Help ValuePrinter find the transaction:

If the ValuePrinter runtime header gets included,
a transaction might be emitted, and the transaction
containing the function body cannot be found anymore.
This causes roottest/root/meta/getFuncBody.C to fail
with runtime modules.

include/cling/Interpreter/Interpreter.h

@@ -713,6 +713,7 @@ namespace cling {
 
     const Transaction* getFirstTransaction() const;
     const Transaction* getLastTransaction() const;
+    const Transaction* getLastWrapperTransaction() const;
     const Transaction* getCurrentTransaction() const;
 
     ///\brief Returns the current or last Transaction.

lib/Interpreter/IncrementalParser.cpp

@@ -392,6 +392,28 @@ namespace cling {
            && (!initialized || (m_TransactionPool && m_Parser));
   }
 
+  namespace {
+    template <class T>
+    struct Reversed {
+      const T &m_orig;
+      auto begin() -> decltype(m_orig.rbegin()) { return m_orig.rbegin(); }
+      auto end() -> decltype (m_orig.rend()) { return m_orig.rend(); }
+    };
+    template <class T>
+    Reversed<T> reverse(const T& orig) { return {orig}; }
+  }
+
+  const Transaction* IncrementalParser::getLastWrapperTransaction() const {
+    if (auto *T = getCurrentTransaction())
+      if (T->getWrapperFD())
+        return T;
+
+    for (auto T: reverse(m_Transactions))
+      if (T->getWrapperFD())
+        return T;
+    return nullptr;
+  }
+
   const Transaction* IncrementalParser::getCurrentTransaction() const {
     return m_Consumer->getTransaction();
   }

lib/Interpreter/IncrementalParser.h

@@ -187,6 +187,11 @@ namespace cling {
       return m_Transactions.back();
     }
 
+    ///\brief Returns the most recent transaction with an input line wrapper,
+    /// which could well be the current one.
+    ///
+    const Transaction* getLastWrapperTransaction() const;
+
     ///\brief Returns the currently active transaction.
     ///
     const Transaction* getCurrentTransaction() const;

lib/Interpreter/Interpreter.cpp

@@ -1598,6 +1598,9 @@ namespace cling {
     return m_IncrParser->getLastTransaction();
   }
 
+  const Transaction* Interpreter::getLastWrapperTransaction() const {
+    return m_IncrParser->getLastWrapperTransaction();
+  }
   const Transaction* Interpreter::getCurrentTransaction() const {
     return m_IncrParser->getCurrentTransaction();
   }

lib/Interpreter/ValuePrinter.cpp

@@ -723,17 +723,16 @@ static std::string printEnumValue(const Value &V) {
   return enumString.str();
 }
 
-static std::string printFunctionValue(const Value &V, const void *ptr, clang::QualType Ty) {
+static std::string printFunctionValue(const Value &V, const void *ptr,
+                                      clang::QualType Ty) {
   cling::largestream o;
   o << "Function @" << ptr;
 
-  // If a function is the first thing printed in a session,
-  // getLastTransaction() will point to the transaction that loaded the
-  // ValuePrinter, and won't have a wrapper FD.
-  // Even if it did have one it wouldn't be the one that was requested to print.
-
   Interpreter &Interp = *const_cast<Interpreter *>(V.getInterpreter());
-  const Transaction *T = Interp.getLastTransaction();
+  const Transaction *T = Interp.getLastWrapperTransaction();
+  if (!T)
+    return o.str();
+
   if (clang::FunctionDecl *WrapperFD = T->getWrapperFD()) {
     clang::ASTContext &C = V.getASTContext();
     const clang::FunctionDecl *FD = nullptr;