Demangler: improve debug logging.

Log allocated memory and indent according to the nesting level

Author: eeckstein

include/swift/Demangling/Demangler.h

@@ -70,18 +70,27 @@ class NodeFactory {
 
   static void freeSlabs(Slab *slab);
 
+#ifdef NODE_FACTORY_DEBUGGING
+  size_t allocatedMemory = 0;
+  static int nestingLevel;
+  std::string indent() { return std::string(nestingLevel * 2, ' '); }
+#endif
+
 public:
 
   NodeFactory() {
 #ifdef NODE_FACTORY_DEBUGGING
-    std::cerr << "## New NodeFactory " << this << "\n";
+    std::cerr << indent() << "## New NodeFactory\n";
+    nestingLevel++;
 #endif
   }
 
   virtual ~NodeFactory() {
     freeSlabs(CurrentSlab);
 #ifdef NODE_FACTORY_DEBUGGING
-    std::cerr << "Delete NodeFactory " << this << "\n";
+    nestingLevel--;
+    std::cerr << indent() << "## Delete NodeFactory: allocated memory = "
+                          << allocatedMemory  << '\n';
 #endif
   }
 
@@ -92,8 +101,9 @@ class NodeFactory {
     size_t ObjectSize = NumObjects * sizeof(T);
     CurPtr = align(CurPtr, alignof(T));
 #ifdef NODE_FACTORY_DEBUGGING
-    std::cerr << "  alloc " << ObjectSize << ", CurPtr = "
+    std::cerr << indent() << "alloc " << ObjectSize << ", CurPtr = "
               << (void *)CurPtr << "\n";
+    allocatedMemory += ObjectSize;
 #endif
 
     // Do we have enough space in the current slab?
@@ -113,7 +123,7 @@ class NodeFactory {
       End = (char *)newSlab + AllocSize;
       assert(CurPtr + ObjectSize <= End);
 #ifdef NODE_FACTORY_DEBUGGING
-      std::cerr << "    ** new slab " << newSlab << ", allocsize = "
+      std::cerr << indent() << "** new slab " << newSlab << ", allocsize = "
                 << AllocSize << ", CurPtr = " << (void *)CurPtr
                 << ", End = " << (void *)End << "\n";
 #endif
@@ -138,8 +148,8 @@ class NodeFactory {
     size_t AdditionalAlloc = MinGrowth * sizeof(T);
 
 #ifdef NODE_FACTORY_DEBUGGING
-    std::cerr << "  realloc " << Objects << ", num = " << NumObjects
-              << " (size = " << OldAllocSize << "), Growth = " << Growth
+    std::cerr << indent() << "realloc: capacity = " << Capacity
+              << " (size = " << OldAllocSize << "), growth = " << MinGrowth
               << " (size = " << AdditionalAlloc << ")\n";
 #endif
     if ((char *)Objects + OldAllocSize == CurPtr
@@ -149,7 +159,8 @@ class NodeFactory {
       CurPtr += AdditionalAlloc;
       Capacity += MinGrowth;
 #ifdef NODE_FACTORY_DEBUGGING
-      std::cerr << "    ** can grow: CurPtr = " << (void *)CurPtr << "\n";
+      std::cerr << indent() << "** can grow: " << (void *)CurPtr << '\n';
+      allocatedMemory += AdditionalAlloc;
 #endif
       return;
     }

lib/Demangling/Demangler.cpp

@@ -402,16 +402,17 @@ void Node::reverseChildren(size_t StartingAt) {
 void NodeFactory::freeSlabs(Slab *slab) {
   while (slab) {
     Slab *prev = slab->Previous;
-#ifdef NODE_FACTORY_DEBUGGING
-    std::cerr << "  free slab = " << slab << "\n";
-#endif
     free(slab);
     slab = prev;
   }
 }
 
 void NodeFactory::clear() {
   if (CurrentSlab) {
+#ifdef NODE_FACTORY_DEBUGGING
+    std::cerr << indent() << "## clear: allocated memory = " << allocatedMemory  << "\n";
+#endif
+
     freeSlabs(CurrentSlab->Previous);
 
     // Recycle the last allocated slab.
@@ -423,6 +424,9 @@ void NodeFactory::clear() {
     CurrentSlab->Previous = nullptr;
     CurPtr = (char *)(CurrentSlab + 1);
     assert(End == CurPtr + SlabSize);
+#ifdef NODE_FACTORY_DEBUGGING
+    allocatedMemory = 0;
+#endif
   }
 }
 
@@ -443,6 +447,10 @@ NodePointer NodeFactory::createNode(Node::Kind K, const char *Text) {
   return new (Allocate<Node>()) Node(K, llvm::StringRef(Text));
 }
 
+#ifdef NODE_FACTORY_DEBUGGING
+int NodeFactory::nestingLevel = 0;
+#endif
+
 //////////////////////////////////
 // CharVector member functions  //
 //////////////////////////////////