FIRAnnotations.cpp

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//===- FIRAnnotations.cpp - FIRRTL Annotation Utilities -------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Provide utilities related to dealing with FIRRTL Annotations.
//
//===----------------------------------------------------------------------===//
 
#include "circt/Dialect/FIRRTL/Import/FIRAnnotations.h"
#include "circt/Support/JSON.h"
#include "mlir/IR/BuiltinAttributes.h"
#include "mlir/IR/OperationSupport.h"
 
namespace json = llvm::json;
 
/// Deserialize a JSON value into FIRRTL Annotations.  Annotations are
/// represented as a Target-keyed arrays of attributes.  The input JSON value is
/// checked, at runtime, to be an array of objects.  Returns true if successful,
/// false if unsuccessful.
bool circt::firrtl::importAnnotationsFromJSONRaw(
    json::Value &value, SmallVectorImpl<Attribute> &annotations,
    json::Path path, MLIRContext *context) {
 
  // The JSON value must be an array of objects.  Anything else is reported as
  // invalid.
  auto *array = value.getAsArray();
  if (!array) {
    path.report(
        "Expected annotations to be an array, but found something else.");
    return false;
  }
 
  // Build an array of annotations.
  for (size_t i = 0, e = (*array).size(); i != e; ++i) {
    auto *object = (*array)[i].getAsObject();
    auto p = path.index(i);
    if (!object) {
      p.report("Expected annotations to be an array of objects, but found an "
               "array of something else.");
      return false;
    }
 
    // Build up the Attribute to represent the Annotation
    NamedAttrList metadata;
 
    for (auto field : *object) {
      if (auto value = convertJSONToAttribute(context, field.second, p)) {
        metadata.append(field.first, value);
        continue;
      }
      return false;
    }
 
    annotations.push_back(DictionaryAttr::get(context, metadata));
  }
 
  return true;
}