Server-side workaround to handle overlapping modules.

src/processor/basic_code_modules.cc

 // Copyright (c) 2006, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 20 matching lines @@
 // were loaded into a single process.
 //
 // See basic_code_modules.h for documentation.
 //
 // Author: Mark Mentovai
 
 #include "processor/basic_code_modules.h"
 
 #include <assert.h>
 
+#include <vector>
+
 #include "google_breakpad/processor/code_module.h"
 #include "processor/linked_ptr.h"
 #include "processor/logging.h"
 #include "processor/range_map-inl.h"
 
 namespace google_breakpad {
 
+using std::vector;
+
 BasicCodeModules::BasicCodeModules(const CodeModules *that)
     : main_address_(0), map_() {
   BPLOG_IF(ERROR, !that) << "BasicCodeModules::BasicCodeModules requires "
                             "|that|";
   assert(that);
 
+  map_.SetEnableShrinkDown(that->IsModuleShrinkEnabled());
+
   const CodeModule *main_module = that->GetMainModule();
   if (main_module)
     main_address_ = main_module->base_address();
 
   unsigned int count = that->module_count();
-  for (unsigned int module_sequence = 0;
-       module_sequence < count;
-       ++module_sequence) {
+  for (unsigned int i = 0; i < count; ++i) {
     // Make a copy of the module and insert it into the map.  Use
     // GetModuleAtIndex because ordering is unimportant when slurping the
     // entire list, and GetModuleAtIndex may be faster than
     // GetModuleAtSequence.
-    linked_ptr<const CodeModule> module(
-        that->GetModuleAtIndex(module_sequence)->Copy());
+    linked_ptr<const CodeModule> module(that->GetModuleAtIndex(i)->Copy());
     if (!map_.StoreRange(module->base_address(), module->size(), module)) {
-      BPLOG(ERROR) << "Module " << module->code_file() <<
-                      " could not be stored";
+      BPLOG(ERROR) << "Module " << module->code_file()
+                   << " could not be stored";
     }
   }
+
+  // Report modules with shrunk ranges.
+  for (unsigned int i = 0; i < count; ++i) {
+    linked_ptr<const CodeModule> module(that->GetModuleAtIndex(i)->Copy());
+    uint64_t delta = 0;
+    if (map_.RetrieveRange(module->base_address() + module->size() - 1,
+                           &module, NULL /* base */, &delta, NULL /* size */) &&
+        delta > 0) {
+      BPLOG(INFO) << "The range for module " << module->code_file()
+                  << " was shrunk down by " << HexString(delta) << " bytes.";
+      linked_ptr<CodeModule> shrunk_range_module(module->Copy());
+      shrunk_range_module->SetShrinkDownDelta(delta);
+      shrunk_range_modules_.push_back(shrunk_range_module);
+    }
+  }
+
+  // TODO(ivanpe): Report modules with conflicting ranges.  The list of such
+  // modules should be copied from |that|.
 }
 
 BasicCodeModules::BasicCodeModules() : main_address_(0), map_() { }
 
 BasicCodeModules::~BasicCodeModules() {
 }
 
 unsigned int BasicCodeModules::module_count() const {
   return map_.GetCount();
 }
@@ skipping 32 matching lines @@
   // way to walk the list of CodeModule objects.  Implement GetModuleAtIndex
   // using GetModuleAtSequence, which meets all of the requirements, and
   // in addition, guarantees ordering.
   return GetModuleAtSequence(index);
 }
 
 const CodeModules* BasicCodeModules::Copy() const {
   return new BasicCodeModules(this);
 }
 
+vector<linked_ptr<const CodeModule> >
+BasicCodeModules::GetShrunkRangeModules() const {
+  return shrunk_range_modules_;
+}
+
+bool BasicCodeModules::IsModuleShrinkEnabled() const {
+  return map_.IsShrinkDownEnabled();
+}
+
 }  // namespace google_breakpad