CheckStl: validation of iterators returned from functions

cfg/std.cfg

@@ -4038,12 +4038,44 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
   <!-- InputIterator std::find(InputIterator first, InputIterator last, T val) -->
   <!-- InputIterator std::find_if(InputIterator first, InputIterator last, UnaryPredicate val) -->
   <!-- InputIterator std::find_if_not(InputIterator first, InputIterator last, UnaryPredicate val) -->
+  <function name="std::find,std::find_if,std::find_if_not">
+    <use-retval/>
+    <noreturn>false</noreturn>
+    <returnValue type="iterator" container="1"/>
+    <arg nr="1">
+      <not-uninit/>
+      <iterator container="1" type="first"/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+      <iterator container="1" type="last"/>
+    </arg>
+    <arg nr="3">
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- bool std::all_of(InputIterator first, InputIterator last, UnaryPredicate pred) -->
   <!-- bool std::any_of(InputIterator first, InputIterator last, UnaryPredicate pred) -->
   <!-- bool std::none_of(InputIterator first, InputIterator last, UnaryPredicate pred) -->
-  <!-- InputIterator std::count(InputIterator first, InputIterator last, T val) -->
-  <!-- InputIterator std::count_if(InputIterator first, InputIterator last, UnaryPredicate val) -->
   <function name="std::find,std::find_if,std::find_if_not,std::count,std::count_if,std::all_of,std::any_of,std::none_of">
+    <use-retval/>
+    <noreturn>false</noreturn>
+    <returnValue type="bool"/>
+    <arg nr="1">
+      <not-uninit/>
+      <iterator container="1" type="first"/>
+    </arg>
+    <arg nr="2">
+      <not-uninit/>
+      <iterator container="1" type="last"/>
+    </arg>
+    <arg nr="3">
+      <not-uninit/>
+    </arg>
+  </function>
+  <!-- difference_type std::count(InputIterator first, InputIterator last, T val) -->
+  <!-- difference_type std::count_if(InputIterator first, InputIterator last, UnaryPredicate val) -->
+  <function name="std::count,std::count_if">
     <use-retval/>
     <noreturn>false</noreturn>
     <arg nr="1">

lib/checkstl.cpp

@@ -298,6 +298,8 @@ static const std::string pattern2 = pattern1x1_1 + pattern1x1_2;
 
 static const Variable *getContainer(const Token *argtok)
 {
+    while (argtok && argtok->astOperand1())
+        argtok = argtok->astOperand1();
     if (!Token::Match(argtok, "%var% . begin|end|rbegin|rend ( )")) // TODO: use Library yield
         return nullptr;
     const Variable *var = argtok->variable();
@@ -341,6 +343,17 @@ void CheckStl::mismatchingContainers()
                     mismatchingContainersError(argTok);
                 }
             }
+            int ret = _settings->library.returnValueContainer(ftok);
+            if (ret != -1 && Token::Match(ftok->next()->astParent(), "==|!=")) {
+                const Token *parent = ftok->next()->astParent();
+                const Token *other = (parent->astOperand1() == ftok->next()) ? parent->astOperand2() : parent->astOperand1();
+                const Variable *c = getContainer(other);
+                if (c) {
+                    std::map<const Variable *, unsigned int>::const_iterator it = containerNr.find(c);
+                    if (it == containerNr.end() || it->second != ret)
+                        mismatchingContainersError(other);
+                }
+            }
         }
     }
     for (unsigned int varid = 0; varid < symbolDatabase->getVariableListSize(); varid++) {

lib/library.cpp

@@ -550,12 +550,14 @@ Library::Error Library::loadFunction(const tinyxml2::XMLElement * const node, co
                 _returnValue[name] = expr;
             if (const char *type = functionnode->Attribute("type"))
                 _returnValueType[name] = type;
+            if (const char *container = functionnode->Attribute("container"))
+                _returnValueContainer[name] = std::atoi(container);
         } else if (functionnodename == "arg") {
             const char* argNrString = functionnode->Attribute("nr");
             if (!argNrString)
                 return Error(MISSING_ATTRIBUTE, "nr");
             const bool bAnyArg = strcmp(argNrString, "any")==0;
-            const int nr = (bAnyArg) ? -1 : atoi(argNrString);
+            const int nr = bAnyArg ? -1 : std::atoi(argNrString);
             ArgumentChecks &ac = argumentChecks[name][nr];
             ac.optional  = functionnode->Attribute("default") != nullptr;
             for (const tinyxml2::XMLElement *argnode = functionnode->FirstChildElement(); argnode; argnode = argnode->NextSiblingElement()) {
@@ -1000,6 +1002,14 @@ std::string Library::returnValueType(const Token *ftok) const
     return it != _returnValueType.end() ? it->second : std::string();
 }
 
+int Library::returnValueContainer(const Token *ftok) const
+{
+    if (isNotLibraryFunction(ftok))
+        return -1;
+    std::map<std::string, int>::const_iterator it = _returnValueContainer.find(getFunctionName(ftok));
+    return it != _returnValueContainer.end() ? it->second : -1;
+}
+
 bool Library::isnoreturn(const Token *ftok) const
 {
     if (ftok->function() && ftok->function()->isAttributeNoreturn())

lib/library.h

@@ -168,6 +168,7 @@ public:
 
     std::string returnValue(const Token *ftok) const;
     std::string returnValueType(const Token *ftok) const;
+    int returnValueContainer(const Token *ftok) const;
 
     bool isnoreturn(const Token *ftok) const;
     bool isnotnoreturn(const Token *ftok) const;
@@ -510,6 +511,7 @@ private:
     std::map<std::string, bool> _noreturn; // is function noreturn?
     std::map<std::string, std::string> _returnValue;
     std::map<std::string, std::string> _returnValueType;
+    std::map<std::string, int> _returnValueContainer;
     std::set<std::string> _ignorefunction; // ignore functions/macros from a library (gtk, qt etc)
     std::map<std::string, bool> _reporterrors;
     std::map<std::string, bool> _processAfterCode;

lib/symboldatabase.cpp

@@ -4619,7 +4619,7 @@ void SymbolDatabase::setValueTypeInTokenList(Token *tokens, bool cpp, const Sett
             // library function
             else if (tok->previous()) {
                 const std::string typestr(settings->library.returnValueType(tok->previous()));
-                if (typestr.empty())
+                if (typestr.empty() || typestr == "iterator")
                     continue;
                 TokenList tokenList(settings);
                 std::istringstream istr(typestr+";");

test/cfg/std.cpp

@@ -3165,10 +3165,11 @@ void nullPointer_wmemcmp(wchar_t *p)
 #include <algorithm>
 #include <list>
 
-void stdfind(const std::list<int> &ints1, const std::list<int> &ints2) {
+void stdfind(const std::list<int> &ints1, const std::list<int> &ints2)
+{
     // cppcheck-suppress mismatchingContainers
     // cppcheck-suppress ignoredReturnValue
     std::find(ints1.begin(), ints2.end(), 123);
-    // TODO cppcheck-suppress mismatchingContainers
-    if (std::find(ints1.begin(), ints1.end(), 123) == ints2.end()){}
+    // cppcheck-suppress mismatchingContainers
+    if (std::find(ints1.begin(), ints1.end(), 123) == ints2.end()) {}
 }