Avoid some wrong compiler warnings (gcc14)

Author: franzpoeschel

examples/8b_benchmark_read_parallel.cpp

@@ -456,8 +456,14 @@ class TestInput
             return;
         Timer blockTime(s.str(), m_MPIRank);
 
-        Offset off(meshExtent.size(), 0);
-        Extent ext(meshExtent.size(), 1);
+        // Avoid the below forms due to a compiler bug on gcc14
+        // warning: 'void operator delete(void*, std::size_t)' called on pointer
+        // '<unknown>' with nonzero offset [1, 9223372036854775800] Offset
+        // off(meshExtent.size(), 0); Extent ext(meshExtent.size(), 1);
+        Offset off(meshExtent.size());
+        Extent ext(meshExtent.size());
+        std::fill(off.begin(), off.end(), 0);
+        std::fill(ext.begin(), ext.end(), 1);
 
         for (unsigned int i = 0; i < meshExtent.size(); i++)
         {
@@ -486,7 +492,7 @@ class TestInput
             }
         }
 
-        auto prettyLambda = [&](Offset oo, Extent cc) {
+        auto prettyLambda = [&](Offset const &oo, Extent const &cc) {
             std::ostringstream o;
             o << "[ ";
             std::ostringstream c;

include/openPMD/snapshots/ContainerImpls.hpp

@@ -34,8 +34,15 @@ class StatefulSnapshotsContainer : public AbstractSnapshotsContainer
          * make_reading_stateful_iterator.
          * The iterator is resolved upon calling get() below.
          */
-        std::variant<std::function<StatefulIterator *()>, StatefulIterator *>
-            m_bufferedIterator;
+
+        // Need to put the deferred function behind a shared_ptr to avoid a
+        // gcc14 compiler bug
+        // warning: '*(std::_Function_base*)((char*)this +
+        // 8).std::_Function_base::_M_manager' may be used uninitialized
+        using Deferred_t = std::shared_ptr<std::function<StatefulIterator *()>>;
+        using Evaluated_t = StatefulIterator *;
+        using BufferedIterator_t = std::variant<Deferred_t, Evaluated_t>;
+        BufferedIterator_t m_bufferedIterator = nullptr;
     };
     Members members;
 

src/snapshots/ContainerImpls.cpp

@@ -14,7 +14,22 @@ namespace openPMD
 {
 StatefulSnapshotsContainer::StatefulSnapshotsContainer(
     std::variant<std::function<StatefulIterator *()>, StatefulIterator *> begin)
-    : members{std::move(begin)}
+    : members{
+          // Need to put the deferred function behind a shared_ptr to avoid a
+          // gcc14 compiler bug
+          // warning: '*(std::_Function_base*)((char*)this +
+          // 8).std::_Function_base::_M_manager' may be used uninitialized
+          std::visit(
+              auxiliary::overloaded{
+                  [](std::function<StatefulIterator *()> &&f)
+                      -> Members::BufferedIterator_t {
+                      return std::make_shared<
+                          Members::Deferred_t::element_type>(std::move(f));
+                  },
+                  [](StatefulIterator *it) -> Members::BufferedIterator_t {
+                      return it;
+                  }},
+              std::move(begin))}
 {}
 
 StatefulSnapshotsContainer::StatefulSnapshotsContainer(
@@ -33,21 +48,19 @@ auto StatefulSnapshotsContainer::get() -> StatefulIterator *
 {
     return std::visit(
         auxiliary::overloaded{
-            [this](
-                std::function<StatefulIterator *()> &deferred_initialization) {
-                auto it = deferred_initialization();
+            [this](Members::Deferred_t &deferred_initialization) {
+                auto it = (*deferred_initialization)();
                 this->members.m_bufferedIterator = it;
                 return it;
             },
-            [](StatefulIterator *it) { return it; }},
+            [](Members::Evaluated_t it) { return it; }},
         members.m_bufferedIterator);
 }
 auto StatefulSnapshotsContainer::get() const -> StatefulIterator const *
 {
     return std::visit(
         auxiliary::overloaded{
-            [](std::function<StatefulIterator *()> const &)
-                -> StatefulIterator const * {
+            [](Members::Deferred_t const &) -> StatefulIterator const * {
                 throw std::runtime_error(
                     "[StatefulSnapshotscontainer] Initialization has been "
                     "deferred, but container is accessed as const, so cannot "