[CodeView] Read and dump LF_ALIAS

llvm/include/llvm/DebugInfo/CodeView/CodeViewTypes.def

@@ -50,6 +50,7 @@ TYPE_RECORD_ALIAS(LF_STRUCTURE, 0x1505, Struct, Class)
 TYPE_RECORD_ALIAS(LF_INTERFACE, 0x1519, Interface, Class)
 TYPE_RECORD(LF_UNION, 0x1506, Union)
 TYPE_RECORD(LF_ENUM, 0x1507, Enum)
+TYPE_RECORD(LF_ALIAS, 0x150a, Alias)
 TYPE_RECORD(LF_TYPESERVER2, 0x1515, TypeServer2)
 TYPE_RECORD(LF_VFTABLE, 0x151d, VFTable)
 TYPE_RECORD(LF_VTSHAPE, 0x000a, VFTableShape)
@@ -187,7 +188,6 @@ CV_TYPE(LF_MANAGED_ST, 0x140f)
 CV_TYPE(LF_ST_MAX, 0x1500)
 CV_TYPE(LF_TYPESERVER, 0x1501)
 CV_TYPE(LF_DIMARRAY, 0x1508)
-CV_TYPE(LF_ALIAS, 0x150a)
 CV_TYPE(LF_DEFARG, 0x150b)
 CV_TYPE(LF_FRIENDFCN, 0x150c)
 CV_TYPE(LF_NESTTYPEEX, 0x1512)

llvm/include/llvm/DebugInfo/CodeView/TypeRecord.h

@@ -952,6 +952,19 @@ class EndPrecompRecord : public TypeRecord {
   uint32_t Signature = 0;
 };
 
+/// `LF_ALIAS` - A typedef where `Name` is typedef'd to `UnderlyingType`.
+class AliasRecord : public TypeRecord {
+public:
+  AliasRecord() = default;
+  explicit AliasRecord(TypeRecordKind Kind) : TypeRecord(Kind) {}
+  AliasRecord(TypeIndex UnderlyingType, StringRef Name)
+      : TypeRecord(TypeRecordKind::Alias), UnderlyingType(UnderlyingType),
+        Name(Name) {}
+
+  TypeIndex UnderlyingType;
+  StringRef Name;
+};
+
 } // end namespace codeview
 } // end namespace llvm
 

llvm/include/llvm/DebugInfo/LogicalView/Readers/LVCodeViewVisitor.h

@@ -428,6 +428,8 @@ class LVLogicalVisitor final {
                                   TypeIndex TI, LVElement *Element);
   LLVM_ABI Error visitKnownRecord(CVType &Record, EndPrecompRecord &EndPrecomp,
                                   TypeIndex TI, LVElement *Element);
+  LLVM_ABI Error visitKnownRecord(CVType &Record, AliasRecord &Alias,
+                                  TypeIndex TI, LVElement *Element);
 
   LLVM_ABI Error visitUnknownMember(CVMemberRecord &Record, TypeIndex TI);
   LLVM_ABI Error visitKnownMember(CVMemberRecord &Record, BaseClassRecord &Base,

llvm/include/llvm/DebugInfo/PDB/Native/NativeTypeTypedefAlias.h

@@ -0,0 +1,57 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEFALIAS_H
+#define LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEFALIAS_H
+
+#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/PDB/IPDBRawSymbol.h"
+#include "llvm/DebugInfo/PDB/Native/NativeRawSymbol.h"
+#include "llvm/DebugInfo/PDB/PDBTypes.h"
+
+namespace llvm {
+
+class raw_ostream;
+
+namespace pdb {
+
+class NativeSession;
+
+/// A typedef from the TPI stream (LF_ALIAS).
+class LLVM_ABI NativeTypeTypedefAlias : public NativeRawSymbol {
+public:
+  NativeTypeTypedefAlias(NativeSession &Session, SymIndexId Id,
+                         codeview::TypeIndex TI, codeview::AliasRecord Typedef);
+
+  NativeTypeTypedefAlias(NativeSession &Session, SymIndexId Id,
+                         NativeTypeTypedefAlias &UnmodifiedType,
+                         codeview::ModifierRecord Modifier);
+
+  ~NativeTypeTypedefAlias() override;
+
+  void dump(raw_ostream &OS, int Indent, PdbSymbolIdField ShowIdFields,
+            PdbSymbolIdField RecurseIdFields) const override;
+
+  std::string getName() const override;
+  SymIndexId getTypeId() const override;
+
+  SymIndexId getUnmodifiedTypeId() const override;
+  bool isConstType() const override;
+  bool isUnalignedType() const override;
+  bool isVolatileType() const override;
+
+protected:
+  codeview::AliasRecord Record;
+  NativeTypeTypedefAlias *UnmodifiedType = nullptr;
+  std::optional<codeview::ModifierRecord> Modifiers;
+};
+
+} // namespace pdb
+} // namespace llvm
+
+#endif // LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEFALIAS_H

llvm/include/llvm/DebugInfo/PDB/Native/NativeTypeTypedef.h → llvm/include/llvm/DebugInfo/PDB/Native/NativeTypeTypedefUDT.h

@@ -1,13 +1,13 @@
-//===- NativeTypeTypedef.h - info about typedef ------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEF_H
-#define LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEF_H
+#ifndef LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEFUDT_H
+#define LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEFUDT_H
 
 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
 #include "llvm/DebugInfo/PDB/IPDBRawSymbol.h"
@@ -22,13 +22,14 @@ namespace pdb {
 
 class NativeSession;
 
-class LLVM_ABI NativeTypeTypedef : public NativeRawSymbol {
+/// A typedef from the module symbol stream (S_UDT).
+class LLVM_ABI NativeTypeTypedefUDT : public NativeRawSymbol {
 public:
   // Create a pointer record for a non-simple type.
-  NativeTypeTypedef(NativeSession &Session, SymIndexId Id,
-                    codeview::UDTSym Typedef);
+  NativeTypeTypedefUDT(NativeSession &Session, SymIndexId Id,
+                       codeview::UDTSym Typedef);
 
-  ~NativeTypeTypedef() override;
+  ~NativeTypeTypedefUDT() override;
 
   void dump(raw_ostream &OS, int Indent, PdbSymbolIdField ShowIdFields,
             PdbSymbolIdField RecurseIdFields) const override;
@@ -43,4 +44,4 @@ class LLVM_ABI NativeTypeTypedef : public NativeRawSymbol {
 } // namespace pdb
 } // namespace llvm
 
-#endif // LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEF_H
+#endif // LLVM_DEBUGINFO_PDB_NATIVE_NATIVETYPETYPEDEFUDT_H

llvm/lib/DebugInfo/CodeView/RecordName.cpp

@@ -251,6 +251,11 @@ Error TypeNameComputer::visitKnownRecord(CVType &CVR,
   return Error::success();
 }
 
+Error TypeNameComputer::visitKnownRecord(CVType &CVR, AliasRecord &Alias) {
+  Name = Alias.Name;
+  return Error::success();
+}
+
 std::string llvm::codeview::computeTypeName(TypeCollection &Types,
                                             TypeIndex Index) {
   TypeNameComputer Computer(Types);

llvm/lib/DebugInfo/CodeView/TypeDumpVisitor.cpp

@@ -439,3 +439,9 @@ Error TypeDumpVisitor::visitKnownRecord(CVType &CVR,
   W->printHex("Signature", EndPrecomp.getSignature());
   return Error::success();
 }
+
+Error TypeDumpVisitor::visitKnownRecord(CVType &CVR, AliasRecord &Alias) {
+  printTypeIndex("UnderlyingType", Alias.UnderlyingType);
+  W->printString("Name", Alias.Name);
+  return Error::success();
+}

llvm/lib/DebugInfo/CodeView/TypeIndexDiscovery.cpp

@@ -352,6 +352,9 @@ static void discoverTypeIndices(ArrayRef<uint8_t> Content, TypeLeafKind Kind,
   case TypeLeafKind::LF_POINTER:
     handlePointer(Content, Refs);
     break;
+  case TypeLeafKind::LF_ALIAS:
+    Refs.push_back({TiRefKind::TypeRef, 0, 1}); // UnderlyingType
+    break;
   default:
     break;
   }

llvm/lib/DebugInfo/CodeView/TypeRecordMapping.cpp

@@ -721,3 +721,9 @@ Error TypeRecordMapping::visitKnownRecord(CVType &CVR,
   error(IO.mapInteger(EndPrecomp.Signature, "Signature"));
   return Error::success();
 }
+
+Error TypeRecordMapping::visitKnownRecord(CVType &CVR, AliasRecord &Alias) {
+  error(IO.mapInteger(Alias.UnderlyingType, "UnderlyingType"));
+  error(IO.mapStringZ(Alias.Name, "Name"));
+  return Error::success();
+}

llvm/lib/DebugInfo/LogicalView/Readers/LVCodeViewVisitor.cpp

@@ -2671,6 +2671,18 @@ Error LVLogicalVisitor::visitKnownRecord(CVType &Record,
   return Error::success();
 }
 
+// LF_ALIAS (TPI)
+Error LVLogicalVisitor::visitKnownRecord(CVType &Record, AliasRecord &Alias,
+                                         TypeIndex TI, LVElement *Element) {
+  LLVM_DEBUG({
+    printTypeBegin(Record, TI, Element, StreamTPI);
+    printTypeIndex("UnderlyingType", Alias.UnderlyingType, StreamTPI);
+    W.printString("Name", Alias.Name);
+    printTypeEnd(Record);
+  });
+  return Error::success();
+}
+
 Error LVLogicalVisitor::visitUnknownMember(CVMemberRecord &Record,
                                            TypeIndex TI) {
   LLVM_DEBUG({ W.printHex("UnknownMember", unsigned(Record.Kind)); });

llvm/lib/DebugInfo/PDB/CMakeLists.txt

@@ -69,7 +69,8 @@ add_pdb_impl_folder(Native
   Native/NativeTypeEnum.cpp
   Native/NativeTypeFunctionSig.cpp
   Native/NativeTypePointer.cpp
-  Native/NativeTypeTypedef.cpp
+  Native/NativeTypeTypedefAlias.cpp
+  Native/NativeTypeTypedefUDT.cpp
   Native/NativeTypeUDT.cpp
   Native/NativeTypeVTShape.cpp
   Native/NamedStreamMap.cpp

llvm/lib/DebugInfo/PDB/Native/NativeTypeTypedefAlias.cpp

@@ -0,0 +1,83 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Native/NativeTypeTypedefAlias.h"
+#include "llvm/DebugInfo/PDB/Native/NativeSession.h"
+#include "llvm/DebugInfo/PDB/PDBExtras.h"
+
+using namespace llvm;
+using namespace llvm::codeview;
+using namespace llvm::pdb;
+
+NativeTypeTypedefAlias::NativeTypeTypedefAlias(NativeSession &Session,
+                                               SymIndexId Id,
+                                               TypeIndex /* TI */,
+                                               codeview::AliasRecord Typedef)
+    : NativeRawSymbol(Session, PDB_SymType::Typedef, Id),
+      Record(std::move(Typedef)) {}
+
+NativeTypeTypedefAlias::NativeTypeTypedefAlias(
+    NativeSession &Session, SymIndexId Id,
+    NativeTypeTypedefAlias &UnmodifiedType, codeview::ModifierRecord Modifier)
+    : NativeRawSymbol(Session, PDB_SymType::Typedef, Id),
+      UnmodifiedType(&UnmodifiedType), Modifiers(Modifier) {}
+
+NativeTypeTypedefAlias::~NativeTypeTypedefAlias() = default;
+
+void NativeTypeTypedefAlias::dump(raw_ostream &OS, int Indent,
+                                  PdbSymbolIdField ShowIdFields,
+                                  PdbSymbolIdField RecurseIdFields) const {
+  NativeRawSymbol::dump(OS, Indent, ShowIdFields, RecurseIdFields);
+  dumpSymbolField(OS, "name", getName(), Indent);
+  dumpSymbolIdField(OS, "typeId", getTypeId(), Indent, Session,
+                    PdbSymbolIdField::Type, ShowIdFields, RecurseIdFields);
+  dumpSymbolField(OS, "constType", isConstType(), Indent);
+  dumpSymbolField(OS, "unalignedType", isUnalignedType(), Indent);
+  dumpSymbolField(OS, "volatileType", isVolatileType(), Indent);
+}
+
+std::string NativeTypeTypedefAlias::getName() const {
+  if (UnmodifiedType)
+    return UnmodifiedType->getName();
+  return std::string(Record.Name);
+}
+
+SymIndexId NativeTypeTypedefAlias::getTypeId() const {
+  if (UnmodifiedType)
+    return UnmodifiedType->getTypeId();
+
+  return Session.getSymbolCache().findSymbolByTypeIndex(Record.UnderlyingType);
+}
+
+SymIndexId NativeTypeTypedefAlias::getUnmodifiedTypeId() const {
+  if (UnmodifiedType)
+    return UnmodifiedType->getSymIndexId();
+
+  return 0;
+}
+
+bool NativeTypeTypedefAlias::isConstType() const {
+  if (!Modifiers)
+    return false;
+  return (Modifiers->Modifiers & ModifierOptions::Const) !=
+         ModifierOptions::None;
+}
+
+bool NativeTypeTypedefAlias::isUnalignedType() const {
+  if (!Modifiers)
+    return false;
+  return (Modifiers->Modifiers & ModifierOptions::Unaligned) !=
+         ModifierOptions::None;
+}
+
+bool NativeTypeTypedefAlias::isVolatileType() const {
+  if (!Modifiers)
+    return false;
+  return (Modifiers->Modifiers & ModifierOptions::Volatile) !=
+         ModifierOptions::None;
+}

llvm/lib/DebugInfo/PDB/Native/NativeTypeTypedefUDT.cpp

@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Native/NativeTypeTypedefUDT.h"
+#include "llvm/DebugInfo/PDB/Native/NativeSession.h"
+#include "llvm/DebugInfo/PDB/PDBExtras.h"
+
+using namespace llvm;
+using namespace llvm::codeview;
+using namespace llvm::pdb;
+
+NativeTypeTypedefUDT::NativeTypeTypedefUDT(NativeSession &Session,
+                                           SymIndexId Id,
+                                           codeview::UDTSym Typedef)
+    : NativeRawSymbol(Session, PDB_SymType::Typedef, Id),
+      Record(std::move(Typedef)) {}
+
+NativeTypeTypedefUDT::~NativeTypeTypedefUDT() = default;
+
+void NativeTypeTypedefUDT::dump(raw_ostream &OS, int Indent,
+                                PdbSymbolIdField ShowIdFields,
+                                PdbSymbolIdField RecurseIdFields) const {
+  NativeRawSymbol::dump(OS, Indent, ShowIdFields, RecurseIdFields);
+  dumpSymbolField(OS, "name", getName(), Indent);
+  dumpSymbolIdField(OS, "typeId", getTypeId(), Indent, Session,
+                    PdbSymbolIdField::Type, ShowIdFields, RecurseIdFields);
+}
+
+std::string NativeTypeTypedefUDT::getName() const {
+  return std::string(Record.Name);
+}
+
+SymIndexId NativeTypeTypedefUDT::getTypeId() const {
+  return Session.getSymbolCache().findSymbolByTypeIndex(Record.Type);
+}