1 files changed, 469 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
new file mode 100644
index 000000000000..7ffd77926cf7
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
@@ -0,0 +1,469 @@
+//===- llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h --------------*- 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 Microsoft CodeView debug info.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/PointerUnion.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
+#include "llvm/CodeGen/DebugHandlerBase.h"
+#include "llvm/DebugInfo/CodeView/CodeView.h"
+#include "llvm/DebugInfo/CodeView/GlobalTypeTableBuilder.h"
+#include "llvm/DebugInfo/CodeView/TypeIndex.h"
+#include "llvm/IR/DebugLoc.h"
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Compiler.h"
+#include <cstdint>
+#include <map>
+#include <string>
+#include <tuple>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+namespace llvm {
+
+struct ClassInfo;
+class StringRef;
+class AsmPrinter;
+class Function;
+class GlobalVariable;
+class MCSectionCOFF;
+class MCStreamer;
+class MCSymbol;
+class MachineFunction;
+
+/// Collects and handles line tables information in a CodeView format.
+class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
+  MCStreamer &OS;
+  BumpPtrAllocator Allocator;
+  codeview::GlobalTypeTableBuilder TypeTable;
+
+  /// Whether to emit type record hashes into .debug$H.
+  bool EmitDebugGlobalHashes = false;
+
+  /// The codeview CPU type used by the translation unit.
+  codeview::CPUType TheCPU;
+
+  /// Represents the most general definition range.
+  struct LocalVarDefRange {
+    /// Indicates that variable data is stored in memory relative to the
+    /// specified register.
+    int InMemory : 1;
+
+    /// Offset of variable data in memory.
+    int DataOffset : 31;
+
+    /// Non-zero if this is a piece of an aggregate.
+    uint16_t IsSubfield : 1;
+
+    /// Offset into aggregate.
+    uint16_t StructOffset : 15;
+
+    /// Register containing the data or the register base of the memory
+    /// location containing the data.
+    uint16_t CVRegister;
+
+    /// Compares all location fields. This includes all fields except the label
+    /// ranges.
+    bool isDifferentLocation(LocalVarDefRange &O) {
+      return InMemory != O.InMemory || DataOffset != O.DataOffset ||
+             IsSubfield != O.IsSubfield || StructOffset != O.StructOffset ||
+             CVRegister != O.CVRegister;
+    }
+
+    SmallVector<std::pair<const MCSymbol *, const MCSymbol *>, 1> Ranges;
+  };
+
+  static LocalVarDefRange createDefRangeMem(uint16_t CVRegister, int Offset);
+
+  /// Similar to DbgVariable in DwarfDebug, but not dwarf-specific.
+  struct LocalVariable {
+    const DILocalVariable *DIVar = nullptr;
+    SmallVector<LocalVarDefRange, 1> DefRanges;
+    bool UseReferenceType = false;
+  };
+
+  struct CVGlobalVariable {
+    const DIGlobalVariable *DIGV;
+    PointerUnion<const GlobalVariable *, const DIExpression *> GVInfo;
+  };
+
+  struct InlineSite {
+    SmallVector<LocalVariable, 1> InlinedLocals;
+    SmallVector<const DILocation *, 1> ChildSites;
+    const DISubprogram *Inlinee = nullptr;
+
+    /// The ID of the inline site or function used with .cv_loc. Not a type
+    /// index.
+    unsigned SiteFuncId = 0;
+  };
+
+  // Combines information from DILexicalBlock and LexicalScope.
+  struct LexicalBlock {
+    SmallVector<LocalVariable, 1> Locals;
+    SmallVector<CVGlobalVariable, 1> Globals;
+    SmallVector<LexicalBlock *, 1> Children;
+    const MCSymbol *Begin;
+    const MCSymbol *End;
+    StringRef Name;
+  };
+
+  // For each function, store a vector of labels to its instructions, as well as
+  // to the end of the function.
+  struct FunctionInfo {
+    FunctionInfo() = default;
+
+    // Uncopyable.
+    FunctionInfo(const FunctionInfo &FI) = delete;
+
+    /// Map from inlined call site to inlined instructions and child inlined
+    /// call sites. Listed in program order.
+    std::unordered_map<const DILocation *, InlineSite> InlineSites;
+
+    /// Ordered list of top-level inlined call sites.
+    SmallVector<const DILocation *, 1> ChildSites;
+
+    SmallVector<LocalVariable, 1> Locals;
+    SmallVector<CVGlobalVariable, 1> Globals;
+
+    std::unordered_map<const DILexicalBlockBase*, LexicalBlock> LexicalBlocks;
+
+    // Lexical blocks containing local variables.
+    SmallVector<LexicalBlock *, 1> ChildBlocks;
+
+    std::vector<std::pair<MCSymbol *, MDNode *>> Annotations;
+    std::vector<std::tuple<MCSymbol *, MCSymbol *, const DIType *>>
+        HeapAllocSites;
+
+    const MCSymbol *Begin = nullptr;
+    const MCSymbol *End = nullptr;
+    unsigned FuncId = 0;
+    unsigned LastFileId = 0;
+
+    /// Number of bytes allocated in the prologue for all local stack objects.
+    unsigned FrameSize = 0;
+
+    /// Number of bytes of parameters on the stack.
+    unsigned ParamSize = 0;
+
+    /// Number of bytes pushed to save CSRs.
+    unsigned CSRSize = 0;
+
+    /// Adjustment to apply on x86 when using the VFRAME frame pointer.
+    int OffsetAdjustment = 0;
+
+    /// Two-bit value indicating which register is the designated frame pointer
+    /// register for local variables. Included in S_FRAMEPROC.
+    codeview::EncodedFramePtrReg EncodedLocalFramePtrReg =
+        codeview::EncodedFramePtrReg::None;
+
+    /// Two-bit value indicating which register is the designated frame pointer
+    /// register for stack parameters. Included in S_FRAMEPROC.
+    codeview::EncodedFramePtrReg EncodedParamFramePtrReg =
+        codeview::EncodedFramePtrReg::None;
+
+    codeview::FrameProcedureOptions FrameProcOpts;
+
+    bool HasStackRealignment = false;
+
+    bool HaveLineInfo = false;
+  };
+  FunctionInfo *CurFn = nullptr;
+
+  // Map used to seperate variables according to the lexical scope they belong
+  // in.  This is populated by recordLocalVariable() before
+  // collectLexicalBlocks() separates the variables between the FunctionInfo
+  // and LexicalBlocks.
+  DenseMap<const LexicalScope *, SmallVector<LocalVariable, 1>> ScopeVariables;
+
+  // Map to separate global variables according to the lexical scope they
+  // belong in. A null local scope represents the global scope.
+  typedef SmallVector<CVGlobalVariable, 1> GlobalVariableList;
+  DenseMap<const DIScope*, std::unique_ptr<GlobalVariableList> > ScopeGlobals;
+
+  // Array of global variables which  need to be emitted into a COMDAT section.
+  SmallVector<CVGlobalVariable, 1> ComdatVariables;
+
+  // Array of non-COMDAT global variables.
+  SmallVector<CVGlobalVariable, 1> GlobalVariables;
+
+  /// The set of comdat .debug$S sections that we've seen so far. Each section
+  /// must start with a magic version number that must only be emitted once.
+  /// This set tracks which sections we've already opened.
+  DenseSet<MCSectionCOFF *> ComdatDebugSections;
+
+  /// Switch to the appropriate .debug$S section for GVSym. If GVSym, the symbol
+  /// of an emitted global value, is in a comdat COFF section, this will switch
+  /// to a new .debug$S section in that comdat. This method ensures that the
+  /// section starts with the magic version number on first use. If GVSym is
+  /// null, uses the main .debug$S section.
+  void switchToDebugSectionForSymbol(const MCSymbol *GVSym);
+
+  /// The next available function index for use with our .cv_* directives. Not
+  /// to be confused with type indices for LF_FUNC_ID records.
+  unsigned NextFuncId = 0;
+
+  InlineSite &getInlineSite(const DILocation *InlinedAt,
+                            const DISubprogram *Inlinee);
+
+  codeview::TypeIndex getFuncIdForSubprogram(const DISubprogram *SP);
+
+  void calculateRanges(LocalVariable &Var,
+                       const DbgValueHistoryMap::Entries &Entries);
+
+  static void collectInlineSiteChildren(SmallVectorImpl<unsigned> &Children,
+                                        const FunctionInfo &FI,
+                                        const InlineSite &Site);
+
+  /// Remember some debug info about each function. Keep it in a stable order to
+  /// emit at the end of the TU.
+  MapVector<const Function *, std::unique_ptr<FunctionInfo>> FnDebugInfo;
+
+  /// Map from full file path to .cv_file id. Full paths are built from DIFiles
+  /// and are stored in FileToFilepathMap;
+  DenseMap<StringRef, unsigned> FileIdMap;
+
+  /// All inlined subprograms in the order they should be emitted.
+  SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;
+
+  /// Map from a pair of DI metadata nodes and its DI type (or scope) that can
+  /// be nullptr, to CodeView type indices. Primarily indexed by
+  /// {DIType*, DIType*} and {DISubprogram*, DIType*}.
+  ///
+  /// The second entry in the key is needed for methods as DISubroutineType
+  /// representing static method type are shared with non-method function type.
+  DenseMap<std::pair<const DINode *, const DIType *>, codeview::TypeIndex>
+      TypeIndices;
+
+  /// Map from DICompositeType* to complete type index. Non-record types are
+  /// always looked up in the normal TypeIndices map.
+  DenseMap<const DICompositeType *, codeview::TypeIndex> CompleteTypeIndices;
+
+  /// Complete record types to emit after all active type lowerings are
+  /// finished.
+  SmallVector<const DICompositeType *, 4> DeferredCompleteTypes;
+
+  /// Number of type lowering frames active on the stack.
+  unsigned TypeEmissionLevel = 0;
+
+  codeview::TypeIndex VBPType;
+
+  const DISubprogram *CurrentSubprogram = nullptr;
+
+  // The UDTs we have seen while processing types; each entry is a pair of type
+  // index and type name.
+  std::vector<std::pair<std::string, const DIType *>> LocalUDTs;
+  std::vector<std::pair<std::string, const DIType *>> GlobalUDTs;
+
+  using FileToFilepathMapTy = std::map<const DIFile *, std::string>;
+  FileToFilepathMapTy FileToFilepathMap;
+
+  StringRef getFullFilepath(const DIFile *File);
+
+  unsigned maybeRecordFile(const DIFile *F);
+
+  void maybeRecordLocation(const DebugLoc &DL, const MachineFunction *MF);
+
+  void clear();
+
+  void setCurrentSubprogram(const DISubprogram *SP) {
+    CurrentSubprogram = SP;
+    LocalUDTs.clear();
+  }
+
+  /// Emit the magic version number at the start of a CodeView type or symbol
+  /// section. Appears at the front of every .debug$S or .debug$T or .debug$P
+  /// section.
+  void emitCodeViewMagicVersion();
+
+  void emitTypeInformation();
+
+  void emitTypeGlobalHashes();
+
+  void emitCompilerInformation();
+
+  void emitBuildInfo();
+
+  void emitInlineeLinesSubsection();
+
+  void emitDebugInfoForThunk(const Function *GV,
+                             FunctionInfo &FI,
+                             const MCSymbol *Fn);
+
+  void emitDebugInfoForFunction(const Function *GV, FunctionInfo &FI);
+
+  void emitDebugInfoForRetainedTypes();
+
+  void
+  emitDebugInfoForUDTs(ArrayRef<std::pair<std::string, const DIType *>> UDTs);
+
+  void emitDebugInfoForGlobals();
+  void emitGlobalVariableList(ArrayRef<CVGlobalVariable> Globals);
+  void emitDebugInfoForGlobal(const CVGlobalVariable &CVGV);
+
+  /// Opens a subsection of the given kind in a .debug$S codeview section.
+  /// Returns an end label for use with endCVSubsection when the subsection is
+  /// finished.
+  MCSymbol *beginCVSubsection(codeview::DebugSubsectionKind Kind);
+  void endCVSubsection(MCSymbol *EndLabel);
+
+  /// Opens a symbol record of the given kind. Returns an end label for use with
+  /// endSymbolRecord.
+  MCSymbol *beginSymbolRecord(codeview::SymbolKind Kind);
+  void endSymbolRecord(MCSymbol *SymEnd);
+
+  /// Emits an S_END, S_INLINESITE_END, or S_PROC_ID_END record. These records
+  /// are empty, so we emit them with a simpler assembly sequence that doesn't
+  /// involve labels.
+  void emitEndSymbolRecord(codeview::SymbolKind EndKind);
+
+  void emitInlinedCallSite(const FunctionInfo &FI, const DILocation *InlinedAt,
+                           const InlineSite &Site);
+
+  using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
+
+  void collectGlobalVariableInfo();
+  void collectVariableInfo(const DISubprogram *SP);
+
+  void collectVariableInfoFromMFTable(DenseSet<InlinedEntity> &Processed);
+
+  // Construct the lexical block tree for a routine, pruning emptpy lexical
+  // scopes, and populate it with local variables.
+  void collectLexicalBlockInfo(SmallVectorImpl<LexicalScope *> &Scopes,
+                               SmallVectorImpl<LexicalBlock *> &Blocks,
+                               SmallVectorImpl<LocalVariable> &Locals,
+                               SmallVectorImpl<CVGlobalVariable> &Globals);
+  void collectLexicalBlockInfo(LexicalScope &Scope,
+                               SmallVectorImpl<LexicalBlock *> &ParentBlocks,
+                               SmallVectorImpl<LocalVariable> &ParentLocals,
+                               SmallVectorImpl<CVGlobalVariable> &ParentGlobals);
+
+  /// Records information about a local variable in the appropriate scope. In
+  /// particular, locals from inlined code live inside the inlining site.
+  void recordLocalVariable(LocalVariable &&Var, const LexicalScope *LS);
+
+  /// Emits local variables in the appropriate order.
+  void emitLocalVariableList(const FunctionInfo &FI,
+                             ArrayRef<LocalVariable> Locals);
+
+  /// Emits an S_LOCAL record and its associated defined ranges.
+  void emitLocalVariable(const FunctionInfo &FI, const LocalVariable &Var);
+
+  /// Emits a sequence of lexical block scopes and their children.
+  void emitLexicalBlockList(ArrayRef<LexicalBlock *> Blocks,
+                            const FunctionInfo& FI);
+
+  /// Emit a lexical block scope and its children.
+  void emitLexicalBlock(const LexicalBlock &Block, const FunctionInfo& FI);
+
+  /// Translates the DIType to codeview if necessary and returns a type index
+  /// for it.
+  codeview::TypeIndex getTypeIndex(const DIType *Ty,
+                                   const DIType *ClassTy = nullptr);
+
+  codeview::TypeIndex
+  getTypeIndexForThisPtr(const DIDerivedType *PtrTy,
+                         const DISubroutineType *SubroutineTy);
+
+  codeview::TypeIndex getTypeIndexForReferenceTo(const DIType *Ty);
+
+  codeview::TypeIndex getMemberFunctionType(const DISubprogram *SP,
+                                            const DICompositeType *Class);
+
+  codeview::TypeIndex getScopeIndex(const DIScope *Scope);
+
+  codeview::TypeIndex getVBPTypeIndex();
+
+  void addToUDTs(const DIType *Ty);
+
+  void addUDTSrcLine(const DIType *Ty, codeview::TypeIndex TI);
+
+  codeview::TypeIndex lowerType(const DIType *Ty, const DIType *ClassTy);
+  codeview::TypeIndex lowerTypeAlias(const DIDerivedType *Ty);
+  codeview::TypeIndex lowerTypeArray(const DICompositeType *Ty);
+  codeview::TypeIndex lowerTypeBasic(const DIBasicType *Ty);
+  codeview::TypeIndex lowerTypePointer(
+      const DIDerivedType *Ty,
+      codeview::PointerOptions PO = codeview::PointerOptions::None);
+  codeview::TypeIndex lowerTypeMemberPointer(
+      const DIDerivedType *Ty,
+      codeview::PointerOptions PO = codeview::PointerOptions::None);
+  codeview::TypeIndex lowerTypeModifier(const DIDerivedType *Ty);
+  codeview::TypeIndex lowerTypeFunction(const DISubroutineType *Ty);
+  codeview::TypeIndex lowerTypeVFTableShape(const DIDerivedType *Ty);
+  codeview::TypeIndex lowerTypeMemberFunction(
+      const DISubroutineType *Ty, const DIType *ClassTy, int ThisAdjustment,
+      bool IsStaticMethod,
+      codeview::FunctionOptions FO = codeview::FunctionOptions::None);
+  codeview::TypeIndex lowerTypeEnum(const DICompositeType *Ty);
+  codeview::TypeIndex lowerTypeClass(const DICompositeType *Ty);
+  codeview::TypeIndex lowerTypeUnion(const DICompositeType *Ty);
+
+  /// Symbol records should point to complete types, but type records should
+  /// always point to incomplete types to avoid cycles in the type graph. Only
+  /// use this entry point when generating symbol records. The complete and
+  /// incomplete type indices only differ for record types. All other types use
+  /// the same index.
+  codeview::TypeIndex getCompleteTypeIndex(const DIType *Ty);
+
+  codeview::TypeIndex lowerCompleteTypeClass(const DICompositeType *Ty);
+  codeview::TypeIndex lowerCompleteTypeUnion(const DICompositeType *Ty);
+
+  struct TypeLoweringScope;
+
+  void emitDeferredCompleteTypes();
+
+  void collectMemberInfo(ClassInfo &Info, const DIDerivedType *DDTy);
+  ClassInfo collectClassInfo(const DICompositeType *Ty);
+
+  /// Common record member lowering functionality for record types, which are
+  /// structs, classes, and unions. Returns the field list index and the member
+  /// count.
+  std::tuple<codeview::TypeIndex, codeview::TypeIndex, unsigned, bool>
+  lowerRecordFieldList(const DICompositeType *Ty);
+
+  /// Inserts {{Node, ClassTy}, TI} into TypeIndices and checks for duplicates.
+  codeview::TypeIndex recordTypeIndexForDINode(const DINode *Node,
+                                               codeview::TypeIndex TI,
+                                               const DIType *ClassTy = nullptr);
+
+  unsigned getPointerSizeInBytes();
+
+protected:
+  /// Gather pre-function debug information.
+  void beginFunctionImpl(const MachineFunction *MF) override;
+
+  /// Gather post-function debug information.
+  void endFunctionImpl(const MachineFunction *) override;
+
+public:
+  CodeViewDebug(AsmPrinter *AP);
+
+  void setSymbolSize(const MCSymbol *, uint64_t) override {}
+
+  /// Emit the COFF section that holds the line table information.
+  void endModule() override;
+
+  /// Process beginning of an instruction.
+  void beginInstruction(const MachineInstr *MI) override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H