[LLVM][IR] Emit diagnostic for invalid pointee type for constant GEP. (#165383)

Fixes #165137

Author: paulwalker-arm

llvm/lib/AsmParser/LLParser.cpp

@@ -4538,6 +4538,9 @@ bool LLParser::parseValID(ValID &ID, PerFunctionState *PFS, Type *ExpectedTy) {
       if (!Indices.empty() && !Ty->isSized(&Visited))
         return error(ID.Loc, "base element of getelementptr must be sized");
 
+      if (!ConstantExpr::isSupportedGetElementPtr(Ty))
+        return error(ID.Loc, "invalid base element for constant getelementptr");
+
       if (!GetElementPtrInst::getIndexedType(Ty, Indices))
         return error(ID.Loc, "invalid getelementptr indices");
 

llvm/test/Assembler/constant-getelementptr-scalable_pointee.ll

@@ -0,0 +1,8 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+; Test the case of an invalid pointee type on a constant GEP
+
+; CHECK: invalid base element for constant getelementptr
+
+define ptr @test_scalable_vector_gep(ptr %a) {
+  ret ptr getelementptr (<vscale x 1 x i8>, ptr @a, i64 1)
+}