[mlir][ODS] Fix TableGen for AttrOrTypeDef::hasStorageCustomConstructor (#147957)

There is a `hasStorageCustomConstructor` flag that allows one to provide
custom attribute/type construction implementation. Unfortunately, it
seems like the flag does not work properly: the generated C++ produces
*empty body* method instead of producing only a declaration.

Author: andrey-golubev

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

@@ -431,4 +431,11 @@ def SlashAttr: Test_Attr<"Slash">{
   let hasCustomAssemblyFormat = 1;
 }
 
+def TestCustomStorageCtorAttr : Test_Attr<"TestCustomStorageCtorAttr"> {
+    let mnemonic = "custom_storage_ctor_attr";
+    let parameters = (ins "int":$value);
+    let assemblyFormat = "`<` $value `>`";
+    let hasStorageCustomConstructor = 1;
+}
+
 #endif // TEST_ATTRDEFS

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

@@ -515,6 +515,18 @@ void SlashAttr::print(AsmPrinter &printer) const {
   printer << "<" << getLhs() << " / " << getRhs() << ">";
 }
 
+//===----------------------------------------------------------------------===//
+// TestCustomStorageCtorAttr
+//===----------------------------------------------------------------------===//
+
+test::detail::TestCustomStorageCtorAttrAttrStorage *
+test::detail::TestCustomStorageCtorAttrAttrStorage::construct(
+    mlir::StorageUniquer::StorageAllocator &, std::tuple<int> &&) {
+  // Note: this tests linker error ("undefined symbol"), the actual
+  // implementation is not important.
+  return nullptr;
+}
+
 //===----------------------------------------------------------------------===//
 // TestDialect
 //===----------------------------------------------------------------------===//

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

@@ -352,6 +352,13 @@ def TestTypeCustomString : Test_Type<"TestTypeCustomString"> {
                               custom<BarString>(ref($foo)) `>` }];
 }
 
+def TestCustomStorageCtor : Test_Type<"TestCustomStorageCtor"> {
+    let mnemonic = "custom_storage_ctor_type";
+    let parameters = (ins "int":$value);
+    let assemblyFormat = "`<` $value `>`";
+    let hasStorageCustomConstructor = 1;
+}
+
 def TestTypeOptionalString : Test_Type<"TestTypeOptionalString"> {
   let parameters = (ins StringRefParameter<"description", [{"default"}]>:$str);
   let mnemonic = "optional_type_string";

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

@@ -392,6 +392,14 @@ getCustomAssemblyFormatDynamicType(TestDialect *testDialect) {
                                     std::move(parser), std::move(printer));
 }
 
+test::detail::TestCustomStorageCtorTypeStorage *
+test::detail::TestCustomStorageCtorTypeStorage::construct(
+    mlir::StorageUniquer::StorageAllocator &, std::tuple<int> &&) {
+  // Note: this tests linker error ("undefined symbol"), the actual
+  // implementation is not important.
+  return nullptr;
+}
+
 //===----------------------------------------------------------------------===//
 // TestDialect
 //===----------------------------------------------------------------------===//

mlir/test/mlir-tblgen/attrdefs.td

@@ -186,3 +186,16 @@ def I_TestGenMnemonicAliasAttr : TestAttr<"TestGenMnemonicAlias"> {
 // DEF-NEXT: os << "test_gen_mnemonic_alias";
 // DEF-NEXT: return ::mlir::OpAsmAliasResult::OverridableAlias;
 // DEF-NEXT: }
+
+def J_CustomStorageCtorAttr : AttrDef<Test_Dialect, "CustomStorageCtorAttr"> {
+  let attrName = "test_custom_storage_ctor_attr";
+  let parameters = (ins "bool":$flag);
+  let hasStorageCustomConstructor = 1;
+}
+
+// Note: ';' at the end of construct method declaration is important - otherwise
+// one cannot provide custom definition
+
+// DEF-LABEL: struct CustomStorageCtorAttrAttrStorage : public ::mlir::AttributeStorage
+// DEF: static CustomStorageCtorAttrAttrStorage *construct
+// DEF-SAME: (::mlir::AttributeStorageAllocator &allocator, KeyTy &&tblgenKey);

mlir/tools/mlir-tblgen/AttrOrTypeDefGen.cpp

@@ -668,10 +668,10 @@ void DefGen::emitHashKey() {
 }
 
 void DefGen::emitConstruct() {
-  Method *construct = storageCls->addMethod<Method::Inline>(
+  Method *construct = storageCls->addMethod(
       strfmt("{0} *", def.getStorageClassName()), "construct",
       def.hasStorageCustomConstructor() ? Method::StaticDeclaration
-                                        : Method::Static,
+                                        : Method::StaticInline,
       MethodParameter(strfmt("::mlir::{0}StorageAllocator &", valueType),
                       "allocator"),
       MethodParameter("KeyTy &&", "tblgenKey"));