[esan|cfrag] Handle binaries built with -esan-aux-field-info=false

Summary:
Handles binaries built with -esan-aux-field-info=false and print less
information.

Updates test struct-simple.cpp.

Reviewers: aizatsky

Subscribers: llvm-commits, bruening, eugenis, kcc, zhaoqin, kubabrecka, vitalybuka

Differential Revision: http://reviews.llvm.org/D22020

llvm-svn: 274727
diff --git a/compiler-rt/lib/esan/cache_frag.cpp b/compiler-rt/lib/esan/cache_frag.cpp
index e3384a9..343abfc 100644
--- a/compiler-rt/lib/esan/cache_frag.cpp
+++ b/compiler-rt/lib/esan/cache_frag.cpp
@@ -28,11 +28,12 @@
   const char *StructName;
   u32 Size;
   u32 NumFields;
-  u32 *FieldOffsets;
-  u32 *FieldSize;
-  const char **FieldTypeNames;
+  u32 *FieldOffset;           // auxiliary struct field info.
+  u32 *FieldSize;             // auxiliary struct field info.
+  const char **FieldTypeName; // auxiliary struct field info.
   u64 *FieldCounters;
   u64 *ArrayCounter;
+  bool hasAuxFieldInfo() { return FieldOffset != nullptr; }
 };
 
 // This should be kept consistent with LLVM's EfficiencySanitizer CacheFragInfo.
@@ -99,10 +100,17 @@
   Report("  %s %.*s\n", type, end - start, start);
   Report("   size = %u, count = %llu, ratio = %llu, array access = %llu\n",
          Struct->Size, Handle->Count, Handle->Ratio, *Struct->ArrayCounter);
-  for (u32 i = 0; i < Struct->NumFields; ++i) {
-    Report("   #%2u: offset = %u,\t size = %u,\t count = %llu,\t type = %.*s\n",
-           i, Struct->FieldOffsets[i], Struct->FieldSize[i],
-           Struct->FieldCounters[i], TypePrintLimit, Struct->FieldTypeNames[i]);
+  if (Struct->hasAuxFieldInfo()) {
+    for (u32 i = 0; i < Struct->NumFields; ++i) {
+      Report("   #%2u: offset = %u,\t size = %u,"
+             "\t count = %llu,\t type = %.*s\n",
+             i, Struct->FieldOffset[i], Struct->FieldSize[i],
+             Struct->FieldCounters[i], TypePrintLimit, Struct->FieldTypeName[i]);
+    }
+  } else {
+    for (u32 i = 0; i < Struct->NumFields; ++i) {
+      Report("   #%2u: count = %llu\n", i, Struct->FieldCounters[i]);
+    }
   }
 }