1 files changed, 189 insertions, 0 deletions
diff --git a/contrib/llvm/lib/TableGen/JSONBackend.cpp b/contrib/llvm/lib/TableGen/JSONBackend.cpp
new file mode 100644
index 000000000000..36cb2208a294
--- /dev/null
+++ b/contrib/llvm/lib/TableGen/JSONBackend.cpp
@@ -0,0 +1,189 @@
+//===- JSONBackend.cpp - Generate a JSON dump of all records. -*- C++ -*-=====//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This TableGen back end generates a machine-readable representation
+// of all the classes and records defined by the input, in JSON format.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/BitVector.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/TableGen/Error.h"
+#include "llvm/TableGen/Record.h"
+#include "llvm/TableGen/TableGenBackend.h"
+#include "llvm/Support/JSON.h"
+
+#define DEBUG_TYPE "json-emitter"
+
+using namespace llvm;
+
+namespace {
+
+class JSONEmitter {
+private:
+  RecordKeeper &Records;
+
+  json::Value translateInit(const Init &I);
+  json::Array listSuperclasses(const Record &R);
+
+public:
+  JSONEmitter(RecordKeeper &R);
+
+  void run(raw_ostream &OS);
+};
+
+} // end anonymous namespace
+
+JSONEmitter::JSONEmitter(RecordKeeper &R) : Records(R) {}
+
+json::Value JSONEmitter::translateInit(const Init &I) {
+
+  // Init subclasses that we return as JSON primitive values of one
+  // kind or another.
+
+  if (isa<UnsetInit>(&I)) {
+    return nullptr;
+  } else if (auto *Bit = dyn_cast<BitInit>(&I)) {
+    return Bit->getValue() ? 1 : 0;
+  } else if (auto *Bits = dyn_cast<BitsInit>(&I)) {
+    json::Array array;
+    for (unsigned i = 0, limit = Bits->getNumBits(); i < limit; i++)
+      array.push_back(translateInit(*Bits->getBit(i)));
+    return std::move(array);
+  } else if (auto *Int = dyn_cast<IntInit>(&I)) {
+    return Int->getValue();
+  } else if (auto *Str = dyn_cast<StringInit>(&I)) {
+    return Str->getValue();
+  } else if (auto *Code = dyn_cast<CodeInit>(&I)) {
+    return Code->getValue();
+  } else if (auto *List = dyn_cast<ListInit>(&I)) {
+    json::Array array;
+    for (auto val : *List)
+      array.push_back(translateInit(*val));
+    return std::move(array);
+  }
+
+  // Init subclasses that we return as JSON objects containing a
+  // 'kind' discriminator. For these, we also provide the same
+  // translation back into TableGen input syntax that -print-records
+  // would give.
+
+  json::Object obj;
+  obj["printable"] = I.getAsString();
+
+  if (auto *Def = dyn_cast<DefInit>(&I)) {
+    obj["kind"] = "def";
+    obj["def"] = Def->getDef()->getName();
+    return std::move(obj);
+  } else if (auto *Var = dyn_cast<VarInit>(&I)) {
+    obj["kind"] = "var";
+    obj["var"] = Var->getName();
+    return std::move(obj);
+  } else if (auto *VarBit = dyn_cast<VarBitInit>(&I)) {
+    if (auto *Var = dyn_cast<VarInit>(VarBit->getBitVar())) {
+      obj["kind"] = "varbit";
+      obj["var"] = Var->getName();
+      obj["index"] = VarBit->getBitNum();
+      return std::move(obj);
+    }
+  } else if (auto *Dag = dyn_cast<DagInit>(&I)) {
+    obj["kind"] = "dag";
+    obj["operator"] = translateInit(*Dag->getOperator());
+    if (auto name = Dag->getName())
+      obj["name"] = name->getAsUnquotedString();
+    json::Array args;
+    for (unsigned i = 0, limit = Dag->getNumArgs(); i < limit; ++i) {
+      json::Array arg;
+      arg.push_back(translateInit(*Dag->getArg(i)));
+      if (auto argname = Dag->getArgName(i))
+        arg.push_back(argname->getAsUnquotedString());
+      else
+        arg.push_back(nullptr);
+      args.push_back(std::move(arg));
+    }
+    obj["args"] = std::move(args);
+    return std::move(obj);
+  }
+
+  // Final fallback: anything that gets past here is simply given a
+  // kind field of 'complex', and the only other field is the standard
+  // 'printable' representation.
+
+  assert(!I.isConcrete());
+  obj["kind"] = "complex";
+  return std::move(obj);
+}
+
+void JSONEmitter::run(raw_ostream &OS) {
+  json::Object root;
+
+  root["!tablegen_json_version"] = 1;
+
+  // Prepare the arrays that will list the instances of every class.
+  // We mostly fill those in by iterating over the superclasses of
+  // each def, but we also want to ensure we store an empty list for a
+  // class with no instances at all, so we do a preliminary iteration
+  // over the classes, invoking std::map::operator[] to default-
+  // construct the array for each one.
+  std::map<std::string, json::Array> instance_lists;
+  for (const auto &C : Records.getClasses()) {
+    auto &Name = C.second->getNameInitAsString();
+    (void)instance_lists[Name];
+  }
+
+  // Main iteration over the defs.
+  for (const auto &D : Records.getDefs()) {
+    auto &Name = D.second->getNameInitAsString();
+    auto &Def = *D.second;
+
+    json::Object obj;
+    json::Array fields;
+
+    for (const RecordVal &RV : Def.getValues()) {
+      if (!Def.isTemplateArg(RV.getNameInit())) {
+        auto Name = RV.getNameInitAsString();
+        if (RV.getPrefix())
+          fields.push_back(Name);
+        obj[Name] = translateInit(*RV.getValue());
+      }
+    }
+
+    obj["!fields"] = std::move(fields);
+
+    json::Array superclasses;
+    for (const auto &SuperPair : Def.getSuperClasses())
+      superclasses.push_back(SuperPair.first->getNameInitAsString());
+    obj["!superclasses"] = std::move(superclasses);
+
+    obj["!name"] = Name;
+    obj["!anonymous"] = Def.isAnonymous();
+
+    root[Name] = std::move(obj);
+
+    // Add this def to the instance list for each of its superclasses.
+    for (const auto &SuperPair : Def.getSuperClasses()) {
+      auto SuperName = SuperPair.first->getNameInitAsString();
+      instance_lists[SuperName].push_back(Name);
+    }
+  }
+
+  // Make a JSON object from the std::map of instance lists.
+  json::Object instanceof;
+  for (auto kv: instance_lists)
+    instanceof[kv.first] = std::move(kv.second);
+  root["!instanceof"] = std::move(instanceof);
+
+  // Done. Write the output.
+  OS << json::Value(std::move(root)) << "\n";
+}
+
+namespace llvm {
+
+void EmitJSON(RecordKeeper &RK, raw_ostream &OS) { JSONEmitter(RK).run(OS); }
+} // end namespace llvm