[mlir] Add OpAsmTypeInterface for pretty-print (llvm#121187)

See
https://discourse.llvm.org/t/rfc-introduce-opasm-type-attr-interface-for-pretty-print-in-asmprinter/83792
for detailed introduction.

This PR acts as the first part of it
* Add `OpAsmTypeInterface` and `getAsmName` API for deducing ASM name
from type
* Add default impl in `OpAsmOpInterface` to respect this API when
available.

The `OpAsmAttrInterface` / hooking into Alias system part should be
another PR, using a `getAlias` API.

### Discussion

* Instead of using `StringRef getAsmName()` as the API, I use `void
getAsmName(OpAsmSetNameFn)`, as returning StringRef might be unsafe
(std::string constructed inside then returned a _ref_; and this aligns
with the design of `getAsmResultNames`.
* On the result packing of an op, the current approach is that when not
all of the result types are `OpAsmTypeInterface`, then do nothing (old
default impl)

### Review 

Cc @j2kun and @AlexanderViand-Intel for downstream; Cc @River707 and
@joker-eph for relevent commit history; Cc @ftynse for discourse.

Author: ZenithalHourlyRate

mlir/include/mlir/IR/CMakeLists.txt

@@ -1,7 +1,14 @@
-add_mlir_interface(OpAsmInterface)
 add_mlir_interface(SymbolInterfaces)
 add_mlir_interface(RegionKindInterface)
 
+set(LLVM_TARGET_DEFINITIONS OpAsmInterface.td)
+mlir_tablegen(OpAsmOpInterface.h.inc -gen-op-interface-decls)
+mlir_tablegen(OpAsmOpInterface.cpp.inc -gen-op-interface-defs)
+mlir_tablegen(OpAsmTypeInterface.h.inc -gen-type-interface-decls)
+mlir_tablegen(OpAsmTypeInterface.cpp.inc -gen-type-interface-defs)
+add_public_tablegen_target(MLIROpAsmInterfaceIncGen)
+add_dependencies(mlir-generic-headers MLIROpAsmInterfaceIncGen)
+
 set(LLVM_TARGET_DEFINITIONS BuiltinAttributes.td)
 mlir_tablegen(BuiltinAttributes.h.inc -gen-attrdef-decls)
 mlir_tablegen(BuiltinAttributes.cpp.inc -gen-attrdef-defs)

mlir/include/mlir/IR/OpAsmInterface.td

@@ -109,6 +109,27 @@ def OpAsmOpInterface : OpInterface<"OpAsmOpInterface"> {
   ];
 }
 
+//===----------------------------------------------------------------------===//
+// OpAsmTypeInterface
+//===----------------------------------------------------------------------===//
+
+def OpAsmTypeInterface : TypeInterface<"OpAsmTypeInterface"> {
+  let description = [{
+    This interface provides hooks to interact with the AsmPrinter and AsmParser
+    classes.
+  }];
+  let cppNamespace = "::mlir";
+
+  let methods = [
+    InterfaceMethod<[{
+        Get a name to use when printing a value of this type.
+      }],
+      "void", "getAsmName",
+      (ins "::mlir::OpAsmSetNameFn":$setNameFn), "", ";"
+    >,
+  ];
+}
+
 //===----------------------------------------------------------------------===//
 // ResourceHandleParameter
 //===----------------------------------------------------------------------===//

mlir/include/mlir/IR/OpImplementation.h

@@ -734,7 +734,7 @@ class AsmParser {
   virtual OptionalParseResult parseOptionalInteger(APInt &result) = 0;
   virtual OptionalParseResult parseOptionalDecimalInteger(APInt &result) = 0;
 
- private:
+private:
   template <typename IntT, typename ParseFn>
   OptionalParseResult parseOptionalIntegerAndCheck(IntT &result,
                                                    ParseFn &&parseFn) {
@@ -756,7 +756,7 @@ class AsmParser {
     return success();
   }
 
- public:
+public:
   template <typename IntT>
   OptionalParseResult parseOptionalInteger(IntT &result) {
     return parseOptionalIntegerAndCheck(
@@ -1727,6 +1727,10 @@ class OpAsmParser : public AsmParser {
 // Dialect OpAsm interface.
 //===--------------------------------------------------------------------===//
 
+/// A functor used to set the name of the result. See 'getAsmResultNames' below
+/// for more details.
+using OpAsmSetNameFn = function_ref<void(StringRef)>;
+
 /// A functor used to set the name of the start of a result group of an
 /// operation. See 'getAsmResultNames' below for more details.
 using OpAsmSetValueNameFn = function_ref<void(Value, StringRef)>;
@@ -1820,7 +1824,8 @@ ParseResult parseDimensionList(OpAsmParser &parser,
 //===--------------------------------------------------------------------===//
 
 /// The OpAsmOpInterface, see OpAsmInterface.td for more details.
-#include "mlir/IR/OpAsmInterface.h.inc"
+#include "mlir/IR/OpAsmOpInterface.h.inc"
+#include "mlir/IR/OpAsmTypeInterface.h.inc"
 
 namespace llvm {
 template <>

mlir/lib/IR/AsmPrinter.cpp

@@ -125,7 +125,8 @@ void OpAsmPrinter::printFunctionalType(Operation *op) {
 //===----------------------------------------------------------------------===//
 
 /// The OpAsmOpInterface, see OpAsmInterface.td for more details.
-#include "mlir/IR/OpAsmInterface.cpp.inc"
+#include "mlir/IR/OpAsmOpInterface.cpp.inc"
+#include "mlir/IR/OpAsmTypeInterface.cpp.inc"
 
 LogicalResult
 OpAsmDialectInterface::parseResource(AsmParsedResourceEntry &entry) const {

mlir/test/IR/op-asm-interface.mlir

@@ -0,0 +1,24 @@
+// RUN: mlir-opt %s -split-input-file -verify-diagnostics | FileCheck %s
+
+//===----------------------------------------------------------------------===//
+// Test OpAsmOpInterface
+//===----------------------------------------------------------------------===//
+
+func.func @result_name_from_op_asm_type_interface() {
+  // CHECK-LABEL: @result_name_from_op_asm_type_interface
+  // CHECK: %op_asm_type_interface
+  %0 = "test.result_name_from_type"() : () -> !test.op_asm_type_interface
+  return
+}
+
+// -----
+
+func.func @block_argument_name_from_op_asm_type_interface() {
+  // CHECK-LABEL: @block_argument_name_from_op_asm_type_interface
+  // CHECK: ^bb0(%op_asm_type_interface
+  test.block_argument_name_from_type {
+    ^bb0(%arg0: !test.op_asm_type_interface):
+      "test.terminator"() : ()->()
+  }
+  return
+}

mlir/test/lib/Dialect/Test/TestOpDefs.cpp

@@ -506,6 +506,38 @@ void CustomResultsNameOp::getAsmResultNames(
         setNameFn(getResult(i), str.getValue());
 }
 
+//===----------------------------------------------------------------------===//
+// ResultNameFromTypeOp
+//===----------------------------------------------------------------------===//
+
+void ResultNameFromTypeOp::getAsmResultNames(
+    function_ref<void(Value, StringRef)> setNameFn) {
+  auto result = getResult();
+  auto setResultNameFn = [&](::llvm::StringRef name) {
+    setNameFn(result, name);
+  };
+  auto opAsmTypeInterface =
+      ::mlir::cast<::mlir::OpAsmTypeInterface>(result.getType());
+  opAsmTypeInterface.getAsmName(setResultNameFn);
+}
+
+//===----------------------------------------------------------------------===//
+// BlockArgumentNameFromTypeOp
+//===----------------------------------------------------------------------===//
+
+void BlockArgumentNameFromTypeOp::getAsmBlockArgumentNames(
+    ::mlir::Region &region, ::mlir::OpAsmSetValueNameFn setNameFn) {
+  for (auto &block : region) {
+    for (auto arg : block.getArguments()) {
+      if (auto opAsmTypeInterface =
+              ::mlir::dyn_cast<::mlir::OpAsmTypeInterface>(arg.getType())) {
+        auto setArgNameFn = [&](StringRef name) { setNameFn(arg, name); };
+        opAsmTypeInterface.getAsmName(setArgNameFn);
+      }
+    }
+  }
+}
+
 //===----------------------------------------------------------------------===//
 // ResultTypeWithTraitOp
 //===----------------------------------------------------------------------===//

mlir/test/lib/Dialect/Test/TestOps.td

@@ -924,6 +924,21 @@ def CustomResultsNameOp
   let results = (outs Variadic<AnyInteger>:$r);
 }
 
+// This is used to test OpAsmTypeInterface::getAsmName for op result name,
+def ResultNameFromTypeOp
+ : TEST_Op<"result_name_from_type",
+           [DeclareOpInterfaceMethods<OpAsmOpInterface, ["getAsmResultNames"]>]> {
+  let results = (outs AnyType:$r);
+}
+
+// This is used to test OpAsmTypeInterface::getAsmName for block argument,
+def BlockArgumentNameFromTypeOp
+  : TEST_Op<"block_argument_name_from_type",
+      [DeclareOpInterfaceMethods<OpAsmOpInterface, ["getAsmBlockArgumentNames"]>]> {
+  let regions = (region AnyRegion:$body);
+  let assemblyFormat = "regions attr-dict-with-keyword";
+}
+
 // This is used to test the OpAsmOpInterface::getDefaultDialect() feature:
 // operations nested in a region under this op will drop the "test." dialect
 // prefix.

mlir/test/lib/Dialect/Test/TestTypeDefs.td

@@ -398,4 +398,9 @@ def TestTypeVerification : Test_Type<"TestTypeVerification"> {
   let assemblyFormat = "`<` $param `>`";
 }
 
+def TestTypeOpAsmTypeInterface : Test_Type<"TestTypeOpAsmTypeInterface",
+    [DeclareTypeInterfaceMethods<OpAsmTypeInterface, ["getAsmName"]>]> {
+  let mnemonic = "op_asm_type_interface";
+}
+
 #endif // TEST_TYPEDEFS

mlir/test/lib/Dialect/Test/TestTypes.cpp

@@ -532,3 +532,8 @@ void TestRecursiveAliasType::print(AsmPrinter &printer) const {
   }
   printer << ">";
 }
+
+void TestTypeOpAsmTypeInterfaceType::getAsmName(
+    OpAsmSetNameFn setNameFn) const {
+  setNameFn("op_asm_type_interface");
+}