diff --git a/lib/checkbufferoverrun.cpp b/lib/checkbufferoverrun.cpp
index 13292adc7..5f93c86f4 100644
--- a/lib/checkbufferoverrun.cpp
+++ b/lib/checkbufferoverrun.cpp
@@ -219,7 +219,7 @@ private:
 static bool bailoutIfSwitch(const Token *tok, const unsigned int varid)
 {
     // Used later to check if the body belongs to a "if"
-    const std::string str1(tok->str());
+    bool is_if = tok->str() == "if";
 
     // Count { and }
     unsigned int indentlevel = 0;
@@ -239,7 +239,7 @@ static bool bailoutIfSwitch(const Token *tok, const unsigned int varid)
         }
 
         // If scanning a "if" block then bailout for "break"
-        else if (str1 == "if" && tok->str() == "break")
+        else if (is_if && tok->str() == "break")
             return true;
 
         // bailout for "return"
@@ -874,7 +874,7 @@ void CheckBufferOverrun::checkScope(const Token *tok, const std::vector<std::str
                     tok3 = tok3->tokAt(-2);
 
                 // just taking the address?
-                const bool addr(tok3 && (Token::simpleMatch(tok3, "&") ||
+                const bool addr(tok3 && (tok3->str() == "&" ||
                                          Token::simpleMatch(tok3->previous(), "& (")));
 
                 // taking address of 1 past end?
@@ -1065,8 +1065,8 @@ void CheckBufferOverrun::checkScope(const Token *tok, const ArrayInfo &arrayInfo
                     tok2 = tok2->tokAt(-2);
 
                 // just taking the address?
-                const bool addr(Token::simpleMatch(tok2, "&") ||
-                                Token::simpleMatch(tok2->previous(), "& ("));
+                const bool addr(tok2 && (tok2->str() == "&" ||
+					                     Token::simpleMatch(tok2->previous(), "& (")));
 
                 // taking address of 1 past end?
                 if (addr && totalIndex == totalElements)
@@ -1278,6 +1278,9 @@ void CheckBufferOverrun::checkGlobalAndLocalVariable()
         else if (tok->str() == "}")
             --indentlevel;
 
+        if (indentlevel <= 0)
+            continue;
+
         // size : Max array index
         MathLib::bigint size = 0;
 
@@ -1298,25 +1301,24 @@ void CheckBufferOverrun::checkGlobalAndLocalVariable()
                                      "Check (BufferOverrun::checkGlobalAndLocalVariable)",
                                      tok->progressValue());
 
-        if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = new %type% [ %num% ]")) {
+        if (Token::Match(tok, "[*;{}] %var% = new %type% [ %num% ]")) {
             size = MathLib::toLongNumber(tok->strAt(6));
             type = tok->strAt(4);
             varid = tok->next()->varId();
             nextTok = 8;
-        } else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = new %type% ( %num% )")) {
+        } else if (Token::Match(tok, "[*;{}] %var% = new %type% ( %num% )")) {
             size = 1;
             type = tok->strAt(4);
             varid = tok->next()->varId();
             nextTok = 8;
-        } else if (indentlevel > 0 &&
-                   Token::Match(tok, "[;{}] %var% = %str% ;") &&
+        } else if (Token::Match(tok, "[;{}] %var% = %str% ;") &&
                    tok->next()->varId() > 0 &&
                    NULL != Token::findmatch(_tokenizer->tokens(), "[;{}] const| %type% * %varid% ;", tok->next()->varId())) {
             size = 1 + int(tok->tokAt(3)->strValue().size());
             type = "char";
             varid = tok->next()->varId();
             nextTok = 4;
-        } else if (indentlevel > 0 && Token::Match(tok, "[*;{}] %var% = malloc|alloca ( %num% ) ;")) {
+        } else if (Token::Match(tok, "[*;{}] %var% = malloc|alloca ( %num% ) ;")) {
             size = MathLib::toLongNumber(tok->strAt(5));
             type = "char";   // minimum type, typesize=1
             varid = tok->next()->varId();
diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 660f75677..f18f915b7 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -1337,25 +1337,13 @@ bool CheckClass::isMemberVar(const Scope *scope, const Token *tok)
 
 static unsigned int countParameters(const Token *tok)
 {
-    if (Token::Match(tok->tokAt(2), "void| )"))
+    tok = tok->tokAt(2);
+    if (tok->str() == ")")
         return 0;
 
     unsigned int numpar = 1;
-    unsigned int parlevel = 0;
-    for (; tok; tok = tok->next()) {
-        if (tok->str() == "(")
-            ++parlevel;
-
-        else if (tok->str() == ")") {
-            if (parlevel <=1)
-                break;
-            --parlevel;
-        }
-
-        else if (parlevel==1 && tok->str() == ",") {
-            ++numpar;
-        }
-    }
+    while ((tok = tok->nextArgument()))
+        numpar++;
 
     return numpar;
 }
@@ -1364,7 +1352,7 @@ bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok)
 {
     unsigned int args = countParameters(tok);
 
-    std::list<Function>::const_iterator    func;
+    std::list<Function>::const_iterator func;
     unsigned int matches = 0;
     unsigned int consts = 0;
 
diff --git a/lib/checkmemoryleak.cpp b/lib/checkmemoryleak.cpp
index 7f4caa8ba..4c196dc54 100644
--- a/lib/checkmemoryleak.cpp
+++ b/lib/checkmemoryleak.cpp
@@ -626,31 +626,17 @@ bool CheckMemoryLeakInFunction::notvar(const Token *tok, unsigned int varid, boo
 }
 
 
-static int countParameters(const Token *tok)
+static unsigned int countParameters(const Token *tok)
 {
-    if (!Token::Match(tok, "%var% ("))
-        return -1;
-    if (Token::Match(tok->tokAt(2), "void| )"))
+    tok = tok->tokAt(2);
+    if (tok->str() == ")")
         return 0;
 
-    int numpar = 1;
-    int parlevel = 0;
-    for (; tok; tok = tok->next()) {
-        if (tok->str() == "(")
-            ++parlevel;
+    unsigned int numpar = 1;
+    while (tok = tok->nextArgument())
+        numpar++;
 
-        else if (tok->str() == ")") {
-            if (parlevel <= 1)
-                return numpar;
-            --parlevel;
-        }
-
-        else if (parlevel == 1 && tok->str() == ",") {
-            ++numpar;
-        }
-    }
-
-    return -1;
+    return numpar;
 }
 
 bool CheckMemoryLeakInFunction::test_white_list(const std::string &funcname)
@@ -729,8 +715,8 @@ const char * CheckMemoryLeakInFunction::call_func(const Token *tok, std::list<co
     }
 
     // how many parameters is there in the function call?
-    int numpar = countParameters(tok);
-    if (numpar <= 0) {
+    unsigned int numpar = countParameters(tok);
+    if (numpar == 0) {
         // Taking return value => it is not a noreturn function
         if (tok->strAt(-1) == "=")
             return NULL;
@@ -2885,7 +2871,7 @@ void CheckMemoryLeakStructMember::checkStructVariable(const Token * const vartok
 
 
 
-#include "checkuninitvar.h"		// CheckUninitVar::analyse
+#include "checkuninitvar.h" // CheckUninitVar::analyse
 
 void CheckMemoryLeakNoVar::check()
 {
diff --git a/lib/checknullpointer.cpp b/lib/checknullpointer.cpp
index ace4daa7d..a99db8cfd 100644
--- a/lib/checknullpointer.cpp
+++ b/lib/checknullpointer.cpp
@@ -336,24 +336,14 @@ void CheckNullPointer::nullPointerLinkedList()
     //    }
     for (const Token *tok1 = _tokenizer->tokens(); tok1; tok1 = tok1->next()) {
         // search for a "for" token..
-        if (!Token::simpleMatch(tok1, "for ("))
+        if (tok1->str() != "for")
             continue;
 
         // is there any dereferencing occurring in the for statement
-        // parlevel2 counts the parentheses when using tok2.
-        unsigned int parlevel2 = 1;
-        for (const Token *tok2 = tok1->tokAt(2); tok2; tok2 = tok2->next()) {
-            // Parentheses..
-            if (tok2->str() == "(")
-                ++parlevel2;
-            else if (tok2->str() == ")") {
-                if (parlevel2 <= 1)
-                    break;
-                --parlevel2;
-            }
-
+        const Token* end2 = tok1->tokAt(1)->link();
+        for (const Token *tok2 = tok1->tokAt(2); tok2 != end2; tok2 = tok2->next()) {
             // Dereferencing a variable inside the "for" parentheses..
-            else if (Token::Match(tok2, "%var% . %var%")) {
+            if (Token::Match(tok2, "%var% . %var%")) {
                 // Variable id for dereferenced variable
                 const unsigned int varid(tok2->varId());
                 if (varid == 0)
diff --git a/lib/path.cpp b/lib/path.cpp
index f1c26aec0..4996f1177 100644
--- a/lib/path.cpp
+++ b/lib/path.cpp
@@ -22,7 +22,7 @@
 #include <cstring>
 #include "path.h"
 
-std::string Path::toNativeSeparators(const std::string &path)
+std::string Path::toNativeSeparators(std::string path)
 {
 #if defined(_WIN32)
     char separ = '/';
@@ -31,18 +31,16 @@ std::string Path::toNativeSeparators(const std::string &path)
     char separ = '\\';
     char native = '/';
 #endif
-    std::string modified(path);
-    std::replace(modified.begin(), modified.end(), separ, native);
-    return modified;
+    std::replace(path.begin(), path.end(), separ, native);
+    return path;
 }
 
-std::string Path::fromNativeSeparators(const std::string &path)
+std::string Path::fromNativeSeparators(std::string path)
 {
     char nonnative = '\\';
     char newsepar = '/';
-    std::string modified(path);
-    std::replace(modified.begin(), modified.end(), nonnative, newsepar);
-    return modified;
+    std::replace(path.begin(), path.end(), nonnative, newsepar);
+    return path;
 }
 
 std::string Path::simplifyPath(const char *originalPath)
@@ -109,11 +107,10 @@ bool Path::sameFileName(const std::string &fname1, const std::string &fname2)
 #endif
 }
 
-std::string Path::removeQuotationMarks(const std::string &path)
+std::string Path::removeQuotationMarks(std::string path)
 {
-    std::string editPath(path);
-    editPath.erase(std::remove(editPath.begin(), editPath.end(), '\"'), editPath.end());
-    return editPath;
+    path.erase(std::remove(path.begin(), path.end(), '\"'), path.end());
+    return path;
 }
 
 std::string Path::getFilenameExtension(const std::string &path)
diff --git a/lib/path.h b/lib/path.h
index 274bfe6c9..5fd71afb8 100644
--- a/lib/path.h
+++ b/lib/path.h
@@ -38,14 +38,14 @@ public:
      * @param path Path string to convert.
      * @return converted path.
      */
-    static std::string toNativeSeparators(const std::string &path);
+    static std::string toNativeSeparators(std::string path);
 
     /**
       * Convert path to use internal path separators.
       * @param path Path string to convert.
       * @return converted path.
       */
-    static std::string fromNativeSeparators(const std::string &path);
+    static std::string fromNativeSeparators(std::string path);
 
     /**
      * @brief Simplify path "foo/bar/.." => "foo"
@@ -68,7 +68,7 @@ public:
      * @param path path to be cleaned.
      * @return Cleaned path without quotation marks.
      */
-    static std::string removeQuotationMarks(const std::string &path);
+    static std::string removeQuotationMarks(std::string path);
 
     /**
       * @brief Get an extension of the filename.
diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 57f2a580b..2f1d27729 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -1107,9 +1107,7 @@ std::list<std::string> Preprocessor::getcfgs(const std::string &filedata, const
             }
             if (from_negation) {
                 ndeflist.push_back(deflist.back());
-                deflist.pop_back();
-                std::string nmark("!");
-                deflist.push_back(nmark);
+                deflist.back() = "!";
             }
 
             if (std::find(ret.begin(), ret.end(), def) == ret.end()) {
@@ -1119,13 +1117,11 @@ std::list<std::string> Preprocessor::getcfgs(const std::string &filedata, const
 
         else if (line.compare(0, 5, "#else") == 0 && ! deflist.empty()) {
             if (deflist.back() == "!") {
-                deflist.pop_back();
-                deflist.push_back(ndeflist.back());
+                deflist.back() = ndeflist.back();
                 ndeflist.pop_back();
             } else {
                 std::string tempDef((deflist.back() == "1") ? "0" : "1");
-                deflist.pop_back();
-                deflist.push_back(tempDef);
+                deflist.back() = tempDef;
             }
         }
 
@@ -2701,11 +2697,8 @@ std::string Preprocessor::expandMacros(const std::string &code, std::string file
         }
     }
 
-    {
-        std::map<std::string, PreprocessorMacro *>::iterator it;
-        for (it = macros.begin(); it != macros.end(); ++it)
-            delete it->second;
-    }
+    for (std::map<std::string, PreprocessorMacro *>::iterator it = macros.begin(); it != macros.end(); ++it)
+        delete it->second;
 
     return ostr.str();
 }
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 1a0e4f593..0f995f01f 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -826,7 +826,7 @@ static Token *processFunc(Token *tok2, bool inOperator)
             tok2 = tok2->linkAt(4)->next();
         else if (Token::Match(tok2->next(), "* ( * %type% ("))
             tok2 = tok2->linkAt(5)->next();
-        else if (Token::Match(tok2->next(), "* [") &&
+        else if (Token::simpleMatch(tok2->next(), "* [") &&
                  Token::simpleMatch(tok2->linkAt(2), "] ;"))
             tok2 = tok2->next();
         else {
@@ -3450,7 +3450,7 @@ void Tokenizer::setVarId()
             tok = tok->next();
 
         // skip global namespace prefix
-        if (Token::simpleMatch(tok, "::"))
+        if (tok && tok->str() == "::")
             tok = tok->next();
 
         while (Token::Match(tok, "%var% ::"))
@@ -8389,9 +8389,9 @@ const char *Tokenizer::getParameterName(const Token *ftok, unsigned int par)
     for (; ftok; ftok = ftok->next()) {
         if (ftok->str() == ")")
             break;
-        if (ftok->str() == ",")
+        else if (ftok->str() == ",")
             ++_par;
-        if (par == _par && Token::Match(ftok, "%var% [,)]"))
+        else if (par == _par && Token::Match(ftok, "%var% [,)]"))
             return ftok->str().c_str();
     }
     return NULL;
@@ -9145,25 +9145,18 @@ void Tokenizer::simplifyStructDecl()
 
 void Tokenizer::simplifyCallingConvention()
 {
-    const char * pattern = "__cdecl|__stdcall|__fastcall|__thiscall|__clrcall|__syscall|__pascal|__fortran|__far|__near|WINAPI|APIENTRY|CALLBACK";
-    while (Token::Match(_tokens, pattern)) {
-        _tokens->deleteThis();
-    }
+    const char pattern[] = "__cdecl|__stdcall|__fastcall|__thiscall|__clrcall|__syscall|__pascal|__fortran|__far|__near|WINAPI|APIENTRY|CALLBACK";
     for (Token *tok = _tokens; tok; tok = tok->next()) {
-        while (Token::Match(tok->next(), pattern)) {
-            tok->deleteNext();
+        while (Token::Match(tok, pattern)) {
+            tok->deleteThis();
         }
     }
 }
 
 void Tokenizer::simplifyDeclspec()
 {
-    while (Token::simpleMatch(_tokens, "__declspec (") && _tokens->next()->link() && _tokens->next()->link()->next()) {
-        Token::eraseTokens(_tokens, _tokens->next()->link()->next());
-        _tokens->deleteThis();
-    }
     for (Token *tok = _tokens; tok; tok = tok->next()) {
-        if (Token::simpleMatch(tok, "__declspec (") && tok->next()->link() && tok->next()->link()->next()) {
+        while (Token::simpleMatch(tok, "__declspec (") && tok->next()->link() && tok->next()->link()->next()) {
             Token::eraseTokens(tok, tok->next()->link()->next());
             tok->deleteThis();
         }
@@ -9172,12 +9165,8 @@ void Tokenizer::simplifyDeclspec()
 
 void Tokenizer::simplifyAttribute()
 {
-    while (Token::simpleMatch(_tokens, "__attribute__ (") && _tokens->next()->link() && _tokens->next()->link()->next()) {
-        Token::eraseTokens(_tokens, _tokens->next()->link()->next());
-        _tokens->deleteThis();
-    }
     for (Token *tok = _tokens; tok; tok = tok->next()) {
-        if (Token::simpleMatch(tok, "__attribute__ (") && tok->next()->link() && tok->next()->link()->next()) {
+        while (Token::simpleMatch(tok, "__attribute__ (") && tok->next()->link() && tok->next()->link()->next()) {
             if (Token::simpleMatch(tok->tokAt(2), "( unused )")) {
                 // check if after variable name
                 if (Token::Match(tok->next()->link()->next(), ";|=")) {
@@ -9192,7 +9181,6 @@ void Tokenizer::simplifyAttribute()
 
             Token::eraseTokens(tok, tok->next()->link()->next());
             tok->deleteThis();
-            tok = tok->previous();
         }
     }
 }
@@ -9201,12 +9189,9 @@ void Tokenizer::simplifyAttribute()
 void Tokenizer::simplifyKeyword()
 {
     const char pattern[] = "volatile|inline|__inline|__forceinline|register|restrict|__restrict|__restrict__";
-    while (Token::Match(_tokens, pattern)) {
-        _tokens->deleteThis();
-    }
     for (Token *tok = _tokens; tok; tok = tok->next()) {
-        while (Token::Match(tok->next(), pattern)) {
-            tok->deleteNext();
+        while (Token::Match(tok, pattern)) {
+            tok->deleteThis();
         }
     }
 }