diff --git a/lib/checkbool.cpp b/lib/checkbool.cpp
index c6f91cc63..cc45c3223 100644
--- a/lib/checkbool.cpp
+++ b/lib/checkbool.cpp
@@ -218,13 +218,11 @@ void CheckBool::checkComparisonOfFuncReturningBool()
         for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
             if (tok->type() != Token::eComparisonOp || tok->str() == "==" || tok->str() == "!=")
                 continue;
-            const Token *first_token;
-            bool first_token_func_of_type_bool = false;
+            const Token *first_token = tok->previous();
             if (tok->strAt(-1) == ")") {
-                first_token = tok->previous()->link()->previous();
-            } else {
-                first_token = tok->previous();
+                first_token = first_token->link()->previous();
             }
+            bool first_token_func_of_type_bool = false;
             if (Token::Match(first_token, "%var% (") && !Token::Match(first_token->previous(), "::|.")) {
                 const Function* func = first_token->function();
                 if (func && func->tokenDef && func->tokenDef->strAt(-1) == "bool") {
@@ -233,10 +231,10 @@ void CheckBool::checkComparisonOfFuncReturningBool()
             }
 
             Token *second_token = tok->next();
-            bool second_token_func_of_type_bool = false;
             while (second_token->str()=="!") {
                 second_token = second_token->next();
             }
+            bool second_token_func_of_type_bool = false;
             if (Token::Match(second_token, "%var% (") && !Token::Match(second_token->previous(), "::|.")) {
                 const Function* func = second_token->function();
                 if (func && func->tokenDef && func->tokenDef->strAt(-1) == "bool") {
@@ -299,7 +297,6 @@ void CheckBool::checkComparisonOfBoolWithBool()
             if (tok->type() != Token::eComparisonOp || tok->str() == "==" || tok->str() == "!=")
                 continue;
             bool first_token_bool = false;
-            bool second_token_bool = false;
 
             const Token *first_token = tok->previous();
             if (first_token->varId()) {
@@ -307,13 +304,17 @@ void CheckBool::checkComparisonOfBoolWithBool()
                     first_token_bool = true;
                 }
             }
+            if (!first_token_bool)
+                continue;
+
+            bool second_token_bool = false;
             const Token *second_token = tok->next();
             if (second_token->varId()) {
                 if (isBool(second_token->variable())) {
                     second_token_bool = true;
                 }
             }
-            if ((first_token_bool == true) && (second_token_bool == true)) {
+            if (second_token_bool) {
                 comparisonOfBoolWithBoolError(first_token->next(), first_token->str());
             }
         }
@@ -374,7 +375,7 @@ void CheckBool::checkComparisonOfBoolExpressionWithInt()
                 continue;
 
             // Skip template parameters
-            if (tok->str() == "<" && tok->link()) {
+            if (tok->link() && tok->str() == "<") {
                 tok = tok->link();
                 continue;
             }
@@ -394,11 +395,11 @@ void CheckBool::checkComparisonOfBoolExpressionWithInt()
                 continue;
             }
 
-            if (Token::Match(boolExpr,"%bool%"))
-                // The CheckBool::checkComparisonOfBoolWithInt warns about this.
+            if (!numTok || !boolExpr)
                 continue;
 
-            if (!numTok || !boolExpr)
+            if (Token::Match(boolExpr,"%bool%"))
+                // The CheckBool::checkComparisonOfBoolWithInt warns about this.
                 continue;
 
             if (boolExpr->isOp() && numTok->isName() && Token::Match(tok, "==|!="))
diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 09c72b1ce..288afe711 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -138,8 +138,6 @@ void CheckClass::constructors()
                 if (var->hasDefault())
                     usage[count].init = true;
 
-                bool inconclusive = false;
-
                 if (usage[count].assign || usage[count].init || var->isStatic())
                     continue;
 
@@ -169,14 +167,19 @@ void CheckClass::constructors()
                     }
                 }
 
+                bool inconclusive = false;
                 // Don't warn about unknown types in copy constructors since we
                 // don't know if they can be copied or not..
                 if (!var->isPointer() &&
                     !(var->type() && var->type()->needInitialization != Type::True) &&
                     (func->type == Function::eCopyConstructor || func->type == Function::eOperatorEqual)) {
                     bool stdtype = false;
-                    for (const Token *type = var->typeStartToken(); type && type->isName(); type = type->next())
-                        stdtype |= type->isStandardType();
+                    for (const Token *type = var->typeStartToken(); type && type->isName(); type = type->next()) {
+                        if (type->isStandardType()) {
+                            stdtype = true;
+                            break;
+                        }
+                    }
                     if (!stdtype) {
                         if (_settings->inconclusive)
                             inconclusive = true;
@@ -942,7 +945,8 @@ void CheckClass::checkMemset()
                 const Token* arg1 = tok->tokAt(2);
                 const Token* arg3 = arg1;
                 arg3 = arg3->nextArgument();
-                arg3 = (arg3 != nullptr) ? arg3->nextArgument() : nullptr;
+                if (arg3)
+                    arg3 = arg3->nextArgument();
                 if (!arg3)
                     // weird, shouldn't happen: memset etc should have
                     // 3 arguments.
@@ -1268,12 +1272,11 @@ void CheckClass::operatorEqToSelf()
     const std::size_t classes = symbolDatabase->classAndStructScopes.size();
     for (std::size_t i = 0; i < classes; ++i) {
         const Scope * scope = symbolDatabase->classAndStructScopes[i];
-        std::list<Function>::const_iterator func;
-
         // skip classes with multiple inheritance
         if (scope->definedType->derivedFrom.size() > 1)
             continue;
 
+        std::list<Function>::const_iterator func;
         for (func = scope->functionList.begin(); func != scope->functionList.end(); ++func) {
             if (func->type == Function::eOperatorEqual && func->hasBody) {
                 // make sure that the operator takes an object of the same type as *this, otherwise we can't detect self-assignment checks
diff --git a/lib/checkio.cpp b/lib/checkio.cpp
index b724f0841..cd9394a85 100644
--- a/lib/checkio.cpp
+++ b/lib/checkio.cpp
@@ -1404,7 +1404,7 @@ CheckIO::ArgumentInfo::ArgumentInfo(const Token * tok, const Settings *settings)
                     break;
                 } else if (tok1->str() == "(" || tok1->str() == "{" || tok1->str() == "[")
                     tok1 = tok1->link();
-                else if (tok1->str() == "<" && tok1->link())
+                else if (tok1->link() && tok1->str() == "<")
                     tok1 = tok1->link();
 
                 // check for some common well known functions
@@ -1419,10 +1419,13 @@ CheckIO::ArgumentInfo::ArgumentInfo(const Token * tok, const Settings *settings)
                             tempToken->str("long");
                             if (settings->sizeof_long != 8)
                                 tempToken->isLong(true);
-                        } else if (settings->sizeof_size_t == 4 && settings->sizeof_long == 4)
-                            tempToken->str("long");
-                        else if (settings->sizeof_size_t == 4)
-                            tempToken->str("int");
+                        } else if (settings->sizeof_size_t == 4) {
+                            if (settings->sizeof_long == 4) {
+                                tempToken->str("long");
+                            } else {
+                                tempToken->str("int");
+                            }
+                        }
 
                         tempToken->originalName("size_t");
                         tempToken->isUnsigned(true);
diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 1cfdd0b09..b126df5d6 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -1820,7 +1820,7 @@ std::string Preprocessor::getcode(const std::string &filedata, const std::string
         const std::string def = getdef(line, true);
         const std::string ndef = getdef(line, false);
 
-        const bool emptymatch = matching_ifdef.empty() | matched_ifdef.empty();
+        const bool emptymatch = matching_ifdef.empty() || matched_ifdef.empty();
 
         if (line.compare(0, 8, "#define ") == 0) {
             match = true;
@@ -1842,8 +1842,14 @@ std::string Preprocessor::getcode(const std::string &filedata, const std::string
                 }
             }
 
-            for (std::list<bool>::const_iterator it = matching_ifdef.begin(); it != matching_ifdef.end(); ++it)
-                match &= bool(*it);
+            if (match) {
+                for (std::list<bool>::const_iterator it = matching_ifdef.begin(); it != matching_ifdef.end(); ++it) {
+                    if (!bool(*it)) {
+                        match = false;
+                        break;
+                    }
+                }
+            }
 
             if (match) {
                 std::string::size_type pos = line.find_first_of(" (", 8);
@@ -1915,8 +1921,12 @@ std::string Preprocessor::getcode(const std::string &filedata, const std::string
 
         if (!line.empty() && line[0] == '#') {
             match = true;
-            for (std::list<bool>::const_iterator it = matching_ifdef.begin(); it != matching_ifdef.end(); ++it)
-                match &= bool(*it);
+            for (std::list<bool>::const_iterator it = matching_ifdef.begin(); it != matching_ifdef.end(); ++it) {
+                if (!bool(*it)) {
+                    match = false;
+                    break;
+                }
+            }
         }
 
         // #error => return ""