[PATCH] D105653: [IR] Don't accept nullptr as GEP element type

[Nikita Popov via Phabricator via llvm-commits]

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`GetElementPtrInst::Create()` (and IRBuilder methods based on it) currently accept `nullptr` as the element type, and will fetch the element type from the pointer in that case. Remove this fallback, as it is incompatible with opaque pointers. I've removed a handful of leftover calls using this behavior as a preliminary step.

Out-of-tree code affected by this change should either pass a proper type, or can temporarily explicitly call getPointerElementType(), if the newly added assertion is encountered.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D105653

Files:
  llvm/include/llvm/IR/Instructions.h


Index: llvm/include/llvm/IR/Instructions.h
===================================================================
--- llvm/include/llvm/IR/Instructions.h
+++ llvm/include/llvm/IR/Instructions.h
@@ -956,13 +956,9 @@
                                    const Twine &NameStr = "",
                                    Instruction *InsertBefore = nullptr) {
     unsigned Values = 1 + unsigned(IdxList.size());
-    if (!PointeeType) {
-      PointeeType =
-          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
-    } else {
-      assert(cast<PointerType>(Ptr->getType()->getScalarType())
-                 ->isOpaqueOrPointeeTypeMatches(PointeeType));
-    }
+    assert(PointeeType && "Must specify element type");
+    assert(cast<PointerType>(Ptr->getType()->getScalarType())
+               ->isOpaqueOrPointeeTypeMatches(PointeeType));
     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
                                           NameStr, InsertBefore);
   }
@@ -972,13 +968,9 @@
                                    const Twine &NameStr,
                                    BasicBlock *InsertAtEnd) {
     unsigned Values = 1 + unsigned(IdxList.size());
-    if (!PointeeType) {
-      PointeeType =
-          cast<PointerType>(Ptr->getType()->getScalarType())->getElementType();
-    } else {
-      assert(cast<PointerType>(Ptr->getType()->getScalarType())
-                 ->isOpaqueOrPointeeTypeMatches(PointeeType));
-    }
+    assert(PointeeType && "Must specify element type");
+    assert(cast<PointerType>(Ptr->getType()->getScalarType())
+               ->isOpaqueOrPointeeTypeMatches(PointeeType));
     return new (Values) GetElementPtrInst(PointeeType, Ptr, IdxList, Values,
                                           NameStr, InsertAtEnd);
   }


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