avoid redundant `Token::declEndToken()` calls (#4363)

lib/astutils.cpp

@@ -374,7 +374,8 @@ bool isVariableDecl(const Token* tok)
         return false;
     if (var->nameToken() == tok)
         return true;
-    if (Token::Match(var->declEndToken(), "; %var%") && var->declEndToken()->next() == tok)
+    const Token * const varDeclEndToken = var->declEndToken();
+    if (Token::Match(varDeclEndToken, "; %var%") && varDeclEndToken->next() == tok)
         return true;
     return false;
 }
@@ -1068,16 +1069,17 @@ std::vector<ReferenceToken> followAllReferences(const Token* tok,
         if (var->nameToken() == tok || isStructuredBindingVariable(var)) {
             return {{tok, std::move(errors)}};
         } else if (var->isReference() || var->isRValueReference()) {
-            if (!var->declEndToken())
+            const Token * const varDeclEndToken = var->declEndToken();
+            if (!varDeclEndToken)
                 return {{tok, std::move(errors)}};
             if (var->isArgument()) {
-                errors.emplace_back(var->declEndToken(), "Passed to reference.");
+                errors.emplace_back(varDeclEndToken, "Passed to reference.");
                 return {{tok, std::move(errors)}};
-            } else if (Token::simpleMatch(var->declEndToken(), "=")) {
+            } else if (Token::simpleMatch(varDeclEndToken, "=")) {
-                if (astHasToken(var->declEndToken(), tok))
+                if (astHasToken(varDeclEndToken, tok))
                     return std::vector<ReferenceToken>{};
-                errors.emplace_back(var->declEndToken(), "Assigned to reference.");
+                errors.emplace_back(varDeclEndToken, "Assigned to reference.");
-                const Token *vartok = var->declEndToken()->astOperand2();
+                const Token *vartok = varDeclEndToken->astOperand2();
                 if (vartok == tok || (!temporary && isTemporary(true, vartok, nullptr, true) &&
                                       (var->isConst() || var->isRValueReference())))
                     return {{tok, std::move(errors)}};

lib/checkautovariables.cpp

@@ -471,11 +471,12 @@ static bool isEscapedReference(const Variable* var)
         return false;
     if (!var->isReference())
         return false;
-    if (!var->declEndToken())
+    const Token * const varDeclEndToken = var->declEndToken();
+    if (!varDeclEndToken)
         return false;
-    if (!Token::simpleMatch(var->declEndToken(), "="))
+    if (!Token::simpleMatch(varDeclEndToken, "="))
         return false;
-    const Token* vartok = var->declEndToken()->astOperand2();
+    const Token* vartok = varDeclEndToken->astOperand2();
     return !isTemporary(true, vartok, nullptr, false);
 }
 

lib/checkother.cpp

@@ -1297,7 +1297,8 @@ void CheckOther::checkPassByReference()
         if (var->scope() && var->scope()->function->arg->link()->strAt(-1) == "...")
             continue; // references could not be used as va_start parameters (#5824)
 
-        if ((var->declEndToken() && var->declEndToken()->isExternC()) ||
+        const Token * const varDeclEndToken = var->declEndToken();
+        if ((varDeclEndToken && varDeclEndToken->isExternC()) ||
             (var->scope() && var->scope()->function && var->scope()->function->tokenDef && var->scope()->function->tokenDef->isExternC()))
             continue; // references cannot be used in functions in extern "C" blocks
 

lib/valueflow.cpp

@@ -3340,14 +3340,15 @@ static std::vector<LifetimeToken> getLifetimeTokens(const Token* tok,
         return {{tok, std::move(errorPath)}};
     if (var && var->declarationId() == tok->varId()) {
         if (var->isReference() || var->isRValueReference()) {
-            if (!var->declEndToken())
+            const Token * const varDeclEndToken = var->declEndToken();
+            if (!varDeclEndToken)
                 return {{tok, true, std::move(errorPath)}};
             if (var->isArgument()) {
-                errorPath.emplace_back(var->declEndToken(), "Passed to reference.");
+                errorPath.emplace_back(varDeclEndToken, "Passed to reference.");
                 return {{tok, true, std::move(errorPath)}};
-            } else if (Token::simpleMatch(var->declEndToken(), "=")) {
+            } else if (Token::simpleMatch(varDeclEndToken, "=")) {
-                errorPath.emplace_back(var->declEndToken(), "Assigned to reference.");
+                errorPath.emplace_back(varDeclEndToken, "Assigned to reference.");
-                const Token *vartok = var->declEndToken()->astOperand2();
+                const Token *vartok = varDeclEndToken->astOperand2();
                 const bool temporary = isTemporary(true, vartok, nullptr, true);
                 const bool nonlocal = var->isStatic() || var->isGlobal();
                 if (vartok == tok || (nonlocal && temporary) ||
@@ -4021,6 +4022,8 @@ struct LifetimeStore {
             return;
         if (!argtok)
             return;
+        if (!tok)
+            return;
         for (const ValueFlow::Value &v : argtok->values()) {
             if (!v.isLifetimeValue())
                 continue;
@@ -4031,7 +4034,8 @@ struct LifetimeStore {
             er.insert(er.end(), errorPath.begin(), errorPath.end());
             if (!var)
                 continue;
-            for (const Token *tok3 = tok; tok3 && tok3 != var->declEndToken(); tok3 = tok3->previous()) {
+            const Token * const varDeclEndToken = var->declEndToken();
+            for (const Token *tok3 = tok; tok3 && tok3 != varDeclEndToken; tok3 = tok3->previous()) {
                 if (tok3->varId() == var->declarationId()) {
                     LifetimeStore{tok3, message, type, inconclusive}.byVal(tok, tokenlist, errorLogger, settings, pred);
                     break;