FIRRTLAnnotationHelper.h

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//===- FIRRTLAnnotationHelper.h - FIRRTL Annotation Lookup ------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file declares helpers mapping annotations to operations.
//
//===----------------------------------------------------------------------===//
 
#ifndef CIRCT_DIALECT_FIRRTL_FIRRTLANNOTATIONHELPER_H
#define CIRCT_DIALECT_FIRRTL_FIRRTLANNOTATIONHELPER_H
 
#include "circt/Dialect/FIRRTL/CHIRRTLDialect.h"
#include "circt/Dialect/FIRRTL/FIRRTLInstanceGraph.h"
#include "circt/Dialect/FIRRTL/FIRRTLOps.h"
#include "circt/Dialect/HW/HWOps.h"
#include "circt/Dialect/HW/InnerSymbolNamespace.h"
#include "llvm/ADT/TypeSwitch.h"
 
namespace circt {
namespace firrtl {
 
/// Stores an index into an aggregate.
struct TargetToken {
  StringRef name;
  bool isIndex;
};
 
/// The parsed annotation path.
struct TokenAnnoTarget {
  StringRef circuit;
  SmallVector<std::pair<StringRef, StringRef>> instances;
  StringRef module;
  // The final name of the target
  StringRef name;
  // Any aggregates indexed.
  SmallVector<TargetToken> component;
 
  /// Append the annotation path to the given `SmallString` or `SmallVector`.
  void toVector(SmallVectorImpl<char> &out) const;
 
  /// Convert the annotation path to a string.
  std::string str() const {
    SmallString<32> out;
    toVector(out);
    return std::string(out);
  }
 
  /// Convert the annotation path to a StringAttr.
  StringAttr toStringAttr(MLIRContext *context) const {
    SmallString<32> out;
    toVector(out);
    return StringAttr::get(context, out);
  }
};
 
// The potentially non-local resolved annotation.
struct AnnoPathValue {
  SmallVector<InstanceOp> instances;
  AnnoTarget ref;
  unsigned fieldIdx = 0;
 
  AnnoPathValue() = default;
  AnnoPathValue(CircuitOp op) : ref(OpAnnoTarget(op)) {}
  AnnoPathValue(Operation *op) : ref(OpAnnoTarget(op)) {}
  AnnoPathValue(const SmallVectorImpl<InstanceOp> &insts, AnnoTarget b,
                unsigned fieldIdx)
      : instances(insts.begin(), insts.end()), ref(b), fieldIdx(fieldIdx) {}
 
  bool isLocal() const { return instances.empty(); }
 
  template <typename... T>
  bool isOpOfType() const {
    if (auto opRef = dyn_cast<OpAnnoTarget>(ref))
      return isa<T...>(opRef.getOp());
    return false;
  }
};
 
template <typename T>
static T &operator<<(T &os, const AnnoPathValue &path) {
  os << "~" << path.ref.getModule()->getParentOfType<CircuitOp>().getName()
     << "|";
 
  if (path.isLocal()) {
    os << path.ref.getModule().getModuleName();
  } else {
    os << path.instances.front()
              ->getParentOfType<FModuleLike>()
              .getModuleName();
  }
  for (auto inst : path.instances)
    os << "/" << inst.getName() << ":" << inst.getModuleName();
  if (!path.isOpOfType<FModuleOp, FExtModuleOp, InstanceOp>()) {
    os << ">" << path.ref;
    auto type = dyn_cast<FIRRTLBaseType>(path.ref.getType());
    if (!type)
      return os;
    auto targetFieldID = path.fieldIdx;
    while (targetFieldID) {
      FIRRTLTypeSwitch<FIRRTLBaseType>(type)
          .Case<FVectorType>([&](FVectorType vector) {
            auto index = vector.getIndexForFieldID(targetFieldID);
            os << "[" << index << "]";
            type = vector.getElementType();
            targetFieldID -= vector.getFieldID(index);
          })
          .template Case<BundleType>([&](BundleType bundle) {
            auto index = bundle.getIndexForFieldID(targetFieldID);
            os << "." << bundle.getElementName(index);
            type = bundle.getElementType(index);
            targetFieldID -= bundle.getFieldID(index);
          })
          .Default([&](auto) { targetFieldID = 0; });
    }
  }
  return os;
}
 
template <typename T>
static T &operator<<(T &os, const OpAnnoTarget &target) {
  os << target.getOp()->getAttrOfType<StringAttr>("name").getValue();
  return os;
}
 
template <typename T>
static T &operator<<(T &os, const PortAnnoTarget &target) {
  os << target.getModule().getPortName(target.getPortNo());
  return os;
}
 
template <typename T>
static T &operator<<(T &os, const AnnoTarget &target) {
  if (auto op = dyn_cast<OpAnnoTarget>(target))
    os << op;
  else if (auto port = dyn_cast<PortAnnoTarget>(target))
    os << port;
  else
    os << "<<Unknown Anno Target>>";
  return os;
}
 
/// Cache AnnoTargets for a module's named things.
struct AnnoTargetCache {
  AnnoTargetCache() = delete;
  AnnoTargetCache(const AnnoTargetCache &other) = default;
  AnnoTargetCache(AnnoTargetCache &&other)
      : targets(std::move(other.targets)) {}
 
  AnnoTargetCache(FModuleLike mod) { gatherTargets(mod); }
 
  /// Lookup the target for 'name', empty if not found.
  /// (check for validity using operator bool()).
  AnnoTarget getTargetForName(StringRef name) const {
    return targets.lookup(name);
  }
 
  void insertOp(Operation *op) {
    TypeSwitch<Operation *>(op)
        .Case<InstanceOp, MemOp, NodeOp, RegOp, RegResetOp, WireOp,
              chirrtl::CombMemOp, chirrtl::SeqMemOp, chirrtl::MemoryPortOp,
              chirrtl::MemoryDebugPortOp, PrintFOp, FPrintFOp>([&](auto op) {
          // To be safe, check attribute and non-empty name before adding.
          if (auto name = op.getNameAttr(); name && !name.getValue().empty())
            targets.insert({name, OpAnnoTarget(op)});
        });
  }
 
  /// Replace `oldOp` with `newOp` in the target cache. The new and old ops can
  /// have different names.
  void replaceOp(Operation *oldOp, Operation *newOp) {
    if (auto name = oldOp->getAttrOfType<StringAttr>("name");
        name && !name.getValue().empty())
      targets.erase(name);
    insertOp(newOp);
  }
 
  /// Add a new module port to the target cache.
  void insertPort(FModuleLike mod, size_t portNo) {
    targets.insert({mod.getPortNameAttr(portNo), PortAnnoTarget(mod, portNo)});
  }
 
private:
  /// Walk the module and add named things to 'targets'.
  void gatherTargets(FModuleLike mod);
 
  llvm::DenseMap<StringRef, AnnoTarget> targets;
};
 
/// Cache AnnoTargets for a circuit's modules, walked as needed.
struct CircuitTargetCache {
  /// Get cache for specified module, creating it as needed.
  /// Returned reference may become invalidated by future calls.
  const AnnoTargetCache &getOrCreateCacheFor(FModuleLike module) {
    auto it = targetCaches.find(module);
    if (it == targetCaches.end())
      it = targetCaches.try_emplace(module, module).first;
    return it->second;
  }
 
  /// Lookup the target for 'name' in 'module'.
  AnnoTarget lookup(FModuleLike module, StringRef name) {
    return getOrCreateCacheFor(module).getTargetForName(name);
  }
 
  /// Clear the cache completely.
  void invalidate() { targetCaches.clear(); }
 
  /// Replace `oldOp` with `newOp` in the target cache. The new and old ops can
  /// have different names.
  void replaceOp(Operation *oldOp, Operation *newOp) {
    auto mod = newOp->getParentOfType<FModuleOp>();
    auto it = targetCaches.find(mod);
    if (it == targetCaches.end())
      return;
    it->getSecond().replaceOp(oldOp, newOp);
  }
 
  /// Add a new module port to the target cache.
  void insertPort(FModuleLike mod, size_t portNo) {
    auto it = targetCaches.find(mod);
    if (it == targetCaches.end())
      return;
    it->getSecond().insertPort(mod, portNo);
  }
 
  /// Add a new op to the target cache.
  void insertOp(Operation *op) {
    auto mod = op->getParentOfType<FModuleOp>();
    auto it = targetCaches.find(mod);
    if (it == targetCaches.end())
      return;
    it->getSecond().insertOp(op);
  }
 
private:
  DenseMap<Operation *, AnnoTargetCache> targetCaches;
};
 
/// Return an input \p target string in canonical form.  This converts a Legacy
/// Annotation (e.g., A.B.C) into a modern annotation (e.g., ~A|B>C).  Trailing
/// subfield/subindex references are preserved.
std::string canonicalizeTarget(StringRef target);
 
/// Parse a FIRRTL annotation path into its constituent parts.
std::optional<TokenAnnoTarget> tokenizePath(StringRef origTarget);
 
/// Convert a parsed target string to a resolved target structure.  This
/// resolves all names and aggregates from a parsed target.
std::optional<AnnoPathValue> resolveEntities(TokenAnnoTarget path,
                                             CircuitOp circuit,
                                             SymbolTable &symTbl,
                                             CircuitTargetCache &cache);
 
/// Resolve a string path to a named item inside a circuit.
std::optional<AnnoPathValue> resolvePath(StringRef rawPath, CircuitOp circuit,
                                         SymbolTable &symTbl,
                                         CircuitTargetCache &cache);
 
/// A representation of a deferred Wiring problem consisting of a source that
/// should be connected to a sink.
struct WiringProblem {
  enum class RefTypeUsage { Prefer, Never };
 
  /// A source to wire from.
  Value source;
 
  /// A sink to wire to.
  Value sink;
 
  /// A base name to use when generating new signals associated with this wiring
  /// problem.
  std::string newNameHint;
 
  /// The usage of ref type ports when solving this problem.
  RefTypeUsage refTypeUsage;
};
 
/// A representation of a legacy Wiring problem consisting of a signal source
/// that should be connected to one or many sinks.
struct LegacyWiringProblem {
  /// A source to wire from.
  Value source;
 
  /// Sink(s) to wire to.
  SmallVector<Value> sinks;
};
 
/// A store of pending modifications to a FIRRTL module associated with solving
/// one or more WiringProblems.
struct ModuleModifications {
  /// A pair of Wiring Problem index and port information.
  using portInfoPair = std::pair<size_t, PortInfo>;
 
  /// A pair of Wiring Problem index and a U-turn Value that should be
  /// connected.
  using uturnPair = std::pair<size_t, Value>;
 
  /// Ports that should be added to a module.
  SmallVector<portInfoPair> portsToAdd;
 
  /// A mapping of a Value that should be connected to either a new port or a
  /// U-turn, for a specific Wiring Problem.  This is pre-populated with the
  /// source and sink.
  DenseMap<size_t, Value> connectionMap;
 
  /// A secondary value that _may_ need to be hooked up.  This is always set
  /// after the Value in the connectionMap.
  SmallVector<uturnPair> uturns;
};
 
/// A cache of existing HierPathOps, mostly used to facilitate HierPathOp reuse.
struct HierPathCache {
  HierPathCache(Operation *op, SymbolTable &symbolTable);
 
  hw::HierPathOp getOpFor(ArrayAttr attr);
 
  StringAttr getSymFor(ArrayAttr attr) {
    return getOpFor(attr).getSymNameAttr();
  }
 
  FlatSymbolRefAttr getRefFor(ArrayAttr attr) {
    return FlatSymbolRefAttr::get(getSymFor(attr));
  }
 
  const SymbolTable &getSymbolTable() const { return symbolTable; }
 
private:
  OpBuilder builder;
  DenseMap<ArrayAttr, hw::HierPathOp> cache;
  SymbolTable &symbolTable;
};
 
/// State threaded through functions for resolving and applying annotations.
struct ApplyState {
  using AddToWorklistFn = llvm::function_ref<void(DictionaryAttr)>;
  ApplyState(CircuitOp circuit, SymbolTable &symTbl,
             AddToWorklistFn addToWorklistFn,
             InstancePathCache &instancePathCache, bool noRefTypePorts)
      : circuit(circuit), symTbl(symTbl), addToWorklistFn(addToWorklistFn),
        instancePathCache(instancePathCache), hierPathCache(circuit, symTbl),
        noRefTypePorts(noRefTypePorts) {}
 
  CircuitOp circuit;
  SymbolTable &symTbl;
  CircuitTargetCache targetCaches;
  AddToWorklistFn addToWorklistFn;
  InstancePathCache &instancePathCache;
  HierPathCache hierPathCache;
  size_t numReusedHierPaths = 0;
 
  // Options that control annotation lowering.
  bool noRefTypePorts;
 
  DenseSet<InstanceOp> wiringProblemInstRefs;
  DenseMap<StringAttr, LegacyWiringProblem> legacyWiringProblems;
  SmallVector<WiringProblem> wiringProblems;
 
  hw::InnerSymbolNamespace &getNamespace(FModuleLike module) {
    return namespaces[module];
  }
 
  IntegerAttr newID() {
    return IntegerAttr::get(IntegerType::get(circuit.getContext(), 64),
                            annotationID++);
  }
 
private:
  hw::InnerSymbolNamespaceCollection namespaces;
  unsigned annotationID = 0;
};
 
LogicalResult applyGCTView(const AnnoPathValue &target, DictionaryAttr anno,
                           ApplyState &state);
 
LogicalResult applyGCTDataTaps(const AnnoPathValue &target, DictionaryAttr anno,
                               ApplyState &state);
 
LogicalResult applyGCTMemTaps(const AnnoPathValue &target, DictionaryAttr anno,
                              ApplyState &state);
 
LogicalResult applyTraceName(const AnnoPathValue &target, DictionaryAttr anno,
                             ApplyState &state);
 
LogicalResult applyWiring(const AnnoPathValue &target, DictionaryAttr anno,
                          ApplyState &state);
 
/// Implements the same behavior as DictionaryAttr::getAs<A> to return the
/// value of a specific type associated with a key in a dictionary. However,
/// this is specialized to print a useful error message, specific to custom
/// processing, on failure.
template <typename A>
A tryGetAsBase(DictionaryAttr dict, Attribute root, StringRef key, Location loc,
               Twine whatSpecific, Twine whatFull, Twine path = Twine()) {
  SmallString<128> msg;
  // Check that the key exists.
  auto value = dict.get(key);
  if (!value) {
    if (path.isTriviallyEmpty())
      (whatSpecific + " did not contain required key '" + key + "'.")
          .toVector(msg);
    else
      (whatSpecific + " with path '" + path +
       "' did not contain required key '" + key + "'.")
          .toVector(msg);
    mlir::emitError(loc, msg).attachNote()
        << "The full " << whatFull << " is reproduced here: " << root;
    return nullptr;
  }
  // Check that the value has the correct type.
  auto valueA = dyn_cast<A>(value);
  if (!valueA) {
    if (path.isTriviallyEmpty())
      (whatSpecific + " did not contain the correct type for key '" + key +
       "'.")
          .toVector(msg);
    else
      (whatSpecific + " with path '" + path +
       "' did not contain the correct type for key '" + key + "'.")
          .toVector(msg);
    mlir::emitError(loc, msg).attachNote()
        << "The full " << whatFull << " is reproduced here: " << root;
    return nullptr;
  }
  return valueA;
}
 
/// Implements the same behavior as DictionaryAttr::getAs<A> to return the
/// value of a specific type associated with a key in a dictionary. However,
/// this is specialized to print a useful error message, specific to custom
/// annotation process, on failure.
template <typename A>
A tryGetAs(DictionaryAttr dict, Attribute root, StringRef key, Location loc,
           Twine clazz, Twine path = Twine()) {
  return tryGetAsBase<A>(dict, root, key, loc, "Annotation '" + clazz + "'",
                         "Annotation", path);
}
 
/// Add ports to the module and all its instances and return the clone for
/// `instOnPath`. This does not connect the new ports to anything. Replace
/// the old instances with the new cloned instance in all the caches.
InstanceOp addPortsToModule(FModuleLike mod, InstanceOp instOnPath,
                            FIRRTLType portType, Direction dir,
                            StringRef newName,
                            InstancePathCache &instancePathcache,
                            CircuitTargetCache *targetCaches = nullptr);
 
///===----------------------------------------------------------------------===//
/// LowerAnnotations
///===----------------------------------------------------------------------===//
 
/// Annotation resolver and handler.
struct AnnoRecord {
  llvm::function_ref<std::optional<AnnoPathValue>(DictionaryAttr, ApplyState &)>
      resolver;
  llvm::function_ref<LogicalResult(const AnnoPathValue &, DictionaryAttr,
                                   ApplyState &)>
      applier;
};
 
/// Register external annotation records.
LogicalResult registerAnnotationRecord(
    StringRef annoClass, AnnoRecord annoRecord,
    const std::function<void(llvm::Twine)> &errorHandler = {});
 
///===----------------------------------------------------------------------===//
/// Standard Utility Resolvers
///===----------------------------------------------------------------------===//
 
/// (SFC) FIRRTL SingleTargetAnnotation resolver.  Uses the 'target' field of
/// the annotation with standard parsing to resolve the path.  This requires
/// 'target' to exist and be normalized (per docs/FIRRTLAnnotations.md).
std::optional<AnnoPathValue> stdResolve(DictionaryAttr anno, ApplyState &state);
 
/// Resolves with target, if it exists.  If not, resolves to the circuit.
std::optional<AnnoPathValue> tryResolve(DictionaryAttr anno, ApplyState &state);
 
///===----------------------------------------------------------------------===//
/// Standard Utility Appliers
///===----------------------------------------------------------------------===//
 
/// An applier which puts the annotation on the target and drops the 'target'
/// field from the annotation.  Optionally handles non-local annotations.
LogicalResult applyWithoutTargetImpl(const AnnoPathValue &target,
                                     DictionaryAttr anno, ApplyState &state,
                                     bool allowNonLocal);
 
/// An applier which puts the annotation on the target and drops the 'target'
/// field from the annotation.  Optionally handles non-local annotations.
/// Ensures the target resolves to an expected type of operation.
template <bool allowNonLocal, bool allowPortAnnoTarget, typename T,
          typename... Tr>
static LogicalResult applyWithoutTarget(const AnnoPathValue &target,
                                        DictionaryAttr anno,
                                        ApplyState &state) {
  if (isa<PortAnnoTarget>(target.ref)) {
    if (!allowPortAnnoTarget)
      return failure();
  } else if (!target.isOpOfType<T, Tr...>())
    return failure();
 
  return applyWithoutTargetImpl(target, anno, state, allowNonLocal);
}
 
template <bool allowNonLocal, typename T, typename... Tr>
static LogicalResult applyWithoutTarget(const AnnoPathValue &target,
                                        DictionaryAttr anno,
                                        ApplyState &state) {
  return applyWithoutTarget<allowNonLocal, false, T, Tr...>(target, anno,
                                                            state);
}
 
/// An applier which puts the annotation on the target and drops the 'target'
/// field from the annotaiton.  Optionally handles non-local annotations.
template <bool allowNonLocal = false>
static LogicalResult applyWithoutTarget(const AnnoPathValue &target,
                                        DictionaryAttr anno,
                                        ApplyState &state) {
  return applyWithoutTargetImpl(target, anno, state, allowNonLocal);
}
 
} // namespace firrtl
} // namespace circt
 
#endif // CIRCT_DIALECT_FIRRTL_FIRRTLANNOTATIONHELPER_H