[ARC][CAPI] Add basic C API for initializing ARC (#6997)

include/circt-c/Dialect/Arc.h

@@ -0,0 +1,25 @@
+//===- Arc.h - C interface for the Arc dialect ------------------*- C -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CIRCT_C_DIALECT_ARC_H
+#define CIRCT_C_DIALECT_ARC_H
+
+#include "mlir-c/IR.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+MLIR_DECLARE_CAPI_DIALECT_REGISTRATION(Arc, arc);
+MLIR_CAPI_EXPORTED void registerArcPasses(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // CIRCT_C_DIALECT_ARC_H

lib/CAPI/Dialect/Arc.cpp

@@ -0,0 +1,18 @@
+//===- Arc.cpp - C interface for the Arc 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "circt-c/Dialect/Arc.h"
+#include "circt/Dialect/Arc/ArcDialect.h"
+#include "circt/Dialect/Arc/ArcPasses.h"
+#include "mlir/CAPI/IR.h"
+#include "mlir/CAPI/Registration.h"
+#include "mlir/CAPI/Support.h"
+
+MLIR_DEFINE_CAPI_DIALECT_REGISTRATION(Arc, arc, circt::arc::ArcDialect)
+
+void registerArcPasses() { circt::arc::registerPasses(); }

lib/CAPI/Dialect/CMakeLists.txt

@@ -1,5 +1,6 @@
 # TODO: Make the check source feature optional as an argument on *_add_library.
 set(LLVM_OPTIONAL_SOURCES
+  Arc.cpp
   CHIRRTL.cpp
   Comb.cpp
   Debug.cpp
@@ -20,6 +21,15 @@ set(LLVM_OPTIONAL_SOURCES
   Verif.cpp
 )
 
+add_circt_public_c_api_library(CIRCTCAPIArc
+  Arc.cpp
+
+  LINK_LIBS PUBLIC
+  MLIRCAPIIR
+  CIRCTArc
+  CIRCTArcTransforms
+)
+
 add_circt_public_c_api_library(CIRCTCAPIComb
   Comb.cpp
 

test/CAPI/CMakeLists.txt

@@ -56,3 +56,16 @@ target_link_libraries(circt-capi-firtool-test
   CIRCTCAPIFIRRTL
   CIRCTCAPIFirtool
 )
+
+add_llvm_executable(circt-capi-arc-test
+  PARTIAL_SOURCES_INTENDED
+  arc.c
+)
+llvm_update_compile_flags(circt-capi-arc-test)
+
+target_link_libraries(circt-capi-arc-test
+  PRIVATE
+
+  MLIRCAPIIR
+  CIRCTCAPIArc
+)

test/CAPI/arc.c

@@ -0,0 +1,67 @@
+/*===- arc.c - Simple test of Arc Dialect C APIs  -------------------------===*\
+|*                                                                            *|
+|* 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                    *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+/* RUN: circt-capi-ir-test 2>&1 | FileCheck %s
+ */
+
+#include "circt-c/Dialect/Arc.h"
+
+#include <stdio.h>
+#include <string.h>
+
+int registerOnlyArc(void) {
+  MlirContext ctx = mlirContextCreate();
+  // The built-in dialect is always loaded.
+  if (mlirContextGetNumLoadedDialects(ctx) != 1)
+    return 1;
+
+  // Arc dialect tests.
+  MlirDialectHandle arcHandle = mlirGetDialectHandle__arc__();
+
+  MlirDialect arc = mlirContextGetOrLoadDialect(
+      ctx, mlirDialectHandleGetNamespace(arcHandle));
+  if (!mlirDialectIsNull(arc))
+    return 2;
+
+  mlirDialectHandleRegisterDialect(arcHandle, ctx);
+  if (mlirContextGetNumRegisteredDialects(ctx) != 2)
+    return 3;
+  if (mlirContextGetNumLoadedDialects(ctx) != 1)
+    return 4;
+
+  arc = mlirContextGetOrLoadDialect(ctx,
+                                    mlirDialectHandleGetNamespace(arcHandle));
+  if (mlirDialectIsNull(arc))
+    return 5;
+  if (mlirContextGetNumLoadedDialects(ctx) != 2)
+    return 6;
+
+  MlirDialect alsoArc = mlirDialectHandleLoadDialect(arcHandle, ctx);
+  if (!mlirDialectEqual(arc, alsoArc))
+    return 7;
+
+  registerArcPasses();
+
+  mlirContextDestroy(ctx);
+
+  return 0;
+}
+
+int main(void) {
+  fprintf(stderr, "@registration\n");
+  int errcode = registerOnlyArc();
+  fprintf(stderr, "%d\n", errcode);
+
+  // clang-format off
+  // CHECK-LABEL: @registration
+  // CHECK: 0
+  // clang-format on
+
+  return 0;
+}