From 4059a2ad05364baed43ea9ce52732b93028d03f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <hyd_danmar@users.sourceforge.net>
Date: Sat, 28 Mar 2009 07:49:47 +0100
Subject: [PATCH] added check for zero division. The code was written by Nguyen
 Duong Tuan

---
 src/checkother.cpp | 17 ++++++++++++++++
 src/checkother.h   |  6 ++++++
 test/testother.cpp | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+)

diff --git a/src/checkother.cpp b/src/checkother.cpp
index e1fe09b72..a3643ac05 100644
--- a/src/checkother.cpp
+++ b/src/checkother.cpp
@@ -962,6 +962,18 @@ void CheckOther::nullPointer()
 
 
 
+void CheckOther::CheckZeroDivision()
+{
+    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
+    {
+        if (Token::simpleMatch(tok, "/ 0"))
+            zerodivWarning(tok);
+    }
+}
+
+
+
+
 void CheckOther::cstyleCastError(const Token *tok)
 {
     reportError(tok, "style", "cstyleCast", "C-style pointer casting");
@@ -1051,3 +1063,8 @@ void CheckOther::nullPointerError(const Token *tok)
 {
     reportError(tok, "error", "nullPointer", "Possible null pointer dereference");
 }
+
+void CheckOther::zerodivWarning(const Token *tok)
+{
+    reportError(tok, "style", "zerodivWarning", "Warning: Division with zero");
+}
diff --git a/src/checkother.h b/src/checkother.h
index f17dd1163..b7313d4ac 100644
--- a/src/checkother.h
+++ b/src/checkother.h
@@ -71,6 +71,7 @@ public:
         checkOther.returnPointerToStackData();
         checkOther.InvalidFunctionUsage();
         checkOther.nullPointer();
+        checkOther.CheckZeroDivision();
     }
 
     // Casting
@@ -112,6 +113,9 @@ public:
     /** possible null pointer dereference */
     void nullPointer();
 
+    /** Check zero division*/
+    void CheckZeroDivision();
+
 protected:
     void CheckVariableScope_LookupVar(const Token *tok1, const char varname[]);
 
@@ -140,6 +144,7 @@ private:
     void strPlusChar(const Token *tok);
     void returnLocalVariable(const Token *tok);
     void nullPointerError(const Token *tok);
+    void zerodivWarning(const Token *tok);
 
     void getErrorMessages()
     {
@@ -161,6 +166,7 @@ private:
         strPlusChar(0);
         returnLocalVariable(0);
         nullPointerError(0);
+        zerodivWarning(0);
     }
 
 };
diff --git a/test/testother.cpp b/test/testother.cpp
index 4d9fbd63e..54ccf1f87 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -35,6 +35,10 @@ private:
 
     void run()
     {
+        TEST_CASE(zeroDiv1);
+        TEST_CASE(zeroDiv2);
+        TEST_CASE(zeroDiv3);
+
         TEST_CASE(delete1);
         TEST_CASE(delete2);
 
@@ -64,6 +68,9 @@ private:
         std::istringstream istr(code);
         tokenizer.tokenize(istr, "test.cpp");
 
+        // Simplify token list..
+        tokenizer.simplifyTokenList();
+
         // Clear the error buffer..
         errout.str("");
 
@@ -71,11 +78,54 @@ private:
         Settings settings;
         CheckOther checkOther(&tokenizer, &settings, this);
         checkOther.WarningRedundantCode();
+        checkOther.CheckZeroDivision();
     }
 
 
 
 
+    void zeroDiv1()
+    {
+        check("void foo()\n"
+              "{\n"
+              "    int a = 0;\n"
+              "    double b = 1.;\n"
+              "    cout<<b/a;\n"
+              "}");
+
+
+        ASSERT_EQUALS(std::string("[test.cpp:5]: (style) Warning: Division with zero\n"), errout.str());
+    }
+
+    void zeroDiv2()
+    {
+        check("void foo()\n"
+              "{\n"
+              "    int sum = 0;\n"
+              "    int n = 100;\n"
+              "    for(int i = 0; i < n; i ++)\n"
+              "    {\n"
+              "        sum += i; \n"
+              "    }\n"
+              "    cout<<b/sum;\n"
+              "}\n");
+        ASSERT_EQUALS(std::string(""), errout.str());
+    }
+
+    void zeroDiv3()
+    {
+        check("int sum = 0;\n"
+              "void foo()\n"
+              "{\n"
+              "    int n = 100;\n"
+              "    cout<<b/sum;\n"
+              "}\n"
+              "}\n");
+        TODO_ASSERT_EQUALS(std::string("[test.cpp:5]: (style) Warning: Division with zero\n"), errout.str());
+    }
+
+
+
     void delete1()
     {
         check("void foo()\n"