From f908959196e2cd6b95481588cd41298185eda4ce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Fri, 1 Aug 2014 16:12:57 +0200
Subject: [PATCH] ValueFlow: improved analysis in for loops to avoid fp

---
 lib/valueflow.cpp      | 17 +++++++++++++++++
 test/testvalueflow.cpp | 20 ++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index bbd3271c2..817104488 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -1208,6 +1208,23 @@ static void valueFlowForLoopSimplify(Token * const bodyStart, const unsigned int
             setTokenValue(tok2, value1);
         }
 
+        if (Token::Match(tok2, "%oror%|&&")) {
+            const std::map<unsigned int, MathLib::bigint> programMemory(getProgramMemory(tok2->astTop(), varid, value));
+            if ((tok2->str() == "&&" && conditionIsFalse(tok2->astOperand1(), programMemory)) ||
+                (tok2->str() == "||" && conditionIsTrue(tok2->astOperand1(), programMemory))) {
+                // Skip second expression..
+                const Token *parent = tok2;
+                while (parent && parent->str() == tok2->str())
+                    parent = parent->astParent();
+                if (parent && parent->str() == "(")
+                    tok2 = parent->link();
+            }
+
+        }
+        if ((tok2->str() == "&&" && conditionIsFalse(tok2->astOperand1(), getProgramMemory(tok2->astTop(), varid, value))) ||
+            (tok2->str() == "||" && conditionIsTrue(tok2->astOperand1(), getProgramMemory(tok2->astTop(), varid, value))))
+            break;
+
         else if (Token::simpleMatch(tok2, ") {") && Token::findmatch(tok2->link(), "%varid%", tok2, varid)) {
             if (Token::findmatch(tok2, "continue|break|return", tok2->linkAt(1), varid)) {
                 if (settings->debugwarnings)
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 6242675b6..bfe3a6145 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -962,6 +962,26 @@ private:
                "  }\n"
                "}\n";
         ASSERT_EQUALS(false, testValueOfX(code, 3U, 0));
+
+        // &&
+        code = "void foo() {\n"
+               "  for (int x = 0; x < 10; x++) {\n"
+               "    if (x > 1\n"
+               "        && x) {}" // <- x is not 0
+               "  }\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfX(code, 4U, 0));
+        ASSERT_EQUALS(true,  testValueOfX(code, 4U, 9));
+
+        // ||
+        code = "void foo() {\n"
+               "  for (int x = 0; x < 10; x++) {\n"
+               "    if (x == 0\n"
+               "        || x) {}" // <- x is not 0
+               "  }\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfX(code, 4U, 0));
+        ASSERT_EQUALS(true,  testValueOfX(code, 4U, 9));
     }
 
     void valueFlowSubFunction() {