Fix dangling pointer bug in AutoFDOProfileReader::ReadNameTable

profile_reader.cc

@@ -132,7 +132,7 @@ void AutoFDOProfileReader::ReadNameTable() {
   }
   uint32_t name_vector_size = gcov_read_unsigned();
   for (uint32_t i = 0; i < name_vector_size; i++) {
-    const char *name = gcov_read_string();
+   std::string name = gcov_read_string();
     uint32_t file_index =
         absl::GetFlag(FLAGS_gcov_version) >= 3 ? gcov_read_unsigned() : -1;
     names_.emplace_back(name, file_index);

profile_writer.cc

@@ -124,13 +124,17 @@ class SourceProfileWriter: public SymbolTraverser {
 
   virtual void VisitTopSymbol(const std::string &name, const Symbol *node) {
     gcov_write_counter(node->head_count);
-    gcov_write_unsigned(GetStringIndex(Symbol::Name(name.c_str())));
+    unsigned NameIdx = GetStringIndex(Symbol::Name(name.c_str()));
+    CHECK(NameIdx != 0 && "name index 0 should never be present as a top-level symbol!");
+    gcov_write_unsigned(NameIdx);
   }
 
   virtual void VisitCallsite(const Callsite &callsite) {
     uint64_t value = callsite.location;
     gcov_write_unsigned(SourceInfo::GenerateCompressedOffset(value));
-    gcov_write_unsigned(GetStringIndex(Symbol::Name(callsite.callee_name)));
+    unsigned NameIdx = GetStringIndex(Symbol::Name(callsite.callee_name));
+    CHECK(NameIdx != 0 && "name index 0 should never be present as a callee!");
+    gcov_write_unsigned(NameIdx);
   }
 
  private:

symbol_map.h

@@ -177,7 +177,8 @@ class Symbol {
   ~Symbol();
 
   static std::string Name(const char *name) {
-    return (name && strlen(name) > 0) ? name : "noname";
+    CHECK(name && strlen(name) > 0 && "Empty string should never occur in profile!");
+    return name;
   }
 
   std::string name() const { return Name(info.func_name); }