[XRay] convert FDR arg1 log entries

Summary:
A new FDR metadata record will support logging a function call argument;
appending multiple metadata records will represent a sequence of arguments
meaning that "holes" are not representable by the buffer format.  Each
call argument is currently a 64-bit value (useful for "this" pointers and
synchronization objects).

If present, we put this argument to the function call "entry" record it
belongs to, and alter its type to notify the user of its presence.

Reviewers: dberris

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32840

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314269 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Martin Pelikan

include/llvm/XRay/XRayRecord.h

@@ -53,7 +53,7 @@ struct XRayFileHeader {
 /// This may or may not correspond to actual record types in the raw trace (as
 /// the loader implementation may synthesize this information in the process of
 /// of loading).
-enum class RecordTypes { ENTER, EXIT, TAIL_EXIT };
+enum class RecordTypes { ENTER, EXIT, TAIL_EXIT, ENTER_ARG };
 
 struct XRayRecord {
   /// The type of record.
@@ -73,6 +73,9 @@ struct XRayRecord {
 
   /// The thread ID for the currently running thread.
   uint32_t TId;
+
+  /// The function call arguments.
+  std::vector<uint64_t> CallArgs;
 };
 
 } // namespace xray

include/llvm/XRay/YAMLXRayRecord.h

@@ -37,6 +37,7 @@ struct YAMLXRayRecord {
   std::string Function;
   uint64_t TSC;
   uint32_t TId;
+  std::vector<uint64_t> CallArgs;
 };
 
 struct YAMLXRayTrace {
@@ -55,6 +56,7 @@ template <> struct ScalarEnumerationTraits<xray::RecordTypes> {
     IO.enumCase(Type, "function-enter", xray::RecordTypes::ENTER);
     IO.enumCase(Type, "function-exit", xray::RecordTypes::EXIT);
     IO.enumCase(Type, "function-tail-exit", xray::RecordTypes::TAIL_EXIT);
+    IO.enumCase(Type, "function-enter-arg", xray::RecordTypes::ENTER_ARG);
   }
 };
 
@@ -74,6 +76,7 @@ template <> struct MappingTraits<xray::YAMLXRayRecord> {
     IO.mapRequired("type", Record.RecordType);
     IO.mapRequired("func-id", Record.FuncId);
     IO.mapOptional("function", Record.Function);
+    IO.mapOptional("args", Record.CallArgs);
     IO.mapRequired("cpu", Record.CPU);
     IO.mapRequired("thread", Record.TId);
     IO.mapRequired("kind", Record.Type);
@@ -83,6 +86,16 @@ template <> struct MappingTraits<xray::YAMLXRayRecord> {
   static constexpr bool flow = true;
 };
 
+template <> struct SequenceTraits<std::vector<uint64_t>> {
+  static constexpr bool flow = true;
+  static size_t size(IO &IO, std::vector<uint64_t> &V) { return V.size(); }
+  static uint64_t &element(IO &IO, std::vector<uint64_t> &V, size_t Index) {
+    if (Index >= V.size())
+      V.resize(Index + 1);
+    return V[Index];
+  }
+};
+
 template <> struct MappingTraits<xray::YAMLXRayTrace> {
   static void mapping(IO &IO, xray::YAMLXRayTrace &Trace) {
     // A trace file contains two parts, the header and the list of all the

lib/XRay/Trace.cpp

@@ -128,6 +128,7 @@ struct FDRState {
     FUNCTION_SEQUENCE,
     SCAN_TO_END_OF_THREAD_BUF,
     CUSTOM_EVENT_DATA,
+    CALL_ARGUMENT,
   };
   Token Expects;
 
@@ -151,6 +152,8 @@ const char *fdrStateToTwine(const FDRState::Token &state) {
     return "SCAN_TO_END_OF_THREAD_BUF";
   case FDRState::Token::CUSTOM_EVENT_DATA:
     return "CUSTOM_EVENT_DATA";
+  case FDRState::Token::CALL_ARGUMENT:
+    return "CALL_ARGUMENT";
   }
   return "UNKNOWN";
 }
@@ -238,14 +241,31 @@ Error processCustomEventMarker(FDRState &State, uint8_t RecordFirstByte,
   return Error::success();
 }
 
+/// State transition when a CallArgumentRecord is encountered.
+Error processFDRCallArgumentRecord(FDRState &State, uint8_t RecordFirstByte,
+                                   DataExtractor &RecordExtractor,
+                                   std::vector<XRayRecord> &Records) {
+  uint32_t OffsetPtr = 1; // Read starting after the first byte.
+  auto &Enter = Records.back();
+
+  if (Enter.Type != RecordTypes::ENTER)
+    return make_error<StringError>(
+        "CallArgument needs to be right after a function entry",
+        std::make_error_code(std::errc::executable_format_error));
+  Enter.Type = RecordTypes::ENTER_ARG;
+  Enter.CallArgs.emplace_back(RecordExtractor.getU64(&OffsetPtr));
+  return Error::success();
+}
+
 /// Advances the state machine for reading the FDR record type by reading one
 /// Metadata Record and updating the State appropriately based on the kind of
 /// record encountered. The RecordKind is encoded in the first byte of the
 /// Record, which the caller should pass in because they have already read it
 /// to determine that this is a metadata record as opposed to a function record.
 Error processFDRMetadataRecord(FDRState &State, uint8_t RecordFirstByte,
                                DataExtractor &RecordExtractor,
-                               size_t &RecordSize) {
+                               size_t &RecordSize,
+                               std::vector<XRayRecord> &Records) {
   // The remaining 7 bits are the RecordKind enum.
   uint8_t RecordKind = RecordFirstByte >> 1;
   switch (RecordKind) {
@@ -279,6 +299,11 @@ Error processFDRMetadataRecord(FDRState &State, uint8_t RecordFirstByte,
                                           RecordExtractor, RecordSize))
       return E;
     break;
+  case 6: // CallArgument
+    if (auto E = processFDRCallArgumentRecord(State, RecordFirstByte,
+                                              RecordExtractor, Records))
+      return E;
+    break;
   default:
     // Widen the record type to uint16_t to prevent conversion to char.
     return make_error<StringError>(
@@ -434,7 +459,7 @@ Error loadFDRLog(StringRef Data, XRayFileHeader &FileHeader,
     if (isMetadataRecord) {
       RecordSize = 16;
       if (auto E = processFDRMetadataRecord(State, BitField, RecordExtractor,
-                                            RecordSize))
+                                            RecordSize, Records))
         return E;
     } else { // Process Function Record
       RecordSize = 8;

test/tools/llvm-xray/X86/Inputs/fdr-log-arg1.xray

@@ -0,0 +1,13 @@
+; RUN: llvm-xray convert %S/Inputs/fdr-log-arg1.xray -f=yaml -o - | FileCheck %s
+
+; CHECK:      ---
+; CHECK-NEXT: header:
+; CHECK-NEXT:   version:         1
+; CHECK-NEXT:   type:            1
+; CHECK-NEXT:   constant-tsc:    true
+; CHECK-NEXT:   nonstop-tsc:     true
+; CHECK-NEXT:   cycle-frequency: 3500000000
+; CHECK-NEXT: records:
+; CHECK-NEXT:   - { type: 0, func-id: 1, function: '1', args: [ 1 ], cpu: 49, thread: 14648, kind: function-enter-arg, tsc: 18828908666543318 }
+; CHECK-NEXT:   - { type: 0, func-id: 1, function: '1', cpu: 49, thread: 14648, kind: function-exit, tsc: 18828908666595604 }
+; CHECK-NEXT: ...

test/tools/llvm-xray/X86/convert-fdr-arg1-to-yaml.txt

@@ -146,7 +146,8 @@ bool LatencyAccountant::accountRecord(const XRayRecord &Record) {
 
   auto &ThreadStack = PerThreadFunctionStack[Record.TId];
   switch (Record.Type) {
-  case RecordTypes::ENTER: {
+  case RecordTypes::ENTER:
+  case RecordTypes::ENTER_ARG: {
     ThreadStack.emplace_back(Record.FuncId, Record.TSC);
     break;
   }

tools/llvm-xray/xray-account.cc

@@ -86,7 +86,7 @@ void TraceConverter::exportAsYAML(const Trace &Records, raw_ostream &OS) {
     Trace.Records.push_back({R.RecordType, R.CPU, R.Type, R.FuncId,
                              Symbolize ? FuncIdHelper.SymbolOrNumber(R.FuncId)
                                        : llvm::to_string(R.FuncId),
-                             R.TSC, R.TId});
+                             R.TSC, R.TId, R.CallArgs});
   }
   Output Out(OS, nullptr, 0);
   Out << Trace;
@@ -123,6 +123,7 @@ void TraceConverter::exportAsRAWv1(const Trace &Records, raw_ostream &OS) {
     Writer.write(static_cast<uint8_t>(R.CPU));
     switch (R.Type) {
     case RecordTypes::ENTER:
+    case RecordTypes::ENTER_ARG:
       Writer.write(uint8_t{0});
       break;
     case RecordTypes::EXIT:

tools/llvm-xray/xray-converter.cc

@@ -208,7 +208,8 @@ Error GraphRenderer::accountRecord(const XRayRecord &Record) {
 
   auto &ThreadStack = PerThreadFunctionStack[Record.TId];
   switch (Record.Type) {
-  case RecordTypes::ENTER: {
+  case RecordTypes::ENTER:
+  case RecordTypes::ENTER_ARG: {
     if (Record.FuncId != 0 && G.count(Record.FuncId) == 0)
       G[Record.FuncId].SymbolName = FuncIdHelper.SymbolOrNumber(Record.FuncId);
     ThreadStack.push_back({Record.FuncId, Record.TSC});