[StackMaps] Add explicit location size accessor to the stackmap parser

The reserved uint8 field in the location block of the stackmap record is used to denote the size of the location.

Patch By: [email protected]
Differential Revision: https://reviews.llvm.org/D59167

llvm-svn: 358319

Author: preames

llvm/include/llvm/Object/StackMapParser.h

@@ -114,6 +114,12 @@ class StackMapV2Parser {
       return LocationKind(P[KindOffset]);
     }
 
+    /// Get the Size for this location.
+    uint8_t getSize() const {
+        return read<uint8_t>(P + SizeOffset);
+
+    }
+
     /// Get the Dwarf register number for this location.
     uint16_t getDwarfRegNum() const {
       return read<uint16_t>(P + DwarfRegNumOffset);
@@ -148,7 +154,8 @@ class StackMapV2Parser {
     }
 
     static const int KindOffset = 0;
-    static const int DwarfRegNumOffset = KindOffset + sizeof(uint16_t);
+    static const int SizeOffset = KindOffset + sizeof(uint8_t);
+    static const int DwarfRegNumOffset = SizeOffset + sizeof(uint8_t);
     static const int SmallConstantOffset = DwarfRegNumOffset + sizeof(uint16_t);
     static const int LocationAccessorSize = sizeof(uint64_t);