[ntuple] improve error message in ReconcileIntegralField()

Use the type trace report to help identify the violating subfield in a
field hiararchy.

Author: jblomer

tree/ntuple/src/RField.cxx

@@ -83,10 +83,12 @@ void ROOT::RCardinalityField::ReconcileOnDiskField(const RNTupleDescriptor &desc
    if (fieldDesc.GetStructure() == ENTupleStructure::kPlain) {
       if (fieldDesc.GetTypeName().rfind("ROOT::RNTupleCardinality<", 0) != 0) {
          throw RException(R__FAIL("RCardinalityField " + GetQualifiedFieldName() +
-                                  " expects an on-disk leaf field of the same type"));
+                                  " expects an on-disk leaf field of the same type\n" +
+                                  Internal::GetTypeTraceReport(*this, desc)));
       }
    } else if (fieldDesc.GetStructure() != ENTupleStructure::kCollection) {
-      throw RException(R__FAIL("invalid on-disk structural role for RCardinalityField " + GetQualifiedFieldName()));
+      throw RException(R__FAIL("invalid on-disk structural role for RCardinalityField " + GetQualifiedFieldName() +
+                               "\n" + Internal::GetTypeTraceReport(*this, desc)));
    }
 }
 
@@ -124,7 +126,7 @@ void ROOT::RSimpleField<T>::ReconcileIntegralField(const RNTupleDescriptor &desc
    if (std::find(std::begin(gIntegralTypeNames), std::end(gIntegralTypeNames), fieldDesc.GetTypeName()) ==
        std::end(gIntegralTypeNames)) {
       throw RException(R__FAIL("unexpected on-disk type name '" + fieldDesc.GetTypeName() + "' for field of type '" +
-                               GetTypeName() + "'"));
+                               GetTypeName() + "'\n" + Internal::GetTypeTraceReport(*this, desc)));
    }
 }
 
@@ -136,7 +138,7 @@ void ROOT::RSimpleField<T>::ReconcileFloatingPointField(const RNTupleDescriptor
    const RFieldDescriptor &fieldDesc = desc.GetFieldDescriptor(GetOnDiskId());
    if (!(fieldDesc.GetTypeName() == "float" || fieldDesc.GetTypeName() == "double")) {
       throw RException(R__FAIL("unexpected on-disk type name '" + fieldDesc.GetTypeName() + "' for field of type '" +
-                               GetTypeName() + "'"));
+                               GetTypeName() + "'\n" + Internal::GetTypeTraceReport(*this, desc)));
    }
 }
 

tree/ntuple/src/RFieldBase.cxx

@@ -1046,7 +1046,7 @@ ROOT::RFieldBase::EnsureMatchingOnDiskField(const RNTupleDescriptor &desc, std::
    if (diffBits & kDiffNRepetitions) {
       errMsg << " repetition count " << GetNRepetitions() << " vs. " << fieldDesc.GetNRepetitions() << ";";
    }
-   return R__FAIL(errMsg.str());
+   return R__FAIL(errMsg.str() + "\n" + Internal::GetTypeTraceReport(*this, desc));
 }
 
 ROOT::RResult<void> ROOT::RFieldBase::EnsureMatchingTypePrefix(const RNTupleDescriptor &desc,
@@ -1057,7 +1057,8 @@ ROOT::RResult<void> ROOT::RFieldBase::EnsureMatchingTypePrefix(const RNTupleDesc
       if (fieldDesc.GetTypeName().rfind(p, 0) == 0)
          return RResult<void>::Success();
    }
-   return R__FAIL("incompatible type " + fieldDesc.GetTypeName() + " for field " + GetQualifiedFieldName());
+   return R__FAIL("incompatible type " + fieldDesc.GetTypeName() + " for field " + GetQualifiedFieldName() + "\n" +
+                  Internal::GetTypeTraceReport(*this, desc));
 }
 
 std::uint32_t ROOT::RFieldBase::CompareOnDiskField(const RFieldDescriptor &fieldDesc, std::uint32_t ignoreBits) const

tree/ntuple/src/RFieldMeta.cxx

@@ -690,8 +690,9 @@ void ROOT::RPairField::ReconcileOnDiskField(const RNTupleDescriptor &desc)
    const auto &fieldDesc = desc.GetFieldDescriptor(GetOnDiskId());
    const auto nOnDiskSubfields = fieldDesc.GetLinkIds().size();
    if (nOnDiskSubfields != 2) {
-      throw ROOT::RException(
-         R__FAIL("invalid number of on-disk subfields for std::pair " + std::to_string(nOnDiskSubfields)));
+      throw ROOT::RException(R__FAIL("invalid number of on-disk subfields for std::pair " +
+                                     std::to_string(nOnDiskSubfields) + "\n" +
+                                     Internal::GetTypeTraceReport(*this, desc)));
    }
 }
 
@@ -1239,7 +1240,8 @@ void ROOT::RTupleField::ReconcileOnDiskField(const RNTupleDescriptor &desc)
    const auto nSubfields = fSubfields.size();
    if (nOnDiskSubfields != nSubfields) {
       throw ROOT::RException(R__FAIL("invalid number of on-disk subfields for std::tuple " +
-                                     std::to_string(nOnDiskSubfields) + " vs. " + std::to_string(nSubfields)));
+                                     std::to_string(nOnDiskSubfields) + " vs. " + std::to_string(nSubfields) + "\n" +
+                                     Internal::GetTypeTraceReport(*this, desc)));
    }
 }
 
@@ -1398,7 +1400,8 @@ void ROOT::RVariantField::ReconcileOnDiskField(const RNTupleDescriptor &desc)
 
    const auto &fieldDesc = desc.GetFieldDescriptor(GetOnDiskId());
    if (fSubfields.size() != fieldDesc.GetLinkIds().size()) {
-      throw RException(R__FAIL("number of variants on-disk do not match for " + GetQualifiedFieldName()));
+      throw RException(R__FAIL("number of variants on-disk do not match for " + GetQualifiedFieldName() + "\n" +
+                               Internal::GetTypeTraceReport(*this, desc)));
    }
 }
 

tree/ntuple/src/RFieldSequenceContainer.cxx

@@ -845,7 +845,8 @@ void ROOT::RArrayAsRVecField::ReconcileOnDiskField(const RNTupleDescriptor &desc
       .ThrowOnError();
    const auto &fieldDesc = desc.GetFieldDescriptor(GetOnDiskId());
    if (fieldDesc.GetTypeName().rfind("std::array<", 0) != 0) {
-      throw RException(R__FAIL("RArrayAsRVecField " + GetQualifiedFieldName() + " expects an on-disk array field"));
+      throw RException(R__FAIL("RArrayAsRVecField " + GetQualifiedFieldName() + " expects an on-disk array field\n" +
+                               Internal::GetTypeTraceReport(*this, desc)));
    }
 }