diff options
Diffstat (limited to 'src/hb-repacker.hh')
| -rw-r--r-- | src/hb-repacker.hh | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/src/hb-repacker.hh b/src/hb-repacker.hh index cd57ade07..e9cd376ad 100644 --- a/src/hb-repacker.hh +++ b/src/hb-repacker.hh @@ -79,7 +79,12 @@ bool _presplit_subtables_if_needed (graph::gsubgpos_graph_context_t& ext_context // pass after this processing is done. Not super necessary as splits are // only done where overflow is likely, so de-dup probably will get undone // later anyways. - for (unsigned lookup_index : ext_context.lookups.keys ()) + + // The loop below can modify the contents of ext_context.lookups if new subtables are added + // to a lookup during a split. So save the initial set of lookup indices so the iteration doesn't + // risk access free'd memory if ext_context.lookups gets resized. + hb_set_t lookup_indices(ext_context.lookups.keys ()); + for (unsigned lookup_index : lookup_indices) { graph::Lookup* lookup = ext_context.lookups.get(lookup_index); if (!lookup->split_subtables_if_needed (ext_context, lookup_index)) @@ -114,11 +119,15 @@ bool _promote_extensions_if_needed (graph::gsubgpos_graph_context_t& ext_context // TODO(grieger): skip this for the 24 bit case. if (!ext_context.lookups) return true; + unsigned total_lookup_table_sizes = 0; hb_vector_t<lookup_size_t> lookup_sizes; lookup_sizes.alloc (ext_context.lookups.get_population (), true); for (unsigned lookup_index : ext_context.lookups.keys ()) { + const auto& lookup_v = ext_context.graph.vertices_[lookup_index]; + total_lookup_table_sizes += lookup_v.table_size (); + const graph::Lookup* lookup = ext_context.lookups.get(lookup_index); hb_set_t visited; lookup_sizes.push (lookup_size_t { @@ -131,14 +140,16 @@ bool _promote_extensions_if_needed (graph::gsubgpos_graph_context_t& ext_context lookup_sizes.qsort (); size_t lookup_list_size = ext_context.graph.vertices_[ext_context.lookup_list_index].table_size (); - size_t l2_l3_size = lookup_list_size; // Lookup List + Lookups - size_t l3_l4_size = 0; // Lookups + SubTables + size_t l2_l3_size = lookup_list_size + total_lookup_table_sizes; // Lookup List + Lookups + size_t l3_l4_size = total_lookup_table_sizes; // Lookups + SubTables size_t l4_plus_size = 0; // SubTables + their descendants // Start by assuming all lookups are using extension subtables, this size will be removed later // if it's decided to not make a lookup extension. for (auto p : lookup_sizes) { + // TODO(garretrieger): this overestimates the extension subtables size because some extension subtables may be + // reused. However, we can't correct this until we have connected component analysis in place. unsigned subtables_size = p.num_subtables * 8; l3_l4_size += subtables_size; l4_plus_size += subtables_size; @@ -159,8 +170,7 @@ bool _promote_extensions_if_needed (graph::gsubgpos_graph_context_t& ext_context size_t subtables_size = ext_context.graph.find_subgraph_size (p.lookup_index, visited, 1) - lookup_size; size_t remaining_size = p.size - subtables_size - lookup_size; - l2_l3_size += lookup_size; - l3_l4_size += lookup_size + subtables_size; + l3_l4_size += subtables_size; l3_l4_size -= p.num_subtables * 8; l4_plus_size += subtables_size + remaining_size; |