Fix FP constParameter with std::map (#3823)

Makefile

@@ -465,7 +465,7 @@ $(libcppdir)/checkmemoryleak.o: lib/checkmemoryleak.cpp lib/astutils.h lib/check
 $(libcppdir)/checknullpointer.o: lib/checknullpointer.cpp lib/astutils.h lib/check.h lib/checknullpointer.h lib/color.h lib/config.h lib/ctu.h lib/errorlogger.h lib/errortypes.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(libcppdir)/checknullpointer.o $(libcppdir)/checknullpointer.cpp
 
-$(libcppdir)/checkother.o: lib/checkother.cpp lib/astutils.h lib/check.h lib/checkother.h lib/checkuninitvar.h lib/color.h lib/config.h lib/ctu.h lib/errorlogger.h lib/errortypes.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h
+$(libcppdir)/checkother.o: lib/checkother.cpp lib/astutils.h lib/check.h lib/checkclass.h lib/checkother.h lib/checkuninitvar.h lib/color.h lib/config.h lib/ctu.h lib/errorlogger.h lib/errortypes.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h
 	$(CXX) ${INCLUDE_FOR_LIB} $(CPPFLAGS) $(CPPFILESDIR) $(CXXFLAGS) $(UNDEF_STRICT_ANSI) -c -o $(libcppdir)/checkother.o $(libcppdir)/checkother.cpp
 
 $(libcppdir)/checkpostfixoperator.o: lib/checkpostfixoperator.cpp lib/check.h lib/checkpostfixoperator.h lib/config.h lib/errortypes.h lib/importproject.h lib/library.h lib/mathlib.h lib/platform.h lib/settings.h lib/standards.h lib/suppressions.h lib/symboldatabase.h lib/templatesimplifier.h lib/timer.h lib/token.h lib/tokenize.h lib/tokenlist.h lib/utils.h lib/valueflow.h

lib/checkclass.cpp

@@ -2131,9 +2131,7 @@ bool CheckClass::isConstMemberFunc(const Scope *scope, const Token *tok) const
     return false;
 }
 
-
+const std::set<std::string> CheckClass::stl_containers_not_const = { "map", "unordered_map" };
-// The container contains the STL types whose operator[] is not a const.
-static const std::set<std::string> stl_containers_not_const = { "map", "unordered_map" };
 
 bool CheckClass::checkConstFunc(const Scope *scope, const Function *func, bool& memberAccessed) const
 {

lib/checkclass.h

@@ -188,6 +188,9 @@ public:
     /** @brief Analyse all file infos for all TU */
     bool analyseWholeProgram(const CTU::FileInfo *ctu, const std::list<Check::FileInfo*> &fileInfo, const Settings& settings, ErrorLogger &errorLogger) override;
 
+    /** @brief Set of the STL types whose operator[] is not const */
+    static const std::set<std::string> stl_containers_not_const;
+
 private:
     const SymbolDatabase *mSymbolDatabase;
 

lib/checkother.cpp

@@ -32,6 +32,7 @@
 #include "valueflow.h"
 
 #include "checkuninitvar.h" // CheckUninitVar::isVariableUsage
+#include "checkclass.h" // CheckClass::stl_containers_not_const
 
 #include <algorithm> // find_if()
 #include <cctype>
@@ -1502,12 +1503,22 @@ void CheckOther::checkConstVariable()
         if (var->isReference()) {
             bool callNonConstMethod = false;
             for (const Token* tok = var->nameToken(); tok != scope->bodyEnd && tok != nullptr; tok = tok->next()) {
-                if (tok->variable() == var && Token::Match(tok, "%var% . * ( & %name% ::")) {
+                if (tok->variable() == var) {
-                    const Token *ftok = tok->linkAt(3)->previous();
+                    if (Token::Match(tok, "%var% . * ( & %name% ::")) {
+                        const Token* ftok = tok->linkAt(3)->previous();
                         if (!ftok->function() || !ftok->function()->isConst())
                             callNonConstMethod = true;
                         break;
                     }
+                    if (var->isStlType() && Token::Match(tok, "%var% [")) { // containers whose operator[] is non-const
+                        const Token* typeTok = var->typeStartToken() ? var->typeStartToken()->tokAt(2) : nullptr;
+                        const auto& notConst = CheckClass::stl_containers_not_const;
+                        if (typeTok && notConst.find(typeTok->str()) != notConst.end()) {
+                            callNonConstMethod = true;
+                            break;
+                        }
+                    }
+                }
             }
             if (callNonConstMethod)
                 continue;

test/testother.cpp

@@ -2746,6 +2746,11 @@ private:
               "    T& g(C& c, T C::*f) { return c.*f; }\n"
               "};\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("void f(std::map<int, int>& m) {\n"
+              "    std::cout << m[0] << std::endl;\n"
+              "};\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void constParameterCallback() {