[clang] [Clang] Prevent null pointer dereferencein SVE tuple functions (PR #94267)

[via cfe-commits]

https://github.com/smanna12 created https://github.com/llvm/llvm-project/pull/94267

This patch replaces dyn_cast<> with cast<> for obtaining ScalableVectorType pointers in the EmitSVETupleSetOrGet() and EmitSVETupleCreate() functions to ensure that the code expects valid ScalableVectorType instances and will cause an assertion if the cast is invalid, preventing possible null pointer dereferences and improving codes safety.

>From 14e4f23d90d3a1590de5b9a1350ecf56aa89cc17 Mon Sep 17 00:00:00 2001
From: "Manna, Soumi" <soumi.manna at intel.com>
Date: Mon, 3 Jun 2024 11:17:33 -0700
Subject: [PATCH] [Clang] Prevent null pointer dereferencein SVE tuple
 functions

This patch replaces dyn_cast<> with cast<> for obtaining ScalableVectorType pointers in the EmitSVETupleSetOrGet() and EmitSVETupleCreate() functions to ensure that the code expects valid ScalableVectorType instances and will cause an assertion if the cast is invalid, preventing possible null pointer dereferences and improving codes safety.
---
 clang/lib/CodeGen/CGBuiltin.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 37d0c478e0330..3ba9f4693170f 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -10211,7 +10211,7 @@ Value *CodeGenFunction::EmitSVETupleSetOrGet(const SVETypeFlags &TypeFlags,
          "Expects TypleFlag isTupleSet or TypeFlags.isTupleSet()");
 
   unsigned I = cast<ConstantInt>(Ops[1])->getSExtValue();
-  auto *SingleVecTy = dyn_cast<llvm::ScalableVectorType>(
+  auto *SingleVecTy = cast<llvm::ScalableVectorType>(
                       TypeFlags.isTupleSet() ? Ops[2]->getType() : Ty);
   Value *Idx = ConstantInt::get(CGM.Int64Ty,
                                 I * SingleVecTy->getMinNumElements());
@@ -10226,7 +10226,7 @@ Value *CodeGenFunction::EmitSVETupleCreate(const SVETypeFlags &TypeFlags,
                                              ArrayRef<Value *> Ops) {
   assert(TypeFlags.isTupleCreate() && "Expects TypleFlag isTupleCreate");
 
-  auto *SrcTy = dyn_cast<llvm::ScalableVectorType>(Ops[0]->getType());
+  auto *SrcTy = cast<llvm::ScalableVectorType>(Ops[0]->getType());
   unsigned MinElts = SrcTy->getMinNumElements();
   Value *Call = llvm::PoisonValue::get(Ty);
   for (unsigned I = 0; I < Ops.size(); I++) {