Don't assert if we can't constant fold extract/insertvalue

A non-constant-foldable static initializer expression containing insertvalue or
extractvalue had been causing an assert:

  Constants.cpp:1971: Assertion `FC && "ExtractValue constant expr couldn't be
                                 folded!"' failed.

Now we report a more-sensible "Unsupported expression in static initializer"
error instead.

Fixes PR15417.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186044 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/Constants.cpp

@@ -1954,14 +1954,22 @@ Constant *ConstantExpr::getShuffleVector(Constant *V1, Constant *V2,
 
 Constant *ConstantExpr::getInsertValue(Constant *Agg, Constant *Val,
                                        ArrayRef<unsigned> Idxs) {
+  assert(Agg->getType()->isFirstClassType() &&
+         "Non-first-class type for constant insertvalue expression");
+
   assert(ExtractValueInst::getIndexedType(Agg->getType(),
                                           Idxs) == Val->getType() &&
          "insertvalue indices invalid!");
-  assert(Agg->getType()->isFirstClassType() &&
-         "Non-first-class type for constant insertvalue expression");
-  Constant *FC = ConstantFoldInsertValueInstruction(Agg, Val, Idxs);
-  assert(FC && "insertvalue constant expr couldn't be folded!");
-  return FC;
+  Type *ReqTy = Val->getType();
+
+  if (Constant *FC = ConstantFoldInsertValueInstruction(Agg, Val, Idxs))
+    return FC;
+
+  Constant *ArgVec[] = { Agg, Val };
+  const ExprMapKeyType Key(Instruction::InsertValue, ArgVec, 0, 0, Idxs);
+
+  LLVMContextImpl *pImpl = Agg->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
 }
 
 Constant *ConstantExpr::getExtractValue(Constant *Agg,
@@ -1975,9 +1983,14 @@ Constant *ConstantExpr::getExtractValue(Constant *Agg,
 
   assert(Agg->getType()->isFirstClassType() &&
          "Non-first-class type for constant extractvalue expression");
-  Constant *FC = ConstantFoldExtractValueInstruction(Agg, Idxs);
-  assert(FC && "ExtractValue constant expr couldn't be folded!");
-  return FC;
+  if (Constant *FC = ConstantFoldExtractValueInstruction(Agg, Idxs))
+    return FC;
+
+  Constant *ArgVec[] = { Agg };
+  const ExprMapKeyType Key(Instruction::ExtractValue, ArgVec, 0, 0, Idxs);
+
+  LLVMContextImpl *pImpl = Agg->getContext().pImpl;
+  return pImpl->ExprConstants.getOrCreate(ReqTy, Key);
 }
 
 Constant *ConstantExpr::getNeg(Constant *C, bool HasNUW, bool HasNSW) {

test/Other/nonconst-static-ev.ll

@@ -0,0 +1,8 @@
+; RUN: not llc < %s 2> %t
+; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
+
+@0 = global i8 extractvalue ([1 x i8] select (i1 ptrtoint (i32* @1 to i1), [1 x i8] [ i8 1 ], [1 x i8] [ i8 2 ]), 0)
+@1 = external global i32
+
+; CHECK-ERRORS: Unsupported expression in static initializer: extractvalue
+

test/Other/nonconst-static-iv.ll

@@ -0,0 +1,8 @@
+; RUN: not llc < %s 2> %t
+; RUN: FileCheck --check-prefix=CHECK-ERRORS < %t %s
+
+@0 = global i8 insertvalue( { i8 } select (i1 ptrtoint (i32* @1 to i1), { i8 } { i8 1 }, { i8 } { i8 2 }), i8 0, 0)
+@1 = external global i32
+
+; CHECK-ERRORS: Unsupported expression in static initializer: insertvalue
+