From ead97b5616f8e6662ac347f2db6cf9b64749bbf0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <hyd_danmar@users.sourceforge.net>
Date: Sun, 7 Dec 2008 20:29:39 +0000
Subject: [PATCH] function variable usage : various fixes. but probably more
 fixes are needed.

---
 CheckOther.cpp    | 46 ++++++++++++++++++++++++++++++++++++----------
 cppcheck.cpp      |  3 +++
 testunusedvar.cpp | 24 ++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/CheckOther.cpp b/CheckOther.cpp
index 6ea1b4393..fb9b8abcc 100644
--- a/CheckOther.cpp
+++ b/CheckOther.cpp
@@ -832,6 +832,21 @@ void CheckOther::unreachableCode()
 // Usage of function variables
 //---------------------------------------------------------------------------
 
+static bool isOp(const TOKEN *tok)
+{
+    return bool(tok &&
+                (tok->str() == "&&" ||
+                 tok->str() == "||" ||
+                 tok->str() == "==" ||
+                 tok->str() == "!=" ||
+                 tok->str() == "<" ||
+                 tok->str() == "<=" ||
+                 tok->str() == ">" ||
+                 tok->str() == ">=" ||
+                 tok->str() == "<<" ||
+                 TOKEN::Match(tok, "[+-*/&|,]")));
+}
+
 void CheckOther::functionVariableUsage()
 {
     // Parse all executing scopes..
@@ -856,18 +871,29 @@ void CheckOther::functionVariableUsage()
                     break;
             }
 
-            if ( TOKEN::Match(tok, "[;{}] %type% %var% ;|=") )
-            {
-                if ( TOKEN::Match(tok->next, "delete|return") )
-                    varUsage[ tok->strAt(2) ] |= USAGE_READ;
-                else
-                    varUsage[ tok->strAt(2) ] = USAGE_DECLARE;
-            }
+            if ( TOKEN::Match(tok, "[;{}] bool|char|short|int|long|float|double %var% ;|=") )
+                varUsage[ tok->strAt(2) ] = USAGE_DECLARE;
 
-            else if ( TOKEN::Match(tok, "[;{}] %var% =") )
-            {
+            else if ( TOKEN::Match(tok, "[;{}] bool|char|short|int|long|float|double * %var% ;|=") )
+                varUsage[ tok->strAt(3) ] = USAGE_DECLARE;
+
+            else if ( TOKEN::Match(tok, "delete|return %var%") )
+                varUsage[ tok->strAt(1) ] |= USAGE_READ;
+
+            else if ( TOKEN::Match(tok, "%var% =") )
+                varUsage[ tok->str() ] |= USAGE_WRITE;
+
+            else if ( TOKEN::Match(tok, "else %var% =") )
                 varUsage[ tok->strAt(1) ] |= USAGE_WRITE;
-            }
+
+            else if ( TOKEN::Match(tok, ">>|& %var%") )
+                varUsage[ tok->strAt(1) ] |= USAGE_WRITE;
+
+            else if ((TOKEN::Match(tok,"[(=&]") || isOp(tok)) && TOKEN::Match(tok->next, "%var%"))
+                varUsage[ tok->strAt(1) ] |= USAGE_READ;
+
+            else if (TOKEN::Match(tok, "%var%") && (tok->next->str()==")" || isOp(tok->next)))
+                varUsage[ tok->str() ] |= USAGE_READ;
         }
 
         // Check usage of all variables in the current scope..
diff --git a/cppcheck.cpp b/cppcheck.cpp
index 92d6fed71..273b64ecd 100644
--- a/cppcheck.cpp
+++ b/cppcheck.cpp
@@ -325,6 +325,9 @@ void CppCheck::checkFile(const std::string &code, const char FileName[])
 
         // Unreachable code below a 'return' statement
         checkOther.unreachableCode();
+
+        // Usage of local functions
+        checkOther.functionVariableUsage();
     }
 }
 //---------------------------------------------------------------------------
diff --git a/testunusedvar.cpp b/testunusedvar.cpp
index faab6f077..d07a9b4dd 100644
--- a/testunusedvar.cpp
+++ b/testunusedvar.cpp
@@ -59,6 +59,8 @@ private:
 
         TEST_CASE( localvar1 );
         TEST_CASE( localvar2 );
+        TEST_CASE( localvar3 );
+        TEST_CASE( localvar4 );
     }
 
     void structmember1()
@@ -152,6 +154,28 @@ private:
         ASSERT_EQUALS( std::string("[test.cpp:2]: Variable 'i' is not assigned a value\n"), errout.str() );
     }
 
+    void localvar3()
+    {
+        functionVariableUsage( "void foo()\n"
+                               "{\n"
+                               "    int i;\n"
+                               "    if ( abc )\n"
+                               "        ;\n"
+                               "    else i = 0;\n"
+                               "}\n" );
+        ASSERT_EQUALS( std::string("[test.cpp:2]: Variable 'i' is assigned a value that is never used\n"), errout.str() );
+    }
+
+    void localvar4()
+    {
+        functionVariableUsage( "void foo()\n"
+                               "{\n"
+                               "    int i = 0;\n"
+                               "    f(i);
+                               "}\n" );
+        ASSERT_EQUALS( std::string(""), errout.str() );
+    }
+
 
 };