Fix issue 10035: FP: knownConditionTrueFalse when bool updated in for loop (cppcheck-opensource#2953)

pfultz2 · web-flow · commit c9d2e55ea905 · 2020-12-16T17:25:21.000+01:00
diff --git a/lib/programmemory.cpp b/lib/programmemory.cpp
@@ -507,18 +507,16 @@ void execute(const Token *expr,
         else {
             bool error2 = false;
             execute(expr->astOperand2(), programMemory, result, &error2);
-            if (error1 && error2)
+            if (error1 || error2)
                 *error = true;
-            if (error2)
-                *result = 1;
-            else
-                *result = !!*result;
         }
     }
 
     else if (expr->str() == "||") {
         execute(expr->astOperand1(), programMemory, result, error);
-        if (*result == 0 && *error == false)
+        if (*result == 1 && *error == false)
+            *result = 1;
+        else if (*result == 0 && *error == false)
             execute(expr->astOperand2(), programMemory, result, error);
     }
 
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
@@ -140,6 +140,7 @@ class TestValueFlow : public TestFixture {
         TEST_CASE(valueFlowCrashConstructorInitialization);
 
         TEST_CASE(valueFlowUnknownMixedOperators);
+        TEST_CASE(valueFlowIdempotent);
     }
 
     static bool isNotTokValue(const ValueFlow::Value &val) {
@@ -5014,6 +5015,42 @@ class TestValueFlow : public TestFixture {
 
         ASSERT_EQUALS(false, testValueOfXKnown(code, 4U, 1));
     }
+
+    void valueFlowIdempotent() {
+        const char *code;
+        
+        code = "void f(bool a, bool b) {\n"
+               "    bool x = true;\n"
+               "    if (a)\n"
+               "        x = x && b;\n"
+               "    bool result = x;\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfXKnown(code, 5U, 1));
+
+        code = "void f(bool a, bool b) {\n"
+               "    bool x = false;\n"
+               "    if (a)\n"
+               "        x = x && b;\n"
+               "    bool result = x;\n"
+               "}\n";
+        ASSERT_EQUALS(true, testValueOfXKnown(code, 5U, 0));
+
+        code = "void f(bool a, bool b) {\n"
+               "    bool x = true;\n"
+               "    if (a)\n"
+               "        x = x || b;\n"
+               "    bool result = x;\n"
+               "}\n";
+        ASSERT_EQUALS(true, testValueOfXKnown(code, 5U, 1));
+
+        code = "void f(bool a, bool b) {\n"
+               "    bool x = false;\n"
+               "    if (a)\n"
+               "        x = x || b;\n"
+               "    bool result = x;\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfXKnown(code, 5U, 0));
+    }
 };
 
 REGISTER_TEST(TestValueFlow)
