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Fixed reflection.h not modifying certain table configurations.

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It would write 64bits offsets instead of 32bit ones, and update
the vtable pointer before the fields were processed.

Change-Id: I0c0fa942bbd3b42839294f5653ba8fa048612624
Tested: on Linux.
This commit is contained in:
Wouter van Oortmerssen
2016-07-25 14:43:41 -07:00
parent f98870715a
commit 1bba4fd9ea
2 changed files with 67 additions and 61 deletions
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122
src/reflection.cpp
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@@ -204,72 +204,76 @@ class ResizeContext {
if (DagCheck(table))
return; // Table already visited.
auto vtable = table->GetVTable();
// Check if the vtable offset points beyond the insertion point.
Straddle<soffset_t, -1>(table, vtable, table);
// This direction shouldn't happen because vtables that sit before tables
// are always directly adjacent, but check just in case we ever change the
// way flatbuffers are built.
Straddle<soffset_t, -1>(vtable, table, table);
// Early out: since all fields inside the table must point forwards in
// memory, if the insertion point is before the table we can stop here.
auto tableloc = reinterpret_cast<uint8_t *>(table);
if (startptr_ <= tableloc) return;
// Check each field.
auto fielddefs = objectdef.fields();
for (auto it = fielddefs->begin(); it != fielddefs->end(); ++it) {
auto &fielddef = **it;
auto base_type = fielddef.type()->base_type();
// Ignore scalars.
if (base_type <= reflection::Double) continue;
// Ignore fields that are not stored.
auto offset = table->GetOptionalFieldOffset(fielddef.offset());
if (!offset) continue;
// Ignore structs.
auto subobjectdef = base_type == reflection::Obj ?
schema_.objects()->Get(fielddef.type()->index()) : nullptr;
if (subobjectdef && subobjectdef->is_struct()) continue;
// Get this fields' offset, and read it if safe.
auto offsetloc = tableloc + offset;
if (DagCheck(offsetloc))
continue; // This offset already visited.
auto ref = offsetloc + ReadScalar<uoffset_t>(offsetloc);
Straddle<uoffset_t, 1>(offsetloc, ref, offsetloc);
// Recurse.
switch (base_type) {
case reflection::Obj: {
ResizeTable(*subobjectdef, reinterpret_cast<Table *>(ref));
break;
}
case reflection::Vector: {
auto elem_type = fielddef.type()->element();
if (elem_type != reflection::Obj && elem_type != reflection::String)
if (startptr_ <= tableloc) {
// Check if insertion point is between the table and a vtable that
// precedes it. This can't happen in current construction code, but check
// just in case we ever change the way flatbuffers are built.
Straddle<soffset_t, -1>(vtable, table, table);
} else {
// Check each field.
auto fielddefs = objectdef.fields();
for (auto it = fielddefs->begin(); it != fielddefs->end(); ++it) {
auto &fielddef = **it;
auto base_type = fielddef.type()->base_type();
// Ignore scalars.
if (base_type <= reflection::Double) continue;
// Ignore fields that are not stored.
auto offset = table->GetOptionalFieldOffset(fielddef.offset());
if (!offset) continue;
// Ignore structs.
auto subobjectdef = base_type == reflection::Obj ?
schema_.objects()->Get(fielddef.type()->index()) : nullptr;
if (subobjectdef && subobjectdef->is_struct()) continue;
// Get this fields' offset, and read it if safe.
auto offsetloc = tableloc + offset;
if (DagCheck(offsetloc))
continue; // This offset already visited.
auto ref = offsetloc + ReadScalar<uoffset_t>(offsetloc);
Straddle<uoffset_t, 1>(offsetloc, ref, offsetloc);
// Recurse.
switch (base_type) {
case reflection::Obj: {
ResizeTable(*subobjectdef, reinterpret_cast<Table *>(ref));
break;
auto vec = reinterpret_cast<Vector<uoffset_t> *>(ref);
auto elemobjectdef = elem_type == reflection::Obj
? schema_.objects()->Get(fielddef.type()->index())
: nullptr;
if (elemobjectdef && elemobjectdef->is_struct()) break;
for (uoffset_t i = 0; i < vec->size(); i++) {
auto loc = vec->Data() + i * sizeof(uoffset_t);
if (DagCheck(loc))
continue; // This offset already visited.
auto dest = loc + vec->Get(i);
Straddle<uoffset_t, 1>(loc, dest ,loc);
if (elemobjectdef)
ResizeTable(*elemobjectdef, reinterpret_cast<Table *>(dest));
}
break;
case reflection::Vector: {
auto elem_type = fielddef.type()->element();
if (elem_type != reflection::Obj && elem_type != reflection::String)
break;
auto vec = reinterpret_cast<Vector<uoffset_t> *>(ref);
auto elemobjectdef = elem_type == reflection::Obj
? schema_.objects()->Get(fielddef.type()->index())
: nullptr;
if (elemobjectdef && elemobjectdef->is_struct()) break;
for (uoffset_t i = 0; i < vec->size(); i++) {
auto loc = vec->Data() + i * sizeof(uoffset_t);
if (DagCheck(loc))
continue; // This offset already visited.
auto dest = loc + vec->Get(i);
Straddle<uoffset_t, 1>(loc, dest ,loc);
if (elemobjectdef)
ResizeTable(*elemobjectdef, reinterpret_cast<Table *>(dest));
}
break;
}
case reflection::Union: {
ResizeTable(GetUnionType(schema_, objectdef, fielddef, *table),
reinterpret_cast<Table *>(ref));
break;
}
case reflection::String:
break;
default:
assert(false);
}
case reflection::Union: {
ResizeTable(GetUnionType(schema_, objectdef, fielddef, *table),
reinterpret_cast<Table *>(ref));
break;
}
case reflection::String:
break;
default:
assert(false);
}
// Check if the vtable offset points beyond the insertion point.
// Must do this last, since GetOptionalFieldOffset above still reads
// this value.
Straddle<soffset_t, -1>(table, vtable, table);
}
}