[llvm] r216255 - [dfsan] Fix non-determinism bug in non-zero label check annotator.

[Peter Collingbourne]

Author: pcc
Date: Thu Aug 21 20:18:18 2014
New Revision: 216255

URL: http://llvm.org/viewvc/llvm-project?rev=216255&view=rev
Log:
[dfsan] Fix non-determinism bug in non-zero label check annotator.

We now use a std::vector instead of a DenseSet to store the list of
label checks so that we can iterate over it deterministically.

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
    llvm/trunk/test/Instrumentation/DataFlowSanitizer/debug-nonzero-labels.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp?rev=216255&r1=216254&r2=216255&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp Thu Aug 21 20:18:18 2014
@@ -280,7 +280,7 @@ struct DFSanFunction {
   DenseMap<AllocaInst *, AllocaInst *> AllocaShadowMap;
   std::vector<std::pair<PHINode *, PHINode *> > PHIFixups;
   DenseSet<Instruction *> SkipInsts;
-  DenseSet<Value *> NonZeroChecks;
+  std::vector<Value *> NonZeroChecks;
   bool AvoidNewBlocks;
 
   struct CachedCombinedShadow {
@@ -802,18 +802,16 @@ bool DataFlowSanitizer::runOnModule(Modu
     // yet).  To make our life easier, do this work in a pass after the main
     // instrumentation.
     if (ClDebugNonzeroLabels) {
-      for (DenseSet<Value *>::iterator i = DFSF.NonZeroChecks.begin(),
-                                       e = DFSF.NonZeroChecks.end();
-           i != e; ++i) {
+      for (Value *V : DFSF.NonZeroChecks) {
         Instruction *Pos;
-        if (Instruction *I = dyn_cast<Instruction>(*i))
+        if (Instruction *I = dyn_cast<Instruction>(V))
           Pos = I->getNextNode();
         else
           Pos = DFSF.F->getEntryBlock().begin();
         while (isa<PHINode>(Pos) || isa<AllocaInst>(Pos))
           Pos = Pos->getNextNode();
         IRBuilder<> IRB(Pos);
-        Value *Ne = IRB.CreateICmpNE(*i, DFSF.DFS.ZeroShadow);
+        Value *Ne = IRB.CreateICmpNE(V, DFSF.DFS.ZeroShadow);
         BranchInst *BI = cast<BranchInst>(SplitBlockAndInsertIfThen(
             Ne, Pos, /*Unreachable=*/false, ColdCallWeights));
         IRBuilder<> ThenIRB(BI);
@@ -878,7 +876,7 @@ Value *DFSanFunction::getShadow(Value *V
         break;
       }
       }
-      NonZeroChecks.insert(Shadow);
+      NonZeroChecks.push_back(Shadow);
     } else {
       Shadow = DFS.ZeroShadow;
     }
@@ -1138,7 +1136,7 @@ void DFSanVisitor::visitLoadInst(LoadIns
     Shadow = DFSF.combineShadows(Shadow, PtrShadow, &LI);
   }
   if (Shadow != DFSF.DFS.ZeroShadow)
-    DFSF.NonZeroChecks.insert(Shadow);
+    DFSF.NonZeroChecks.push_back(Shadow);
 
   DFSF.setShadow(&LI, Shadow);
 }
@@ -1480,7 +1478,7 @@ void DFSanVisitor::visitCallSite(CallSit
       LoadInst *LI = NextIRB.CreateLoad(DFSF.getRetvalTLS());
       DFSF.SkipInsts.insert(LI);
       DFSF.setShadow(CS.getInstruction(), LI);
-      DFSF.NonZeroChecks.insert(LI);
+      DFSF.NonZeroChecks.push_back(LI);
     }
   }
 
@@ -1534,7 +1532,7 @@ void DFSanVisitor::visitCallSite(CallSit
           ExtractValueInst::Create(NewCS.getInstruction(), 1, "", Next);
       DFSF.SkipInsts.insert(ExShadow);
       DFSF.setShadow(ExVal, ExShadow);
-      DFSF.NonZeroChecks.insert(ExShadow);
+      DFSF.NonZeroChecks.push_back(ExShadow);
 
       CS.getInstruction()->replaceAllUsesWith(ExVal);
     }

Modified: llvm/trunk/test/Instrumentation/DataFlowSanitizer/debug-nonzero-labels.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/DataFlowSanitizer/debug-nonzero-labels.ll?rev=216255&r1=216254&r2=216255&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/DataFlowSanitizer/debug-nonzero-labels.ll (original)
+++ llvm/trunk/test/Instrumentation/DataFlowSanitizer/debug-nonzero-labels.ll Thu Aug 21 20:18:18 2014
@@ -3,13 +3,16 @@ target datalayout = "e-p:64:64:64-i1:8:8
 
 declare i32 @g()
 
-; CHECK: define { i32, i16 } @"dfs$f"(i32, i16)
-define i32 @f(i32) {
+; CHECK: define { i32, i16 } @"dfs$f"(i32, i32, i16, i16)
+define i32 @f(i32, i32) {
   ; CHECK: [[LOCALLABELALLOCA:%.*]] = alloca i16
-  ; CHECK: [[ARGCMP:%.*]] = icmp ne i16 %1, 0
-  ; CHECK: br i1 [[ARGCMP]]
   %i = alloca i32
-  store i32 %0, i32* %i
+  ; CHECK: [[ARGCMP1:%.*]] = icmp ne i16 %3, 0
+  ; CHECK: br i1 [[ARGCMP1]]
+  ; CHECK: [[ARGCMP2:%.*]] = icmp ne i16 %2, 0
+  ; CHECK: br i1 [[ARGCMP2]]
+  %x = add i32 %0, %1
+  store i32 %x, i32* %i
   ; CHECK: [[CALL:%.*]] = call { i32, i16 } @"dfs$g"()
   ; CHECK: [[CALLLABEL:%.*]] = extractvalue { i32, i16 } [[CALL]], 1
   ; CHECK: [[CALLCMP:%.*]] = icmp ne i16 [[CALLLABEL]], 0