[IR] add positon member in block. (#54565)

paddle/ir/core/block.cc

@@ -38,4 +38,10 @@ void Block::clear() {
     ops_.pop_back();
   }
 }
+
+void Block::SetParent(Region *parent, Region::iterator position) {
+  parent_ = parent;
+  position_ = position;
+}
+
 }  // namespace ir

paddle/ir/core/block.h

@@ -17,8 +17,9 @@
 #include <cstddef>
 #include <list>
 
+#include "paddle/ir/core/region.h"
+
 namespace ir {
-class Region;
 class Operation;
 
 class Block {
@@ -47,16 +48,19 @@ class Block {
   void push_front(Operation *op);
   iterator insert(const_iterator iterator, Operation *op);
   void clear();
+  operator Region::iterator() { return position_; }
 
  private:
   Block(Block &) = delete;
   Block &operator=(const Block &) = delete;
 
+  // Allow access to 'SetParent'.
   friend class Region;
-  void SetParent(Region *parent) { parent_ = parent; }
+  void SetParent(Region *parent, Region::iterator position);
 
  private:
-  Region *parent_;              // not owned
+  Region *parent_;  // not owned
+  Region::iterator position_;
   std::list<Operation *> ops_;  // owned
 };
 }  // namespace ir

paddle/ir/core/operation.cc

@@ -236,4 +236,9 @@ Region &Operation::GetRegion(unsigned index) {
   return regions_[index];
 }
 
+void Operation::SetParent(Block *parent, const Block::iterator &position) {
+  parent_ = parent;
+  position_ = position;
+}
+
 }  // namespace ir

paddle/ir/core/operation.h

@@ -112,11 +112,9 @@ class alignas(8) Operation final {
     }
   };
 
+  // Allow access to 'SetParent'.
   friend class Block;
-  void SetParent(Block *parent, const Block::iterator &position) {
-    parent_ = parent;
-    position_ = position;
-  }
+  void SetParent(Block *parent, const Block::iterator &position);
 
   template <typename T>
   struct CastUtil<

paddle/ir/core/region.cc

@@ -18,27 +18,22 @@
 namespace ir {
 Region::~Region() { clear(); }
 
-void Region::push_back(Block *block) {
-  block->SetParent(this);
-  blocks_.push_back(block);
-}
+void Region::push_back(Block *block) { insert(blocks_.end(), block); }
 
 void Region::emplace_back() { push_back(new Block); }
 
-void Region::push_front(Block *block) {
-  block->SetParent(this);
-  blocks_.push_front(block);
-}
+void Region::push_front(Block *block) { insert(blocks_.begin(), block); }
 
 Region::iterator Region::insert(const_iterator position, Block *block) {
-  block->SetParent(this);
-  return blocks_.insert(position, block);
+  Region::iterator iter = blocks_.insert(position, block);
+  block->SetParent(this, iter);
+  return iter;
 }
 void Region::TakeBody(Region &&other) {
   clear();
   blocks_.swap(other.blocks_);
-  for (auto &block : blocks_) {
-    block->SetParent(this);
+  for (auto iter = blocks_.begin(); iter != blocks_.end(); ++iter) {
+    (*iter)->SetParent(this, iter);
   }
 }