From 3819c66f3649135af9550578dc1266acadb2eec2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <hyd_danmar@users.sourceforge.net>
Date: Sun, 3 May 2009 07:37:39 +0200
Subject: [PATCH] stl: Fixed ticket #277 - dereferencing an iterator that has
 been erased

---
 src/checkstl.cpp | 14 +++++++++++++-
 src/checkstl.h   |  4 ++++
 test/teststl.cpp | 33 ++++++++++++++++++---------------
 3 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/src/checkstl.cpp b/src/checkstl.cpp
index 2c989f471..6f1baedea 100644
--- a/src/checkstl.cpp
+++ b/src/checkstl.cpp
@@ -35,18 +35,24 @@ void CheckStl::iteratorsError(const Token *tok, const std::string &container1, c
     reportError(tok, "error", "iterators", "Same iterator is used with both " + container1 + " and " + container2);
 }
 
+// Error message used when dereferencing an iterator that has been erased..
+void CheckStl::dereferenceErasedError(const Token *tok, const std::string &itername)
+{
+    reportError(tok, "error", "eraseDereference", "Dereferenced iterator '" + itername + "' has been erased");
+}
 
 void CheckStl::iterators()
 {
     for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
     {
-        if (Token::Match(tok, "%var% = %var% . begin ( ) ;"))
+        if (Token::Match(tok, "%var% = %var% . begin ( ) ;|+"))
         {
             const unsigned int iteratorId(tok->varId());
             const unsigned int containerId(tok->tokAt(2)->varId());
             if (iteratorId == 0 || containerId == 0)
                 continue;
 
+            bool validIterator = true;
             for (const Token *tok2 = tok->tokAt(6); tok2; tok2 = tok2->next())
             {
                 if (tok2->str() == "}")
@@ -60,6 +66,12 @@ void CheckStl::iterators()
                 {
                     if (tok2->varId() != containerId)
                         iteratorsError(tok2, tok->strAt(2), tok2->str());
+                    else if (tok2->strAt(2) == std::string("erase"))
+                        validIterator = false;
+                }
+                else if (!validIterator && tok2->Match(tok2, "* %varid%", iteratorId))
+                {
+                    dereferenceErasedError(tok2, tok2->strAt(1));
                 }
             }
         }
diff --git a/src/checkstl.h b/src/checkstl.h
index 8d3e207b1..846cc25ab 100644
--- a/src/checkstl.h
+++ b/src/checkstl.h
@@ -63,6 +63,9 @@ public:
      */
     void iterators();
 
+    /** Dereferencing an erased iterator */
+    void dereferenceErasedError(const Token *tok, const std::string &itername);
+
     /**
      * Dangerous usage of erase
      */
@@ -97,6 +100,7 @@ private:
     void getErrorMessages()
     {
         iteratorsError(0, "container1", "container2");
+        dereferenceErasedError(0, "iter");
         stlOutOfBoundsError(0, "i", "foo");
         eraseError(0);
         pushbackError(0, "iterator");
diff --git a/test/teststl.cpp b/test/teststl.cpp
index c0c4c2700..fce35b64d 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -39,6 +39,8 @@ private:
         TEST_CASE(iterator2);
         TEST_CASE(iterator3);
 
+        TEST_CASE(dereference);
+
         TEST_CASE(STLSize);
         TEST_CASE(STLSizeNoErr);
         TEST_CASE(erase);
@@ -46,7 +48,6 @@ private:
         TEST_CASE(eraseReturn);
         TEST_CASE(eraseGoto);
         TEST_CASE(eraseAssign);
-        TEST_CASE(eraseDereference);
         TEST_CASE(eraseErase);
 
         TEST_CASE(pushback1);
@@ -118,6 +119,22 @@ private:
     }
 
 
+    // Dereferencing invalid pointer
+    void dereference()
+    {
+        check("void f()\n"
+              "{\n"
+              "    std::vector<int> ints;"
+              "    std::vector<int>::iterator iter;\n"
+              "    iter = ints.begin() + 2;\n"
+              "    ints.erase(iter);\n"
+              "    std::cout << (*iter) << std::endl;\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:6]: (error) Dereferenced iterator 'iter' has been erased\n", errout.str());
+    }
+
+
+
     void STLSize()
     {
         check("void foo()\n"
@@ -258,20 +275,6 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
-    void eraseDereference()
-    {
-        check("void f(std::vector<ints> &ints)\n"
-              "{\n"
-              "    std::vector<int>::iterator iter;\n"
-              "    iter = ints.begin() + 2;\n"
-              "    ints.erase(iter);\n"
-              "    std::cout << (*iter) << std::endl;\n"
-              "}\n");
-
-        // Ticket #277 - STL: Dereferencing an erased iterator
-        TODO_ASSERT_EQUALS("[test.cpp:6]: (error) Dereferencing invalid iterator\n", errout.str());
-    }
-
     void eraseErase()
     {
         check("void f(std::vector<ints> &ints)\n"