From efa158377fcc6b8ddd8115bcd0268dd198e52137 Mon Sep 17 00:00:00 2001
From: Xiao <jumormt@163.com>
Date: Wed, 25 Dec 2024 16:38:27 +1100
Subject: [PATCH] add process unreachable bbs (#1619) to resolve issue #1618

* add process unreachable bbs

* add process unreachable bbs

* add process unreachable bbs

* cache fun2domtree
---
 svf-llvm/include/SVF-LLVM/ICFGBuilder.h |  2 +-
 svf-llvm/include/SVF-LLVM/LLVMModule.h  |  4 ++++
 svf-llvm/lib/ICFGBuilder.cpp            | 23 +++++++++++------------
 svf-llvm/lib/LLVMLoopAnalysis.cpp       |  3 +--
 svf-llvm/lib/LLVMModule.cpp             | 12 ++++++++++--
 svf-llvm/lib/LLVMUtil.cpp               |  3 +--
 6 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/svf-llvm/include/SVF-LLVM/ICFGBuilder.h b/svf-llvm/include/SVF-LLVM/ICFGBuilder.h
index 1367568e2..6ce771c2a 100644
--- a/svf-llvm/include/SVF-LLVM/ICFGBuilder.h
+++ b/svf-llvm/include/SVF-LLVM/ICFGBuilder.h
@@ -75,7 +75,7 @@ class ICFGBuilder
     ///@{
     void processFunEntry(const Function*  fun, WorkList& worklist);
 
-    void processNoPrecessorBasicBlocks(const Function*  fun, WorkList& worklist);
+    void processUnreachableFromEntry(const Function*  fun, WorkList& worklist);
 
     void processFunBody(WorkList& worklist);
 
diff --git a/svf-llvm/include/SVF-LLVM/LLVMModule.h b/svf-llvm/include/SVF-LLVM/LLVMModule.h
index be1c14797..82d2cafec 100644
--- a/svf-llvm/include/SVF-LLVM/LLVMModule.h
+++ b/svf-llvm/include/SVF-LLVM/LLVMModule.h
@@ -109,6 +109,8 @@ class LLVMModuleSet
     FunToFunExitNodeMapTy FunToFunExitNodeMap; ///< map a function to its FunEntryICFGNode
     CallGraph* callgraph;
 
+    Map<const Function*, DominatorTree> FunToDominatorTree;
+
     /// Constructor
     LLVMModuleSet();
 
@@ -397,6 +399,8 @@ class LLVMModuleSet
         return icfg;
     }
 
+    DominatorTree& getDomTree(const Function* fun);
+
 private:
     /// Create SVFTypes
     SVFType* addSVFTypeInfo(const Type* t);
diff --git a/svf-llvm/lib/ICFGBuilder.cpp b/svf-llvm/lib/ICFGBuilder.cpp
index 4dde63ae7..2a9f0939c 100644
--- a/svf-llvm/lib/ICFGBuilder.cpp
+++ b/svf-llvm/lib/ICFGBuilder.cpp
@@ -70,7 +70,7 @@ ICFG* ICFGBuilder::build()
                 continue;
             WorkList worklist;
             processFunEntry(fun,worklist);
-            processNoPrecessorBasicBlocks(fun, worklist);
+            processUnreachableFromEntry(fun, worklist);
             processFunBody(worklist);
             processFunExit(fun);
 
@@ -122,21 +122,20 @@ void ICFGBuilder::processFunEntry(const Function*  fun, WorkList& worklist)
 }
 
 /*!
- * bbs with no predecessors
+ * bbs unreachable from function entry
  */
-void ICFGBuilder::processNoPrecessorBasicBlocks(const Function* fun, WorkList& worklist)
+void ICFGBuilder::processUnreachableFromEntry(const Function* fun, WorkList& worklist)
 {
-    for (const auto& bb: *fun)
+    SVFLoopAndDomInfo* pInfo =
+        llvmModuleSet()->getSVFFunction(fun)->getLoopAndDomInfo();
+    for (const auto& bb : *fun)
     {
-        for (const auto& inst: bb)
+        if (pInfo->isUnreachable(llvmModuleSet()->getSVFBasicBlock(&bb)) &&
+            !visited.count(&bb.front()))
         {
-            if (LLVMUtil::isNoPrecessorBasicBlock(inst.getParent()) &&
-                    !visited.count(&inst))
-            {
-                visited.insert(&inst);
-                (void)addBlockICFGNode(&inst);
-                worklist.push(&inst);
-            }
+            visited.insert(&bb.front());
+            (void)addBlockICFGNode(&bb.front());
+            worklist.push(&bb.front());
         }
     }
 }
diff --git a/svf-llvm/lib/LLVMLoopAnalysis.cpp b/svf-llvm/lib/LLVMLoopAnalysis.cpp
index 58b2fca62..c2a9d842e 100644
--- a/svf-llvm/lib/LLVMLoopAnalysis.cpp
+++ b/svf-llvm/lib/LLVMLoopAnalysis.cpp
@@ -48,7 +48,6 @@ using namespace SVFUtil;
  */
 void LLVMLoopAnalysis::buildLLVMLoops(SVFModule *mod, ICFG* icfg)
 {
-    llvm::DominatorTree DT = llvm::DominatorTree();
     std::vector<const Loop *> loop_stack;
     for (Module& M : LLVMModuleSet::getLLVMModuleSet()->getLLVMModules())
     {
@@ -59,7 +58,7 @@ void LLVMLoopAnalysis::buildLLVMLoops(SVFModule *mod, ICFG* icfg)
             if (func->isDeclaration()) continue;
             // do not analyze external call
             if (SVFUtil::isExtCall(svffun)) continue;
-            DT.recalculate(const_cast<Function&>(*func));
+            llvm::DominatorTree& DT = LLVMModuleSet::getLLVMModuleSet()->getDomTree(func);
             llvm::LoopInfoBase<llvm::BasicBlock, llvm::Loop> loopInfo;
             std::vector<const Loop*> llvmLoops;
             loopInfo.analyze(DT);
diff --git a/svf-llvm/lib/LLVMModule.cpp b/svf-llvm/lib/LLVMModule.cpp
index dc559368b..3cd05d0ac 100644
--- a/svf-llvm/lib/LLVMModule.cpp
+++ b/svf-llvm/lib/LLVMModule.cpp
@@ -99,6 +99,15 @@ ObjTypeInference* LLVMModuleSet::getTypeInference()
     return typeInference;
 }
 
+DominatorTree& LLVMModuleSet::getDomTree(const SVF::Function* fun)
+{
+    auto it = FunToDominatorTree.find(fun);
+    if(it != FunToDominatorTree.end()) return it->second;
+    DominatorTree& dt = FunToDominatorTree[fun];
+    dt.recalculate(const_cast<Function&>(*fun));
+    return dt;
+}
+
 SVFModule* LLVMModuleSet::buildSVFModule(Module &mod)
 {
     LLVMModuleSet* mset = getLLVMModuleSet();
@@ -407,9 +416,8 @@ void LLVMModuleSet::initDomTree(SVFFunction* svffun, const Function* fun)
     if (fun->isDeclaration())
         return;
     //process and stored dt & df
-    DominatorTree dt;
     DominanceFrontier df;
-    dt.recalculate(const_cast<Function&>(*fun));
+    DominatorTree& dt = getDomTree(fun);
     df.analyze(dt);
     LoopInfo loopInfo = LoopInfo(dt);
     PostDominatorTree pdt = PostDominatorTree(const_cast<Function&>(*fun));
diff --git a/svf-llvm/lib/LLVMUtil.cpp b/svf-llvm/lib/LLVMUtil.cpp
index 10bde5152..315de6a36 100644
--- a/svf-llvm/lib/LLVMUtil.cpp
+++ b/svf-llvm/lib/LLVMUtil.cpp
@@ -75,8 +75,7 @@ void LLVMUtil::getFunReachableBBs (const Function* fun, std::vector<const SVFBas
 {
     assert(!SVFUtil::isExtCall(LLVMModuleSet::getLLVMModuleSet()->getSVFFunction(fun)) && "The calling function cannot be an external function.");
     //initial DominatorTree
-    DominatorTree dt;
-    dt.recalculate(const_cast<Function&>(*fun));
+    DominatorTree& dt = LLVMModuleSet::getLLVMModuleSet()->getDomTree(fun);
 
     Set<const BasicBlock*> visited;
     std::vector<const BasicBlock*> bbVec;