Fix #11777 (False positive: uninitialized variable, handling 'false ||' in valueflow) (cppcheck-opensource#5169)

danmar · web-flow · commit 38b2c5ee3fdc · 2023-06-17T21:08:22.000+02:00
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
@@ -7852,14 +7852,14 @@ bool findTokenSkipDeadCodeImpl(const Library* library, Token* start, const Token
                 tok = thenStart->link();
             }
         } else if (Token::Match(tok->astParent(), "&&|?|%oror%") && astIsLHS(tok) && tok->hasKnownIntValue()) {
-            int r = tok->values().front().intvalue;
+            const bool cond = tok->values().front().intvalue != 0;
             Token* next = nullptr;
-            if ((r == 0 && Token::simpleMatch(tok->astParent(), "||")) ||
-                (r != 0 && Token::simpleMatch(tok->astParent(), "&&"))) {
+            if ((cond && Token::simpleMatch(tok->astParent(), "||")) ||
+                (!cond && Token::simpleMatch(tok->astParent(), "&&"))) {
                 next = nextAfterAstRightmostLeaf(tok->astParent());
             } else if (Token::simpleMatch(tok->astParent(), "?")) {
                 Token* colon = tok->astParent()->astOperand2();
-                if (r == 0) {
+                if (!cond) {
                     next = colon;
                 } else {
                     if (findTokenSkipDeadCodeImpl(library, tok->astParent()->next(), colon, pred, found))
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
@@ -5554,6 +5554,17 @@ class TestValueFlow : public TestFixture {
                "}\n";
         values = tokenValues(code, ". id", ValueFlow::Value::ValueType::UNINIT);
         ASSERT_EQUALS(0, values.size());
+
+        // #11777 - false || ...
+        code = "bool init(int *p);\n"
+               "\n"
+               "void uninitvar_FP9() {\n"
+               "  int x;\n"
+               "  if (false || init(&x)) {}\n"
+               "  int b = x+1;\n"
+               "}";
+        values = tokenValues(code, "x + 1", ValueFlow::Value::ValueType::UNINIT);
+        ASSERT_EQUALS(0, values.size());
     }
 
     void valueFlowConditionExpressions() {
