[PATCH] D158939: FixProtect against null dereferences

[Akshay Khadse via Phabricator via llvm-commits]

akshaykhadse created this revision.
Herald added subscribers: pengfei, hiraditya.
Herald added a project: All.
akshaykhadse requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D158939

Files:
  llvm/lib/CodeGen/CodeGenPrepare.cpp
  llvm/lib/TableGen/TGParser.cpp
  llvm/lib/Target/X86/X86ISelLowering.cpp


Index: llvm/lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- llvm/lib/Target/X86/X86ISelLowering.cpp
+++ llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -5963,6 +5963,8 @@
     if (DAG.ComputeNumSignBits(Src, DemandedSrcElts) != NumBitsPerSrcElt)
       return false;
 
+    // Call DAG->ComputeNumSignBits(Src, DemandedSrcElts, 0U) may return 0
+    assert(NumBitsPerSrcElt != 0 && "Modulo by zero");
     assert((NumBitsPerElt % NumBitsPerSrcElt) == 0 && "Unexpected extension");
     unsigned Scale = NumBitsPerElt / NumBitsPerSrcElt;
     for (unsigned I = 0; I != NumElts; ++I)
Index: llvm/lib/TableGen/TGParser.cpp
===================================================================
--- llvm/lib/TableGen/TGParser.cpp
+++ llvm/lib/TableGen/TGParser.cpp
@@ -581,9 +581,11 @@
       ArgName = Arg->getName();
 
     // We can only specify the template argument once.
-    if (!is_contained(UnsolvedArgNames, ArgName))
+    if (!is_contained(UnsolvedArgNames, ArgName)){
+      assert(ArgName != nullptr && "ArgName must be initialized");
       return Error(Loc, "We can only specify the template argument '" +
                             ArgName->getAsUnquotedString() + "' once");
+    }
 
     ArgValueHandler(ArgName, ArgValue);
     llvm::erase_value(UnsolvedArgNames, ArgName);
Index: llvm/lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -7067,10 +7067,14 @@
 
   // Sink expensive instructions into the conditional blocks to avoid executing
   // them speculatively.
-  for (Instruction *I : TrueInstrs)
+  for (Instruction *I : TrueInstrs) {
+    assert(TrueBranch != nullptr && "TrueBranch must be initialized");
     I->moveBefore(TrueBranch);
-  for (Instruction *I : FalseInstrs)
+  }
+  for (Instruction *I : FalseInstrs) {
+    assert(FalseBranch != nullptr && "FalseBranch must be initialized");
     I->moveBefore(FalseBranch);
+  }
 
   // If we did not create a new block for one of the 'true' or 'false' paths
   // of the condition, it means that side of the branch goes to the end block


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