[cfe-commits] r76450 - in /cfe/trunk: include/clang/Analysis/PathSensitive/GRCoreEngine.h lib/Analysis/GRCoreEngine.cpp lib/Analysis/GRExprEngine.cpp

[Ted Kremenek]

Author: kremenek
Date: Mon Jul 20 13:44:36 2009
New Revision: 76450

URL: http://llvm.org/viewvc/llvm-project?rev=76450&view=rev
Log:
Enhance GRBranchNodeBuilderImpl (part of GRCoreEngine) to understand the case
where the true or false CFGBlock* for a branch could be NULL. This will handle
the case where we can determine during CFG construction that a branch is
infeasible.

Modified:
    cfe/trunk/include/clang/Analysis/PathSensitive/GRCoreEngine.h
    cfe/trunk/lib/Analysis/GRCoreEngine.cpp
    cfe/trunk/lib/Analysis/GRExprEngine.cpp

Modified: cfe/trunk/include/clang/Analysis/PathSensitive/GRCoreEngine.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Analysis/PathSensitive/GRCoreEngine.h?rev=76450&r1=76449&r2=76450&view=diff

==============================================================================
--- cfe/trunk/include/clang/Analysis/PathSensitive/GRCoreEngine.h (original)
+++ cfe/trunk/include/clang/Analysis/PathSensitive/GRCoreEngine.h Mon Jul 20 13:44:36 2009
@@ -311,12 +311,15 @@
   
   bool GeneratedTrue;
   bool GeneratedFalse;
+  bool InFeasibleTrue;
+  bool InFeasibleFalse;
   
 public:
   GRBranchNodeBuilderImpl(CFGBlock* src, CFGBlock* dstT, CFGBlock* dstF,
                           ExplodedNodeImpl* pred, GRCoreEngineImpl* e) 
   : Eng(*e), Src(src), DstT(dstT), DstF(dstF), Pred(pred),
-    GeneratedTrue(false), GeneratedFalse(false) {}
+    GeneratedTrue(false), GeneratedFalse(false),
+    InFeasibleTrue(!DstT), InFeasibleFalse(!DstF) {}
   
   ~GRBranchNodeBuilderImpl();
   
@@ -331,8 +334,14 @@
   }    
   
   void markInfeasible(bool branch) {
-    if (branch) GeneratedTrue = true;
-    else GeneratedFalse = true;
+    if (branch)
+      InFeasibleTrue = GeneratedTrue = true;
+    else
+      InFeasibleFalse = GeneratedFalse = true;
+  }
+  
+  bool isFeasible(bool branch) {
+    return branch ? !InFeasibleTrue : !InFeasibleFalse;
   }
 };
 
@@ -374,6 +383,10 @@
   void markInfeasible(bool branch) {
     NB.markInfeasible(branch);
   }
+  
+  bool isFeasible(bool branch) {
+    return NB.isFeasible(branch);
+  }
 };
   
 class GRIndirectGotoNodeBuilderImpl {

Modified: cfe/trunk/lib/Analysis/GRCoreEngine.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/GRCoreEngine.cpp?rev=76450&r1=76449&r2=76450&view=diff

==============================================================================
--- cfe/trunk/lib/Analysis/GRCoreEngine.cpp (original)
+++ cfe/trunk/lib/Analysis/GRCoreEngine.cpp Mon Jul 20 13:44:36 2009
@@ -452,7 +452,12 @@
 }
 
 ExplodedNodeImpl* GRBranchNodeBuilderImpl::generateNodeImpl(const void* State,
-                                                            bool branch) {  
+                                                            bool branch) {
+  
+  // If the branch has been marked infeasible we should not generate a node.
+  if (!isFeasible(branch))
+    return NULL;
+  
   bool IsNew;
   
   ExplodedNodeImpl* Succ =
@@ -460,8 +465,10 @@
   
   Succ->addPredecessor(Pred);
   
-  if (branch) GeneratedTrue = true;
-  else GeneratedFalse = true;  
+  if (branch)
+    GeneratedTrue = true;
+  else
+    GeneratedFalse = true;  
   
   if (IsNew) {
     Deferred.push_back(Succ);

Modified: cfe/trunk/lib/Analysis/GRExprEngine.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/GRExprEngine.cpp?rev=76450&r1=76449&r2=76450&view=diff

==============================================================================
--- cfe/trunk/lib/Analysis/GRExprEngine.cpp (original)
+++ cfe/trunk/lib/Analysis/GRExprEngine.cpp Mon Jul 20 13:44:36 2009
@@ -706,16 +706,20 @@
   }
     
   // Process the true branch.
-  if (const GRState *state = PrevState->assume(V, true))
-    builder.generateNode(MarkBranch(state, Term, true), true);
-  else
-    builder.markInfeasible(true);
+  if (builder.isFeasible(true)) {
+    if (const GRState *state = PrevState->assume(V, true))
+      builder.generateNode(MarkBranch(state, Term, true), true);
+    else
+      builder.markInfeasible(true);
+  }
       
   // Process the false branch.  
-  if (const GRState *state = PrevState->assume(V, false))
-    builder.generateNode(MarkBranch(state, Term, false), false);
-  else
-    builder.markInfeasible(false);
+  if (builder.isFeasible(false)) {
+    if (const GRState *state = PrevState->assume(V, false))
+      builder.generateNode(MarkBranch(state, Term, false), false);
+    else
+      builder.markInfeasible(false);
+  }
 }
 
 /// ProcessIndirectGoto - Called by GRCoreEngine.  Used to generate successor