Fix #7908 FN: redundant assignment in loop (#3650)

lib/checkio.cpp

@@ -974,7 +974,6 @@ void CheckIO::checkFormatString(const Token * const tok,
                         bool done = false;
                         while (!done) {
                             if (i == formatString.end()) {
-                                done = true;
                                 break;
                             }
                             switch (*i) {

lib/checkunusedvar.cpp

@@ -1278,7 +1278,8 @@ void CheckUnusedVar::checkFunctionVariableUsage()
                 continue;
 
             FwdAnalysis fwdAnalysis(mTokenizer->isCPP(), mSettings->library);
-            if (fwdAnalysis.unusedValue(expr, start, scope->bodyEnd)) {
+            const Token* scopeEnd = getEndOfExprScope(expr, scope, /*smallest*/ false);
+            if (fwdAnalysis.unusedValue(expr, start, scopeEnd)) {
                 if (!bailoutTypeName.empty() && bailoutTypeName != "auto") {
                     if (mSettings->checkLibrary && mSettings->severity.isEnabled(Severity::information)) {
                         reportError(tok,

lib/cppcheck.cpp

@@ -1646,7 +1646,6 @@ void CppCheck::analyseClangTidy(const ImportProject::FileSettings &fileSettings)
 
         const std::string lineNumString = line.substr(endNamePos + 1, endLinePos - endNamePos - 1);
         const std::string columnNumString = line.substr(endLinePos + 1, endColumnPos - endLinePos - 1);
-        const std::string errorTypeString = line.substr(endColumnPos + 1, endMsgTypePos - endColumnPos - 1);
         const std::string messageString = line.substr(endMsgTypePos + 1, endErrorPos - endMsgTypePos - 1);
         const std::string errorString = line.substr(endErrorPos, line.length());
 

lib/templatesimplifier.cpp

@@ -941,7 +941,6 @@ void TemplateSimplifier::getTemplateInstantiations()
 
             // Add outer template..
             if (templateParameters(tok->next()) || tok->strAt(2) == ">") {
-                const std::string scopeName1(scopeName);
                 while (true) {
                     const std::string fullName = scopeName + (scopeName.empty()?"":" :: ") +
                                                  qualification + (qualification.empty()?"":" :: ") + tok->str();
@@ -1141,6 +1140,8 @@ void TemplateSimplifier::useDefaultArgumentValues(TokenAndName &declaration)
                                                   "noparamend",
                                                   "TemplateSimplifier couldn't find end of template parameter.",
                                                   Certainty::normal);
+                        if (mErrorLogger && mSettings->severity.isEnabled(Severity::debug))
+                            mErrorLogger->reportErr(errmsg);
                     }
                     break;
                 }
@@ -1936,20 +1937,11 @@ void TemplateSimplifier::expandTemplate(
 
                         // replace type with given type..
                         if (itype < typeParametersInDeclaration.size() && itype < mTypesUsedInTemplateInstantiation.size()) {
-                            unsigned int typeindentlevel = 0;
                             std::stack<Token *> brackets1; // holds "(" and "{" tokens
                             for (const Token *typetok = mTypesUsedInTemplateInstantiation[itype].token();
-                                 typetok && (typeindentlevel>0 || !Token::Match(typetok, ",|>"));
+                                 typetok && !Token::Match(typetok, ",|>");
                                  typetok = typetok->next()) {
                                 if (!Token::simpleMatch(typetok, "...")) {
-                                    if (Token::Match(typetok, "%name% <") && (typetok->strAt(2) == ">" || templateParameters(typetok->next())))
-                                        ++typeindentlevel;
-                                    else if (typeindentlevel > 0 && typetok->str() == ">")
-                                        --typeindentlevel;
-                                    else if (typetok->str() == "(")
-                                        ++typeindentlevel;
-                                    else if (typetok->str() == ")")
-                                        --typeindentlevel;
                                     mTokenList.addtoken(typetok, tok5);
                                     Token *back = mTokenList.back();
                                     if (Token::Match(back, "{|(|[")) {

lib/valueflow.cpp

@@ -3427,7 +3427,7 @@ static const Token* getEndOfVarScope(const Variable* var)
     return innerScope->bodyEnd;
 }
 
-static const Token* getEndOfExprScope(const Token* tok, const Scope* defaultScope = nullptr)
+const Token* getEndOfExprScope(const Token* tok, const Scope* defaultScope, bool smallest)
 {
     const Token* end = nullptr;
     bool local = false;
@@ -3436,7 +3436,7 @@ static const Token* getEndOfExprScope(const Token* tok, const Scope* defaultScop
             local |= var->isLocal();
             if (var->isLocal() || var->isArgument()) {
                 const Token* varEnd = getEndOfVarScope(var);
-                if (!end || precedes(varEnd, end))
+                if (!end || (smallest ? precedes(varEnd, end) : succeeds(varEnd, end)))
                     end = varEnd;
             }
         }
@@ -3477,9 +3477,10 @@ static const Token* getEndOfVarScope(const Token* tok, const std::vector<const V
                     varScope = varScope->nestedIn;
             }
         }
-        if (varScope && (!endOfVarScope || precedes(varScope->bodyEnd, endOfVarScope)))
+        if (varScope && (!endOfVarScope || precedes(endOfVarScope, varScope->bodyEnd))) {
             endOfVarScope = varScope->bodyEnd;
         }
+    }
     return endOfVarScope;
 }
 

lib/valueflow.h

@@ -42,6 +42,7 @@ class Token;
 class TokenList;
 class ValueType;
 class Variable;
+class Scope;
 
 template<class T>
 class ValuePtr;
@@ -518,4 +519,6 @@ CPPCHECKLIB std::vector<ValueFlow::Value> getLifetimeObjValues(const Token* tok,
                                                                bool inconclusive = false,
                                                                MathLib::bigint path = 0);
 
+const Token* getEndOfExprScope(const Token* tok, const Scope* defaultScope = nullptr, bool smallest = true);
+
 #endif // valueflowH

test/testunusedvar.cpp

@@ -3362,6 +3362,61 @@ private:
                               "}");
         ASSERT_EQUALS("[test.cpp:3]: (style) Variable 'sum' is assigned a value that is never used.\n"
                       "[test.cpp:5]: (style) Variable 'sum' is assigned a value that is never used.\n", errout.str());
+
+        functionVariableUsage("void f(int c) {\n" // #7908
+                              "    int b = 0;\n"
+                              "    while (g()) {\n"
+                              "        int a = c;\n"
+                              "        b = a;\n"
+                              "        if (a == 4)\n"
+                              "            a = 5;\n"
+                              "    }\n"
+                              "    h(b);\n"
+                              "}\n");
+        ASSERT_EQUALS("[test.cpp:7]: (style) Variable 'a' is assigned a value that is never used.\n", errout.str());
+
+        functionVariableUsage("void f(const std::vector<int>& v) {\n"
+                              "    while (g()) {\n"
+                              "        const std::vector<int>& v2 = h();\n"
+                              "        if (std::vector<int>{ 1, 2, 3 }.size() > v2.size()) {}\n"
+                              "    }\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f(const std::vector<int>& v) {\n"
+                              "    while (g()) {\n"
+                              "        const std::vector<int>& v2 = h();\n"
+                              "        if (std::vector<int>({ 1, 2, 3 }).size() > v2.size()) {}\n"
+                              "    }\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f(const std::string &c) {\n"
+                              "    std::string s = str();\n"
+                              "    if (s[0] == '>')\n"
+                              "        s[0] = '<';\n"
+                              "    if (s == c) {}\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("void f(bool b) {\n"
+                              "    std::map<std::string, std::vector<std::string>> m;\n"
+                              "    if (b) {\n"
+                              "        const std::string n = g();\n"
+                              "        std::vector<std::string> c = h();\n"
+                              "        m[n] = c;\n"
+                              "    }\n"
+                              "    j(m);\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        functionVariableUsage("struct S { int i; };\n"
+                              "S f(S s, bool b) {\n"
+                              "    if (b)\n"
+                              "        s.i = 1;\n"
+                              "    return s;\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void localvaralias1() {