cppcheck-opensource · pfultz2 · Jul 7, 2026 · Jul 7, 2026 · Jul 7, 2026 · Jul 7, 2026
diff --git a/.clang-tidy b/.clang-tidy
@@ -18,6 +18,7 @@ Checks: >
         -objc-*,
         -openmp-*,
         -zircon-*,
+        cppcoreguidelines-avoid-const-or-ref-data-members,
         cppcoreguidelines-pro-type-static-cast-downcast,
         cppcoreguidelines-rvalue-reference-param-not-moved,
         google-explicit-constructor,

diff --git a/.github/workflows/selfcheck.yml b/.github/workflows/selfcheck.yml
@@ -121,7 +121,7 @@ jobs:
 
       - name: Self check (unusedFunction / no test / no gui)
         run: |
-          supprs="--suppress=unusedFunction:lib/errorlogger.h:197 --suppress=unusedFunction:lib/importproject.cpp:1671 --suppress=unusedFunction:lib/importproject.cpp:1695"
+          supprs="--suppress=unusedFunction:lib/errorlogger.h:198 --suppress=unusedFunction:lib/importproject.cpp:1671 --suppress=unusedFunction:lib/importproject.cpp:1695"
           ./cppcheck -q --template=selfcheck --error-exitcode=1 --library=cppcheck-lib -D__CPPCHECK__ -D__GNUC__ --enable=unusedFunction,information --exception-handling -rp=. --project=cmake.output.notest_nogui/compile_commands.json --suppressions-list=.selfcheck_unused_suppressions --inline-suppr $supprs
         env:
           DISABLE_VALUEFLOW: 1

diff --git a/Makefile b/Makefile
diff --git a/clang-tidy.md b/clang-tidy.md
@@ -138,7 +138,6 @@ Does not improve the readability.
 To be evaluated (need to remove exclusion).
 
 `cppcoreguidelines-missing-std-forward`<br/>
-`cppcoreguidelines-avoid-const-or-ref-data-members`<br/>
 `cppcoreguidelines-macro-usage`<br/>
 `cppcoreguidelines-pro-type-member-init`<br/>
 `cppcoreguidelines-prefer-member-initializer`<br/>

diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
diff --git a/cli/cmdlineparser.h b/cli/cmdlineparser.h
@@ -27,6 +27,7 @@
 
 #include "cmdlinelogger.h"
 #include "filesettings.h"
+#include "nonnullptr.h"
 #include "standards.h"
 #include "utils.h"
 
@@ -117,11 +118,11 @@ class CmdLineParser {
         T tmp;
         std::string err;
         if (!strToInt(arg + offset, tmp, &err)) {
-            mLogger.printError("argument to '" + std::string(arg, offset) + "' is not valid - " + err + ".");
+            mLogger->printError("argument to '" + std::string(arg, offset) + "' is not valid - " + err + ".");
             return false;
         }
         if (mustBePositive && tmp < 0) {
-            mLogger.printError("argument to '" + std::string(arg, offset) + "' needs to be a positive integer.");
+            mLogger->printError("argument to '" + std::string(arg, offset) + "' needs to be a positive integer.");
             return false;
         }
         num = tmp;
@@ -152,10 +153,10 @@ class CmdLineParser {
 
     void outputFormatOptionMixingError() const;
 
-    CmdLineLogger &mLogger;
+    NonNullPtr<CmdLineLogger> mLogger;
 
-    Settings &mSettings;
-    Suppressions &mSuppressions;
+    NonNullPtr<Settings> mSettings;
+    NonNullPtr<Suppressions> mSuppressions;
 
 protected:
     std::vector<std::string> mPathNames;

diff --git a/cli/processexecutor.cpp b/cli/processexecutor.cpp
@@ -172,8 +172,8 @@ namespace {
                 writeToPipeInternal(type, data.c_str(), len);
         }
 
-        const int mWpipe;
-        const bool mDebug;
+        int mWpipe;
+        bool mDebug;
     };
 }
 

diff --git a/gui/resultitem.h b/gui/resultitem.h
@@ -53,8 +53,8 @@ class ResultItem : public QStandardItem
         return mIconFileName;
     }
 private:
-    const Type mType;
-    const int mErrorPathIndex;
+    Type mType;
+    int mErrorPathIndex;
     QString mIconFileName;
 };
 

diff --git a/lib/astutils.cpp b/lib/astutils.cpp
@@ -26,6 +26,7 @@
 #include "infer.h"
 #include "library.h"
 #include "mathlib.h"
+#include "nonnullptr.h"
 #include "settings.h"
 #include "symboldatabase.h"
 #include "token.h"
@@ -3142,7 +3143,7 @@ namespace {
     };
 
     struct ExpressionChangedSkipDeadCode {
-        const Library& library;
+        NonNullPtr<const Library> library;
         const std::function<std::vector<MathLib::bigint>(const Token* tok)>* evaluate;
         ExpressionChangedSkipDeadCode(const Library& library,
                                       const std::function<std::vector<MathLib::bigint>(const Token* tok)>& evaluate)

diff --git a/lib/checkersreport.cpp b/lib/checkersreport.cpp
@@ -129,19 +129,19 @@ void CheckersReport::countCheckers()
     mActiveCheckersCount = mAllCheckersCount = 0;
 
     for (const auto& checkReq: checkers::allCheckers) {
-        if (mActiveCheckers.count(checkReq.first) > 0)
+        if (mActiveCheckers->count(checkReq.first) > 0)
             ++mActiveCheckersCount;
         ++mAllCheckersCount;
     }
-    for (const auto& addonInfo: mSettings.addonInfos) {
+    for (const auto& addonInfo: mSettings->addonInfos) {
         for (const auto& checkReq: addonInfo.checkers) {
-            if (mActiveCheckers.count(checkReq.first) > 0)
+            if (mActiveCheckers->count(checkReq.first) > 0)
                 ++mActiveCheckersCount;
             ++mAllCheckersCount;
         }
     }
 
-    if (mSettings.addons.count("misra")) {
+    if (mSettings->addons.count("misra")) {
         const bool doUnusedFunctionOnly = Settings::unusedFunctionOnly();
         for (const checkers::MisraInfo& info: checkers::misraC2012Rules) {
             const std::string rule = std::to_string(info.a) + "." + std::to_string(info.b);
@@ -185,20 +185,20 @@ std::string CheckersReport::getReport(const std::string& criticalErrors) const
     }
     for (const auto& checkReq: checkers::allCheckers) {
         const std::string& checker = checkReq.first;
-        const bool active = mActiveCheckers.count(checkReq.first) > 0;
+        const bool active = mActiveCheckers->count(checkReq.first) > 0;
         const std::string& req = checkReq.second;
         fout << (active ? "Yes  " : "No   ") << checker;
         if (!active && !req.empty())
             fout << std::string(maxCheckerSize + 4 - checker.size(), ' ') << "require:" + req;
         fout << std::endl;
     }
 
-    for (const auto& addonInfo: mSettings.addonInfos) {
+    for (const auto& addonInfo: mSettings->addonInfos) {
         if (addonInfo.checkers.empty())
             continue;
         fout << std::endl << std::endl;
         std::string title;
-        if (mSettings.premium && addonInfo.name == "premiumaddon.json")
+        if (mSettings->premium && addonInfo.name == "premiumaddon.json")
             title = "Cppcheck Premium";
         else {
             title = addonInfo.name;
@@ -217,7 +217,7 @@ std::string CheckersReport::getReport(const std::string& criticalErrors) const
 
         for (const auto& checkReq: addonInfo.checkers) {
             const std::string& checker = checkReq.first;
-            const bool active = mActiveCheckers.count(checkReq.first) > 0;
+            const bool active = mActiveCheckers->count(checkReq.first) > 0;
             const std::string& req = checkReq.second;
             fout << (active ? "Yes  " : "No   ") << checker;
             if (!active && !req.empty())
@@ -238,7 +238,7 @@ std::string CheckersReport::getXmlReport(const std::string& criticalErrors) cons
         ret += "    <critical-errors/>\n";
     ret += "    <checkers-report>\n";
     const int misraCVersion = getMisraCVersion(mSettings);
-    for (std::string checker: mActiveCheckers) {
+    for (std::string checker: *mActiveCheckers) {
         if (checker.compare(0,8,"Misra C:") == 0)
             checker = "Misra C " + std::to_string(misraCVersion) + ":" + checker.substr(8);
         ret += "        <checker id=\"" + checker + "\"/>\n";

diff --git a/lib/checkersreport.h b/lib/checkersreport.h
@@ -20,6 +20,7 @@
 #define checkersReportH
 
 #include "config.h"
+#include "nonnullptr.h"
 
 #include <set>
 #include <string>
@@ -37,8 +38,8 @@ class CPPCHECKLIB CheckersReport {
     std::string getXmlReport(const std::string& criticalErrors) const;
 
 private:
-    const Settings& mSettings;
-    const std::set<std::string>& mActiveCheckers;
+    NonNullPtr<const Settings> mSettings;
+    NonNullPtr<const std::set<std::string>> mActiveCheckers;
 
     void countCheckers();
 

diff --git a/lib/checkother.cpp b/lib/checkother.cpp
@@ -24,6 +24,7 @@
 #include "fwdanalysis.h"
 #include "library.h"
 #include "mathlib.h"
+#include "nonnullptr.h"
 #include "platform.h"
 #include "settings.h"
 #include "standards.h"
@@ -4513,7 +4514,7 @@ struct UnionMember {
         : name(name)
         , size(size) {}
 
-    const std::string &name;
+    NonNullPtr<const std::string> name;
     size_t size;
 };
 
@@ -4523,7 +4524,7 @@ struct Union {
         , name(scope.className) {}
 
     const Scope *scope;
-    const std::string &name;
+    NonNullPtr<const std::string> name;
     std::vector<UnionMember> members;
 
     const UnionMember *largestMember() const {
@@ -4632,7 +4633,7 @@ void CheckOtherImpl::unionZeroInitError(const Token *tok,
                 "Zero initializing union '$symbol' does not guarantee " +
                 "its complete storage to be zero initialized as its largest member " +
                 "is not declared as the first member. Consider making " +
-                largestMember.name + " the first member or favor memset().");
+                *largestMember.name + " the first member or favor memset().");
 }
 
 //-----------------------------------------------------------------------------

diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
@@ -22,6 +22,7 @@
 #include "errortypes.h"
 #include "library.h"
 #include "mathlib.h"
+#include "nonnullptr.h"
 #include "pathanalysis.h"
 #include "settings.h"
 #include "standards.h"
@@ -2872,7 +2873,7 @@ namespace {
     private:
         const Token* mBodyTok;
         const Token* mLoopVar{};
-        const Settings& mSettings;
+        NonNullPtr<const Settings> mSettings;
         std::set<nonneg int> mVarsChanged;
 
     public:
@@ -2895,7 +2896,7 @@ namespace {
             int n = 1 + (astIsPointer(tok) ? 1 : 0);
             for (int i = 0; i < n; i++) {
                 bool inconclusive = false;
-                if (isVariableChangedByFunctionCall(tok, i, mSettings.library, &inconclusive))
+                if (isVariableChangedByFunctionCall(tok, i, mSettings->library, &inconclusive))
                     return true;
                 if (inconclusive)
                     return true;

diff --git a/lib/clangimport.cpp b/lib/clangimport.cpp
@@ -20,6 +20,7 @@
 
 #include "errortypes.h"
 #include "mathlib.h"
+#include "nonnullptr.h"
 #include "standards.h"
 #include "symboldatabase.h"
 #include "token.h"
@@ -233,8 +234,8 @@ namespace clangimport {
             , mSymbolDatabase(symbolDatabase)
         {}
 
-        const Settings &mSettings;
-        SymbolDatabase &mSymbolDatabase;
+        NonNullPtr<const Settings> mSettings;
+        NonNullPtr<SymbolDatabase> mSymbolDatabase;
 
         int enumValue = 0;
 
@@ -643,7 +644,7 @@ const ::Type * clangimport::AstNode::addTypeTokens(TokenList &tokenList, const s
     for (const Token *typeToken = tokenList.back(); Token::Match(typeToken, "&|*|%name%"); typeToken = typeToken->previous()) {
         if (!typeToken->isName())
             continue;
-        const ::Type *recordType = scope->symdb.findVariableType(scope, typeToken);
+        const ::Type *recordType = scope->symdb->findVariableType(scope, typeToken);
         if (recordType) {
             const_cast<Token*>(typeToken)->type(recordType);
             return recordType;
@@ -672,7 +673,7 @@ void clangimport::AstNode::addFullScopeNameTokens(TokenList &tokenList, const Sc
 const Scope *clangimport::AstNode::getNestedInScope(TokenList &tokenList)
 {
     if (!tokenList.back())
-        return &mData->mSymbolDatabase.scopeList.front();
+        return &mData->mSymbolDatabase->scopeList.front();
     if (tokenList.back()->str() == "}" && mData->mNotScope.find(tokenList.back()) == mData->mNotScope.end())
         return tokenList.back()->scope()->nestedIn;
     return tokenList.back()->scope();
@@ -1071,8 +1072,8 @@ Token *clangimport::AstNode::createTokens(TokenList &tokenList)
             const_cast<Token *>(enumscope->bodyEnd)->deletePrevious();
 
         // Create enum type
-        mData->mSymbolDatabase.typeList.emplace_back(enumtok, enumscope, enumtok->scope());
-        enumscope->definedType = &mData->mSymbolDatabase.typeList.back();
+        mData->mSymbolDatabase->typeList.emplace_back(enumtok, enumscope, enumtok->scope());
+        enumscope->definedType = &mData->mSymbolDatabase->typeList.back();
         if (nametok)
             const_cast<Scope *>(enumtok->scope())->definedTypesMap[nametok->str()] = enumscope->definedType;
 
@@ -1238,8 +1239,8 @@ Token *clangimport::AstNode::createTokens(TokenList &tokenList)
         }
 
         Scope *recordScope = createScope(tokenList, ScopeType::eStruct, children, classDef);
-        mData->mSymbolDatabase.typeList.emplace_back(classDef, recordScope, classDef->scope());
-        recordScope->definedType = &mData->mSymbolDatabase.typeList.back();
+        mData->mSymbolDatabase->typeList.emplace_back(classDef, recordScope, classDef->scope());
+        recordScope->definedType = &mData->mSymbolDatabase->typeList.back();
         if (!recordName.empty()) {
             recordScope->className = recordName;
             const_cast<Scope *>(classDef->scope())->definedTypesMap[recordName] = recordScope->definedType;
@@ -1520,8 +1521,8 @@ void clangimport::AstNode::createTokensForCXXRecord(TokenList &tokenList)
         const std::string addr = mExtTokens[0];
         mData->scopeDecl(addr, scope);
         scope->className = className;
-        mData->mSymbolDatabase.typeList.emplace_back(classToken, scope, classToken->scope());
-        scope->definedType = &mData->mSymbolDatabase.typeList.back();
+        mData->mSymbolDatabase->typeList.emplace_back(classToken, scope, classToken->scope());
+        scope->definedType = &mData->mSymbolDatabase->typeList.back();
         const_cast<Scope *>(classToken->scope())->definedTypesMap[className] = scope->definedType;
     }
     addtoken(tokenList, ";");

diff --git a/lib/cppcheck.vcxproj b/lib/cppcheck.vcxproj
@@ -159,6 +159,7 @@
     <ClInclude Include="library.h" />
     <ClInclude Include="matchcompiler.h" />
     <ClInclude Include="mathlib.h" />
+    <ClInclude Include="nonnullptr.h" />
     <ClInclude Include="path.h" />
     <ClInclude Include="pathanalysis.h" />
     <ClInclude Include="pathmatch.h" />

diff --git a/lib/errorlogger.h b/lib/errorlogger.h
@@ -23,6 +23,7 @@
 
 #include "config.h"
 #include "errortypes.h"
+#include "nonnullptr.h"
 
 #include <cstdint>
 #include <ctime>
@@ -301,25 +302,25 @@
     ~ProgressReporter() {
         if (mReportProgressInterval < 0)
             return;
-        mErrorLogger.reportProgress(mFilename, mStage.c_str(), 100);
+        mErrorLogger->reportProgress(mFilename, mStage.c_str(), 100);
     }
 
     void report(int value) {
         if (mReportProgressInterval < 0 || value == mLastValue)
             return;
         const std::time_t t = std::time(nullptr);
         if (t >= mLastTime + mReportProgressInterval) {
-            mErrorLogger.reportProgress(mFilename, mStage.c_str(), value);
+            mErrorLogger->reportProgress(mFilename, mStage.c_str(), value);
             mLastTime = t;
             mLastValue = value;
         }
     }
 
 private:
-    ErrorLogger& mErrorLogger;
-    const int mReportProgressInterval;
-    const std::string mFilename;
-    const std::string mStage;
+    NonNullPtr<ErrorLogger> mErrorLogger;
+    int mReportProgressInterval;
+    std::string mFilename;
+    std::string mStage;
     std::time_t mLastTime{0};
     int mLastValue{-1};
 };