Add CodeViewRecordIO for reading and writing.

Using a pattern similar to that of YamlIO, this allows
us to have a single codepath for translating codeview
records to and from serialized byte streams.  The
current patch only hooks this up to the reading of
CodeView type records.  A subsequent patch will hook
it up for writing of CodeView type records, and then a
third patch will hook up the reading and writing of
CodeView symbols.

Differential Revision: https://reviews.llvm.org/D26040

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285836 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/DebugInfo/CodeView/CodeViewRecordIO.h

@@ -0,0 +1,135 @@
+//===- CodeViewRecordIO.h ---------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_CODEVIEW_CODEVIEWRECORDIO_H
+#define LLVM_DEBUGINFO_CODEVIEW_CODEVIEWRECORDIO_H
+
+#include "llvm/ADT/APSInt.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/DebugInfo/CodeView/TypeIndex.h"
+#include "llvm/DebugInfo/MSF/StreamReader.h"
+#include "llvm/DebugInfo/MSF/StreamWriter.h"
+#include "llvm/Support/Error.h"
+
+#include <stdint.h>
+#include <type_traits>
+
+namespace llvm {
+namespace msf {
+class StreamReader;
+class StreamWriter;
+}
+namespace codeview {
+
+class CodeViewRecordIO {
+  struct ActiveRecord {
+    uint16_t Kind;
+  };
+
+public:
+  explicit CodeViewRecordIO(msf::StreamReader &Reader) : Reader(&Reader) {}
+  explicit CodeViewRecordIO(msf::StreamWriter &Writer) : Writer(&Writer) {}
+
+  Error beginRecord(uint16_t Kind);
+  Error endRecord();
+  Error mapInteger(TypeIndex &TypeInd);
+
+  bool isReading() const { return Reader != nullptr; }
+  bool isWriting() const { return !isReading(); }
+
+  template <typename T> Error mapInteger(T &Value) {
+    if (isWriting())
+      return Writer->writeInteger(Value);
+
+    return Reader->readInteger(Value);
+  }
+
+  template <typename T> Error mapEnum(T &Value) {
+    using U = typename std::underlying_type<T>::type;
+    U X;
+    if (isWriting())
+      X = static_cast<U>(Value);
+
+    if (auto EC = mapInteger(X))
+      return EC;
+    if (isReading())
+      Value = static_cast<T>(X);
+    return Error::success();
+  }
+
+  Error mapEncodedInteger(int64_t &Value);
+  Error mapEncodedInteger(uint64_t &Value);
+  Error mapEncodedInteger(APSInt &Value);
+  Error mapStringZ(StringRef &Value);
+  Error mapGuid(StringRef &Guid);
+
+  template <typename SizeType, typename T, typename ElementMapper>
+  Error mapVectorN(T &Items, const ElementMapper &Mapper) {
+    SizeType Size;
+    if (isWriting()) {
+      Size = static_cast<SizeType>(Items.size());
+      if (auto EC = Writer->writeInteger(Size))
+        return EC;
+
+      for (auto &X : Items) {
+        if (auto EC = Mapper(*this, X))
+          return EC;
+      }
+    } else {
+      if (auto EC = Reader->readInteger(Size))
+        return EC;
+      for (SizeType I = 0; I < Size; ++I) {
+        typename T::value_type Item;
+        if (auto EC = Mapper(*this, Item))
+          return EC;
+        Items.push_back(Item);
+      }
+    }
+
+    return Error::success();
+  }
+
+  template <typename T, typename ElementMapper>
+  Error mapVectorTail(T &Items, const ElementMapper &Mapper) {
+    if (isWriting()) {
+      for (auto &Item : Items) {
+        if (auto EC = Mapper(*this, Item))
+          return EC;
+      }
+    } else {
+      typename T::value_type Field;
+      // Stop when we run out of bytes or we hit record padding bytes.
+      while (!Reader->empty() && Reader->peek() < LF_PAD0) {
+        if (auto EC = Mapper(*this, Field))
+          return EC;
+        Items.push_back(Field);
+      }
+    }
+    return Error::success();
+  }
+
+  Error mapByteVectorTail(ArrayRef<uint8_t> &Bytes);
+
+  Error skipPadding();
+
+private:
+  Error writeEncodedSignedInteger(const int64_t &Value);
+  Error writeEncodedUnsignedInteger(const uint64_t &Value);
+
+  Optional<ActiveRecord> CurrentRecord;
+
+  msf::StreamReader *Reader = nullptr;
+  msf::StreamWriter *Writer = nullptr;
+};
+}
+}
+
+#endif

include/llvm/DebugInfo/CodeView/TypeDeserializer.h

@@ -10,57 +10,108 @@
 #ifndef LLVM_DEBUGINFO_CODEVIEW_TYPEDESERIALIZER_H
 #define LLVM_DEBUGINFO_CODEVIEW_TYPEDESERIALIZER_H
 
+#include "llvm/ADT/Optional.h"
+#include "llvm/DebugInfo/CodeView/CodeViewRecordIO.h"
+#include "llvm/DebugInfo/CodeView/TypeRecordMapping.h"
 #include "llvm/DebugInfo/CodeView/TypeVisitorCallbacks.h"
 #include "llvm/DebugInfo/MSF/ByteStream.h"
 #include "llvm/DebugInfo/MSF/StreamReader.h"
+#include "llvm/DebugInfo/MSF/StreamWriter.h"
 #include "llvm/Support/Error.h"
 
 namespace llvm {
 namespace codeview {
+
 class TypeDeserializer : public TypeVisitorCallbacks {
+  struct MappingInfo {
+    explicit MappingInfo(ArrayRef<uint8_t> RecordData)
+        : Stream(RecordData), Reader(Stream), Mapping(Reader) {}
+
+    msf::ByteStream Stream;
+    msf::StreamReader Reader;
+    TypeRecordMapping Mapping;
+  };
+
 public:
   TypeDeserializer() {}
 
+  Error visitTypeBegin(CVType &Record) override {
+    assert(!Mapping && "Already in a type mapping!");
+    Mapping = llvm::make_unique<MappingInfo>(Record.content());
+    return Mapping->Mapping.visitTypeBegin(Record);
+  }
+  Error visitTypeEnd(CVType &Record) override {
+    assert(Mapping && "Not in a type mapping!");
+    auto EC = Mapping->Mapping.visitTypeEnd(Record);
+    Mapping.reset();
+    return EC;
+  }
+
 #define TYPE_RECORD(EnumName, EnumVal, Name)                                   \
   Error visitKnownRecord(CVType &CVR, Name##Record &Record) override {         \
-    return defaultVisitKnownRecord(CVR, Record);                               \
-  }
-#define MEMBER_RECORD(EnumName, EnumVal, Name)                                 \
-  Error visitKnownMember(CVMemberRecord &CVR, Name##Record &Record) override { \
-    return defaultVisitKnownMember(CVR, Record);                               \
+    return visitKnownRecordImpl<Name##Record>(CVR, Record);                    \
   }
+#define MEMBER_RECORD(EnumName, EnumVal, Name)
 #define TYPE_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
 #define MEMBER_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
 #include "TypeRecords.def"
 
-protected:
-  template <typename T>
-  Error deserializeRecord(msf::StreamReader &Reader, TypeLeafKind Kind,
-                          T &Record) const {
-    TypeRecordKind RK = static_cast<TypeRecordKind>(Kind);
-    auto ExpectedRecord = T::deserialize(RK, Reader);
-    if (!ExpectedRecord)
-      return ExpectedRecord.takeError();
-    Record = std::move(*ExpectedRecord);
-    return Error::success();
+private:
+  template <typename RecordType>
+  Error visitKnownRecordImpl(CVType &CVR, RecordType &Record) {
+    return Mapping->Mapping.visitKnownRecord(CVR, Record);
   }
 
-private:
-  template <typename T> Error defaultVisitKnownRecord(CVType &CVR, T &Record) {
-    msf::ByteStream S(CVR.content());
-    msf::StreamReader SR(S);
-    if (auto EC = deserializeRecord(SR, CVR.Type, Record))
+  std::unique_ptr<MappingInfo> Mapping;
+};
+
+class FieldListDeserializer : public TypeVisitorCallbacks {
+  struct MappingInfo {
+    explicit MappingInfo(msf::StreamReader &R)
+        : Reader(R), Mapping(Reader), StartOffset(0) {}
+
+    msf::StreamReader &Reader;
+    TypeRecordMapping Mapping;
+    uint32_t StartOffset;
+  };
+
+public:
+  explicit FieldListDeserializer(msf::StreamReader &Reader) : Mapping(Reader) {}
+
+  Error visitMemberBegin(CVMemberRecord &Record) override {
+    Mapping.StartOffset = Mapping.Reader.getOffset();
+    return Mapping.Mapping.visitMemberBegin(Record);
+  }
+  Error visitMemberEnd(CVMemberRecord &Record) override {
+    if (auto EC = Mapping.Mapping.visitMemberEnd(Record))
       return EC;
     return Error::success();
   }
-  template <typename T>
-  Error defaultVisitKnownMember(CVMemberRecord &CVMR, T &Record) {
-    msf::ByteStream S(CVMR.Data);
-    msf::StreamReader SR(S);
-    if (auto EC = deserializeRecord(SR, CVMR.Kind, Record))
+
+#define TYPE_RECORD(EnumName, EnumVal, Name)
+#define MEMBER_RECORD(EnumName, EnumVal, Name)                                 \
+  Error visitKnownMember(CVMemberRecord &CVR, Name##Record &Record) override { \
+    return visitKnownMemberImpl<Name##Record>(CVR, Record);                    \
+  }
+#define TYPE_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
+#define MEMBER_RECORD_ALIAS(EnumName, EnumVal, Name, AliasName)
+#include "TypeRecords.def"
+
+private:
+  template <typename RecordType>
+  Error visitKnownMemberImpl(CVMemberRecord &CVR, RecordType &Record) {
+    if (auto EC = Mapping.Mapping.visitKnownMember(CVR, Record))
+      return EC;
+
+    uint32_t EndOffset = Mapping.Reader.getOffset();
+    uint32_t RecordLength = EndOffset - Mapping.StartOffset;
+    Mapping.Reader.setOffset(Mapping.StartOffset);
+    if (auto EC = Mapping.Reader.readBytes(CVR.Data, RecordLength))
       return EC;
+    assert(Mapping.Reader.getOffset() == EndOffset);
     return Error::success();
   }
+  MappingInfo Mapping;
 };
 }
 }

include/llvm/DebugInfo/CodeView/TypeIndex.h

@@ -101,6 +101,7 @@ class TypeIndex {
       : Index(static_cast<uint32_t>(Kind) | static_cast<uint32_t>(Mode)) {}
 
   uint32_t getIndex() const { return Index; }
+  void setIndex(uint32_t I) { Index = I; }
   bool isSimple() const { return Index < FirstNonSimpleIndex; }
 
   bool isNoneType() const { return *this == None(); }