Partial fix for 12031: False positive: uninitialized variable (danmar…

…#5573)
chrchr-github · Oct 18, 2023 · e1a120e · e1a120e
1 parent 09f426d
commit e1a120e
Show file tree

Hide file tree

Showing 2 changed files with 23 additions and 3 deletions.
diff --git a/lib/programmemory.cpp b/lib/programmemory.cpp
@@ -204,8 +204,10 @@ static bool evaluateCondition(const std::string& op,
     if (!condition)
         return false;
     if (condition->str() == op) {
-        return evaluateCondition(op, r, condition->astOperand1(), pm, settings) ||
-               evaluateCondition(op, r, condition->astOperand2(), pm, settings);
+        if (evaluateCondition(op, r, condition->astOperand1(), pm, settings) ||
+            evaluateCondition(op, r, condition->astOperand2(), pm, settings)) {
+            return true;
+        }
     }
     MathLib::bigint result = 0;
     bool error = false;
@@ -309,8 +311,10 @@ void programMemoryParseCondition(ProgramMemory& pm, const Token* tok, const Toke
         if (lhs.empty() || rhs.empty()) {
             if (frontIs(lhs, !then))
                 programMemoryParseCondition(pm, tok->astOperand2(), endTok, settings, then);
-            if (frontIs(rhs, !then))
+            else if (frontIs(rhs, !then))
                 programMemoryParseCondition(pm, tok->astOperand1(), endTok, settings, then);
+            else
+                pm.setIntValue(tok, 0, then);
         }
     } else if (tok->exprId() > 0) {
         if (endTok && isExpressionChanged(tok, tok->next(), endTok, settings, true))

diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
@@ -5605,6 +5605,22 @@ class TestValueFlow : public TestFixture {
                "}\n";
         values = tokenValues(code, "x >", ValueFlow::Value::ValueType::UNINIT);
         ASSERT_EQUALS(0, values.size());
+
+        // #12031
+        code = "bool g(int *p);\n"
+               "bool h();\n"
+               "void f(bool b, int y) {\n"
+               "    int x;\n"
+               "    if (b && y > 0) {\n"
+               "        b = g(&x);\n"
+               "    }\n"
+               "    while (b && y > 0) {\n"
+               "        if (x < 0) {}\n"
+               "        break;\n"
+               "    }\n"
+               "}\n";
+        values = tokenValues(code, "x <", ValueFlow::Value::ValueType::UNINIT);
+        ASSERT_EQUALS(0, values.size());
     }
 
     void valueFlowConditionExpressions() {