Small allocation fix in fbx loader

code/AssetLib/FBX/FBXBinaryTokenizer.cpp

@@ -341,8 +341,7 @@ void ReadData(const char*& sbegin_out, const char*& send_out, const char* input,
 
 
 // ------------------------------------------------------------------------------------------------
-bool ReadScope(TokenList& output_tokens, const char* input, const char*& cursor, const char* end, bool const is64bits)
-{
+bool ReadScope(TokenList &output_tokens, StackAllocator &token_allocator, const char *input, const char *&cursor, const char *end, bool const is64bits) {
     // the first word contains the offset at which this block ends
 	const uint64_t end_offset = is64bits ? ReadDoubleWord(input, cursor, end) : ReadWord(input, cursor, end);
 
@@ -408,7 +407,7 @@ bool ReadScope(TokenList& output_tokens, const char* input, const char*& cursor,
 
         // XXX this is vulnerable to stack overflowing ..
         while(Offset(input, cursor) < end_offset - sentinel_block_length) {
-			ReadScope(output_tokens, input, cursor, input + end_offset - sentinel_block_length, is64bits);
+            ReadScope(output_tokens, token_allocator, input, cursor, input + end_offset - sentinel_block_length, is64bits);
         }
         output_tokens.push_back(new_Token(cursor, cursor + 1, TokenType_CLOSE_BRACKET, Offset(input, cursor) ));
 
@@ -431,8 +430,7 @@ bool ReadScope(TokenList& output_tokens, const char* input, const char*& cursor,
 
 // ------------------------------------------------------------------------------------------------
 // TODO: Test FBX Binary files newer than the 7500 version to check if the 64 bits address behaviour is consistent
-void TokenizeBinary(TokenList& output_tokens, const char* input, size_t length)
-{
+void TokenizeBinary(TokenList &output_tokens, const char *input, size_t length, StackAllocator &token_allocator) {
 	ai_assert(input);
 	ASSIMP_LOG_DEBUG("Tokenizing binary FBX file");
 
@@ -465,7 +463,7 @@ void TokenizeBinary(TokenList& output_tokens, const char* input, size_t length)
     try
     {
         while (cursor < end ) {
-		    if (!ReadScope(output_tokens, input, cursor, input + length, is64bits)) {
+            if (!ReadScope(output_tokens, token_allocator, input, cursor, input + length, is64bits)) {
                 break;
             }
         }

code/AssetLib/FBX/FBXDocument.cpp

@@ -235,7 +235,7 @@ FileGlobalSettings::FileGlobalSettings(const Document &doc, std::shared_ptr<cons
 }
 
 // ------------------------------------------------------------------------------------------------
-Document::Document(const Parser& parser, const ImportSettings& settings) :
+Document::Document(Parser& parser, const ImportSettings& settings) :
      settings(settings), parser(parser) {
 	ASSIMP_LOG_DEBUG("Creating FBX Document");
 
@@ -257,13 +257,17 @@ Document::Document(const Parser& parser, const ImportSettings& settings) :
 }
 
 // ------------------------------------------------------------------------------------------------
-Document::~Document() {
-    for(ObjectMap::value_type& v : objects) {
-        delete v.second;
+Document::~Document()
+{
+	// The document does not own the memory for the following objects, but we need to call their d'tor
+	// so they can properly free memory like string members:
+
+    for (ObjectMap::value_type &v : objects) {
+        delete_LazyObject(v.second);
     }
 
-    for(ConnectionMap::value_type& v : src_connections) {
-        delete v.second;
+    for (ConnectionMap::value_type &v : src_connections) {
+        delete_Connection(v.second);
     }
     // |dest_connections| contain the same Connection objects as the |src_connections|
 }
@@ -348,9 +352,11 @@ void Document::ReadObjects() {
         DOMError("no Objects dictionary found");
     }
 
+    StackAllocator &allocator = parser.GetAllocator();
+
     // add a dummy entry to represent the Model::RootNode object (id 0),
     // which is only indirectly defined in the input file
-    objects[0] = new LazyObject(0L, *eobjects, *this);
+    objects[0] = new_LazyObject(0L, *eobjects, *this);
 
     const Scope& sobjects = *eobjects->Compound();
     for(const ElementMap::value_type& el : sobjects.Elements()) {
@@ -377,7 +383,7 @@ void Document::ReadObjects() {
             DOMWarning("encountered duplicate object id, ignoring first occurrence",el.second);
         }
 
-        objects[id] = new LazyObject(id, *el.second, *this);
+        objects[id] = new_LazyObject(id, *el.second, *this);
 
         // grab all animation stacks upfront since there is no listing of them
         if(!strcmp(el.first.c_str(),"AnimationStack")) {
@@ -444,8 +450,10 @@ void Document::ReadPropertyTemplates() {
 }
 
 // ------------------------------------------------------------------------------------------------
-void Document::ReadConnections() {
-    const Scope& sc = parser.GetRootScope();
+void Document::ReadConnections()
+{
+    StackAllocator &allocator = parser.GetAllocator();
+    const Scope &sc = parser.GetRootScope();
     // read property templates from "Definitions" section
     const Element* const econns = sc["Connections"];
     if(!econns || !econns->Compound()) {
@@ -484,7 +492,7 @@ void Document::ReadConnections() {
         }
 
         // add new connection
-        const Connection* const c = new Connection(insertionOrder++,src,dest,prop,*this);
+        const Connection* const c = new_Connection(insertionOrder++,src,dest,prop,*this);
         src_connections.insert(ConnectionMap::value_type(src,c));
         dest_connections.insert(ConnectionMap::value_type(dest,c));
     }

code/AssetLib/FBX/FBXDocument.h

@@ -80,6 +80,10 @@ class BlendShape;
 class Skin;
 class Cluster;
 
+#define new_LazyObject new (allocator.Allocate(sizeof(LazyObject))) LazyObject
+#define new_Connection new (allocator.Allocate(sizeof(Connection))) Connection
+#define delete_LazyObject(_p) (_p)->~LazyObject()
+#define delete_Connection(_p) (_p)->~Connection()
 
 /** Represents a delay-parsed FBX objects. Many objects in the scene
  *  are not needed by assimp, so it makes no sense to parse them
@@ -1072,7 +1076,7 @@ class FileGlobalSettings {
 /** DOM root for a FBX file */
 class Document {
 public:
-    Document(const Parser& parser, const ImportSettings& settings);
+    Document(Parser& parser, const ImportSettings& settings);
 
     ~Document();
 
@@ -1156,7 +1160,7 @@ class Document {
     const ImportSettings& settings;
 
     ObjectMap objects;
-    const Parser& parser;
+    Parser& parser;
 
     PropertyTemplateMap templates;
     ConnectionMap src_connections;

code/AssetLib/FBX/FBXImporter.cpp

@@ -156,19 +156,19 @@ void FBXImporter::InternReadFile(const std::string &pFile, aiScene *pScene, IOSy
 	// broad-phase tokenized pass in which we identify the core
 	// syntax elements of FBX (brackets, commas, key:value mappings)
 	TokenList tokens;
-	try {
-
+    Assimp::StackAllocator tempAllocator;
+    try {
 		bool is_binary = false;
 		if (!strncmp(begin, "Kaydara FBX Binary", 18)) {
 			is_binary = true;
-			TokenizeBinary(tokens, begin, contents.size());
+            TokenizeBinary(tokens, begin, contents.size(), tempAllocator);
 		} else {
-			Tokenize(tokens, begin);
+            Tokenize(tokens, begin, tempAllocator);
 		}
 
 		// use this information to construct a very rudimentary
 		// parse-tree representing the FBX scope structure
-		Parser parser(tokens, is_binary);
+        Parser parser(tokens, tempAllocator, is_binary);
 
 		// take the raw parse-tree and convert it to a FBX DOM
 		Document doc(parser, mSettings);
@@ -187,10 +187,12 @@ void FBXImporter::InternReadFile(const std::string &pFile, aiScene *pScene, IOSy
 		// assimp universal format (M)
 		SetFileScale(size_relative_to_cm * 0.01f);
 
-		std::for_each(tokens.begin(), tokens.end(), Util::delete_fun<Token>());
-	} catch (std::exception &) {
-		std::for_each(tokens.begin(), tokens.end(), Util::delete_fun<Token>());
-		throw;
+		// This collection does not own the memory for the tokens, but we need to call their d'tor
+        std::for_each(tokens.begin(), tokens.end(), Util::destructor_fun<Token>());
+
+    } catch (std::exception &) {
+        std::for_each(tokens.begin(), tokens.end(), Util::destructor_fun<Token>());
+        throw;
 	}
 }
 

code/AssetLib/FBX/FBXParser.cpp

@@ -115,8 +115,11 @@ namespace Assimp {
 namespace FBX {
 
 // ------------------------------------------------------------------------------------------------
-Element::Element(const Token& key_token, Parser& parser) : key_token(key_token) {
+Element::Element(const Token& key_token, Parser& parser) :
+    key_token(key_token), compound(nullptr)
+{
     TokenPtr n = nullptr;
+    StackAllocator &allocator = parser.GetAllocator();
     do {
         n = parser.AdvanceToNextToken();
         if(!n) {
@@ -145,7 +148,7 @@ Element::Element(const Token& key_token, Parser& parser) : key_token(key_token)
         }
 
         if (n->Type() == TokenType_OPEN_BRACKET) {
-            compound.reset(new Scope(parser));
+            compound = new_Scope(parser);
 
             // current token should be a TOK_CLOSE_BRACKET
             n = parser.CurrentToken();
@@ -163,6 +166,15 @@ Element::Element(const Token& key_token, Parser& parser) : key_token(key_token)
 }
 
 // ------------------------------------------------------------------------------------------------
+Element::~Element()
+{
+    if (compound) {
+        delete_Scope(compound);
+    }
+
+     // no need to delete tokens, they are owned by the parser
+}
+
 Scope::Scope(Parser& parser,bool topLevel)
 {
     if(!topLevel) {
@@ -172,6 +184,7 @@ Scope::Scope(Parser& parser,bool topLevel)
         }
     }
 
+    StackAllocator &allocator = parser.GetAllocator();
     TokenPtr n = parser.AdvanceToNextToken();
     if (n == nullptr) {
         ParseError("unexpected end of file");
@@ -202,22 +215,27 @@ Scope::Scope(Parser& parser,bool topLevel)
 }
 
 // ------------------------------------------------------------------------------------------------
-Scope::~Scope() {
-    for(ElementMap::value_type& v : elements) {
-        delete v.second;
+Scope::~Scope()
+{
+	// This collection does not own the memory for the elements, but we need to call their d'tor:
+
+    for (ElementMap::value_type &v : elements) {
+        delete_Element(v.second);
     }
 }
 
 // ------------------------------------------------------------------------------------------------
-Parser::Parser (const TokenList& tokens, bool is_binary)
-: tokens(tokens)
-, last()
-, current()
-, cursor(tokens.begin())
-, is_binary(is_binary)
+Parser::Parser(const TokenList &tokens, StackAllocator &allocator, bool is_binary) :
+        tokens(tokens), allocator(allocator), last(), current(), cursor(tokens.begin()), is_binary(is_binary)
 {
     ASSIMP_LOG_DEBUG("Parsing FBX tokens");
-    root.reset(new Scope(*this,true));
+    root = new_Scope(*this, true);
+}
+
+// ------------------------------------------------------------------------------------------------
+Parser::~Parser()
+{
+    delete_Scope(root);
 }
 
 // ------------------------------------------------------------------------------------------------

code/AssetLib/FBX/FBXParser.h

@@ -52,6 +52,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <assimp/LogAux.h>
 #include <assimp/fast_atof.h>
 
+#include "Common/StackAllocator.h"
 #include "FBXCompileConfig.h"
 #include "FBXTokenizer.h"
 
@@ -68,9 +69,10 @@ typedef std::fbx_unordered_multimap< std::string, Element* > ElementMap;
 
 typedef std::pair<ElementMap::const_iterator,ElementMap::const_iterator> ElementCollection;
 
-#   define new_Scope new Scope
-#   define new_Element new Element
-
+#define new_Scope new (allocator.Allocate(sizeof(Scope))) Scope
+#define new_Element new (allocator.Allocate(sizeof(Element))) Element
+#define delete_Scope(_p) (_p)->~Scope()
+#define delete_Element(_p) (_p)->~Element()
 
 /** FBX data entity that consists of a key:value tuple.
  *
@@ -87,10 +89,10 @@ class Element
 {
 public:
     Element(const Token& key_token, Parser& parser);
-    ~Element() = default;
+    ~Element():
 
     const Scope* Compound() const {
-        return compound.get();
+        return compound;
     }
 
     const Token& KeyToken() const {
@@ -104,7 +106,7 @@ class Element
 private:
     const Token& key_token;
     TokenList tokens;
-    std::unique_ptr<Scope> compound;
+    Scope* compound;
 };
 
 /** FBX data entity that consists of a 'scope', a collection
@@ -159,17 +161,21 @@ class Parser
 public:
     /** Parse given a token list. Does not take ownership of the tokens -
      *  the objects must persist during the entire parser lifetime */
-    Parser (const TokenList& tokens,bool is_binary);
-    ~Parser() = default;
+    Parser(const TokenList &tokens, StackAllocator &allocator, bool is_binary);
+    ~Parser();
 
     const Scope& GetRootScope() const {
-        return *root.get();
+        return *root;
     }
 
     bool IsBinary() const {
         return is_binary;
     }
 
+    StackAllocator &GetAllocator() {
+        return allocator;
+    }
+
 private:
     friend class Scope;
     friend class Element;
@@ -180,10 +186,10 @@ class Parser
 
 private:
     const TokenList& tokens;
-
+    StackAllocator &allocator;
     TokenPtr last, current;
     TokenList::const_iterator cursor;
-    std::unique_ptr<Scope> root;
+    Scope *root;
 
     const bool is_binary;
 };