[llvm] r257742 - [CodeView] Add support for dumping binary annotations

[David Majnemer via llvm-commits]

Author: majnemer
Date: Thu Jan 14 00:12:30 2016
New Revision: 257742

URL: http://llvm.org/viewvc/llvm-project?rev=257742&view=rev
Log:
[CodeView] Add support for dumping binary annotations

Binary annotations are encoded along the lines of UTF-8 and ECI but with
a few minor differences.

The algorithm specified in "ECMA-335 CLI Section II.3.2 - Blobs and
Signatures" is used to compress binary annotations.  Signed binary
annotations are encoded like unsigned annotations except the sign bit is
rotated left to reduce the number of bits needed to be encoded.

Modified:
    llvm/trunk/include/llvm/DebugInfo/CodeView/SymbolRecord.h
    llvm/trunk/tools/llvm-readobj/COFFDumper.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/CodeView/SymbolRecord.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/CodeView/SymbolRecord.h?rev=257742&r1=257741&r2=257742&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/CodeView/SymbolRecord.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/CodeView/SymbolRecord.h Thu Jan 14 00:12:30 2016
@@ -66,6 +66,23 @@ struct ProcSym {
   // Name: The null-terminated name follows.
 };
 
+enum BinaryAnnotationsOpCode : uint32_t {
+  Invalid,
+  CodeOffset,
+  ChangeCodeOffsetBase,
+  ChangeCodeOffset,
+  ChangeCodeLength,
+  ChangeFile,
+  ChangeLineOffset,
+  ChangeLineEndDelta,
+  ChangeRangeKind,
+  ChangeColumnStart,
+  ChangeColumnEndDelta,
+  ChangeCodeOffsetAndLineOffset,
+  ChangeCodeLengthAndCodeOffset,
+  ChangeColumnEnd,
+};
+
 // S_INLINESITE
 struct InlineSiteSym {
   ulittle32_t PtrParent;

Modified: llvm/trunk/tools/llvm-readobj/COFFDumper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-readobj/COFFDumper.cpp?rev=257742&r1=257741&r2=257742&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-readobj/COFFDumper.cpp (original)
+++ llvm/trunk/tools/llvm-readobj/COFFDumper.cpp Thu Jan 14 00:12:30 2016
@@ -1321,7 +1321,106 @@ void COFFDumper::printCodeViewSymbolsSub
       W.printHex("PtrParent", InlineSite->PtrParent);
       W.printHex("PtrEnd", InlineSite->PtrEnd);
       printTypeIndex("Inlinee", InlineSite->Inlinee);
-      W.printBinaryBlock("BinaryAnnotations", SymData);
+
+      auto GetCompressedAnnotation = [&]() -> uint32_t {
+        if (SymData.empty())
+          return -1;
+
+        uint8_t FirstByte = SymData.front();
+        SymData = SymData.drop_front();
+
+        if ((FirstByte & 0x80) == 0x00)
+          return FirstByte;
+
+        if (SymData.empty())
+          return -1;
+
+        uint8_t SecondByte = SymData.front();
+        SymData = SymData.drop_front();
+
+        if ((FirstByte & 0xC0) == 0x80)
+          return ((FirstByte & 0x3F) << 8) | SecondByte;
+
+        if (SymData.empty())
+          return -1;
+
+        uint8_t ThirdByte = SymData.front();
+        SymData = SymData.drop_front();
+
+        if (SymData.empty())
+          return -1;
+
+        uint8_t FourthByte = SymData.front();
+        SymData = SymData.drop_front();
+
+        if ((FirstByte & 0xE0) == 0xC0)
+          return ((FirstByte & 0x1F) << 24) | (SecondByte << 16) |
+                 (ThirdByte << 8) | FourthByte;
+
+        return -1;
+      };
+      auto DecodeSignedOperand = [](uint32_t Operand) -> int32_t {
+        if (Operand & 1)
+          return -(Operand >> 1);
+        return Operand >> 1;
+      };
+
+      ListScope BinaryAnnotations(W, "BinaryAnnotations");
+      while (!SymData.empty()) {
+        uint32_t OpCode = GetCompressedAnnotation();
+        switch (OpCode) {
+        default:
+        case Invalid:
+          return error(object_error::parse_failed);
+        case CodeOffset:
+          W.printNumber("CodeOffset", GetCompressedAnnotation());
+          break;
+        case ChangeCodeOffsetBase:
+          W.printNumber("ChangeCodeOffsetBase", GetCompressedAnnotation());
+          break;
+        case ChangeCodeOffset:
+          W.printNumber("ChangeCodeOffset", GetCompressedAnnotation());
+          break;
+        case ChangeCodeLength:
+          W.printNumber("ChangeCodeLength", GetCompressedAnnotation());
+          break;
+        case ChangeFile:
+          W.printNumber("ChangeFile", GetCompressedAnnotation());
+          break;
+        case ChangeLineOffset:
+          W.printNumber("ChangeLineOffset",
+                        DecodeSignedOperand(GetCompressedAnnotation()));
+          break;
+        case ChangeLineEndDelta:
+          W.printNumber("ChangeLineEndDelta", GetCompressedAnnotation());
+          break;
+        case ChangeRangeKind:
+          W.printNumber("ChangeRangeKind", GetCompressedAnnotation());
+          break;
+        case ChangeColumnStart:
+          W.printNumber("ChangeColumnStart", GetCompressedAnnotation());
+          break;
+        case ChangeColumnEndDelta:
+          W.printNumber("ChangeColumnEndDelta",
+                        DecodeSignedOperand(GetCompressedAnnotation()));
+          break;
+        case ChangeCodeOffsetAndLineOffset: {
+          uint32_t Annotation = GetCompressedAnnotation();
+          uint32_t Operands[] = {Annotation >> 4, Annotation & 0xf};
+          W.printList("ChangeCodeOffsetAndLineOffset", Operands);
+          break;
+        }
+        case ChangeCodeLengthAndCodeOffset: {
+          uint32_t Operands[] = {GetCompressedAnnotation(),
+                                 GetCompressedAnnotation()};
+          W.printList("ChangeCodeLengthAndCodeOffset", Operands);
+          break;
+        }
+        case ChangeColumnEnd:
+          W.printNumber("ChangeColumnEnd", GetCompressedAnnotation());
+          break;
+        }
+      }
       break;
     }