1 files changed, 241 insertions, 95 deletions
diff --git a/3rdParty/Breakpad/src/common/dwarf_cu_to_module.cc b/3rdParty/Breakpad/src/common/dwarf_cu_to_module.cc
index ded5f83..a16bee7 100644
--- a/3rdParty/Breakpad/src/common/dwarf_cu_to_module.cc
+++ b/3rdParty/Breakpad/src/common/dwarf_cu_to_module.cc
@@ -40,23 +40,24 @@
 
 #include <assert.h>
 #include <inttypes.h>
+#include <stdint.h>
 #include <stdio.h>
 
 #include <algorithm>
-#include <set>
 #include <utility>
 
 #include "common/dwarf_line_to_module.h"
+#include "common/unordered.h"
 
 namespace google_breakpad {
 
 using std::map;
 using std::pair;
-using std::set;
+using std::sort;
 using std::vector;
 
 // Data provided by a DWARF specification DIE.
-// 
+//
 // In DWARF, the DIE for a definition may contain a DW_AT_specification
 // attribute giving the offset of the corresponding declaration DIE, and
 // the definition DIE may omit information given in the declaration. For
@@ -73,6 +74,9 @@ using std::vector;
 // A Specification holds information gathered from a declaration DIE that
 // we may need if we find a DW_AT_specification link pointing to it.
 struct DwarfCUToModule::Specification {
+  // The qualified name that can be found by demangling DW_AT_MIPS_linkage_name.
+  string qualified_name;
+
   // The name of the enclosing scope, or the empty string if there is none.
   string enclosing_name;
 
@@ -84,7 +88,7 @@ struct DwarfCUToModule::Specification {
 // An abstract origin -- base definition of an inline function.
 struct AbstractOrigin {
   AbstractOrigin() : name() {}
-  AbstractOrigin(const string& name) : name(name) {}
+  explicit AbstractOrigin(const string& name) : name(name) {}
 
   string name;
 };
@@ -97,13 +101,21 @@ struct DwarfCUToModule::FilePrivate {
   // A set of strings used in this CU. Before storing a string in one of
   // our data structures, insert it into this set, and then use the string
   // from the set.
-  // 
-  // Because std::string uses reference counting internally, simply using
-  // strings from this set, even if passed by value, assigned, or held
-  // directly in structures and containers (map<string, ...>, for example),
-  // causes those strings to share a single instance of each distinct piece
-  // of text.
-  set<string> common_strings;
+  //
+  // In some STL implementations, strings are reference-counted internally,
+  // meaning that simply using strings from this set, even if passed by
+  // value, assigned, or held directly in structures and containers
+  // (map<string, ...>, for example), causes those strings to share a
+  // single instance of each distinct piece of text. GNU's libstdc++ uses
+  // reference counts, and I believe MSVC did as well, at some point.
+  // However, C++ '11 implementations are moving away from reference
+  // counting.
+  //
+  // In other implementations, string assignments copy the string's text,
+  // so this set will actually hold yet another copy of the string (although
+  // everything will still work). To improve memory consumption portably,
+  // we will probably need to use pointers to strings held in this set.
+  unordered_set<string> common_strings;
 
   // A map from offsets of DIEs within the .debug_info section to
   // Specifications describing those DIEs. Specification references can
@@ -113,14 +125,42 @@ struct DwarfCUToModule::FilePrivate {
   AbstractOriginByOffset origins;
 };
 
-DwarfCUToModule::FileContext::FileContext(const string &filename_arg,
-                                          Module *module_arg)
-    : filename(filename_arg), module(module_arg) {
-  file_private = new FilePrivate();
+DwarfCUToModule::FileContext::FileContext(const string &filename,
+                                          Module *module,
+                                          bool handle_inter_cu_refs)
+    : filename_(filename),
+      module_(module),
+      handle_inter_cu_refs_(handle_inter_cu_refs),
+      file_private_(new FilePrivate()) {
 }
 
 DwarfCUToModule::FileContext::~FileContext() {
-  delete file_private;
+}
+
+void DwarfCUToModule::FileContext::AddSectionToSectionMap(
+    const string& name, const uint8_t *contents, uint64 length) {
+  section_map_[name] = std::make_pair(contents, length);
+}
+
+void DwarfCUToModule::FileContext::ClearSectionMapForTest() {
+  section_map_.clear();
+}
+
+const dwarf2reader::SectionMap&
+DwarfCUToModule::FileContext::section_map() const {
+  return section_map_;
+}
+
+void DwarfCUToModule::FileContext::ClearSpecifications() {
+  if (!handle_inter_cu_refs_)
+    file_private_->specifications.clear();
+}
+
+bool DwarfCUToModule::FileContext::IsUnhandledInterCUReference(
+    uint64 offset, uint64 compilation_unit_start) const {
+  if (handle_inter_cu_refs_)
+    return false;
+  return offset < compilation_unit_start;
 }
 
 // Information global to the particular compilation unit we're
@@ -130,11 +170,13 @@ struct DwarfCUToModule::CUContext {
   CUContext(FileContext *file_context_arg, WarningReporter *reporter_arg)
       : file_context(file_context_arg),
         reporter(reporter_arg),
-        language(Language::CPlusPlus) { }
+        language(Language::CPlusPlus) {}
+
   ~CUContext() {
     for (vector<Module::Function *>::iterator it = functions.begin();
-         it != functions.end(); it++)
+         it != functions.end(); ++it) {
       delete *it;
+    }
   };
 
   // The DWARF-bearing file into which this CU was incorporated.
@@ -218,6 +260,14 @@ class DwarfCUToModule::GenericDIEHandler: public dwarf2reader::DIEHandler {
   DIEContext *parent_context_;
   uint64 offset_;
 
+  // Place the name in the global set of strings. Even though this looks
+  // like a copy, all the major string implementations use reference
+  // counting internally, so the effect is to have all the data structures
+  // share copies of strings whenever possible.
+  // FIXME: Should this return something like a string_ref to avoid the
+  // assumption about how strings are implemented?
+  string AddStringToPool(const string &str);
+
   // If this DIE has a DW_AT_declaration attribute, this is its value.
   // It is false on DIEs with no DW_AT_declaration attribute.
   bool declaration_;
@@ -230,6 +280,11 @@ class DwarfCUToModule::GenericDIEHandler: public dwarf2reader::DIEHandler {
   // The value of the DW_AT_name attribute, or the empty string if the
   // DIE has no such attribute.
   string name_attribute_;
+
+  // The demangled value of the DW_AT_MIPS_linkage_name attribute, or the empty
+  // string if the DIE has no such attribute or its content could not be
+  // demangled.
+  string demangled_name_;
 };
 
 void DwarfCUToModule::GenericDIEHandler::ProcessAttributeUnsigned(
@@ -248,14 +303,19 @@ void DwarfCUToModule::GenericDIEHandler::ProcessAttributeReference(
     uint64 data) {
   switch (attr) {
     case dwarf2reader::DW_AT_specification: {
+      FileContext *file_context = cu_context_->file_context;
+      if (file_context->IsUnhandledInterCUReference(
+              data, cu_context_->reporter->cu_offset())) {
+        cu_context_->reporter->UnhandledInterCUReference(offset_, data);
+        break;
+      }
       // Find the Specification to which this attribute refers, and
       // set specification_ appropriately. We could do more processing
       // here, but it's better to leave the real work to our
       // EndAttribute member function, at which point we know we have
       // seen all the DIE's attributes.
-      FileContext *file_context = cu_context_->file_context;
-      SpecificationByOffset *specifications
-          = &file_context->file_private->specifications;
+      SpecificationByOffset *specifications =
+          &file_context->file_private_->specifications;
       SpecificationByOffset::iterator spec = specifications->find(data);
       if (spec != specifications->end()) {
         specification_ = &spec->second;
@@ -273,20 +333,37 @@ void DwarfCUToModule::GenericDIEHandler::ProcessAttributeReference(
   }
 }
 
+string DwarfCUToModule::GenericDIEHandler::AddStringToPool(const string &str) {
+  pair<unordered_set<string>::iterator, bool> result =
+    cu_context_->file_context->file_private_->common_strings.insert(str);
+  return *result.first;
+}
+
 void DwarfCUToModule::GenericDIEHandler::ProcessAttributeString(
     enum DwarfAttribute attr,
     enum DwarfForm form,
     const string &data) {
   switch (attr) {
-    case dwarf2reader::DW_AT_name: {
-      // Place the name in our global set of strings, and then use the
-      // string from the set. Even though the assignment looks like a copy,
-      // all the major std::string implementations use reference counting
-      // internally, so the effect is to have all our data structures share
-      // copies of strings whenever possible.
-      pair<set<string>::iterator, bool> result =
-          cu_context_->file_context->file_private->common_strings.insert(data);
-      name_attribute_ = *result.first; 
+    case dwarf2reader::DW_AT_name:
+      name_attribute_ = AddStringToPool(data);
+      break;
+    case dwarf2reader::DW_AT_MIPS_linkage_name:
+    case dwarf2reader::DW_AT_linkage_name: {
+      string demangled;
+      Language::DemangleResult result =
+          cu_context_->language->DemangleName(data, &demangled);
+      switch (result) {
+        case Language::kDemangleSuccess:
+          demangled_name_ = AddStringToPool(demangled);
+          break;
+
+        case Language::kDemangleFailure:
+          cu_context_->reporter->DemangleError(data);
+          // fallthrough
+        case Language::kDontDemangle:
+          demangled_name_.clear();
+          break;
+      }
       break;
     }
     default: break;
@@ -294,37 +371,64 @@ void DwarfCUToModule::GenericDIEHandler::ProcessAttributeString(
 }
 
 string DwarfCUToModule::GenericDIEHandler::ComputeQualifiedName() {
-  // Find our unqualified name. If the DIE has its own DW_AT_name
-  // attribute, then use that; otherwise, check our specification.
-  const string *unqualified_name;
-  if (name_attribute_.empty() && specification_)
-    unqualified_name = &specification_->unqualified_name;
-  else
-    unqualified_name = &name_attribute_;
-
-  // Find the name of our enclosing context. If we have a
-  // specification, it's the specification's enclosing context that
-  // counts; otherwise, use this DIE's context.
+  // Use the demangled name, if one is available. Demangled names are
+  // preferable to those inferred from the DWARF structure because they
+  // include argument types.
+  const string *qualified_name = NULL;
+  if (!demangled_name_.empty()) {
+    // Found it is this DIE.
+    qualified_name = &demangled_name_;
+  } else if (specification_ && !specification_->qualified_name.empty()) {
+    // Found it on the specification.
+    qualified_name = &specification_->qualified_name;
+  }
+
+  const string *unqualified_name = NULL;
   const string *enclosing_name;
-  if (specification_)
-    enclosing_name = &specification_->enclosing_name;
-  else
-    enclosing_name = &parent_context_->name;
+  if (!qualified_name) {
+    // Find the unqualified name. If the DIE has its own DW_AT_name
+    // attribute, then use that; otherwise, check the specification.
+    if (!name_attribute_.empty())
+      unqualified_name = &name_attribute_;
+    else if (specification_)
+      unqualified_name = &specification_->unqualified_name;
+
+    // Find the name of the enclosing context. If this DIE has a
+    // specification, it's the specification's enclosing context that
+    // counts; otherwise, use this DIE's context.
+    if (specification_)
+      enclosing_name = &specification_->enclosing_name;
+    else
+      enclosing_name = &parent_context_->name;
+  }
+
+  // Prepare the return value before upcoming mutations possibly invalidate the
+  // existing pointers.
+  string return_value;
+  if (qualified_name) {
+    return_value = *qualified_name;
+  } else if (unqualified_name && enclosing_name) {
+    // Combine the enclosing name and unqualified name to produce our
+    // own fully-qualified name.
+    return_value = cu_context_->language->MakeQualifiedName(*enclosing_name,
+                                                            *unqualified_name);
+  }
 
   // If this DIE was marked as a declaration, record its names in the
   // specification table.
-  if (declaration_) {
-    FileContext *file_context = cu_context_->file_context;
+  if ((declaration_ && qualified_name) ||
+      (unqualified_name && enclosing_name)) {
     Specification spec;
-    spec.enclosing_name = *enclosing_name;
-    spec.unqualified_name = *unqualified_name;
-    file_context->file_private->specifications[offset_] = spec;
+    if (qualified_name) {
+      spec.qualified_name = *qualified_name;
+    } else {
+      spec.enclosing_name = *enclosing_name;
+      spec.unqualified_name = *unqualified_name;
+    }
+    cu_context_->file_context->file_private_->specifications[offset_] = spec;
   }
 
-  // Combine the enclosing name and unqualified name to produce our
-  // own fully-qualified name.
-  return cu_context_->language->MakeQualifiedName(*enclosing_name,
-                                                  *unqualified_name);
+  return return_value;
 }
 
 // A handler class for DW_TAG_subprogram DIEs.
@@ -333,7 +437,8 @@ class DwarfCUToModule::FuncHandler: public GenericDIEHandler {
   FuncHandler(CUContext *cu_context, DIEContext *parent_context,
               uint64 offset)
       : GenericDIEHandler(cu_context, parent_context, offset),
-        low_pc_(0), high_pc_(0), abstract_origin_(NULL), inline_(false) { }
+        low_pc_(0), high_pc_(0), high_pc_form_(dwarf2reader::DW_FORM_addr),
+        abstract_origin_(NULL), inline_(false) { }
   void ProcessAttributeUnsigned(enum DwarfAttribute attr,
                                 enum DwarfForm form,
                                 uint64 data);
@@ -352,6 +457,7 @@ class DwarfCUToModule::FuncHandler: public GenericDIEHandler {
   // specification_, parent_context_.  Computed in EndAttributes.
   string name_;
   uint64 low_pc_, high_pc_; // DW_AT_low_pc, DW_AT_high_pc
+  DwarfForm high_pc_form_; // DW_AT_high_pc can be length or address.
   const AbstractOrigin* abstract_origin_;
   bool inline_;
 };
@@ -367,7 +473,11 @@ void DwarfCUToModule::FuncHandler::ProcessAttributeUnsigned(
     case dwarf2reader::DW_AT_inline:      inline_  = true; break;
 
     case dwarf2reader::DW_AT_low_pc:      low_pc_  = data; break;
-    case dwarf2reader::DW_AT_high_pc:     high_pc_ = data; break;
+    case dwarf2reader::DW_AT_high_pc:
+      high_pc_form_ = form;
+      high_pc_ = data;
+      break;
+
     default:
       GenericDIEHandler::ProcessAttributeUnsigned(attr, form, data);
       break;
@@ -393,10 +503,10 @@ void DwarfCUToModule::FuncHandler::ProcessAttributeReference(
     enum DwarfAttribute attr,
     enum DwarfForm form,
     uint64 data) {
-  switch(attr) {
+  switch (attr) {
     case dwarf2reader::DW_AT_abstract_origin: {
       const AbstractOriginByOffset& origins =
-          cu_context_->file_context->file_private->origins;
+          cu_context_->file_context->file_private_->origins;
       AbstractOriginByOffset::const_iterator origin = origins.find(data);
       if (origin != origins.end()) {
         abstract_origin_ = &(origin->second);
@@ -421,33 +531,39 @@ bool DwarfCUToModule::FuncHandler::EndAttributes() {
 }
 
 void DwarfCUToModule::FuncHandler::Finish() {
+  // Make high_pc_ an address, if it isn't already.
+  if (high_pc_form_ != dwarf2reader::DW_FORM_addr) {
+    high_pc_ += low_pc_;
+  }
+
   // Did we collect the information we need?  Not all DWARF function
   // entries have low and high addresses (for example, inlined
   // functions that were never used), but all the ones we're
   // interested in cover a non-empty range of bytes.
   if (low_pc_ < high_pc_) {
-    // Create a Module::Function based on the data we've gathered, and
-    // add it to the functions_ list.
-    Module::Function *func = new Module::Function;
     // Malformed DWARF may omit the name, but all Module::Functions must
     // have names.
+    string name;
     if (!name_.empty()) {
-      func->name = name_;
+      name = name_;
     } else {
       cu_context_->reporter->UnnamedFunction(offset_);
-      func->name = "<name omitted>";
+      name = "<name omitted>";
     }
-    func->address = low_pc_;
+
+    // Create a Module::Function based on the data we've gathered, and
+    // add it to the functions_ list.
+    scoped_ptr<Module::Function> func(new Module::Function(name, low_pc_));
     func->size = high_pc_ - low_pc_;
     func->parameter_size = 0;
     if (func->address) {
        // If the function address is zero this is a sign that this function
        // description is just empty debug data and should just be discarded.
-       cu_context_->functions.push_back(func);
+       cu_context_->functions.push_back(func.release());
      }
   } else if (inline_) {
     AbstractOrigin origin(name_);
-    cu_context_->file_context->file_private->origins[offset_] = origin;
+    cu_context_->file_context->file_private_->origins[offset_] = origin;
   }
 }
 
@@ -459,8 +575,7 @@ class DwarfCUToModule::NamedScopeHandler: public GenericDIEHandler {
                     uint64 offset)
       : GenericDIEHandler(cu_context, parent_context, offset) { }
   bool EndAttributes();
-  DIEHandler *FindChildHandler(uint64 offset, enum DwarfTag tag,
-                               const AttributeList &attrs);
+  DIEHandler *FindChildHandler(uint64 offset, enum DwarfTag tag);
 
  private:
   DIEContext child_context_; // A context for our children.
@@ -473,8 +588,7 @@ bool DwarfCUToModule::NamedScopeHandler::EndAttributes() {
 
 dwarf2reader::DIEHandler *DwarfCUToModule::NamedScopeHandler::FindChildHandler(
     uint64 offset,
-    enum DwarfTag tag,
-    const AttributeList &attrs) {
+    enum DwarfTag tag) {
   switch (tag) {
     case dwarf2reader::DW_TAG_subprogram:
       return new FuncHandler(cu_context_, &child_context_, offset);
@@ -561,17 +675,31 @@ void DwarfCUToModule::WarningReporter::UnnamedFunction(uint64 offset) {
           filename_.c_str(), offset);
 }
 
+void DwarfCUToModule::WarningReporter::DemangleError(const string &input) {
+  CUHeading();
+  fprintf(stderr, "%s: warning: failed to demangle %s\n",
+          filename_.c_str(), input.c_str());
+}
+
+void DwarfCUToModule::WarningReporter::UnhandledInterCUReference(
+    uint64 offset, uint64 target) {
+  CUHeading();
+  fprintf(stderr, "%s: warning: the DIE at offset 0x%llx has a "
+                  "DW_FORM_ref_addr attribute with an inter-CU reference to "
+                  "0x%llx, but inter-CU reference handling is turned off.\n",
+                  filename_.c_str(), offset, target);
+}
+
 DwarfCUToModule::DwarfCUToModule(FileContext *file_context,
-                                 LineToModuleFunctor *line_reader,
+                                 LineToModuleHandler *line_reader,
                                  WarningReporter *reporter)
-    : line_reader_(line_reader), has_source_line_info_(false) { 
-  cu_context_ = new CUContext(file_context, reporter);
-  child_context_ = new DIEContext();
+    : line_reader_(line_reader),
+      cu_context_(new CUContext(file_context, reporter)),
+      child_context_(new DIEContext()),
+      has_source_line_info_(false) {
 }
 
 DwarfCUToModule::~DwarfCUToModule() {
-  delete cu_context_;
-  delete child_context_;
 }
 
 void DwarfCUToModule::ProcessAttributeSigned(enum DwarfAttribute attr,
@@ -605,8 +733,16 @@ void DwarfCUToModule::ProcessAttributeUnsigned(enum DwarfAttribute attr,
 void DwarfCUToModule::ProcessAttributeString(enum DwarfAttribute attr,
                                              enum DwarfForm form,
                                              const string &data) {
-  if (attr == dwarf2reader::DW_AT_name)
-    cu_context_->reporter->SetCUName(data);
+  switch (attr) {
+    case dwarf2reader::DW_AT_name:
+      cu_context_->reporter->SetCUName(data);
+      break;
+    case dwarf2reader::DW_AT_comp_dir:
+      line_reader_->StartCompilationUnit(data);
+      break;
+    default:
+      break;
+  }
 }
 
 bool DwarfCUToModule::EndAttributes() {
@@ -615,16 +751,17 @@ bool DwarfCUToModule::EndAttributes() {
 
 dwarf2reader::DIEHandler *DwarfCUToModule::FindChildHandler(
     uint64 offset,
-    enum DwarfTag tag,
-    const AttributeList &attrs) {
+    enum DwarfTag tag) {
   switch (tag) {
     case dwarf2reader::DW_TAG_subprogram:
-      return new FuncHandler(cu_context_, child_context_, offset);
+      return new FuncHandler(cu_context_.get(), child_context_.get(), offset);
     case dwarf2reader::DW_TAG_namespace:
     case dwarf2reader::DW_TAG_class_type:
     case dwarf2reader::DW_TAG_structure_type:
     case dwarf2reader::DW_TAG_union_type:
-      return new NamedScopeHandler(cu_context_, child_context_, offset);
+    case dwarf2reader::DW_TAG_module:
+      return new NamedScopeHandler(cu_context_.get(), child_context_.get(),
+                                   offset);
     default:
       return NULL;
   }
@@ -636,6 +773,14 @@ void DwarfCUToModule::SetLanguage(DwarfLanguage language) {
       cu_context_->language = Language::Java;
       break;
 
+    case dwarf2reader::DW_LANG_Swift:
+      cu_context_->language = Language::Swift;
+      break;
+
+    case dwarf2reader::DW_LANG_Rust:
+      cu_context_->language = Language::Rust;
+      break;
+
     // DWARF has no generic language code for assembly language; this is
     // what the GNU toolchain uses.
     case dwarf2reader::DW_LANG_Mips_Assembler:
@@ -649,7 +794,7 @@ void DwarfCUToModule::SetLanguage(DwarfLanguage language) {
     // Objective C and Objective C++ seem to create entries for
     // methods whose DW_AT_name values are already fully-qualified:
     // "-[Classname method:]".  These appear at the top level.
-    // 
+    //
     // DWARF data for C should never include namespaces or functions
     // nested in struct types, but if it ever does, then C++'s
     // notation is probably not a bad choice for that.
@@ -667,7 +812,7 @@ void DwarfCUToModule::SetLanguage(DwarfLanguage language) {
 
 void DwarfCUToModule::ReadSourceLines(uint64 offset) {
   const dwarf2reader::SectionMap &section_map
-      = cu_context_->file_context->section_map;
+      = cu_context_->file_context->section_map();
   dwarf2reader::SectionMap::const_iterator map_entry
       = section_map.find(".debug_line");
   // Mac OS X puts DWARF data in sections whose names begin with "__"
@@ -678,14 +823,14 @@ void DwarfCUToModule::ReadSourceLines(uint64 offset) {
     cu_context_->reporter->MissingSection(".debug_line");
     return;
   }
-  const char *section_start = map_entry->second.first;
+  const uint8_t *section_start = map_entry->second.first;
   uint64 section_length = map_entry->second.second;
   if (offset >= section_length) {
     cu_context_->reporter->BadLineInfoOffset(offset);
     return;
   }
-  (*line_reader_)(section_start + offset, section_length - offset,
-                  cu_context_->file_context->module, &lines_);
+  line_reader_->ReadProgram(section_start + offset, section_length - offset,
+                            cu_context_->file_context->module_, &lines_);
 }
 
 namespace {
@@ -715,9 +860,9 @@ void DwarfCUToModule::AssignLinesToFunctions() {
   // complexity from here on out is linear.
 
   // Put both our functions and lines in order by address.
-  sort(functions->begin(), functions->end(),
-       Module::Function::CompareByAddress);
-  sort(lines_.begin(), lines_.end(), Module::Line::CompareByAddress);
+  std::sort(functions->begin(), functions->end(),
+            Module::Function::CompareByAddress);
+  std::sort(lines_.begin(), lines_.end(), Module::Line::CompareByAddress);
 
   // The last line that we used any piece of.  We use this only for
   // generating warnings.
@@ -852,7 +997,7 @@ void DwarfCUToModule::AssignLinesToFunctions() {
         // both func and line begin after CURRENT. The next transition
         // is the start of the next function or next line, whichever
         // is earliest.
-        assert (func || line);
+        assert(func || line);
         if (func && line)
           next_transition = std::min(func->address, line->address);
         else if (func)
@@ -910,12 +1055,14 @@ void DwarfCUToModule::Finish() {
 
   // Add our functions, which now have source lines assigned to them,
   // to module_.
-  cu_context_->file_context->module->AddFunctions(functions->begin(),
-                                                  functions->end());
+  cu_context_->file_context->module_->AddFunctions(functions->begin(),
+                                                   functions->end());
 
   // Ownership of the function objects has shifted from cu_context to
   // the Module.
   functions->clear();
+
+  cu_context_->file_context->ClearSpecifications();
 }
 
 bool DwarfCUToModule::StartCompilationUnit(uint64 offset,
@@ -926,8 +1073,7 @@ bool DwarfCUToModule::StartCompilationUnit(uint64 offset,
   return dwarf_version >= 2;
 }
 
-bool DwarfCUToModule::StartRootDIE(uint64 offset, enum DwarfTag tag,
-                                   const AttributeList& attrs) {
+bool DwarfCUToModule::StartRootDIE(uint64 offset, enum DwarfTag tag) {
   // We don't deal with partial compilation units (the only other tag
   // likely to be used for root DIE).
   return tag == dwarf2reader::DW_TAG_compile_unit;