llvm · mikeurbach · May 24, 2023 · May 19, 2023 · May 23, 2023 · May 24, 2023
diff --git a/include/circt-c/Dialect/OM.h b/include/circt-c/Dialect/OM.h
@@ -0,0 +1,125 @@
+//===-- circt-c/Dialect/OM.h - C API for OM dialect -----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This header declares the C interface for registering and accessing the
+// OM dialect. A dialect should be registered with a context to make it
+// available to users of the context. These users must load the dialect
+// before using any of its attributes, operations or types. Parser and pass
+// manager can load registered dialects automatically.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CIRCT_C_DIALECT_OM_H
+#define CIRCT_C_DIALECT_OM_H
+
+#include "mlir-c/IR.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//===----------------------------------------------------------------------===//
+// Dialect API.
+//===----------------------------------------------------------------------===//
+
+MLIR_DECLARE_CAPI_DIALECT_REGISTRATION(OM, om);
+
+//===----------------------------------------------------------------------===//
+// Evaluator data structures.
+//===----------------------------------------------------------------------===//
+
+/// A value type for use in C APIs that just wraps a pointer to an Evaluator.
+/// This is in line with the usual MLIR DEFINE_C_API_STRUCT.
+struct OMEvaluator {
+  void *ptr;
+};
+
+// clang-tidy doesn't respect extern "C".
+// see https://github.com/llvm/llvm-project/issues/35272.
+// NOLINTNEXTLINE(modernize-use-using)
+typedef struct OMEvaluator OMEvaluator;
+
+/// A value type for use in C APIs that just wraps a pointer to an Object.
+/// This is in line with the usual MLIR DEFINE_C_API_STRUCT.
+struct OMObject {
+  void *ptr;
+};
+
+// clang-tidy doesn't respect extern "C".
+// see https://github.com/llvm/llvm-project/issues/35272.
+// NOLINTNEXTLINE(modernize-use-using)
+typedef struct OMObject OMObject;
+
+/// A value type for use in C APIs that represents an ObjectValue.
+/// Because ObjectValue is a std::variant, which doesn't work well with C APIs,
+/// we use a struct with both fields, one of which will always be null.
+struct OMObjectValue {
+  MlirAttribute primitive;
+  OMObject object;
+};
+
+// clang-tidy doesn't respect extern "C".
+// see https://github.com/llvm/llvm-project/issues/35272.
+// NOLINTNEXTLINE(modernize-use-using)
+typedef struct OMObjectValue OMObjectValue;
+
+//===----------------------------------------------------------------------===//
+// Evaluator API.
+//===----------------------------------------------------------------------===//
+
+/// Construct an Evaluator with an IR module.
+MLIR_CAPI_EXPORTED OMEvaluator omEvaluatorNew(MlirModule mod);
+
+/// Use the Evaluator to Instantiate an Object from its class name and actual
+/// parameters.
+MLIR_CAPI_EXPORTED OMObject omEvaluatorInstantiate(
+    OMEvaluator evaluator, MlirAttribute className, intptr_t nActualParams,
+    MlirAttribute const *actualParams);
+
+/// Get the Module the Evaluator is built from.
+MLIR_CAPI_EXPORTED MlirModule omEvaluatorGetModule(OMEvaluator evaluator);
+
+//===----------------------------------------------------------------------===//
+// Object API.
+//===----------------------------------------------------------------------===//
+
+/// Query if the Object is null.
+MLIR_CAPI_EXPORTED bool omEvaluatorObjectIsNull(OMObject object);
+
+/// Get a field from an Object, which must contain a field of that name.
+MLIR_CAPI_EXPORTED OMObjectValue omEvaluatorObjectGetField(OMObject object,
+                                                           MlirAttribute name);
+
+//===----------------------------------------------------------------------===//
+// ObjectValue API.
+//===----------------------------------------------------------------------===//
+
+// Query if the ObjectValue is null.
+MLIR_CAPI_EXPORTED bool omEvaluatorObjectValueIsNull(OMObjectValue objectValue);
+
+/// Query if the ObjectValue is an Object.
+MLIR_CAPI_EXPORTED bool
+omEvaluatorObjectValueIsAObject(OMObjectValue objectValue);
+
+/// Get the Object from an  ObjectValue, which must contain an Object.
+MLIR_CAPI_EXPORTED OMObject
+omEvaluatorObjectValueGetObject(OMObjectValue objectValue);
+
+/// Query if the ObjectValue is a Primitive.
+MLIR_CAPI_EXPORTED bool
+omEvaluatorObjectValueIsAPrimitive(OMObjectValue objectValue);
+
+/// Get the Primitive from an  ObjectValue, which must contain a Primitive.
+MLIR_CAPI_EXPORTED MlirAttribute
+omEvaluatorObjectValueGetPrimitive(OMObjectValue objectValue);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // CIRCT_C_DIALECT_OM_H
diff --git a/lib/CAPI/Dialect/CMakeLists.txt b/lib/CAPI/Dialect/CMakeLists.txt
@@ -8,6 +8,7 @@ set(LLVM_OPTIONAL_SOURCES
   HWArith.cpp
   LLHD.cpp
   Moore.cpp
+  OM.cpp
   Seq.cpp
   SV.cpp
   FSM.cpp
@@ -75,6 +76,15 @@ add_mlir_public_c_api_library(CIRCTCAPIMoore
   CIRCTMoore
 )
 
+add_mlir_public_c_api_library(CIRCTCAPIOM
+  OM.cpp
+
+  LINK_LIBS PUBLIC
+  MLIRCAPIIR
+  CIRCTOM
+  CIRCTOMEvaluator
+)
+
 add_mlir_public_c_api_library(CIRCTCAPISeq
   Seq.cpp
 

diff --git a/lib/CAPI/Dialect/OM.cpp b/lib/CAPI/Dialect/OM.cpp
@@ -0,0 +1,151 @@
+//===- OM.cpp - C Interface for the OM Dialect ----------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  Implements a C Interface for the OM Dialect
+//
+//===----------------------------------------------------------------------===//
+
+#include "circt-c/Dialect/OM.h"
+#include "circt/Dialect/OM/Evaluator/Evaluator.h"
+#include "circt/Dialect/OM/OMDialect.h"
+#include "mlir/CAPI/Registration.h"
+#include "mlir/CAPI/Wrap.h"
+
+using namespace mlir;
+using namespace circt::om;
+
+//===----------------------------------------------------------------------===//
+// Dialect API.
+//===----------------------------------------------------------------------===//
+
+MLIR_DEFINE_CAPI_DIALECT_REGISTRATION(OM, om, OMDialect)
+
+//===----------------------------------------------------------------------===//
+// Evaluator data structures.
+//===----------------------------------------------------------------------===//
+
+DEFINE_C_API_PTR_METHODS(OMEvaluator, circt::om::Evaluator)
+DEFINE_C_API_PTR_METHODS(OMObject, std::shared_ptr<circt::om::Object>)
+
+//===----------------------------------------------------------------------===//
+// Evaluator API.
+//===----------------------------------------------------------------------===//
+
+/// Construct an Evaluator with an IR module.
+OMEvaluator omEvaluatorNew(MlirModule mod) {
+  // Just allocate and wrap the Evaluator.
+  return wrap(new Evaluator(unwrap(mod)));
+}
+
+/// Use the Evaluator to Instantiate an Object from its class name and actual
+/// parameters.
+OMObject omEvaluatorInstantiate(OMEvaluator evaluator, MlirAttribute className,
+                                intptr_t nActualParams,
+                                MlirAttribute const *actualParams) {
+  // Unwrap the Evaluator.
+  Evaluator *cppEvaluator = unwrap(evaluator);
+
+  // Unwrap the className, which the client must supply as a StringAttr.
+  StringAttr cppClassName = unwrap(className).cast<StringAttr>();
+
+  // Unwrap the actual parameters, which the client must supply as Attributes.
+  SmallVector<Attribute> actualParamsTmp;
+  SmallVector<ObjectValue> cppActualParams(
+      unwrapList(nActualParams, actualParams, actualParamsTmp));
+
+  // Invoke the Evaluator to instantiate the Object.
+  FailureOr<std::shared_ptr<Object>> result =
+      cppEvaluator->instantiate(cppClassName, cppActualParams);
+
+  // If instantiation failed, return a null Object. A Diagnostic will be emitted
+  // in this case.
+  if (failed(result))
+    return OMObject();
+
+  // Wrap and return a *new* shared pointer to the Object, to ensure the
+  // reference count is kept up to date.
+  return wrap(new std::shared_ptr<Object>(result.value()));
+}
+
+/// Get the Module the Evaluator is built from.
+MlirModule omEvaluatorGetModule(OMEvaluator evaluator) {
+  // Just unwrap the Evaluator, get the Module, and wrap it.
+  return wrap(unwrap(evaluator)->getModule());
+}
+
+//===----------------------------------------------------------------------===//
+// Object API.
+//===----------------------------------------------------------------------===//
+
+/// Query if the Object is null.
+bool omEvaluatorObjectIsNull(OMObject object) {
+  // Just check if the Object shared pointer is null.
+  return !object.ptr;
+}
+
+/// Get a field from an Object, which must contain a field of that name.
+OMObjectValue omEvaluatorObjectGetField(OMObject object, MlirAttribute name) {
+  // Unwrap the Object and get the field of the name, which the client must
+  // supply as a StringAttr.
+  FailureOr<ObjectValue> result =
+      (*unwrap(object))->getField(unwrap(name).cast<StringAttr>());
+
+  // If getField failed, return a null ObjectValue. A Diagnostic will be emitted
+  // in this case.
+  if (failed(result))
+    return OMObjectValue();
+
+  // If the field is an Object, return an ObjectValue with the Object set.
+  if (auto *object = std::get_if<std::shared_ptr<Object>>(&result.value()))
+    return OMObjectValue{MlirAttribute(), wrap(object)};
+
+  // If the field is an Attribute, return an ObjectValue with the Primitive set.
+  if (auto *primitive = std::get_if<Attribute>(&result.value()))
+    return OMObjectValue{wrap(*primitive), OMObject()};
+
+  // This case should never be hit, but return a null ObjectValue that is
+  // neither an Object nor a Primitive.
+  return OMObjectValue();
+}
+
+//===----------------------------------------------------------------------===//
+// ObjectValue API.
+//===----------------------------------------------------------------------===//
+
+// Query if the ObjectValue is null.
+bool omEvaluatorObjectValueIsNull(OMObjectValue objectValue) {
+  // Check if both Object and Attribute are null.
+  return !omEvaluatorObjectValueIsAObject(objectValue) &&
+         !omEvaluatorObjectValueIsAPrimitive(objectValue);
+}
+
+/// Query if the ObjectValue is an Object.
+bool omEvaluatorObjectValueIsAObject(OMObjectValue objectValue) {
+  // Check if the Object is non-null.
+  return !omEvaluatorObjectIsNull(objectValue.object);
+}
+
+/// Get the Object from an  ObjectValue, which must contain an Object.
+OMObject omEvaluatorObjectValueGetObject(OMObjectValue objectValue) {
+  // Assert the Object is non-null, and return it.
+  assert(omEvaluatorObjectValueIsAObject(objectValue));
+  return objectValue.object;
+}
+
+/// Query if the ObjectValue is a Primitive.
+bool omEvaluatorObjectValueIsAPrimitive(OMObjectValue objectValue) {
+  // Check if the Attribute is non-null.
+  return !mlirAttributeIsNull(objectValue.primitive);
+}
+
+/// Get the Primitive from an  ObjectValue, which must contain a Primitive.
+MlirAttribute omEvaluatorObjectValueGetPrimitive(OMObjectValue objectValue) {
+  // Assert the Attribute is non-null, and return it.
+  assert(omEvaluatorObjectValueIsAPrimitive(objectValue));
+  return objectValue.primitive;
+}
diff --git a/test/CAPI/CMakeLists.txt b/test/CAPI/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_llvm_executable(circt-capi-ir-test
+  PARTIAL_SOURCES_INTENDED
   ir.c
 )
 llvm_update_compile_flags(circt-capi-ir-test)
@@ -13,3 +14,16 @@ target_link_libraries(circt-capi-ir-test
   CIRCTCAPIFSM
   CIRCTCAPIExportVerilog
 )
+
+add_llvm_executable(circt-capi-om-test
+  PARTIAL_SOURCES_INTENDED
+  om.c
+)
+llvm_update_compile_flags(circt-capi-om-test)
+
+target_link_libraries(circt-capi-om-test
+  PRIVATE
+
+  MLIRCAPIIR
+  CIRCTCAPIOM
+)