[DebugInfo][test] Fix calculation of generated line table size

[jhenderson]

Summary

The change rG1271cde47456 incorrectly calculated the size of a line table's contents, when non-byte operands were used as arguments for extended or standard opcodes. This change fixes the calculation.

[dblaikie]

Perhaps worth a test case that exercises this new functionality/change in behavior?

[jhenderson]

In D73901#1855137, @dblaikie wrote:

Perhaps worth a test case that exercises this new functionality/change in behavior?

I've got one in the pipeline (it's how I found this bug). Will upload later today.

[jhenderson]

In D73901#1856447, @jhenderson wrote:

In D73901#1855137, @dblaikie wrote:

Perhaps worth a test case that exercises this new functionality/change in behavior?

I've got one in the pipeline (it's how I found this bug). Will upload later today.

One of the unit tests introduced in D73962 uses this functionality.

[dblaikie]

In D73901#1856901, @jhenderson wrote:

In D73901#1856447, @jhenderson wrote:

In D73901#1855137, @dblaikie wrote:

Perhaps worth a test case that exercises this new functionality/change in behavior?

I've got one in the pipeline (it's how I found this bug). Will upload later today.

One of the unit tests introduced in D73962 uses this functionality.

While small patches are generally good - changes in functionality should be exercised when added, so might be best to include this change in that one?

[jhenderson]

Okay, I'll go ahead and fold this into D73962.

[jhenderson]

I've folded this change into D73962 as requested.

llvm/unittests/DebugInfo/DWARF/DwarfGenerator.h

 private:
   void writeData(ArrayRef<ValueAndLength> Data, AsmPrinter &Asm) const;
   MCSymbol *writeDefaultPrologue(AsmPrinter &Asm) const;
   void writePrologue(AsmPrinter &Asm) const;
 
   void writeProloguePayload(const DWARFDebugLine::Prologue &Prologue,
                             AsmPrinter &Asm) const;
 
+  // Calculate the number of bytes the Contents will take up.
+  size_t getContentsSize() const;
+
   llvm::Optional<DWARFDebugLine::Prologue> Prologue;
   std::vector<ValueAndLength> CustomPrologue;
   std::vector<ValueAndLength> Contents;
 
   // The Version field is used for determining how to write the Prologue, if a
   // non-custom prologue is used. The version value actually written, will be
   // that specified in the Prologue, if a custom prologue has been passed in.
   // Otherwise, it will be this value.

llvm/unittests/DebugInfo/DWARF/DwarfGenerator.cpp

 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCObjectFileInfo.h"
 #include "llvm/MC/MCObjectWriter.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCTargetOptionsCommandFlags.inc"
 #include "llvm/PassAnalysisSupport.h"
+#include "llvm/Support/LEB128.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"
 
 using namespace llvm;
 using namespace dwarf;
case 5:
     break;
   default:
     llvm_unreachable("unsupported version");
   }
   if (Format == DWARF64) {
     P.TotalLength += 4;
     P.FormParams.Format = DWARF64;
   }
-  P.TotalLength += Contents.size();
+  P.TotalLength += getContentsSize();
   P.FormParams.Version = Version;
   P.MinInstLength = 1;
   P.MaxOpsPerInst = 1;
   P.DefaultIsStmt = 1;
   P.LineBase = -5;
   P.LineRange = 14;
   P.OpcodeBase = 13;
   P.StandardOpcodeLengths = {0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1};
for (auto Entry : Data) {
     case SLEB:
       Asm.EmitSLEB128(Entry.Value);
       continue;
     }
     llvm_unreachable("unsupported ValueAndLength Length value");
   }
 }
 
+size_t dwarfgen::LineTable::getContentsSize() const {
+  size_t Size = 0;
+  for (auto Entry : Contents) {
+    switch (Entry.Length) {
+    case ULEB:
+      Size += getULEB128Size(Entry.Value);
+      break;
+    case SLEB:
+      Size += getSLEB128Size(Entry.Value);
+      break;
+    default:
+      Size += Entry.Length;
+      break;
+    }
+  }
+  return Size;
+}
+
 MCSymbol *dwarfgen::LineTable::writeDefaultPrologue(AsmPrinter &Asm) const {
   MCSymbol *UnitStart = Asm.createTempSymbol("line_unit_start");
   MCSymbol *UnitEnd = Asm.createTempSymbol("line_unit_end");
   if (Format == DwarfFormat::DWARF64) {
     Asm.emitInt32((int)dwarf::DW_LENGTH_DWARF64);
     Asm.EmitLabelDifference(UnitEnd, UnitStart, 8);
   } else {
     Asm.EmitLabelDifference(UnitEnd, UnitStart, 4);