Support for reading run counts in llvm-cov.

This patch enables llvm-cov to correctly output the run count stored in
the GCDA file. GCOVProfiling currently does not generate this
information, so the GCDA run data had to be hacked on from a GCDA file
generated by gcc. This is corrected by a subsequent patch.

With the run and program data included, both llvm-cov and gcov produced
the same output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194033 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/GCOV.cpp b/lib/IR/GCOV.cpp
index 794ead9..a33da2a 100644
--- a/lib/IR/GCOV.cpp
+++ b/lib/IR/GCOV.cpp
@@ -59,8 +59,18 @@
       (void)ReadGCDA;
       assert(ReadGCDA && ".gcda data does not match .gcno data");
     }
-    while (Buffer.readProgramTag())
+    if (Buffer.readObjectTag()) {
+      uint32_t Length = Buffer.readInt();
+      Buffer.readInt(); // checksum
+      Buffer.readInt(); // num
+      RunCount = Buffer.readInt();
+      Buffer.advanceCursor(Length-3);
+    }
+    while (Buffer.readProgramTag()) {
+      uint32_t Length = Buffer.readInt();
+      Buffer.advanceCursor(Length);
       ++ProgramCount;
+    }
   }
 
   return true;
@@ -79,6 +89,7 @@
   for (SmallVectorImpl<GCOVFunction *>::iterator I = Functions.begin(),
          E = Functions.end(); I != E; ++I) 
     (*I)->collectLineCounts(FI);
+  FI.setRunCount(RunCount);
   FI.setProgramCount(ProgramCount);
 }
 
@@ -258,6 +269,7 @@
     OS << "        -:    0:Source:" << Filename << "\n";
     OS << "        -:    0:Graph:" << gcnoFile << "\n";
     OS << "        -:    0:Data:" << gcdaFile << "\n";
+    OS << "        -:    0:Runs:" << RunCount << "\n";
     OS << "        -:    0:Programs:" << ProgramCount << "\n";
     LineCounts &L = LineInfo[Filename];
     OwningPtr<MemoryBuffer> Buff;