Fix 12031: False positive: uninitialized variable (#5637)

Author: pfultz2

lib/astutils.cpp

@@ -107,31 +107,17 @@ static int getArgumentPos(const Token* ftok, const Token* tokToFind){
     return findArgumentPos(startTok, tokToFind);
 }
 
-template<class T, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
-static void astFlattenRecursive(T* tok, std::vector<T*>& result, const char* op, nonneg int depth = 0)
-{
-    ++depth;
-    if (!tok || depth >= 100)
-        return;
-    if (tok->str() == op) {
-        astFlattenRecursive(tok->astOperand1(), result, op, depth);
-        astFlattenRecursive(tok->astOperand2(), result, op, depth);
-    } else {
-        result.push_back(tok);
-    }
-}
-
 std::vector<const Token*> astFlatten(const Token* tok, const char* op)
 {
     std::vector<const Token*> result;
-    astFlattenRecursive(tok, result, op);
+    astFlattenCopy(tok, op, std::back_inserter(result));
     return result;
 }
 
 std::vector<Token*> astFlatten(Token* tok, const char* op)
 {
     std::vector<Token*> result;
-    astFlattenRecursive(tok, result, op);
+    astFlattenCopy(tok, op, std::back_inserter(result));
     return result;
 }
 
@@ -163,6 +149,15 @@ bool astHasVar(const Token * tok, nonneg int varid)
     return astHasVar(tok->astOperand1(), varid) || astHasVar(tok->astOperand2(), varid);
 }
 
+bool astHasExpr(const Token* tok, nonneg int exprid)
+{
+    if (!tok)
+        return false;
+    if (tok->exprId() == exprid)
+        return true;
+    return astHasExpr(tok->astOperand1(), exprid) || astHasExpr(tok->astOperand2(), exprid);
+}
+
 static bool astIsCharWithSign(const Token *tok, ValueType::Sign sign)
 {
     if (!tok)

lib/astutils.h

@@ -116,13 +116,29 @@ const Token* findExpression(const nonneg int exprid,
                             const std::function<bool(const Token*)>& pred);
 const Token* findExpression(const Token* start, const nonneg int exprid);
 
+template<class T, class OuputIterator, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
+void astFlattenCopy(T* tok, const char* op, OuputIterator out, nonneg int depth = 100)
+{
+    --depth;
+    if (!tok || depth < 0)
+        return;
+    if (tok->str() == op) {
+        astFlattenCopy(tok->astOperand1(), op, out, depth);
+        astFlattenCopy(tok->astOperand2(), op, out, depth);
+    } else {
+        *out = tok;
+        ++out;
+    }
+}
+
 std::vector<const Token*> astFlatten(const Token* tok, const char* op);
 std::vector<Token*> astFlatten(Token* tok, const char* op);
 
 nonneg int astCount(const Token* tok, const char* op, int depth = 100);
 
 bool astHasToken(const Token* root, const Token * tok);
 
+bool astHasExpr(const Token* tok, nonneg int exprid);
 bool astHasVar(const Token * tok, nonneg int varid);
 
 bool astIsPrimitive(const Token* tok);

lib/forwardanalyzer.cpp

@@ -40,14 +40,6 @@
 #include <vector>
 
 namespace {
-    struct OnExit {
-        std::function<void()> f;
-
-        ~OnExit() {
-            f();
-        }
-    };
-
     struct ForwardTraversal {
         enum class Progress { Continue, Break, Skip };
         enum class Terminate { None, Bail, Inconclusive };