Fix #14202 FP duplicateExpression with enumerator (danmar#8117)

Author: chrchr-github

lib/checkother.cpp

@@ -2924,6 +2924,9 @@ void CheckOther::checkDuplicateExpression()
             if (tok->isOp() && tok->astOperand1() && !Token::Match(tok, "+|*|<<|>>|+=|*=|<<=|>>=") && !isInsideLambdaCaptureList(tok)) {
                 if (Token::Match(tok, "==|!=|-") && astIsFloat(tok->astOperand1(), true))
                     continue;
+                if (tok->isArithmeticalOp() &&
+                    (tok->astOperand1()->isEnumerator() || (tok->astOperand2() && tok->astOperand2()->isEnumerator())))
+                    continue;
                 const bool pointerDereference = (tok->astOperand1() && tok->astOperand1()->isUnaryOp("*")) ||
                                                 (tok->astOperand2() && tok->astOperand2()->isUnaryOp("*"));
                 const bool followVar = (!isConstVarExpression(tok) || Token::Match(tok, "%comp%|%oror%|&&")) && !pointerDereference;

test/testother.cpp

@@ -196,6 +196,7 @@ class TestOther : public TestFixture {
         TEST_CASE(duplicateExpression17); // #12036
         TEST_CASE(duplicateExpression18);
         TEST_CASE(duplicateExpression19);
+        TEST_CASE(duplicateExpression20);
         TEST_CASE(duplicateExpressionLoop);
         TEST_CASE(duplicateValueTernary);
         TEST_CASE(duplicateValueTernarySizeof); // #13773
@@ -8010,6 +8011,12 @@ class TestOther : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void duplicateExpression20() {
+        check("enum { N = 1 };\n" // #14202
+              "int f() { return N - 1; }");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void duplicateExpressionLoop() {
         check("void f() {\n"
               "    int a = 1;\n"