Fix #15144 FN knownConditionTrueFalse (binary or)

Author: web-flow

lib/checkcondition.cpp

@@ -327,8 +327,10 @@ void CheckConditionImpl::checkBadBitmaskCheck()
             const bool isTrue = (tok->astOperand1()->hasKnownIntValue() && tok->astOperand1()->getKnownIntValue() != 0) ||
                                 (tok->astOperand2()->hasKnownIntValue() && tok->astOperand2()->getKnownIntValue() != 0);
 
-            if (isBoolean && isTrue)
+            if (isBoolean && isTrue) {
                 badBitmaskCheckError(tok);
+                diag(tok);
+            }
 
             // If there are #ifdef in the expression don't warn about redundant | to avoid FP
             const auto& startStop = tok->findExpressionStartEndTokens();

lib/valueflow.cpp

@@ -1096,7 +1096,7 @@ static void valueFlowImpossibleValues(TokenList& tokenList, const Settings& sett
             value.setImpossible();
             setTokenValue(tok, std::move(value), settings);
         }
-        if (Token::simpleMatch(tok, "?") && Token::Match(tok->astOperand1(), "<|<=|>|>=")) {
+        else if (Token::simpleMatch(tok, "?") && Token::Match(tok->astOperand1(), "<|<=|>|>=")) {
             const Token* condTok = tok->astOperand1();
             const Token* branchesTok = tok->astOperand2();
 
@@ -1139,11 +1139,20 @@ static void valueFlowImpossibleValues(TokenList& tokenList, const Settings& sett
                 setTokenValue(tok, std::move(value), settings);
             }
 
-        } else if (Token::simpleMatch(tok, "%") && tok->astOperand2() && tok->astOperand2()->hasKnownIntValue()) {
+        } else if (tok->isBinaryOp() && tok->str() == "%" && tok->astOperand2()->hasKnownIntValue()) {
             ValueFlow::Value value{tok->astOperand2()->getKnownIntValue()};
             value.bound = ValueFlow::Value::Bound::Lower;
             value.setImpossible();
             setTokenValue(tok, std::move(value), settings);
+        } else if (tok->isBinaryOp() && tok->str() == "|") {
+            const ValueFlow::Value* opVal = tok->astOperand1()->getKnownValue(ValueFlow::Value::ValueType::INT);
+            if (!opVal)
+                opVal = tok->astOperand2()->getKnownValue(ValueFlow::Value::ValueType::INT);
+            if (opVal && opVal->intvalue != 0) {
+                ValueFlow::Value value{0};
+                value.setImpossible();
+                setTokenValue(tok, std::move(value), settings);
+            }
         } else if (Token::Match(tok, "abs|labs|llabs|fabs|fabsf|fabsl (")) {
             ValueFlow::Value value{-1};
             value.bound = ValueFlow::Value::Bound::Upper;

test/testcondition.cpp

@@ -4999,6 +4999,13 @@ class TestCondition : public TestFixture {
                       "[test.cpp:9:9]: (style) Condition '0b101010' is always true [knownConditionTrueFalse]\n"
                       "[test.cpp:10:9]: (style) Condition '!42' is always false [knownConditionTrueFalse]\n",
                       errout_str());
+
+        check("void f(int i) {\n" // #15144
+              "    int c = i | 1;\n"
+              "    if (c) {}\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3:9]: (style) Condition 'c' is always true [knownConditionTrueFalse]\n",
+                      errout_str());
     }
 
     void alwaysTrueSymbolic()

test/testvalueflow.cpp

@@ -57,6 +57,7 @@ class TestValueFlow : public TestFixture {
         TEST_CASE(valueFlowMove);
 
         TEST_CASE(valueFlowBitAnd);
+        TEST_CASE(valueFlowBitOr);
         TEST_CASE(valueFlowRightShift);
 
         TEST_CASE(valueFlowCalculations);
@@ -4416,6 +4417,16 @@ class TestValueFlow : public TestFixture {
         ASSERT_EQUALS(false, testValueOfX(code,3U,16));
     }
 
+    void valueFlowBitOr() {
+        const char *code;
+
+        code = "int f(int a) {\n"
+               "  int x = a | 0x80;\n"
+               "  return x;\n"
+               "}\n";        
+        ASSERT_EQUALS(true, testValueOfXImpossible(code, 3U, 0));
+    }
+
     void valueFlowForwardInconclusiveImpossible() {
         const char *code;