[mlir][ODS] Refactor BuildableType to use $_builder as part of the format

Summary:
Currently BuildableType is assumed to be preceded by a builder. This prevents constructing types that don't have a callable 'get' method with the builder. This revision reworks the format to be like attribute builders, i.e. by accepting $_builder within the format itself.

Differential Revision: https://reviews.llvm.org/D73736

mlir/include/mlir/IR/OpBase.td

@@ -259,12 +259,14 @@ class Dialect {
 class Type<Pred condition, string descr = ""> :
     TypeConstraint<condition, descr> {
   string typeDescription = "";
+  string builderCall = "";
 }
 
 // Allows providing an alternative name and description to an existing type def.
 class TypeAlias<Type t, string description = t.description> :
     Type<t.predicate, description> {
   let typeDescription = t.typeDescription;
+  let builderCall = t.builderCall;
 }
 
 // A type of a specific dialect.
@@ -289,7 +291,6 @@ class Variadic<Type type> : TypeConstraint<type.predicate, type.description> {
 // making some Types and some Attrs buildable.
 class BuildableType<code builder> {
   // The builder call to invoke (if specified) to construct the BuildableType.
-  // Format: this will be affixed to the builder.
   code builderCall = builder;
 }
 
@@ -313,13 +314,13 @@ def AnyInteger : Type<CPred<"$_self.isa<IntegerType>()">, "integer">;
 
 // Index type.
 def Index : Type<CPred<"$_self.isa<IndexType>()">, "index">,
-            BuildableType<"getIndexType()">;
+            BuildableType<"$_builder.getIndexType()">;
 
 // Integer type of a specific width.
 class I<int width>
     : Type<CPred<"$_self.isInteger(" # width # ")">,
                   width # "-bit integer">,
-      BuildableType<"getIntegerType(" # width # ")"> {
+      BuildableType<"$_builder.getIntegerType(" # width # ")"> {
   int bitwidth = width;
 }
 
@@ -342,7 +343,7 @@ def AnyFloat : Type<CPred<"$_self.isa<FloatType>()">, "floating-point">;
 class F<int width>
     : Type<CPred<"$_self.isF" # width # "()">,
                 width # "-bit float">,
-      BuildableType<"getF" # width # "Type()"> {
+      BuildableType<"$_builder.getF" # width # "Type()"> {
   int bitwidth = width;
 }
 
@@ -355,7 +356,7 @@ def F32 : F<32>;
 def F64 : F<64>;
 
 def BF16 : Type<CPred<"$_self.isBF16()">, "bfloat16 type">,
-           BuildableType<"getBF16Type()">;
+           BuildableType<"$_builder.getBF16Type()">;
 
 class Complex<Type type>
     : Type<And<[
@@ -482,8 +483,8 @@ class 3DTensorOf<list<Type> allowedTypes> : TensorRankOf<allowedTypes, [3]>;
 class 4DTensorOf<list<Type> allowedTypes> : TensorRankOf<allowedTypes, [4]>;
 
 // Unranked Memref type
-def AnyUnrankedMemRef : 
-    ShapedContainerType<[AnyType], 
+def AnyUnrankedMemRef :
+    ShapedContainerType<[AnyType],
                         IsUnrankedMemRefTypePred, "unranked.memref">;
 // Memref type.
 
@@ -685,7 +686,7 @@ class OptionalAttr<Attr attr> : Attr<attr.predicate, attr.description> {
 class TypedAttrBase<BuildableType attrValType, string attrKind,
                     Pred condition, string descr> :
     Attr<condition, descr> {
-  let constBuilderCall = "$_builder.get" # attrKind # "($_builder." #
+  let constBuilderCall = "$_builder.get" # attrKind # "(" #
                          attrValType.builderCall # ", $0)";
   let storageType = attrKind;
 }

mlir/lib/TableGen/Type.cpp

@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "mlir/TableGen/Type.h"
+#include "mlir/ADT/TypeSwitch.h"
 #include "llvm/TableGen/Record.h"
 
 using namespace mlir;
@@ -36,9 +37,16 @@ Optional<StringRef> TypeConstraint::getBuilderCall() const {
   if (isVariadic())
     baseType = baseType->getValueAsDef("baseType");
 
-  if (!baseType->isSubClassOf("BuildableType"))
-    return None;
-  return baseType->getValueAsString("builderCall");
+  // Check to see if this type constraint has a builder call.
+  const llvm::RecordVal *builderCall = baseType->getValue("builderCall");
+  if (!builderCall || !builderCall->getValue())
+    return llvm::None;
+  return TypeSwitch<llvm::Init *, Optional<StringRef>>(builderCall->getValue())
+      .Case<llvm::StringInit, llvm::CodeInit>([&](auto *init) {
+        StringRef value = init->getValue();
+        return value.empty() ? Optional<StringRef>() : value;
+      })
+      .Default([](auto *) { return llvm::None; });
 }
 
 Type::Type(const llvm::Record *record) : TypeConstraint(record) {}

mlir/tools/mlir-tblgen/OpFormatGen.cpp

@@ -410,9 +410,15 @@ void OperationFormat::genParser(Operator &op, OpClass &opClass) {
 void OperationFormat::genParserTypeResolution(Operator &op,
                                               OpMethodBody &body) {
   // Initialize the set of buildable types.
-  for (auto &it : buildableTypes)
-    body << "  Type odsBuildableType" << it.second << " = parser.getBuilder()."
-         << it.first << ";\n";
+  if (!buildableTypes.empty()) {
+    body << "  Builder &builder = parser.getBuilder();\n";
+
+    FmtContext typeBuilderCtx;
+    typeBuilderCtx.withBuilder("builder");
+    for (auto &it : buildableTypes)
+      body << "  Type odsBuildableType" << it.second << " = "
+           << tgfmt(it.first, &typeBuilderCtx) << ";\n";
+  }
 
   // Resolve each of the result types.
   if (allResultTypes) {