From e49c3c8f2ef97bdf256ca76f3d001eeb79361d56 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Fri, 10 Jan 2020 14:58:07 +0100
Subject: [PATCH] Sprinkle some constexpr on default ctors so the compiler can
 diagnose unused instances. NFCI.

---
 mlir/include/mlir/IR/Attributes.h        | 2 +-
 mlir/include/mlir/IR/Types.h             | 2 +-
 mlir/include/mlir/IR/Value.h             | 2 +-
 mlir/lib/Dialect/SPIRV/SPIRVOps.cpp      | 1 -
 mlir/lib/Dialect/VectorOps/VectorOps.cpp | 1 -
 5 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/mlir/include/mlir/IR/Attributes.h b/mlir/include/mlir/IR/Attributes.h
index 64b8063bdcb5..49f42affb566 100644
--- a/mlir/include/mlir/IR/Attributes.h
+++ b/mlir/include/mlir/IR/Attributes.h
@@ -69,7 +69,7 @@ public:
   using ImplType = AttributeStorage;
   using ValueType = void;
 
-  Attribute() : impl(nullptr) {}
+  constexpr Attribute() : impl(nullptr) {}
   /* implicit */ Attribute(const ImplType *impl)
       : impl(const_cast<ImplType *>(impl)) {}
 
diff --git a/mlir/include/mlir/IR/Types.h b/mlir/include/mlir/IR/Types.h
index 6246e9bedd0d..21d6493a4176 100644
--- a/mlir/include/mlir/IR/Types.h
+++ b/mlir/include/mlir/IR/Types.h
@@ -108,7 +108,7 @@ public:
 
   using ImplType = TypeStorage;
 
-  Type() : impl(nullptr) {}
+  constexpr Type() : impl(nullptr) {}
   /* implicit */ Type(const ImplType *impl)
       : impl(const_cast<ImplType *>(impl)) {}
 
diff --git a/mlir/include/mlir/IR/Value.h b/mlir/include/mlir/IR/Value.h
index d4869f242c0f..3fb5a91c73ae 100644
--- a/mlir/include/mlir/IR/Value.h
+++ b/mlir/include/mlir/IR/Value.h
@@ -70,7 +70,7 @@ public:
   using ImplType = llvm::PointerIntPair<void *, 2, Kind, ImplTypeTraits>;
 
 public:
-  Value(std::nullptr_t) : ownerAndKind() {}
+  constexpr Value(std::nullptr_t) : ownerAndKind() {}
   Value(ImplType ownerAndKind = {}) : ownerAndKind(ownerAndKind) {}
   Value(const Value &) = default;
   Value &operator=(const Value &) = default;
diff --git a/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp b/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp
index 1de7bceaf232..ff20e091f91b 100644
--- a/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp
+++ b/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp
@@ -1470,7 +1470,6 @@ spirv::ConstantOp spirv::ConstantOp::getZero(Type type, Location loc,
                                              OpBuilder *builder) {
   if (auto intType = type.dyn_cast<IntegerType>()) {
     unsigned width = intType.getWidth();
-    Attribute val;
     if (width == 1)
       return builder->create<spirv::ConstantOp>(loc, type,
                                                 builder->getBoolAttr(false));
diff --git a/mlir/lib/Dialect/VectorOps/VectorOps.cpp b/mlir/lib/Dialect/VectorOps/VectorOps.cpp
index 4afd05758ed3..92a230eb5d1b 100644
--- a/mlir/lib/Dialect/VectorOps/VectorOps.cpp
+++ b/mlir/lib/Dialect/VectorOps/VectorOps.cpp
@@ -1650,7 +1650,6 @@ static ParseResult parseTupleGetOp(OpAsmParser &parser,
   StringRef indexAttrName = TupleGetOp::getIndexAttrName();
   Type indexType = parser.getBuilder().getIndexType();
   TupleType tupleType;
-  VectorType resultVectorType;
   if (parser.parseOperand(operandInfo) || parser.parseComma() ||
       parser.parseAttribute(indexAttr, indexType, indexAttrName,
                             result.attributes) ||