Added NodeList to abstract double linked list of nodes

src/asmjit/core/builder.cpp

@@ -151,14 +151,13 @@ BaseNode* BaseBuilder::addNode(BaseNode* node) noexcept {
   ASMJIT_ASSERT(!node->isActive());
 
   if (!_cursor) {
-    if (!_firstNode) {
+    if (_nodeList.empty()) {
-      _firstNode = node;
+      _nodeList.reset(node, node);
-      _lastNode = node;
     }
     else {
-      node->_next = _firstNode;
+      node->_next = _nodeList.first();
-      _firstNode->_prev = node;
+      _nodeList._first->_prev = node;
-      _firstNode = node;
+      _nodeList._first = node;
     }
   }
   else {
@@ -172,7 +171,7 @@ BaseNode* BaseBuilder::addNode(BaseNode* node) noexcept {
     if (next)
       next->_prev = node;
     else
-      _lastNode = node;
+      _nodeList._last = node;
   }
 
   node->addFlags(NodeFlags::kIsActive);
@@ -201,7 +200,7 @@ BaseNode* BaseBuilder::addAfter(BaseNode* node, BaseNode* ref) noexcept {
   if (next)
     next->_prev = node;
   else
-    _lastNode = node;
+    _nodeList._last = node;
 
   return node;
 }
@@ -226,7 +225,7 @@ BaseNode* BaseBuilder::addBefore(BaseNode* node, BaseNode* ref) noexcept {
   if (prev)
     prev->_next = node;
   else
-    _firstNode = node;
+    _nodeList._first = node;
 
   return node;
 }
@@ -238,13 +237,13 @@ BaseNode* BaseBuilder::removeNode(BaseNode* node) noexcept {
   BaseNode* prev = node->prev();
   BaseNode* next = node->next();
 
-  if (_firstNode == node)
+  if (_nodeList._first == node)
-    _firstNode = next;
+    _nodeList._first = next;
   else
     prev->_next = next;
 
-  if (_lastNode == node)
+  if (_nodeList._last == node)
-    _lastNode  = prev;
+    _nodeList._last  = prev;
   else
     next->_prev = prev;
 
@@ -272,13 +271,13 @@ void BaseBuilder::removeNodes(BaseNode* first, BaseNode* last) noexcept {
   BaseNode* prev = first->prev();
   BaseNode* next = last->next();
 
-  if (_firstNode == first)
+  if (_nodeList._first == first)
-    _firstNode = next;
+    _nodeList._first = next;
   else
     prev->_next = next;
 
-  if (_lastNode == last)
+  if (_nodeList._last == last)
-    _lastNode  = prev;
+    _nodeList._last  = prev;
   else
     next->_prev = prev;
 
@@ -368,7 +367,7 @@ Error BaseBuilder::section(Section* section) {
     if (node->_nextSection)
       _cursor = node->_nextSection->_prev;
     else
-      _cursor = _lastNode;
+      _cursor = _nodeList.last();
   }
 
   return kErrorOk;
@@ -378,7 +377,7 @@ void BaseBuilder::updateSectionLinks() noexcept {
   if (!_dirtySectionLinks)
     return;
 
-  BaseNode* node_ = _firstNode;
+  BaseNode* node_ = _nodeList.first();
   SectionNode* currentSection = nullptr;
 
   while (node_) {
@@ -758,7 +757,7 @@ Error BaseBuilder::comment(const char* data, size_t size) {
 
 Error BaseBuilder::serializeTo(BaseEmitter* dst) {
   Error err = kErrorOk;
-  BaseNode* node_ = _firstNode;
+  BaseNode* node_ = _nodeList.first();
 
   Operand_ opArray[Globals::kMaxOpCount];
 
@@ -854,8 +853,7 @@ Error BaseBuilder::onAttach(CodeHolder* code) noexcept {
 
   ASMJIT_ASSUME(initialSection != nullptr);
   _cursor = initialSection;
-  _firstNode = initialSection;
+  _nodeList.reset(initialSection, initialSection);
-  _lastNode = initialSection;
   initialSection->setFlags(NodeFlags::kIsActive);
 
   return kErrorOk;
@@ -873,8 +871,7 @@ Error BaseBuilder::onDetach(CodeHolder* code) noexcept {
 
   _nodeFlags = NodeFlags::kNone;
   _cursor = nullptr;
-  _firstNode = nullptr;
+  _nodeList.reset();
-  _lastNode = nullptr;
 
   return Base::onDetach(code);
 }

src/asmjit/core/builder.h

@@ -109,7 +109,7 @@ enum class NodeFlags : uint8_t {
 };
 ASMJIT_DEFINE_ENUM_FLAGS(NodeFlags)
 
-//! Type of the sentinel (purery informative purpose).
+//! Type of the sentinel (purely informative purpose).
 enum class SentinelType : uint8_t {
   //! Type of the sentinel is not known.
   kUnknown = 0u,
@@ -117,6 +117,60 @@ enum class SentinelType : uint8_t {
   kFuncEnd = 1u
 };
 
+//! Node list.
+//!
+//! A double-linked list of pointers to \ref BaseNode, managed by \ref BaseBuilder or \ref BaseCompiler.
+//!
+//! \note At the moment NodeList is just a view, but it's planned that it will get more functionality in the future.
+class NodeList {
+public:
+  //! \name Members
+  //! \{
+
+  //! First node in the list or nullptr if there are no nodes in the list.
+  BaseNode* _first = nullptr;
+  //! Last node in the list or nullptr if there are no nodes in the list.
+  BaseNode* _last = nullptr;
+
+  //! \}
+
+  //! \name Construction & Destruction
+  //! \{
+
+  ASMJIT_INLINE_NODEBUG NodeList() noexcept {}
+
+  ASMJIT_INLINE_NODEBUG NodeList(BaseNode* first, BaseNode* last) noexcept
+    : _first(first),
+      _last(last) {}
+
+  //! \}
+
+  //! \name Reset
+  //! \{
+
+  ASMJIT_INLINE_NODEBUG void reset() noexcept {
+    _first = nullptr;
+    _last = nullptr;
+  }
+
+  ASMJIT_INLINE_NODEBUG void reset(BaseNode* first, BaseNode* last) noexcept {
+    _first = first;
+    _last = last;
+  }
+
+  //! \}
+
+  //! \name Accessors
+  //! \{
+
+  ASMJIT_INLINE_NODEBUG bool empty() const noexcept { return _first == nullptr; }
+
+  ASMJIT_INLINE_NODEBUG BaseNode* first() const noexcept { return _first; }
+  ASMJIT_INLINE_NODEBUG BaseNode* last() const noexcept { return _last; }
+
+  //! \}
+};
+
 //! Builder interface.
 //!
 //! `BaseBuilder` interface was designed to be used as a \ref BaseAssembler replacement in case pre-processing or
@@ -153,10 +207,8 @@ public:
 
   //! Current node (cursor).
   BaseNode* _cursor = nullptr;
-  //! First node of the current section.
+  //! First and last nodes.
-  BaseNode* _firstNode = nullptr;
+  NodeList _nodeList;
-  //! Last node of the current section.
-  BaseNode* _lastNode = nullptr;
 
   //! Flags assigned to each new node.
   NodeFlags _nodeFlags = NodeFlags::kNone;
@@ -178,10 +230,12 @@ public:
   //! \name Node Management
   //! \{
 
+  ASMJIT_INLINE_NODEBUG NodeList nodeList() const noexcept { return _nodeList; }
+
   //! Returns the first node.
-  ASMJIT_INLINE_NODEBUG BaseNode* firstNode() const noexcept { return _firstNode; }
+  ASMJIT_INLINE_NODEBUG BaseNode* firstNode() const noexcept { return _nodeList.first(); }
   //! Returns the last node.
-  ASMJIT_INLINE_NODEBUG BaseNode* lastNode() const noexcept { return _lastNode; }
+  ASMJIT_INLINE_NODEBUG BaseNode* lastNode() const noexcept { return _nodeList.last(); }
 
   //! Allocates and instantiates a new node of type `T` and returns its instance. If the allocation fails `nullptr`
   //! is returned.