Eliminate usage of vector<>[0] for 0-sized vectors in processor library (#84).

r=bryner

8eb9277ac0


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@72 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/minidump.cc

@@ -643,6 +643,9 @@ const u_int8_t* MinidumpMemoryRegion::GetMemory() {
     return NULL;
 
   if (!memory_) {
+    if (descriptor_->memory.data_size == 0)
+      return NULL;
+
     if (!minidump_->SeekSet(descriptor_->memory.rva))
       return NULL;
 
@@ -920,6 +923,7 @@ bool MinidumpThreadList::Read(u_int32_t expected_size) {
     return false;
   }
 
+  if (thread_count) {
     // TODO(mmentovai): verify rational size!
     scoped_ptr<MinidumpThreads> threads(
         new MinidumpThreads(thread_count, MinidumpThread(minidump_)));
@@ -945,6 +949,8 @@ bool MinidumpThreadList::Read(u_int32_t expected_size) {
     }
 
     threads_ = threads.release();
+  }
+
   thread_count_ = thread_count;
 
   valid_ = true;
@@ -1275,6 +1281,7 @@ const string* MinidumpModule::GetDebugFilename() {
     // UTF16ToUTF8 expects a vector<u_int16_t>, so create a temporary one and
     // copy the UTF-16 data into it.
     vector<u_int16_t> string_utf16(utf16_words);
+    if (utf16_words)
       memcpy(&string_utf16[0], &misc_record->data, bytes);
 
     // GetMiscRecord already byte-swapped the data[] field if it contains
@@ -1451,6 +1458,7 @@ bool MinidumpModuleList::Read(u_int32_t expected_size) {
     return false;
   }
 
+  if (module_count) {
     // TODO(mmentovai): verify rational size!
     scoped_ptr<MinidumpModules> modules(
         new MinidumpModules(module_count, MinidumpModule(minidump_)));
@@ -1466,7 +1474,7 @@ bool MinidumpModuleList::Read(u_int32_t expected_size) {
 
       u_int64_t base_address = module->base_address();
       u_int64_t module_size = module->size();
-    if (base_address == (u_int64_t)-1)
+      if (base_address == static_cast<u_int64_t>(-1))
         return false;
 
       if (!range_map_->StoreRange(base_address, module_size, module_index))
@@ -1474,6 +1482,8 @@ bool MinidumpModuleList::Read(u_int32_t expected_size) {
     }
 
     modules_ = modules.release();
+  }
+
   module_count_ = module_count;
 
   valid_ = true;
@@ -1566,6 +1576,7 @@ bool MinidumpMemoryList::Read(u_int32_t expected_size) {
     return false;
   }
 
+  if (region_count) {
     // TODO(mmentovai): verify rational size!
     scoped_ptr<MemoryDescriptors> descriptors(
         new MemoryDescriptors(region_count));
@@ -1586,7 +1597,7 @@ bool MinidumpMemoryList::Read(u_int32_t expected_size) {
       MDMemoryDescriptor* descriptor = &(*descriptors)[region_index];
 
       if (minidump_->swap())
-      Swap(&*descriptor);
+        Swap(descriptor);
 
       u_int64_t base_address = descriptor->start_of_memory_range;
       u_int32_t region_size = descriptor->memory.data_size;
@@ -1603,9 +1614,11 @@ bool MinidumpMemoryList::Read(u_int32_t expected_size) {
       (*regions)[region_index].SetDescriptor(descriptor);
     }
 
-  region_count_ = region_count;
     descriptors_ = descriptors.release();
     regions_ = regions.release();
+  }
+
+  region_count_ = region_count;
 
   valid_ = true;
   return true;
@@ -2110,7 +2123,7 @@ void MinidumpAirbagInfo::Print() {
 Minidump::Minidump(const string& path)
     : header_(),
       directory_(NULL),
-      stream_map_(NULL),
+      stream_map_(new MinidumpStreamMap()),
       path_(path),
       fd_(-1),
       swap_(false),
@@ -2147,8 +2160,7 @@ bool Minidump::Read() {
   // Invalidate cached data.
   delete directory_;
   directory_ = NULL;
-  delete stream_map_;
-  stream_map_ = NULL;
+  stream_map_->clear();
 
   valid_ = false;
 
@@ -2195,6 +2207,7 @@ bool Minidump::Read() {
   if (!SeekSet(header_.stream_directory_rva))
     return false;
 
+  if (header_.stream_count) {
     // TODO(mmentovai): verify rational size!
     scoped_ptr<MinidumpDirectoryEntries> directory(
         new MinidumpDirectoryEntries(header_.stream_count));
@@ -2205,8 +2218,6 @@ bool Minidump::Read() {
                    sizeof(MDRawDirectory) * header_.stream_count))
       return false;
 
-  scoped_ptr<MinidumpStreamMap> stream_map(new MinidumpStreamMap());
-
     for (unsigned int stream_index = 0;
          stream_index < header_.stream_count;
          ++stream_index) {
@@ -2217,7 +2228,7 @@ bool Minidump::Read() {
         Swap(&directory_entry->location);
       }
 
-    // Initialize the stream_map map, which speeds locating a stream by
+      // Initialize the stream_map_ map, which speeds locating a stream by
       // type.
       unsigned int stream_type = directory_entry->stream_type;
       switch (stream_type) {
@@ -2228,7 +2239,7 @@ bool Minidump::Read() {
         case MD_SYSTEM_INFO_STREAM:
         case MD_MISC_INFO_STREAM:
         case MD_AIRBAG_INFO_STREAM: {
-        if (stream_map->find(stream_type) != stream_map->end()) {
+          if (stream_map_->find(stream_type) != stream_map_->end()) {
             // Another stream with this type was already found.  A minidump
             // file should contain at most one of each of these stream types.
             return false;
@@ -2239,13 +2250,13 @@ bool Minidump::Read() {
         default: {
           // Overwrites for stream types other than those above, but it's
           // expected to be the user's burden in that case.
-        (*stream_map)[stream_type].stream_index = stream_index;
+          (*stream_map_)[stream_type].stream_index = stream_index;
         }
       }
     }
 
     directory_ = directory.release();
-  stream_map_ = stream_map.release();
+  }
 
   valid_ = true;
   return true;
@@ -2391,8 +2402,11 @@ string* Minidump::ReadString(off_t offset) {
   // TODO(mmentovai): verify rational size!
   vector<u_int16_t> string_utf16(utf16_words);
 
-  if (!ReadBytes(&string_utf16[0], bytes))
+  if (utf16_words) {
+    if (!ReadBytes(&string_utf16[0], bytes)) {
       return NULL;
+    }
+  }
 
   return UTF16ToUTF8(string_utf16, swap_);
 }