Fixed #1680 (Bad iterators checks fail to detect invalidation of iterator for deletion by value)

lib/checkstl.cpp

@@ -46,6 +46,11 @@ void CheckStl::dereferenceErasedError(const Token *tok, const std::string &itern
     reportError(tok, Severity::error, "eraseDereference", "Dereferenced iterator '" + itername + "' has been erased");
 }
 
+void CheckStl::eraseByValueError(const Token *tok, const std::string &containername, const std::string &itername)
+{
+    reportError(tok, Severity::error, "eraseByValue", "Iterator '" +  itername + "' becomes invalid when deleted by value from '" + containername +  "'");
+}
+
 void CheckStl::iterators()
 {
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
@@ -111,6 +116,10 @@ void CheckStl::iterators()
                 dereferenceErasedError(tok2, tok2->strAt(0));
                 tok2 = tok2->tokAt(2);
             }
+            else if (Token::Match(tok2, "%var% . erase ( * %varid%", iteratorId) && tok2->varId() == containerId)
+            {
+                eraseByValueError(tok2, tok2->strAt(0), tok2->strAt(5));
+            }
         }
     }
 }

lib/checkstl.h

@@ -124,6 +124,7 @@ private:
     void stlBoundriesError(const Token *tok, const std::string &container_name);
     void if_findError(const Token *tok, bool str);
     void sizeError(const Token *tok);
+    void eraseByValueError(const Token *tok, const std::string &containername, const std::string &itername);
 
     void getErrorMessages()
     {
@@ -139,6 +140,7 @@ private:
         if_findError(0, false);
         if_findError(0, true);
         sizeError(0);
+        eraseByValueError(0, "container", "iterator");
     }
 
     std::string name() const

test/teststl.cpp

@@ -56,6 +56,7 @@ private:
         TEST_CASE(eraseGoto);
         TEST_CASE(eraseAssign);
         TEST_CASE(eraseErase);
+        TEST_CASE(eraseByValue);
 
         TEST_CASE(pushback1);
         TEST_CASE(pushback2);
@@ -475,6 +476,18 @@ private:
         ASSERT_EQUALS("[test.cpp:6]: (error) Invalid iterator: iter\n", errout.str());
     }
 
+    void eraseByValue()
+    {
+        check("void f()\n"
+              "{\n"
+              "    std::set<int> foo;\n"
+              "    for (std::set<int> it = foo.begin(); it != foo.end(); ++it)\n"
+              "    {\n"
+              "        foo.erase(*it);\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:6]: (error) Iterator 'it' becomes invalid when deleted by value from 'foo'\n", errout.str());
+    }
 
 
     void pushback1()