fix #13954

Author: ludviggunne

lib/checkclass.cpp

@@ -231,6 +231,9 @@ void CheckClass::constructors()
                 if (usage.assign || usage.init || var.isStatic())
                     continue;
 
+                if (var.nameToken() && var.nameToken()->isAnonymousBitfield())
+                    continue;
+
                 if (var.valueType() && var.valueType()->pointer == 0 && var.type() && var.type()->needInitialization == Type::NeedInitialization::False && var.type()->derivedFrom.empty())
                     continue;
 

lib/checkunusedvar.cpp

@@ -1575,6 +1575,9 @@ void CheckUnusedVar::checkStructMemberUsage()
             if (isInherited && !var.isPrivate())
                 continue;
 
+            if (var.nameToken() && (var.nameToken()->isAttributeUnused() || var.nameToken()->isAnonymousBitfield()))
+                continue;
+
             if (mTokenizer->isVarUsedInTemplate(var.declarationId()))
                 continue;
 

lib/token.h

@@ -742,6 +742,13 @@ class CPPCHECKLIB Token {
         setFlag(fIsInitBracket, b);
     }
 
+    bool isAnonymousBitfield() const {
+        return getFlag(fIsAnonymousBitfield);
+    }
+    void isAnonymousBitfield(bool b) {
+        setFlag(fIsAnonymousBitfield, b);
+    }
+
     // cppcheck-suppress unusedFunction
     bool isBitfield() const {
         return mImpl->mBits > 0;
@@ -1426,6 +1433,7 @@ class CPPCHECKLIB Token {
         fIsFinalType            = (1ULL << 42), // Is this a type with final specifier
         fIsInitComma            = (1ULL << 43), // Is this comma located inside some {..}. i.e: {1,2,3,4}
         fIsInitBracket          = (1ULL << 44), // Is this bracket used as a part of variable initialization i.e: int a{5}, b(2);
+        fIsAnonymousBitfield    = (1ULL << 45), // Is this a token added for an unnamed bit-field
     };
 
     enum : std::uint8_t {

lib/tokenize.cpp

@@ -9985,12 +9985,8 @@ void Tokenizer::simplifyAt()
 // Simplify bitfields
 void Tokenizer::simplifyBitfields()
 {
-    bool goback = false;
+    std::size_t anonymousBitfieldCounter = 0;
     for (Token *tok = list.front(); tok; tok = tok->next()) {
-        if (goback) {
-            goback = false;
-            tok = tok->previous();
-        }
         Token *last = nullptr;
 
         if (Token::simpleMatch(tok, "for ("))
@@ -10040,8 +10036,15 @@ void Tokenizer::simplifyBitfields()
             }
         } else if (Token::Match(typeTok, "%type% : %num%|%bool% ;") &&
                    typeTok->str() != "default") {
-            tok->deleteNext(4 + tokDistance(tok, typeTok) - 1);
-            goback = true;
+            const std::size_t id = anonymousBitfieldCounter++;
+            const std::string name = "__cppcheck_anon_bit_field_" + std::to_string(id) + "__";
+            Token *newTok = typeTok->insertToken(name);
+            newTok->isAnonymousBitfield(true);
+            if (newTok->tokAt(2)->isBoolean())
+                newTok->setBits(static_cast<unsigned char>(newTok->strAt(2) == "true"));
+            else
+                newTok->setBits(static_cast<unsigned char>(MathLib::toBigNumber(newTok->tokAt(2))));
+            newTok->deleteNext(2);
         }
 
         if (last && last->str() == ",") {