From 219d82e180ae70063aedae5497b43f6a48691937 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <hyd_danmar@users.sourceforge.net>
Date: Fri, 9 May 2008 18:29:42 +0000
Subject: [PATCH] CheckStructMemberUsage: Check for unused struct members

---
 CheckOther.cpp | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++
 CheckOther.h   |  3 +++
 main.cpp       |  5 ++++-
 tests.cpp      | 14 +++++++++++++
 4 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/CheckOther.cpp b/CheckOther.cpp
index d48c8af47..32315d41e 100644
--- a/CheckOther.cpp
+++ b/CheckOther.cpp
@@ -732,4 +732,60 @@ void CheckConstantFunctionParameter()
         }
     }
 }
+//---------------------------------------------------------------------------
+ 
+
+
+//---------------------------------------------------------------------------
+// Check that all struct members are used
+//---------------------------------------------------------------------------
+
+void CheckStructMemberUsage()
+{
+    const char *structname = 0;
+
+    for ( const TOKEN *tok = tokens; tok; tok = tok->next )
+    {
+        if ( tok->FileIndex != 0 )
+            continue;
+        if ( tok->str[0] == '}' )
+            structname = 0;
+        if ( Match(tok, "struct %type% {") )
+            structname = getstr(tok, 1);
+            
+        if (structname && Match(tok, "[{;]"))
+        {
+            const char *varname = 0;
+            if (Match(tok->next, "%type% %var% ;"))
+                varname = getstr( tok, 2 );
+            else
+                continue;
+            
+            const char *varnames[2];
+            varnames[0] = varname;
+            varnames[1] = 0;
+            bool used = false;            
+            for ( const TOKEN *tok2 = tokens; tok2; tok2 = tok2->next )
+            {
+                if ( tok->FileIndex != 0 )
+                    continue;
+                    
+                if (Match(tok2, ". %var%", varnames))
+                {
+                    if ( strcmp("=", getstr(tok2,2)) == 0 )
+                        continue;
+                    used = true;
+                    break;
+                }
+            }
+            
+            if ( ! used )
+            {
+                std::ostringstream errmsg;
+                errmsg << FileLine(tok) << ": struct member '" << structname << "::" << varname << "' is never read";
+                ReportErr(errmsg.str());
+            }
+        }
+    }
+}
 
diff --git a/CheckOther.h b/CheckOther.h
index 07e376bb2..d8c90b9ed 100644
--- a/CheckOther.h
+++ b/CheckOther.h
@@ -43,6 +43,9 @@ void CheckVariableScope();
 // Check for constant function parameter
 void CheckConstantFunctionParameter();
 
+// Check that all struct members are used
+void CheckStructMemberUsage();
+
 //---------------------------------------------------------------------------
 #endif
 
diff --git a/main.cpp b/main.cpp
index 21524102b..ed5ccf0aa 100644
--- a/main.cpp
+++ b/main.cpp
@@ -300,7 +300,10 @@ static void CppCheck(const char FileName[], unsigned int FileId)
         CheckVariableScope();
 
         // Check if a constant function parameter is passed by value
-        CheckConstantFunctionParameter();
+        CheckConstantFunctionParameter();
+        
+        // Unused struct members..
+        CheckStructMemberUsage();
     }
 
     // Clean up tokens..
diff --git a/tests.cpp b/tests.cpp
index 54ea3a94a..614b6092d 100644
--- a/tests.cpp
+++ b/tests.cpp
@@ -29,6 +29,7 @@ static void memleak_in_class();
 static void division();
 static void unused_variable();
 static void fpar_byvalue();
+static void unused_struct_member();
 //---------------------------------------------------------------------------
 
 int main()
@@ -61,6 +62,9 @@ int main()
     unused_variable();
 
     fpar_byvalue();
+    
+    // unused struct member..
+    unused_struct_member();
 
     std::cout << "Success Rate: " 
               << SuccessCount 
@@ -925,3 +929,13 @@ static void fpar_byvalue()
 }
 //---------------------------------------------------------------------------
 
+static void unused_struct_member()
+{
+    check( CheckStructMemberUsage,
+           __LINE__,
+           "struct abc {int i;};",
+           "[test.cpp:1]: struct member 'abc::i' is never read\n" );
+}
+
+
+