[MsgPack] New MsgPackDocument class

Summary:
A class that exposes a simple in-memory representation of a document of
MsgPack objects, that can be read from and written to MsgPack, read from
and written to YAML, and inspected and modified in memory. This is
intended to be a lighter-weight (in terms of memory allocations)
replacement for MsgPackTypes.

Two subsequent changes will:
1. switch AMDGPU HSA metadata to using MsgPackDocument instead of
   MsgPackTypes;
2. add MsgPack AMDGPU PAL metadata via MsgPackDocument.

Differential Revision: https://reviews.llvm.org/D57023

Change-Id: Ie15a054831d5a6467c5867c064c8f8f6b80270e1
llvm-svn: 356080

1 files changed, 249 insertions, 0 deletions

diff --git a/llvm/lib/BinaryFormat/MsgPackDocumentYAML.cpp b/llvm/lib/BinaryFormat/MsgPackDocumentYAML.cpp
new file mode 100644
index 00000000000..ae67d7be132
--- /dev/null
+++ b/llvm/lib/BinaryFormat/MsgPackDocumentYAML.cpp
@@ -0,0 +1,249 @@
+//===-- MsgPackDocumentYAML.cpp - MsgPack Document YAML interface -------*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// This file implements YAMLIO on a msgpack::Document.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/BinaryFormat/MsgPackDocument.h"
+#include "llvm/Support/YAMLTraits.h"
+
+using namespace llvm;
+using namespace msgpack;
+
+namespace {
+
+// Struct used to represent scalar node. (MapDocNode and ArrayDocNode already
+// exist in MsgPackDocument.h.)
+struct ScalarDocNode : DocNode {
+  ScalarDocNode(DocNode N) : DocNode(N) {}
+
+  /// Get the YAML tag for this ScalarDocNode. This normally returns ""; it only
+  /// returns something else if the result of toString would be ambiguous, e.g.
+  /// a string that parses as a number or boolean.
+  StringRef getYAMLTag() const;
+};
+
+} // namespace
+
+/// Convert this DocNode to a string, assuming it is scalar.
+std::string DocNode::toString() const {
+  std::string S;
+  raw_string_ostream OS(S);
+  switch (getKind()) {
+  case msgpack::Type::String:
+    OS << Raw;
+    break;
+  case msgpack::Type::Nil:
+    break;
+  case msgpack::Type::Boolean:
+    OS << (Bool ? "true" : "false");
+    break;
+  case msgpack::Type::Int:
+    OS << Int;
+    break;
+  case msgpack::Type::UInt:
+    if (getDocument()->getHexMode())
+      OS << format("%#llx", (unsigned long long)UInt);
+    else
+      OS << UInt;
+    break;
+  case msgpack::Type::Float:
+    OS << Float;
+    break;
+  default:
+    llvm_unreachable("not scalar");
+    break;
+  }
+  return S;
+}
+
+/// Convert the StringRef and use it to set this DocNode (assuming scalar). If
+/// it is a string, copy the string into the Document's strings list so we do
+/// not rely on S having a lifetime beyond this call. Tag is "" or a YAML tag.
+StringRef DocNode::fromString(StringRef S, StringRef Tag) {
+  if (Tag == "tag:yaml.org,2002:str")
+    Tag = "";
+  if (Tag == "!int" || Tag == "") {
+    // Try unsigned int then signed int.
+    *this = getDocument()->getNode(uint64_t(0));
+    StringRef Err = yaml::ScalarTraits<uint64_t>::input(S, nullptr, getUInt());
+    if (Err != "") {
+      *this = getDocument()->getNode(int64_t(0));
+      Err = yaml::ScalarTraits<int64_t>::input(S, nullptr, getInt());
+    }
+    if (Err == "" || Tag != "")
+      return Err;
+  }
+  if (Tag == "!nil") {
+    *this = getDocument()->getNode();
+    return "";
+  }
+  if (Tag == "!bool" || Tag == "") {
+    *this = getDocument()->getNode(false);
+    StringRef Err = yaml::ScalarTraits<bool>::input(S, nullptr, getBool());
+    if (Err == "" || Tag != "")
+      return Err;
+  }
+  if (Tag == "!float" || Tag == "") {
+    *this = getDocument()->getNode(0.0);
+    StringRef Err = yaml::ScalarTraits<double>::input(S, nullptr, getFloat());
+    if (Err == "" || Tag != "")
+      return Err;
+  }
+  assert((Tag == "!str" || Tag == "") && "unsupported tag");
+  std::string V;
+  StringRef Err = yaml::ScalarTraits<std::string>::input(S, nullptr, V);
+  if (Err == "")
+    *this = getDocument()->getNode(V, /*Copy=*/true);
+  return Err;
+}
+
+/// Get the YAML tag for this ScalarDocNode. This normally returns ""; it only
+/// returns something else if the result of toString would be ambiguous, e.g.
+/// a string that parses as a number or boolean.
+StringRef ScalarDocNode::getYAMLTag() const {
+  if (getKind() == msgpack::Type::Nil)
+    return "!nil";
+  // Try converting both ways and see if we get the same kind. If not, we need
+  // a tag.
+  ScalarDocNode N = getDocument()->getNode();
+  N.fromString(toString(), "");
+  if (N.getKind() == getKind())
+    return "";
+  // Tolerate signedness of int changing, as tags do not differentiate between
+  // them anyway.
+  if (N.getKind() == msgpack::Type::UInt && getKind() == msgpack::Type::Int)
+    return "";
+  if (N.getKind() == msgpack::Type::Int && getKind() == msgpack::Type::UInt)
+    return "";
+  // We do need a tag.
+  switch (getKind()) {
+  case msgpack::Type::String:
+    return "!str";
+  case msgpack::Type::Int:
+    return "!int";
+  case msgpack::Type::UInt:
+    return "!int";
+  case msgpack::Type::Boolean:
+    return "!bool";
+  case msgpack::Type::Float:
+    return "!float";
+  default:
+    llvm_unreachable("unrecognized kind");
+  }
+}
+
+namespace llvm {
+namespace yaml {
+
+/// YAMLIO for DocNode
+template <> struct PolymorphicTraits<DocNode> {
+
+  static NodeKind getKind(const DocNode &N) {
+    switch (N.getKind()) {
+    case msgpack::Type::Map:
+      return NodeKind::Map;
+    case msgpack::Type::Array:
+      return NodeKind::Sequence;
+    default:
+      return NodeKind::Scalar;
+    }
+  }
+
+  static MapDocNode &getAsMap(DocNode &N) { return N.getMap(/*Convert=*/true); }
+
+  static ArrayDocNode &getAsSequence(DocNode &N) {
+    N.getArray(/*Convert=*/true);
+    return *static_cast<ArrayDocNode *>(&N);
+  }
+
+  static ScalarDocNode &getAsScalar(DocNode &N) {
+    return *static_cast<ScalarDocNode *>(&N);
+  }
+};
+
+/// YAMLIO for ScalarDocNode
+template <> struct TaggedScalarTraits<ScalarDocNode> {
+
+  static void output(const ScalarDocNode &S, void *Ctxt, raw_ostream &OS,
+                     raw_ostream &TagOS) {
+    TagOS << S.getYAMLTag();
+    OS << S.toString();
+  }
+
+  static StringRef input(StringRef Str, StringRef Tag, void *Ctxt,
+                         ScalarDocNode &S) {
+    return S.fromString(Str, Tag);
+  }
+
+  static QuotingType mustQuote(const ScalarDocNode &S, StringRef ScalarStr) {
+    switch (S.getKind()) {
+    case Type::Int:
+      return ScalarTraits<int64_t>::mustQuote(ScalarStr);
+    case Type::UInt:
+      return ScalarTraits<uint64_t>::mustQuote(ScalarStr);
+    case Type::Nil:
+      return ScalarTraits<StringRef>::mustQuote(ScalarStr);
+    case Type::Boolean:
+      return ScalarTraits<bool>::mustQuote(ScalarStr);
+    case Type::Float:
+      return ScalarTraits<double>::mustQuote(ScalarStr);
+    case Type::Binary:
+    case Type::String:
+      return ScalarTraits<std::string>::mustQuote(ScalarStr);
+    default:
+      llvm_unreachable("unrecognized ScalarKind");
+    }
+  }
+};
+
+/// YAMLIO for MapDocNode
+template <> struct CustomMappingTraits<MapDocNode> {
+
+  static void inputOne(IO &IO, StringRef Key, MapDocNode &M) {
+    ScalarDocNode KeyObj = M.getDocument()->getNode();
+    KeyObj.fromString(Key, "");
+    IO.mapRequired(Key.str().c_str(), M.getMap()[KeyObj]);
+  }
+
+  static void output(IO &IO, MapDocNode &M) {
+    for (auto I : M.getMap()) {
+      IO.mapRequired(I.first.toString().c_str(), I.second);
+    }
+  }
+};
+
+/// YAMLIO for ArrayNode
+template <> struct SequenceTraits<ArrayDocNode> {
+
+  static size_t size(IO &IO, ArrayDocNode &A) { return A.size(); }
+
+  static DocNode &element(IO &IO, ArrayDocNode &A, size_t Index) {
+    return A[Index];
+  }
+};
+
+} // namespace yaml
+} // namespace llvm
+
+/// Convert MsgPack Document to YAML text.
+void msgpack::Document::toYAML(raw_ostream &OS) {
+  yaml::Output Yout(OS);
+  Yout << getRoot();
+}
+
+/// Read YAML text into the MsgPack document. Returns false on failure.
+bool msgpack::Document::fromYAML(StringRef S) {
+  clear();
+  yaml::Input Yin(S);
+  Yin >> getRoot();
+  return !Yin.error();
+}
+