Bug fix/clang-tidy-performance (#300)

Various clang-tidy-performance fixes:
* noexcept
* performance-noexcept-swap
* performance
* performance-move-const-arg
* performance-unnecessary-value-param
* performance-inefficient-vector-operation
* performance-no-int-to-ptr
* add performance
* performance-inefficient-string-concatenation
* clang-analyzer-deadcode.DeadStores
* performance-inefficient-vector-operation
* clang-analyzer-core.NullDereference
* clang-analyzer-core.UndefinedBinaryOperatorResult
* clang-analyzer-core.CallAndMessage

---------

Co-authored-by: gtsoul-tech <gtsoulkanakis@gmail.com>

tools/hsbench/huge.cpp

@@ -90,7 +90,7 @@ hs_database_t *get_huge(hs_database_t *db) {
     }
 
     shmaddr = shmat(hsdb_shmid, nullptr, SHM_RND);
-    if (shmaddr == (char *)-1) {
+    if (shmaddr == (char *)-1) {                //NOLINT (performance-no-int-to-ptr)
         perror("Shared memory attach failure");
         goto fini;
     }

tools/hscheck/main.cpp

@@ -98,7 +98,7 @@ unsigned int countFailures = 0;
 class ParsedExpr {
 public:
     ParsedExpr(string regex_in, unsigned int flags_in, const hs_expr_ext& ext_in)
-        : regex(regex_in), flags(flags_in), ext(ext_in) {}
+        : regex(std::move(regex_in)), flags(flags_in), ext(ext_in) {}
     ~ParsedExpr() {}
     string regex;
     unsigned int flags;
@@ -308,7 +308,7 @@ void checkExpression(UNUSED void *threadarg) {
                 ch_free_compile_error(ch_compile_err);
             }
 #else
-            cerr << "Hybrid mode not available in this build." << endl;
+            cerr << "Hybrid mode not available in this build.\n";
             exit(1);
 #endif // HS_HYBRID
         } else {
@@ -468,26 +468,25 @@ void checkLogicalExpression(UNUSED void *threadarg) {
 static
 void usage() {
     cout << "Usage: hscheck [OPTIONS...]"  << endl << endl
-         << "  -e PATH         Path to expression directory." << endl
-         << "  -s FILE         Signature file to use." << endl
-         << "  -z NUM          Signature ID to use." << endl
-         << "  -E DISTANCE     Force edit distance to DISTANCE for all patterns." << endl
+         << "  -e PATH         Path to expression directory.\n"
+         << "  -s FILE         Signature file to use.\n"
+         << "  -z NUM          Signature ID to use.\n"
+         << "  -E DISTANCE     Force edit distance to DISTANCE for all patterns.\n"
 #ifndef RELEASE_BUILD
-         << "  -G OVERRIDES    Overrides for the grey." << endl
+         << "  -G OVERRIDES    Overrides for the grey.\n"
 #endif
-         << "  -V              Operate in vectored mode." << endl
-         << "  -N              Operate in block mode (default: streaming)." << endl
+         << "  -V              Operate in vectored mode.\n"
+         << "  -N              Operate in block mode (default: streaming).\n"
 #ifdef HS_HYBRID
-         << "  -H              Operate in hybrid mode." << endl
+         << "  -H              Operate in hybrid mode.\n"
 #endif
-         << "  -L              Pass HS_FLAG_SOM_LEFTMOST for all expressions (default: off)." << endl
-         << "  -8              Force UTF8 mode on all patterns." << endl
-         << "  -T NUM          Run with NUM threads." << endl
-         << "  -h              Display this help." << endl
-         << "  -B              Build signature set." << endl
-         << "  -C              Check logical combinations (default: off)." << endl
-         << "  --literal-on    Processing pure literals, no need to check." << endl
-         << endl;
+         << "  -L              Pass HS_FLAG_SOM_LEFTMOST for all expressions (default: off).\n"
+         << "  -8              Force UTF8 mode on all patterns.\n"
+         << "  -T NUM          Run with NUM threads.\n"
+         << "  -h              Display this help.\n"
+         << "  -B              Build signature set.\n"
+         << "  -C              Check logical combinations (default: off).\n"
+         << "  --literal-on    Processing pure literals, no need to check.\n\n";
 }
 
 static
@@ -599,7 +598,7 @@ void failLine(unsigned lineNum, const string &file,
               const string &line, const string &error) {
     cerr << "Parse error in file " << file
         << " on line " << lineNum << ": " << error
-        << endl << "Line is: '" << line << "'" << endl;
+        << endl << "Line is: '" << line << "'\n";
     exit(1);
 }
 
@@ -612,7 +611,7 @@ void loadSignatureBuildSigs(const string &inFile,
                        SignatureSet &signatures) {
     ifstream f(inFile.c_str());
     if (!f.good()) {
-        cerr << "Can't open file: '" << inFile << "'" << endl;
+        cerr << "Can't open file: '" << inFile << "'\n";
         exit(1);
     }
 
@@ -665,7 +664,7 @@ int HS_CDECL main(int argc, char **argv) {
     processArgs(argc, argv, g_grey);
 
     if (num_of_threads == 0) {
-        cout << "Error: Must have at least one thread." << endl;
+        cout << "Error: Must have at least one thread.\n";
         exit(1);
     }
 
@@ -687,7 +686,7 @@ int HS_CDECL main(int argc, char **argv) {
     }
 
     if (g_exprMap.empty()) {
-        cout << "Warning: no signatures to scan. Exiting." << endl;
+        cout << "Warning: no signatures to scan. Exiting.\n";
         exit(0);
     }
 
@@ -717,7 +716,7 @@ int HS_CDECL main(int argc, char **argv) {
 
     if (!g_exprMap.empty() && !build_sigs) {
         cout << "SUMMARY: " << countFailures << " of "
-             << g_exprMap.size() << " failed." << endl;
+             << g_exprMap.size() << " failed.\n";
     }
     return 0;
 }

tools/hsdump/main.cpp

@@ -337,7 +337,9 @@ void clearDir(const string &path) {
         if (name == "." || name == "..") {
             continue;
         }
-        string f = path + '/' + name;
+        string f = path;
+        f += '/';
+        f += name;
         if (unlink(f.c_str()) < 0) {
             printf("ERROR: couldn't remove file %s: %s\n", f.c_str(),
                    strerror(errno));