Fix #12861 Hang in valueFlowCondition() with huge array

Author: clock999

lib/token.cpp

@@ -1412,6 +1412,10 @@ std::string Token::stringifyList(bool varid) const
     return stringifyList(varid, false, true, true, true, nullptr, nullptr);
 }
 
+void Token::astTop(Token * tok) {
+    mImpl->mAstTop = tok;
+}
+
 void Token::astParent(Token* tok)
 {
     const Token* tok2 = tok;

lib/token.h

@@ -88,6 +88,7 @@ struct TokenImpl {
     Token* mAstOperand1{};
     Token* mAstOperand2{};
     Token* mAstParent{};
+    Token* mAstTop{};
 
     // symbol database information
     const Scope* mScope{};
@@ -1492,6 +1493,7 @@ class CPPCHECKLIB Token {
     void astOperand1(Token *tok);
     void astOperand2(Token *tok);
     void astParent(Token* tok);
+    void astTop(Token* tok);
 
     Token * astOperand1() {
         return mImpl->mAstOperand1;
@@ -1511,6 +1513,31 @@ class CPPCHECKLIB Token {
     const Token * astParent() const {
         return mImpl->mAstParent;
     }
+    Token * astTop() {
+        Token *ret = this;
+        if (ret->mImpl->mAstTop) {
+            return ret->mImpl->mAstTop;
+        } else {
+            if (ret->mImpl->mAstParent) {
+                return ret->mImpl->mAstParent->astTop();
+            } else {
+                return ret;
+            }
+        }
+    }
+    const Token * astTop() const {
+        const Token *ret = this;
+        if (ret->mImpl->mAstTop) {
+            return ret->mImpl->mAstTop;
+        } else {
+            if (ret->mImpl->mAstParent) {
+                return ret->mImpl->mAstParent->astTop();
+            } else {
+                return ret;
+            }
+        }
+    }
+
     Token * astSibling() {
         if (!astParent())
             return nullptr;
@@ -1531,19 +1558,6 @@ class CPPCHECKLIB Token {
         return nullptr;
 
     }
-    RET_NONNULL Token *astTop() {
-        Token *ret = this;
-        while (ret->mImpl->mAstParent)
-            ret = ret->mImpl->mAstParent;
-        return ret;
-    }
-
-    RET_NONNULL const Token *astTop() const {
-        const Token *ret = this;
-        while (ret->mImpl->mAstParent)
-            ret = ret->mImpl->mAstParent;
-        return ret;
-    }
 
     std::pair<const Token *, const Token *> findExpressionStartEndTokens() const;
 

lib/tokenize.cpp

@@ -3423,6 +3423,15 @@ bool Tokenizer::simplifyTokens1(const std::string &configuration, int fileIndex)
 
     if (!mSettings.buildDir.empty())
         Summaries::create(*this, configuration, fileIndex);
+    Token * it_tok = list.front();
+    while(it_tok) {
+        if (it_tok->astParent()) {
+            it_tok->astTop(it_tok->astParent()->astTop());
+        } else {
+            it_tok->astTop(it_tok);
+        }
+        it_tok = it_tok->next();
+    }
 
     // TODO: apply this through Settings::ValueFlowOptions
     // TODO: do not run valueflow if no checks are being performed at all - e.g. unusedFunctions only