newparser: post-merge fixes

changelog/current.md

@@ -1,13 +1,36 @@
-**All the changes described come from a single PR: [#PR414](https://github.com/biojppm/rapidyaml/pull/414).**
+Most of the changes are from the giant Parser refactor described below. Before getting to that, a couple of other minor changes first.
 
 
+### Fixes
+
+- [#PR431](https://github.com/biojppm/rapidyaml/pull/431) - Emitter: prevent stack overflows when emitting malicious trees by providing a max tree depth for the emit visitor. This was done by adding an `EmitOptions` structure as an argument both to the emitter and to the emit functions, which is then forwarded to the emitter. This `EmitOptions` structure has a max tree depth setting with a default value of 64.
+- [#PR431](https://github.com/biojppm/rapidyaml/pull/431) - Fix `_RYML_CB_ALLOC()` using `(T)` in parenthesis, making the macro unusable.
+
+
+### New features
+
+- [#PR431](https://github.com/biojppm/rapidyaml/pull/431) - append-emitting to existing containers in the `emitrs_` functions, suggested in [#345](https://github.com/biojppm/rapidyaml/issues/345). This was achieved by adding a `bool append=false` as the last parameter of these functions.
+- [#PR431](https://github.com/biojppm/rapidyaml/pull/431) - add depth query methods:
+  ```cpp
+  Tree::depth_asc(id_type) const;   // O(log(num_tree_nodes)) get the depth of a node ascending (ie, from root to node)
+  Tree::depth_desc(id_type) const;  // O(num_tree_nodes) get the depth of a node descending (ie, from node to deep-most leaf node)
+  ConstNodeRef::depth_asc() const;  // likewise
+  ConstNodeRef::depth_desc() const;
+  NodeRef::depth_asc() const;
+  NodeRef::depth_desc() const;
+  ```
+
+
+------
+All other changes come from [#PR414](https://github.com/biojppm/rapidyaml/pull/414).
+
 ### Parser refactor
 
-The parser was completely refactored ([#PR414](https://github.com/biojppm/rapidyaml/pull/414)). This was a large and hard job carried out over several months, and the result is:
+The parser was completely refactored ([#PR414](https://github.com/biojppm/rapidyaml/pull/414)). This was a large and hard job carried out over several months, but it brings important improvements.
 
-- A new event-based parser engine is now in place, enabling the improvements described below. This engine uses a templated event handler, where each event is a function call, which spares branches on the event handler. The parsing code was fully rewritten, and is now much more simple (albeit longer), and much easier to work with and fix.
+- The new parser is an event-based parser, based on an event dispatcher engine. This engine is templated on event handler, where each event is a function call, which spares branches on the event handler. The parsing code was fully rewritten, and is now much more simple (albeit longer), and much easier to work with and fix.
 - YAML standard-conformance was improved significantly. Along with many smaller fixes and additions, (too many to list here), the main changes are the following:
-  - The parser engine can now successfully parse container keys, emitting all the events in the correct , **but** as before, the ryml tree cannot accomodate these (and this constraint is no longer enforced by the parser, but instead by `EventHandlerTree`). For an example of a handler which can accomodate key containers, see the one which is used for the test suite at `test/test_suite/test_suite_event_handler.hpp`
+  - The parser engine can now successfully parse container keys, emitting all the events in correctly, **but** as before, the ryml tree cannot accomodate these (and this constraint is no longer enforced by the parser, but instead by `EventHandlerTree`). For an example of a handler which can accomodate key containers, see the one which is used for the test suite at `test/test_suite/test_suite_event_handler.hpp`
   - Anchor keys can now be terminated with colon (eg, `&anchor: key: val`), as dictated by the standard.
 - The parser engine can now be used to create native trees in other programming languages, or in cases where the user *must* have container keys.
 - Performance of both parsing and emitting improved significantly; see some figures below.

src/c4/yml/common.hpp

@@ -468,7 +468,7 @@ do                                                                      \
         }                                                               \
     } while(0)
 #define _RYML_CB_ALLOC_HINT(cb, T, num, hint) (T*) (cb).m_allocate((num) * sizeof(T), (hint), (cb).m_user_data)
-#define _RYML_CB_ALLOC(cb, T, num) _RYML_CB_ALLOC_HINT((cb), (T), (num), nullptr)
+#define _RYML_CB_ALLOC(cb, T, num) _RYML_CB_ALLOC_HINT((cb), T, (num), nullptr)
 #define _RYML_CB_FREE(cb, buf, T, num)                              \
     do {                                                            \
         (cb).m_free((buf), (num) * sizeof(T), (cb).m_user_data);    \

src/c4/yml/emit.def.hpp

@@ -29,28 +29,13 @@
     if(type == EMIT_YAML)
         _emit_yaml(id);
     else if(type == EMIT_JSON)
-        _do_visit_json(id);
+        _do_visit_json(id, 0);
     else
         _RYML_CB_ERR(m_tree->callbacks(), "unknown emit type");
     m_tree = nullptr;
     return this->Writer::_get(error_on_excess);
 }
 
-template<class Writer>
-substr Emitter<Writer>::emit_as(EmitType_e type, Tree const& t, bool error_on_excess)
-{
-    if(t.empty())
-        return {};
-    return this->emit_as(type, t, t.root_id(), error_on_excess);
-}
-
-template<class Writer>
-substr Emitter<Writer>::emit_as(EmitType_e type, ConstNodeRef const& n, bool error_on_excess)
-{
-    _RYML_CB_CHECK(n.tree()->callbacks(), n.readable());
-    return this->emit_as(type, *n.tree(), n.id(), error_on_excess);
-}
-
 
 //-----------------------------------------------------------------------------
 
@@ -82,7 +67,7 @@
                 this->Writer::_do_write(":\n");
                 ++ilevel;
             }
-            _do_visit_block_container(id, ilevel, ilevel);
+            _do_visit_block_container(id, 0, ilevel, ilevel);
             return;
         }
     }
@@ -256,13 +241,15 @@
 }
 
 template<class Writer>
-void Emitter<Writer>::_do_visit_flow_sl(id_type node, id_type ilevel)
+void Emitter<Writer>::_do_visit_flow_sl(id_type node, id_type depth, id_type ilevel)
 {
     const bool prev_flow = m_flow;
     m_flow = true;
     RYML_ASSERT(!m_tree->is_stream(node));
     RYML_ASSERT(m_tree->is_container(node) || m_tree->is_doc(node));
     RYML_ASSERT(m_tree->is_root(node) || (m_tree->parent_is_map(node) || m_tree->parent_is_seq(node)));
+    if(C4_UNLIKELY(depth > m_opts.max_depth()))
+        _RYML_CB_ERR(m_tree->callbacks(), "max depth exceeded");
 
     if(m_tree->is_doc(node))
     {
@@ -345,7 +332,7 @@
         else
         {
             // with single-line flow, we can never go back to block
-            _do_visit_flow_sl(child, ilevel + 1);
+            _do_visit_flow_sl(child, depth + 1, ilevel + 1);
         }
     }
 
@@ -363,19 +350,25 @@
 C4_SUPPRESS_WARNING_MSVC_WITH_PUSH(4702) // unreachable error, triggered by flow_ml not implemented
 
 template<class Writer>
-void Emitter<Writer>::_do_visit_flow_ml(id_type id, id_type ilevel, id_type do_indent)
+void Emitter<Writer>::_do_visit_flow_ml(id_type id, id_type depth, id_type ilevel, id_type do_indent)
 {
     C4_UNUSED(id);
+    C4_UNUSED(depth);
     C4_UNUSED(ilevel);
     C4_UNUSED(do_indent);
+    c4::yml::error("not implemented");
+    #ifdef THIS_IS_A_WORK_IN_PROGRESS
+    if(C4_UNLIKELY(depth > m_opts.max_depth()))
+        _RYML_CB_ERR(m_tree->callbacks(), "max depth exceeded");
     const bool prev_flow = m_flow;
     m_flow = true;
-    c4::yml::error("not implemented");
+    // do it...
     m_flow = prev_flow;
+    #endif
 }
 
 template<class Writer>
-void Emitter<Writer>::_do_visit_block_container(id_type node, id_type level, bool do_indent)
+void Emitter<Writer>::_do_visit_block_container(id_type node, id_type depth, id_type level, bool do_indent)
 {
     if(m_tree->is_seq(node))
     {
@@ -397,19 +390,19 @@
                 {
                     _indent(level, do_indent);
                     this->Writer::_do_write("- ");
-                    _do_visit_flow_sl(child, 0u);
+                    _do_visit_flow_sl(child, depth+1, 0u);
                     this->Writer::_do_write('\n');
                 }
                 else if(ty.is_flow_ml())
                 {
                     _indent(level, do_indent);
                     this->Writer::_do_write("- ");
-                    _do_visit_flow_ml(child, 0u, do_indent);
+                    _do_visit_flow_ml(child, depth+1, 0u, do_indent);
                     this->Writer::_do_write('\n');
                 }
                 else
                 {
-                    _do_visit_block(child, level, do_indent); // same level
+                    _do_visit_block(child, depth+1, level, do_indent); // same indentation level
                 }
             }
             do_indent = true;
@@ -436,18 +429,18 @@
                 if(ty.is_flow_sl())
                 {
                     _indent(level, do_indent);
-                    _do_visit_flow_sl(ich, 0u);
+                    _do_visit_flow_sl(ich, depth+1, 0u);
                     this->Writer::_do_write('\n');
                 }
                 else if(ty.is_flow_ml())
                 {
                     _indent(level, do_indent);
-                    _do_visit_flow_ml(ich, 0u);
+                    _do_visit_flow_ml(ich, depth+1, 0u);
                     this->Writer::_do_write('\n');
                 }
                 else
                 {
-                    _do_visit_block(ich, level, do_indent); // same level!
+                    _do_visit_block(ich, depth+1, level, do_indent); // same level!
                 }
             } // keyval vs container
             do_indent = true;
@@ -456,11 +449,13 @@
 }
 
 template<class Writer>
-void Emitter<Writer>::_do_visit_block(id_type node, id_type ilevel, id_type do_indent)
+void Emitter<Writer>::_do_visit_block(id_type node, id_type depth, id_type ilevel, id_type do_indent)
 {
     RYML_ASSERT(!m_tree->is_stream(node));
     RYML_ASSERT(m_tree->is_container(node) || m_tree->is_doc(node));
     RYML_ASSERT(m_tree->is_root(node) || (m_tree->parent_is_map(node) || m_tree->parent_is_seq(node)));
+    if(C4_UNLIKELY(depth > m_opts.max_depth()))
+        _RYML_CB_ERR(m_tree->callbacks(), "max depth exceeded");
     if(m_tree->is_doc(node))
     {
         _write_doc(node);
@@ -537,16 +532,18 @@
     if(m_tree->is_root(node) || m_tree->is_doc(node))
         next_level = ilevel; // do not indent at top level
 
-    _do_visit_block_container(node, next_level, do_indent);
+    _do_visit_block_container(node, depth, next_level, do_indent);
 }
 
 C4_SUPPRESS_WARNING_MSVC_POP
 
 
 template<class Writer>
-void Emitter<Writer>::_do_visit_json(id_type id)
+void Emitter<Writer>::_do_visit_json(id_type id, id_type depth)
 {
     _RYML_CB_CHECK(m_tree->callbacks(), !m_tree->is_stream(id)); // JSON does not have streams
+    if(C4_UNLIKELY(depth > m_opts.max_depth()))
+        _RYML_CB_ERR(m_tree->callbacks(), "max depth exceeded");
     if(m_tree->is_keyval(id))
     {
         _writek_json(id);
@@ -574,7 +571,7 @@
     {
         if(ich != m_tree->first_child(id))
             this->Writer::_do_write(',');
-        _do_visit_json(ich);
+        _do_visit_json(ich, depth+1);
     }
 
     if(m_tree->is_seq(id))