[clang] [clang][NFC] Assert not llvm_unreachable (PR #70149)

[Nathan Sidwell via cfe-commits]

https://github.com/urnathan created https://github.com/llvm/llvm-project/pull/70149

An assert is better here.

>From 1120a9bd5490dba672898f6902e60e461792b711 Mon Sep 17 00:00:00 2001
From: Nathan Sidwell <nathan at acm.org>
Date: Tue, 24 Oct 2023 20:20:18 -0400
Subject: [PATCH] [clang][NFC] Assert not llvm_unreachable

An assert is better here.
---
 clang/lib/CodeGen/CGExprScalar.cpp | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index c25ddeff9adc3a7..7633c6b17db88eb 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -2084,11 +2084,10 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
     Value *Src = Visit(const_cast<Expr*>(E));
     llvm::Type *SrcTy = Src->getType();
     llvm::Type *DstTy = ConvertType(DestTy);
-    if (SrcTy->isPtrOrPtrVectorTy() && DstTy->isPtrOrPtrVectorTy() &&
-        SrcTy->getPointerAddressSpace() != DstTy->getPointerAddressSpace()) {
-      llvm_unreachable("wrong cast for pointers in different address spaces"
-                       "(must be an address space cast)!");
-    }
+    assert(
+        (!SrcTy->isPtrOrPtrVectorTy() || !DstTy->isPtrOrPtrVectorTy() ||
+         SrcTy->getPointerAddressSpace() == DstTy->getPointerAddressSpace()) &&
+        "Address-space cast must be used to convert address spaces");
 
     if (CGF.SanOpts.has(SanitizerKind::CFIUnrelatedCast)) {
       if (auto *PT = DestTy->getAs<PointerType>()) {