klocwork: fix risk issues

tools/hsbench/data_corpus.cpp

@@ -58,7 +58,10 @@ void readRow(sqlite3_stmt *statement, vector<DataBlock> &blocks,
     }
     auto internal_stream_index = stream_indices[stream_id];
 
-    assert(blob || bytes > 0);
+    if (!(blob &&  bytes > 0)) {
+        assert(0);
+        throw std::domain_error("Invalid blob or bytes from sqlite3.");
+    }
     blocks.emplace_back(id, stream_id, internal_stream_index,
                         string(blob, blob + bytes));
 }

tools/hsbench/main.cpp

@@ -740,6 +740,11 @@ u64a byte_size(const vector<DataBlock> &corpus_blocks) {
         total += block.payload.size();
     }
 
+    if (total == 0) {
+        assert(0);
+        throw std::invalid_argument("Empty corpus.");
+    }
+
     return total;
 }
 

tools/hscollider/DatabaseProxy.h

@@ -61,7 +61,7 @@ public:
         std::lock_guard<std::mutex> lock(mutex);
         if (failed) {
             // We have previously failed to compile this database.
-            return nullptr;
+            throw CompileFailed("Unable to compile db previously.");
         }
         if (db) {
             return db;

tools/hscollider/NfaGeneratedCorpora.cpp

@@ -101,7 +101,7 @@ void NfaGeneratedCorpora::generate(unsigned id, vector<Corpus> &data) {
         pl.logicalKeyRenumber();
         const auto &m_lkey = pl.getLkeyMap();
         assert(!m_lkey.empty());
-        u32 a_subid; // arbitrary sub id
+        u32 a_subid = 0; // arbitrary sub id
         unordered_map<u32, vector<Corpus>> m_data;
         for (const auto &it : m_lkey) {
             a_subid = it.first;

tools/hscollider/Thread.cpp

@@ -98,6 +98,6 @@ void *Thread::runThread(void *thr) {
 }
 
 
-Thread::Thread(size_t num) : thread_id(num) {}
+Thread::Thread(size_t num) : thread_id(num), thread() {}
 
 Thread::~Thread() {}