From 5285635354713ba420a6a9803c1e8a11b88899ee Mon Sep 17 00:00:00 2001
From: Slava Semushin <php-coder@altlinux.ru>
Date: Sun, 27 Sep 2009 14:59:19 +0700
Subject: [PATCH] Fixed #735 (Detects invalid iterator after push_back() when
 iterator declared inside for())

http://sourceforge.net/apps/trac/cppcheck/ticket/735
---
 src/checkstl.cpp | 27 +++++++++++++++++++++++----
 test/teststl.cpp | 30 ++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/src/checkstl.cpp b/src/checkstl.cpp
index e8bce38af..4ab3e5883 100644
--- a/src/checkstl.cpp
+++ b/src/checkstl.cpp
@@ -273,6 +273,14 @@ void CheckStl::pushback()
     {
         if (Token::simpleMatch(tok, "vector <"))
         {
+            // if iterator declaration inside for() loop
+            bool iteratorDeclaredInsideLoop = false;
+            if ((tok->tokAt(-2) && Token::simpleMatch(tok->tokAt(-2), "for (")) ||
+                (tok->tokAt(-4) && Token::simpleMatch(tok->tokAt(-4), "for ( std ::")))
+            {
+                iteratorDeclaredInsideLoop = true;
+            }
+
             while (tok && tok->str() != ">")
                 tok = tok->next();
             if (!tok)
@@ -283,6 +291,12 @@ void CheckStl::pushback()
                 if (iteratorid == 0)
                     continue;
 
+                if (iteratorDeclaredInsideLoop && tok->tokAt(4)->str() == "=")
+                {
+                    // skip "> :: iterator|const_iterator"
+                    tok = tok->tokAt(3);
+                }
+
                 std::string vectorname;
                 int indent = 0;
                 bool invalidIterator = false;
@@ -299,15 +313,20 @@ void CheckStl::pushback()
                     }
 
                     // Using push_back or push_front inside a loop..
-                    if (Token::Match(tok2, "for ( %varid% = %var% . begin ( ) ; %varid% != %var% . end ( ) ; ++ %varid% ) {", iteratorid))
+                    if (Token::Match(tok2, "for ("))
                     {
-                        const unsigned int vectorid(tok2->tokAt(4)->varId());
+                        tok2 = tok2->tokAt(2);
+                    }
+
+                    if (Token::Match(tok2, "%varid% = %var% . begin ( ) ; %varid% != %var% . end ( ) ; ++ %varid% ) {", iteratorid))
+                    {
+                        const unsigned int vectorid(tok2->tokAt(2)->varId());
                         if (vectorid == 0)
                             continue;
 
                         const Token *pushback = 0;
                         unsigned int indent3 = 0;
-                        for (const Token *tok3 = tok2->tokAt(22); tok3; tok3 = tok3->next())
+                        for (const Token *tok3 = tok2->tokAt(20); tok3; tok3 = tok3->next())
                         {
                             if (tok3->str() == "{")
                                 ++indent3;
@@ -329,7 +348,7 @@ void CheckStl::pushback()
                         }
 
                         if (pushback)
-                            pushbackError(pushback, tok2->strAt(2));
+                            pushbackError(pushback, tok2->strAt(0));
                     }
 
                     // Assigning iterator..
diff --git a/test/teststl.cpp b/test/teststl.cpp
index 33aaf3a51..211fc9773 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -56,6 +56,7 @@ private:
         TEST_CASE(pushback3);
         TEST_CASE(pushback4);
         TEST_CASE(pushback5);
+        TEST_CASE(pushback6);
 
         TEST_CASE(insert1);
 
@@ -390,6 +391,35 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void pushback6()
+    {
+        // ticket #735
+        check("void f()\n"
+              "{\n"
+              "    vector<int> v;\n"
+              "    vector.push_back(1);\n"
+              "    vector.push_back(2);\n"
+              "    for (vector<int>::iterator it = v.begin(); it != v.end(); ++it)\n"
+              "    {\n"
+              "        if (*it == 1)\n"
+              "            v.push_back(10);\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:9]: (error) After push_back or push_front, the iterator 'it' may be invalid\n", errout.str());
+
+        check("void f()\n"
+              "{\n"
+              "    std::vector<int> v;\n"
+              "    vector.push_back(1);\n"
+              "    vector.push_back(2);\n"
+              "    for (std::vector<int>::iterator it = v.begin(); it != v.end(); ++it)\n"
+              "    {\n"
+              "        if (*it == 1)\n"
+              "            v.push_back(10);\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:9]: (error) After push_back or push_front, the iterator 'it' may be invalid\n", errout.str());
+    }
 
 
     void insert1()