integer);
+
+  void addSInt(DIELoc &Die, Optional<dwarf::Form> Form, int64_t Integer);
+
+  /// Add a string attribute data and value.
+  ///
+  /// We always emit a reference to the string pool instead of immediate
+  /// strings so that DIEs have more predictable sizes. In the case of split
+  /// dwarf we emit an index into another table which gets us the static offset
+  /// into the string table.
+  void addString(DIE &Die, dwarf::Attribute Attribute, StringRef Str);
+
+  /// Add a Dwarf label attribute data and value.
+  DIEValueList::value_iterator addLabel(DIEValueList &Die,
+                                        dwarf::Attribute Attribute,
+                                        dwarf::Form Form,
+                                        const MCSymbol *Label);
+
+  void addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label);
+
+  /// Add an offset into a section attribute data and value.
+  void addSectionOffset(DIE &Die, dwarf::Attribute Attribute, uint64_t Integer);
+
+  /// Add a dwarf op address data and value using the form given and an
+  /// op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
+  void addOpAddress(DIELoc &Die, const MCSymbol *Sym);
+
+  /// Add a label delta attribute data and value.
+  void addLabelDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
+                     const MCSymbol *Lo);
+
+  /// Add a DIE attribute data and value.
+  void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry);
+
+  /// Add a DIE attribute data and value.
+  void addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIEEntry Entry);
+
+  /// Add a type's DW_AT_signature and set the  declaration flag.
+  void addDIETypeSignature(DIE &Die, uint64_t Signature);
+
+  /// Add block data.
+  void addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc);
+
+  /// Add block data.
+  void addBlock(DIE &Die, dwarf::Attribute Attribute, DIEBlock *Block);
+
+  /// Add location information to specified debug information entry.
+  void addSourceLine(DIE &Die, unsigned Line, const DIFile *File);
+  void addSourceLine(DIE &Die, const DILocalVariable *V);
+  void addSourceLine(DIE &Die, const DIGlobalVariable *G);
+  void addSourceLine(DIE &Die, const DISubprogram *SP);
+  void addSourceLine(DIE &Die, const DILabel *L);
+  void addSourceLine(DIE &Die, const DIType *Ty);
+  void addSourceLine(DIE &Die, const DIObjCProperty *Ty);
+
+  /// Add constant value entry in variable DIE.
+  void addConstantValue(DIE &Die, const MachineOperand &MO, const DIType *Ty);
+  void addConstantValue(DIE &Die, const ConstantInt *CI, const DIType *Ty);
+  void addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty);
+  void addConstantValue(DIE &Die, const APInt &Val, bool Unsigned);
+  void addConstantValue(DIE &Die, uint64_t Val, const DIType *Ty);
+  void addConstantValue(DIE &Die, bool Unsigned, uint64_t Val);
+
+  /// Add constant value entry in variable DIE.
+  void addConstantFPValue(DIE &Die, const MachineOperand &MO);
+  void addConstantFPValue(DIE &Die, const ConstantFP *CFP);
+
+  /// Add a linkage name, if it isn't empty.
+  void addLinkageName(DIE &Die, StringRef LinkageName);
+
+  /// Add template parameters in buffer.
+  void addTemplateParams(DIE &Buffer, DINodeArray TParams);
+
+  /// Add thrown types.
+  void addThrownTypes(DIE &Die, DINodeArray ThrownTypes);
+
+  /// Add a new type attribute to the specified entity.
+  ///
+  /// This takes and attribute parameter because DW_AT_friend attributes are
+  /// also type references.
+  void addType(DIE &Entity, const DIType *Ty,
+               dwarf::Attribute Attribute = dwarf::DW_AT_type);
+
+  DIE *getOrCreateNameSpace(const DINamespace *NS);
+  DIE *getOrCreateModule(const DIModule *M);
+  DIE *getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal = false);
+
+  void applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
+                                 bool SkipSPAttributes = false);
+
+  /// Creates type DIE with specific context.
+  DIE *createTypeDIE(const DIScope *Context, DIE &ContextDIE, const DIType *Ty);
+
+  /// Find existing DIE or create new DIE for the given type.
+  DIE *getOrCreateTypeDIE(const MDNode *TyNode);
+
+  /// Get context owner's DIE.
+  DIE *getOrCreateContextDIE(const DIScope *Context);
+
+  /// Construct DIEs for types that contain vtables.
+  void constructContainingTypeDIEs();
+
+  /// Construct function argument DIEs.
+  void constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args);
+
+  /// Create a DIE with the given Tag, add the DIE to its parent, and
+  /// call insertDIE if MD is not null.
+  DIE &createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N = nullptr);
+
+  bool useSegmentedStringOffsetsTable() const {
+    return DD->useSegmentedStringOffsetsTable();
+  }
+
+  /// Compute the size of a header for this unit, not including the initial
+  /// length field.
+  virtual unsigned getHeaderSize() const {
+    return sizeof(int16_t) + // DWARF version number
+           sizeof(int32_t) + // Offset Into Abbrev. Section
+           sizeof(int8_t) +  // Pointer Size (in bytes)
+           (DD->getDwarfVersion() >= 5 ? sizeof(int8_t)
+                                       : 0); // DWARF v5 unit type
+  }
+
+  /// Emit the header for this unit, not including the initial length field.
+  virtual void emitHeader(bool UseOffsets) = 0;
+
+  /// Add the DW_AT_str_offsets_base attribute to the unit DIE.
+  void addStringOffsetsStart();
+
+  /// Add the DW_AT_rnglists_base attribute to the unit DIE.
+  void addRnglistsBase();
+
+  virtual DwarfCompileUnit &getCU() = 0;
+
+  void constructTypeDIE(DIE &Buffer, const DICompositeType *CTy);
+
+  /// addSectionDelta - Add a label delta attribute data and value.
+  DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
+                                      const MCSymbol *Hi, const MCSymbol *Lo);
+
+  /// Add a Dwarf section label attribute data and value.
+  DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
+                                      const MCSymbol *Label,
+                                      const MCSymbol *Sec);
+
+  /// If the \p File has an MD5 checksum, return it as an MD5Result
+  /// allocated in the MCContext.
+  Optional<MD5::MD5Result> getMD5AsBytes(const DIFile *File) const;
+
+  /// Get context owner's DIE.
+  DIE *createTypeDIE(const DICompositeType *Ty);
+
+protected:
+  ~DwarfUnit();
+
+  /// Create new static data member DIE.
+  DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT);
+
+  /// Look up the source ID for the given file. If none currently exists,
+  /// create a new ID and insert it in the line table.
+  virtual unsigned getOrCreateSourceID(const DIFile *File) = 0;
+
+  /// Emit the common part of the header for this unit.
+  void emitCommonHeader(bool UseOffsets, dwarf::UnitType UT);
+
+private:
+  void constructTypeDIE(DIE &Buffer, const DIBasicType *BTy);
+  void constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy);
+  void constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy);
+  void constructSubrangeDIE(DIE &Buffer, const DISubrange *SR, DIE *IndexTy);
+  void constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy);
+  void constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy);
+  DIE &constructMemberDIE(DIE &Buffer, const DIDerivedType *DT);
+  void constructTemplateTypeParameterDIE(DIE &Buffer,
+                                         const DITemplateTypeParameter *TP);
+  void constructTemplateValueParameterDIE(DIE &Buffer,
+                                          const DITemplateValueParameter *TVP);
+
+  /// Return the default lower bound for an array.
+  ///
+  /// If the DWARF version doesn't handle the language, return -1.
+  int64_t getDefaultLowerBound() const;
+
+  /// Get an anonymous type for index type.
+  DIE *getIndexTyDie();
+
+  /// Set D as anonymous type for index which can be reused later.
+  void setIndexTyDie(DIE *D) { IndexTyDie = D; }
+
+  virtual void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) = 0;
+
+  /// If this is a named finished type then include it in the list of types for
+  /// the accelerator tables.
+  void updateAcceleratorTables(const DIScope *Context, const DIType *Ty,
+                               const DIE &TyDIE);
+
+  virtual bool isDwoUnit() const = 0;
+  const MCSymbol *getCrossSectionRelativeBaseAddress() const override;
+};
+
+class DwarfTypeUnit final : public DwarfUnit {
+  uint64_t TypeSignature;
+  const DIE *Ty;
+  DwarfCompileUnit &CU;
+  MCDwarfDwoLineTable *SplitLineTable;
+  bool UsedLineTable = false;
+
+  unsigned getOrCreateSourceID(const DIFile *File) override;
+  void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override;
+  bool isDwoUnit() const override;
+
+public:
+  DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A, DwarfDebug *DW,
+                DwarfFile *DWU, MCDwarfDwoLineTable *SplitLineTable = nullptr);
+
+  void setTypeSignature(uint64_t Signature) { TypeSignature = Signature; }
+  void setType(const DIE *Ty) { this->Ty = Ty; }
+
+  /// Emit the header for this unit, not including the initial length field.
+  void emitHeader(bool UseOffsets) override;
+  unsigned getHeaderSize() const override {
+    return DwarfUnit::getHeaderSize() + sizeof(uint64_t) + // Type Signature
+           sizeof(uint32_t);                               // Type DIE Offset
+  }
+  void addGlobalName(StringRef Name, const DIE &Die,
+                     const DIScope *Context) override;
+  void addGlobalType(const DIType *Ty, const DIE &Die,
+                     const DIScope *Context) override;
+  DwarfCompileUnit &getCU() override { return CU; }
+};
+} // end llvm namespace
+#endif