From e33985dbf0e45b52f772e463d88544f129d76637 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <hyd_danmar@users.sourceforge.net>
Date: Sat, 22 Nov 2008 11:30:50 +0000
Subject: [PATCH] Memory leak: Handle conditions that are always true / false

---
 CheckMemoryLeak.cpp | 14 ++++++++++++--
 testmemleak.cpp     | 24 +++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/CheckMemoryLeak.cpp b/CheckMemoryLeak.cpp
index 6e17cacf5..b6997c392 100644
--- a/CheckMemoryLeak.cpp
+++ b/CheckMemoryLeak.cpp
@@ -370,7 +370,7 @@ TOKEN *CheckMemoryLeakClass::getcode(const TOKEN *tok, std::list<const TOKEN *>
             dealloctype = dealloc;
         }
 
-        // if else switch
+        // if else switch
         if ( Tokenizer::Match(tok, "if ( %var1% )", varnames) ||
              Tokenizer::Match(tok, "if ( %var1% != 0 )", varnames) ||
              Tokenizer::Match(tok, "if ( 0 != %var1% )", varnames)  )
@@ -381,7 +381,15 @@ TOKEN *CheckMemoryLeakClass::getcode(const TOKEN *tok, std::list<const TOKEN *>
         else if ( Tokenizer::Match(tok, "if (") && notvar(Tokenizer::gettok(tok,2), varnames) )
         {
             addtoken("if(!var)");
-        }
+        }
+        else if ( Tokenizer::Match(tok, "if (") && _tokenizer->alwaysTrue(tok->next) )
+        {
+            addtoken("if(true)");
+        }
+        else if ( Tokenizer::Match(tok, "if (") && _tokenizer->alwaysTrue(tok->next) )
+        {
+            addtoken("if(false)");
+        }
         else if ( Tokenizer::Match(tok, "if") )
         {
             // Check if the condition depends on var somehow..
@@ -599,6 +607,8 @@ void CheckMemoryLeakClass::simplifycode(TOKEN *tok)
             if ( Tokenizer::Match(tok2,"[;{}] if ;") ||
                  Tokenizer::Match(tok2,"[;{}] if(var) ;") ||
                  Tokenizer::Match(tok2,"[;{}] if(!var) ;") ||
+                 Tokenizer::Match(tok2,"[;{}] if(true) ;") ||
+                 Tokenizer::Match(tok2,"[;{}] if(false) ;") ||
                  Tokenizer::Match(tok2,"[;{}] ifv ;") )
             {
                 if ( ! Tokenizer::Match(Tokenizer::gettok(tok2,3), "else") )
diff --git a/testmemleak.cpp b/testmemleak.cpp
index 960f37669..ca247ec70 100644
--- a/testmemleak.cpp
+++ b/testmemleak.cpp
@@ -84,7 +84,9 @@ private:
         TEST_CASE( if2 );
         TEST_CASE( if3 );
         TEST_CASE( if4 );
-        TEST_CASE( if5 );
+        TEST_CASE( if5 );
+
+        TEST_CASE( alwaysTrue );
 
         TEST_CASE( forwhile1 );
         TEST_CASE( forwhile2 );
@@ -453,6 +455,26 @@ private:
         ASSERT_EQUALS( std::string(""), err );
     }
 
+
+
+
+
+    void alwaysTrue()
+    {
+        check( "void f()\n"
+               "{\n"
+               "    char *p = 0;\n"
+               "    for (;;)\n"
+               "    {\n"
+               "        p = malloc(256);\n"
+               "        if (1)\n"
+               "            break;\n"
+               "    }\n"
+               "    free(p);\n"
+               "}\n" );
+        std::string err( errout.str() );
+        ASSERT_EQUALS( std::string(""), err );
+    }