[midend-BuildCFG]修复逻辑

src/include/midend/Pass/Optimize/BuildCFG.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include "IR.h"
+#include "Pass.h"
+#include <queue>
+#include <set>
+
+namespace sysy {
+
+class BuildCFG : public OptimizationPass {
+public:
+  static void *ID;
+  BuildCFG() : OptimizationPass("BuildCFG", Granularity::Function) {}
+  bool runOnFunction(Function *F, AnalysisManager &AM) override;
+  void getAnalysisUsage(std::set<void *> &analysisDependencies, std::set<void *> &analysisInvalidations) const override;
+  void *getPassID() const override { return &ID; }
+
+};
+
+} // namespace sysy

src/midend/CMakeLists.txt

@@ -11,6 +11,7 @@ add_library(midend_lib STATIC
     Pass/Optimize/Reg2Mem.cpp
     Pass/Optimize/SysYIRCFGOpt.cpp
     Pass/Optimize/SCCP.cpp
+    Pass/Optimize/BuildCFG.cpp
 )
 
 # 包含中端模块所需的头文件路径

src/midend/Pass/Optimize/BuildCFG.cpp

@@ -0,0 +1,79 @@
+#include "BuildCFG.h"
+#include "Dom.h"
+#include "Liveness.h"
+#include <iostream>
+#include <queue>
+#include <set>
+
+namespace sysy {
+
+void *BuildCFG::ID = (void *)&BuildCFG::ID; // 定义唯一的 Pass ID
+
+// 声明Pass的分析使用
+void BuildCFG::getAnalysisUsage(std::set<void *> &analysisDependencies, std::set<void *> &analysisInvalidations) const {
+  // BuildCFG不依赖其他分析
+  // analysisDependencies.insert(&DominatorTreeAnalysisPass::ID); // 错误的例子
+
+  // BuildCFG会使所有依赖于CFG的分析结果失效，所以它必须声明这些失效
+  analysisInvalidations.insert(&DominatorTreeAnalysisPass::ID);
+  analysisInvalidations.insert(&LivenessAnalysisPass::ID);
+}
+
+bool BuildCFG::runOnFunction(Function *F, AnalysisManager &AM) {
+  if (DEBUG) {
+    std::cout << "Running BuildCFG pass on function: " << F->getName() << std::endl;
+  }
+
+  bool changed = false;
+
+  // 1. 清空所有基本块的前驱和后继列表
+  for (auto &bb : F->getBasicBlocks()) {
+    bb->clearPredecessors();
+    bb->clearSuccessors();
+  }
+
+  // 2. 遍历每个基本块，重建CFG
+  for (auto &bb : F->getBasicBlocks()) {
+    // 获取基本块的最后一条指令
+    auto &inst = *bb->terminator();
+    Instruction *termInst = inst.get();
+    // 确保基本块有终结指令
+    if (!termInst) {
+      continue;
+    }
+
+    // 根据终结指令类型，建立前驱后继关系
+    if (termInst->isBranch()) {
+      // 无条件跳转
+      if (termInst->isUnconditional()) {
+        auto brInst = dynamic_cast<UncondBrInst *>(termInst);
+        BasicBlock *succ = dynamic_cast<BasicBlock *>(brInst->getBlock());
+        assert(succ && "Branch instruction's target must be a BasicBlock");
+        bb->addSuccessor(succ);
+        succ->addPredecessor(bb.get());
+        changed = true;
+
+        // 条件跳转
+      } else if (termInst->isConditional()) {
+        auto brInst = dynamic_cast<CondBrInst *>(termInst);
+        BasicBlock *trueSucc = dynamic_cast<BasicBlock *>(brInst->getThenBlock());
+        BasicBlock *falseSucc = dynamic_cast<BasicBlock *>(brInst->getElseBlock());
+
+        assert(trueSucc && falseSucc && "Branch instruction's targets must be BasicBlocks");
+
+        bb->addSuccessor(trueSucc);
+        trueSucc->addPredecessor(bb.get());
+        bb->addSuccessor(falseSucc);
+        falseSucc->addPredecessor(bb.get());
+        changed = true;
+      }
+    } else if (auto retInst = dynamic_cast<ReturnInst *>(termInst)) {
+      // RetInst没有后继，无需处理
+      // ...
+    }
+  }
+
+  return changed;
+}
+
+} // namespace sysy

src/midend/Pass/Pass.cpp

@@ -6,6 +6,7 @@
 #include "Mem2Reg.h"
 #include "Reg2Mem.h"
 #include "SCCP.h"
+#include "BuildCFG.h"
 #include "Pass.h"
 #include <iostream>
 #include <queue>
@@ -35,10 +36,12 @@ void PassManager::runOptimizationPipeline(Module* moduleIR, IRBuilder* builderIR
         3. 添加优化passid
     */
     // 注册分析遍
-    registerAnalysisPass<sysy::DominatorTreeAnalysisPass>();
-    registerAnalysisPass<sysy::LivenessAnalysisPass>();
+    registerAnalysisPass<DominatorTreeAnalysisPass>();
+    registerAnalysisPass<LivenessAnalysisPass>();
 
     // 注册优化遍
+    registerOptimizationPass<BuildCFG>();
+    
     registerOptimizationPass<SysYDelInstAfterBrPass>();
     registerOptimizationPass<SysYDelNoPreBLockPass>();
     registerOptimizationPass<SysYBlockMergePass>();
@@ -58,6 +61,15 @@ void PassManager::runOptimizationPipeline(Module* moduleIR, IRBuilder* builderIR
       if (DEBUG) std::cout << "Applying -O1 optimizations.\n";
       if (DEBUG) std::cout << "--- Running custom optimization sequence ---\n";
 
+      if(DEBUG) {
+        std::cout << "=== IR Before CFGOpt Optimizations ===\n";
+        printPasses();
+      }
+
+      this->clearPasses();
+      this->addPass(&BuildCFG::ID);
+      this->run();
+
       this->clearPasses(); 
       this->addPass(&SysYDelInstAfterBrPass::ID);
       this->addPass(&SysYDelNoPreBLockPass::ID);