修正分支指令的 Use 更新

Author: Lord-Turmoil

libs/llvm/src/ir/value/User.cpp

@@ -46,7 +46,11 @@ ValuePtr User::RemoveUse(ValuePtr use) {
 ValuePtr User::ReplaceUse(ValuePtr oldValue, ValuePtr newValue) {
     for (auto it = _useList.begin(); it != _useList.end(); ++it) {
         if ((*it)->GetValue() == oldValue) {
-            *it = Use::New(this, newValue);
+            if (newValue) {
+                *it = Use::New(this, newValue);
+            } else {
+                _useList.erase(it);
+            }
             return oldValue;
         }
     }

libs/llvm/src/ir/value/inst/Instructions.cpp

@@ -1,9 +1,9 @@
 #include "llvm/ir/value/inst/Instructions.h"
-#include "llvm/utils.h"
 #include "llvm/ir/LlvmContext.h"
 #include "llvm/ir/Type.h"
 #include "llvm/ir/value/BasicBlock.h"
 #include "llvm/ir/value/Function.h"
+#include "llvm/utils.h"
 
 #pragma region AllocaInst
 
@@ -73,27 +73,31 @@ BranchInstPtr BranchInst::New(ValuePtr condition, BasicBlockPtr trueBlock,
 }
 
 BasicBlockPtr BranchInst::SetTrueBlock(BasicBlockPtr block) {
+    BasicBlockPtr old = _trueBlock;
+
     if (_trueBlock) {
         ReplaceOperand(_trueBlock, block);
-        return _trueBlock;
     }
-
     _trueBlock = block;
-    AddOperand(_trueBlock);
+    if (_trueBlock) {
+        AddOperand(_trueBlock);
+    }
 
-    return nullptr;
+    return old;
 }
 
 BasicBlockPtr BranchInst::SetFalseBlock(BasicBlockPtr block) {
+    BasicBlockPtr old = _falseBlock;
+
     if (_falseBlock) {
         ReplaceOperand(_falseBlock, block);
-        return _falseBlock;
     }
-
     _falseBlock = block;
-    AddOperand(_falseBlock);
+    if (_falseBlock) {
+        AddOperand(_falseBlock);
+    }
 
-    return nullptr;
+    return old;
 }
 
 #pragma endregion
@@ -119,14 +123,17 @@ JumpInstPtr JumpInst::New(LlvmContextPtr context) {
 }
 
 BasicBlockPtr JumpInst::SetTarget(BasicBlockPtr block) {
+    BasicBlockPtr old = _target;
+
     if (_target) {
         ReplaceOperand(_target, block);
-        return _target;
     }
-
     _target = block;
-    AddOperand(_target);
-    return nullptr;
+    if (_target) {
+        AddOperand(_target);
+    }
+
+    return old;
 }
 
 #pragma endregion