diff --git a/lib/checkautovariables.cpp b/lib/checkautovariables.cpp
index 64158c400..7eab3f38f 100644
--- a/lib/checkautovariables.cpp
+++ b/lib/checkautovariables.cpp
@@ -371,6 +371,9 @@ static bool astHasAutoResult(const Token *tok)
 
 void CheckAutoVariables::returnReference()
 {
+    if (_tokenizer->isC())
+        return;
+
     const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
 
     const std::size_t functions = symbolDatabase->functionScopes.size();
diff --git a/lib/checkio.cpp b/lib/checkio.cpp
index cec3053b9..91a33e783 100644
--- a/lib/checkio.cpp
+++ b/lib/checkio.cpp
@@ -38,6 +38,9 @@ namespace {
 //---------------------------------------------------------------------------
 void CheckIO::checkCoutCerrMisusage()
 {
+    if (_tokenizer->isC())
+        return;
+
     const SymbolDatabase * const symbolDatabase = _tokenizer->getSymbolDatabase();
     std::size_t functions = symbolDatabase->functionScopes.size();
     for (std::size_t i = 0; i < functions; ++i) {
diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index 945d7fa01..749501c40 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -777,31 +777,33 @@ SymbolDatabase::SymbolDatabase(const Tokenizer *tokenizer, const Settings *setti
         }
     }
 
-    // fill in base class info
-    for (std::list<Type>::iterator it = typeList.begin(); it != typeList.end(); ++it) {
-        // finish filling in base class info
-        for (unsigned int i = 0; i < it->derivedFrom.size(); ++i)
-            it->derivedFrom[i].type = findType(it->derivedFrom[i].nameTok, it->enclosingScope);
-    }
-
-    // fill in friend info
-    for (std::list<Type>::iterator it = typeList.begin(); it != typeList.end(); ++it) {
-        for (std::list<Type::FriendInfo>::iterator i = it->friendList.begin(); i != it->friendList.end(); ++i) {
-            i->type = findType(i->nameStart, it->enclosingScope);
+    if (!_tokenizer->isC()) {
+        // fill in base class info
+        for (std::list<Type>::iterator it = typeList.begin(); it != typeList.end(); ++it) {
+            // finish filling in base class info
+            for (unsigned int i = 0; i < it->derivedFrom.size(); ++i)
+                it->derivedFrom[i].type = findType(it->derivedFrom[i].nameTok, it->enclosingScope);
         }
-    }
 
-    // fill in using info
-    for (std::list<Scope>::iterator it = scopeList.begin(); it != scopeList.end(); ++it) {
-        for (std::list<Scope::UsingInfo>::iterator i = it->usingList.begin(); i != it->usingList.end(); ++i) {
-            // only find if not already found
-            if (i->scope == nullptr) {
-                // check scope for match
-                scope = findScope(i->start->tokAt(2), &(*it));
-                if (scope) {
-                    // set found scope
-                    i->scope = scope;
-                    break;
+        // fill in friend info
+        for (std::list<Type>::iterator it = typeList.begin(); it != typeList.end(); ++it) {
+            for (std::list<Type::FriendInfo>::iterator i = it->friendList.begin(); i != it->friendList.end(); ++i) {
+                i->type = findType(i->nameStart, it->enclosingScope);
+            }
+        }
+
+        // fill in using info
+        for (std::list<Scope>::iterator it = scopeList.begin(); it != scopeList.end(); ++it) {
+            for (std::list<Scope::UsingInfo>::iterator i = it->usingList.begin(); i != it->usingList.end(); ++i) {
+                // only find if not already found
+                if (i->scope == nullptr) {
+                    // check scope for match
+                    scope = findScope(i->start->tokAt(2), &(*it));
+                    if (scope) {
+                        // set found scope
+                        i->scope = scope;
+                        break;
+                    }
                 }
             }
         }
@@ -1210,14 +1212,14 @@ void Variable::evaluate()
 bool Function::argsMatch(const Scope *scope, const Token *first, const Token *second, const std::string &path, unsigned int depth)
 {
     const bool isCPP = scope->check->isCPP();
+    if (!isCPP) // C does not support overloads
+        return true;
 
-    // skip "struct" if it is C++
-    if (isCPP) {
-        if (first->str() == "struct")
-            first = first->next();
-        if (second->str() == "struct")
-            second = second->next();
-    }
+    // skip "struct"
+    if (first->str() == "struct")
+        first = first->next();
+    if (second->str() == "struct")
+        second = second->next();
 
     // skip const on type passed by value
     if (Token::Match(first, "const %type% %var%|,|)"))
@@ -1339,13 +1341,11 @@ bool Function::argsMatch(const Scope *scope, const Token *first, const Token *se
         first = first->next();
         second = second->next();
 
-        // skip "struct" if it is C++
-        if (isCPP) {
-            if (first->str() == "struct")
-                first = first->next();
-            if (second->str() == "struct")
-                second = second->next();
-        }
+        // skip "struct"
+        if (first->str() == "struct")
+            first = first->next();
+        if (second->str() == "struct")
+            second = second->next();
 
         // skip const on type passed by value
         if (Token::Match(first, "const %type% %var%|,|)"))
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index a77a9b915..cd51d749c 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3247,7 +3247,7 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
     // ";a+=b;" => ";a=a+b;"
     simplifyCompoundAssignment();
 
-    if (!_settings->library.markupFile(FileName)) {
+    if (!isC() && !_settings->library.markupFile(FileName)) {
         findComplicatedSyntaxErrorsInTemplates();
     }
 
@@ -3461,7 +3461,8 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
     // then unsimplified function calls etc remain. These have the
     // "wrong" syntax. So this function will just fix so that the
     // syntax is corrected.
-    TemplateSimplifier::cleanupAfterSimplify(list.front());
+    if (!isC())
+        TemplateSimplifier::cleanupAfterSimplify(list.front());
 
     // Collapse operator name tokens into single token
     // operator = => operator=
@@ -6220,6 +6221,9 @@ bool Tokenizer::simplifyCAlternativeTokens()
 // int i(0), j; => int i; i = 0; int j;
 void Tokenizer::simplifyInitVar()
 {
+    if (isC())
+        return;
+
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (!tok->isName() || (tok->previous() && !Token::Match(tok->previous(), "[;{}]")))
             continue;
diff --git a/lib/tokenlist.cpp b/lib/tokenlist.cpp
index 2d09550b6..790ba7477 100644
--- a/lib/tokenlist.cpp
+++ b/lib/tokenlist.cpp
@@ -563,7 +563,7 @@ static void compilePrecedence2(Token *&tok, AST_state& state)
             } else
                 compileBinOp(tok, state, compileScope);
         } else if (tok->str() == "[") {
-            if (isPrefixUnary(tok, state.cpp) && tok->link()->strAt(1) == "(") { // Lambda
+            if (state.cpp && isPrefixUnary(tok, state.cpp) && tok->link()->strAt(1) == "(") { // Lambda
                 // What we do here:
                 // - Nest the round bracket under the square bracket.
                 // - Nest what follows the lambda (if anything) with the lambda opening [