commit d1e3e722d649dfcccf8699a801743c9a5426b0bc
author kasperl@chromium.org <kasperl@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00> Tue Apr 14 13:38:25 2009 +0000
committer kasperl@chromium.org <kasperl@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00> Tue Apr 14 13:38:25 2009 +0000
tree 3caa618740e16882a9efb24c00c281596b2f1ee6
parent acae37894ae73146c7a4788ca8af931d446bd2ca

Made the stack traversal code in the profiler robust by avoiding to look into the heap.

Added name inferencing for anonymous functions to facilitate debugging and profiling.

Re-enabled stats timers in the developer shell (d8).

Fixed issue 303 by avoiding to shortcut cons-symbols.


git-svn-id: http://v8.googlecode.com/svn/trunk@1702 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

diff --git a/src/heap.cc b/src/heap.cc
index 26be5a4..de12d3f 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -374,9 +374,34 @@
 }
 
 
+static void VerifySymbolTable() {
+#ifdef DEBUG
+  // Helper class for verifying the symbol table.
+  class SymbolTableVerifier : public ObjectVisitor {
+   public:
+    SymbolTableVerifier() { }
+    void VisitPointers(Object** start, Object** end) {
+      // Visit all HeapObject pointers in [start, end).
+      for (Object** p = start; p < end; p++) {
+        if ((*p)->IsHeapObject()) {
+          // Check that the symbol is actually a symbol.
+          ASSERT((*p)->IsNull() || (*p)->IsUndefined() || (*p)->IsSymbol());
+        }
+      }
+    }
+  };
+
+  SymbolTableVerifier verifier;
+  SymbolTable* symbol_table = SymbolTable::cast(Heap::symbol_table());
+  symbol_table->IterateElements(&verifier);
+#endif  // DEBUG
+}
+
+
 void Heap::PerformGarbageCollection(AllocationSpace space,
                                     GarbageCollector collector,
                                     GCTracer* tracer) {
+  VerifySymbolTable();
   if (collector == MARK_COMPACTOR && global_gc_prologue_callback_) {
     ASSERT(!allocation_allowed_);
     global_gc_prologue_callback_();
@@ -421,6 +446,7 @@
     ASSERT(!allocation_allowed_);
     global_gc_epilogue_callback_();
   }
+  VerifySymbolTable();
 }
 
 
@@ -813,12 +839,12 @@
 
 
 static inline bool IsShortcutCandidate(HeapObject* object, Map* map) {
-  // A ConsString object with Heap::empty_string() as the right side
-  // is a candidate for being shortcut by the scavenger.
+  STATIC_ASSERT(kNotStringTag != 0 && kSymbolTag != 0);
   ASSERT(object->map() == map);
-  if (map->instance_type() >= FIRST_NONSTRING_TYPE) return false;
-  return (StringShape(map).representation_tag() == kConsStringTag) &&
-         (ConsString::cast(object)->unchecked_second() == Heap::empty_string());
+  InstanceType type = map->instance_type();
+  if ((type & kShortcutTypeMask) != kShortcutTypeTag) return false;
+  ASSERT(object->IsString() && !object->IsSymbol());
+  return ConsString::cast(object)->unchecked_second() == Heap::empty_string();
 }
 
 
@@ -1384,6 +1410,7 @@
   share->set_script(undefined_value());
   share->set_start_position_and_type(0);
   share->set_debug_info(undefined_value());
+  share->set_inferred_name(empty_string());
   return result;
 }