From 4e293d47c5550cb695cc7d81834a519b32cf75c1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 26 Jul 2015 11:27:52 +0200
Subject: [PATCH] CheckMemoryLeak: Fix handling of comparisons after
 simplifyIfNotNull is removed, detected problem with run_more_tests

---
 lib/checkmemoryleak.cpp | 19 ++++++++++++++++++-
 lib/valueflow.cpp       | 37 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/lib/checkmemoryleak.cpp b/lib/checkmemoryleak.cpp
index 539a66e85..e51263d31 100644
--- a/lib/checkmemoryleak.cpp
+++ b/lib/checkmemoryleak.cpp
@@ -543,6 +543,23 @@ static bool ifvar(const Token *tok, unsigned int varid, const std::string &comp,
     return (vartok && vartok->varId() == varid);
 }
 
+static bool alwaysTrue(const Token *tok)
+{
+    if (!tok)
+        return false;
+    if (tok->values.size() == 1U &&
+        tok->values.front().intvalue != 0 &&
+        tok->values.front().isKnown())
+        return true;
+    if (tok->str() == "||")
+        return alwaysTrue(tok->astOperand1()) || alwaysTrue(tok->astOperand2());
+    if (tok->str() == "true")
+        return true;
+    return (tok->isComparisonOp() &&
+            tok->values.size() == 1U &&
+            tok->values.front().isKnown() &&
+            tok->values.front().intvalue != 0);
+}
 
 bool CheckMemoryLeakInFunction::test_white_list(const std::string &funcname, const Settings *settings, bool cpp)
 {
@@ -1090,7 +1107,7 @@ Token *CheckMemoryLeakInFunction::getcode(const Token *tok, std::list<const Toke
         else if ((tok->str() == "for") || (tok->str() == "while")) {
             const Token* const end = tok->linkAt(1);
 
-            if (Token::simpleMatch(tok, "while ( true )") ||
+            if ((Token::simpleMatch(tok, "while (") && alwaysTrue(tok->next()->astOperand2())) ||
                 Token::simpleMatch(tok, "for ( ; ; )")) {
                 addtoken(&rettail, tok, "while1");
                 tok = end;
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 58e92a8b6..a4bcd78ff 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -389,7 +389,9 @@ static void setTokenValue(Token* tok, const ValueFlow::Value &value)
     }
 
     // Calculations..
-    else if (parent->isArithmeticalOp() && parent->astOperand1() && parent->astOperand2()) {
+    else if ((parent->isArithmeticalOp() || parent->isComparisonOp()) &&
+             parent->astOperand1() &&
+             parent->astOperand2()) {
         const bool known = ((parent->astOperand1()->values.size() == 1U &&
                              parent->astOperand1()->values.front().isKnown()) ||
                             (parent->astOperand2()->values.size() == 1U &&
@@ -431,6 +433,39 @@ static void setTokenValue(Token* tok, const ValueFlow::Value &value)
                         result.intvalue = value1->intvalue % value2->intvalue;
                         setTokenValue(parent, result);
                         break;
+                    case '=':
+                        if (parent->str() == "==") {
+                            result.intvalue = value1->intvalue == value2->intvalue;
+                            setTokenValue(parent, result);
+                        }
+                        break;
+                    case '!':
+                        if (parent->str() == "!=") {
+                            result.intvalue = value1->intvalue != value2->intvalue;
+                            setTokenValue(parent, result);
+                        }
+                        break;
+                    case '>':
+                        if (parent->str() == ">")
+                            result.intvalue = value1->intvalue > value2->intvalue;
+                        else if (parent->str() == ">=")
+                            result.intvalue = value1->intvalue >= value2->intvalue;
+                        else
+                            break;
+                        setTokenValue(parent, result);
+                        break;
+                    case '<':
+                        if (parent->str() == "<")
+                            result.intvalue = value1->intvalue < value2->intvalue;
+                        else if (parent->str() == "<=")
+                            result.intvalue = value1->intvalue <= value2->intvalue;
+                        else
+                            break;
+                        setTokenValue(parent, result);
+                        break;
+                    default:
+                        // unhandled operator, do nothing
+                        break;
                     }
                 }
             }