[Reproducer] Add `reproducer dump` command

[JDevlieghere]

Summary

This adds a reproducer dump commands which makes it possible to inspect a reproducer from inside LLDB. Currently it supports the Files, Commands and Version providers. I'm planning to add support for the GDB Remote provider in a future patch.

[jingham]

If I've run lldb like:

$ lldb -capture-path <PATH>

and then I want to dump the reproducer I've loaded, it seems annoying to have to say:

(lldb) reproducer dump -f <PATH>

Why do I need to type it again? So it seems like you could make -f optional, and if it isn't provided use the currently loaded reproducer?

[JDevlieghere]

Inspect the current reproducer when in replay mode and no path is specified.

Thanks for the suggestions, Jim!

[jingham]

The help for -f should say what happens if this option isn't provided. Otherwise this looks fine.

[jingham]

Approved with that addition.

lldb/lit/Reproducer/TestDump.test

+# This tests the reproducer dump functionality.
+
+# Generate a reproducer.
+# RUN: mkdir -p %t
+# RUN: rm -rf %t.repro
+# RUN: %clang %S/Inputs/simple.c -g -o %t/reproducer.out
+# RUN: %lldb -x -b -s %S/Inputs/FileCapture.in --capture --capture-path %t.repro %t/reproducer.out
+
+# RUN: %lldb -b -o 'reproducer dump -p files -f %t.repro' | FileCheck %s --check-prefix FILES
+# FILES: 'reproducer.out'
+# FILES: 'FileCapture.in'
+
+# RUN: %lldb -b -o 'reproducer dump -p version -f %t.repro' | FileCheck %s --check-prefix VERSION
+# VERSION: lldb version
+
+# RUN: %lldb -b -o 'reproducer dump -p commands -f %t.repro' | FileCheck %s --check-prefix COMMANDS
+# COMMANDS: command source
+# COMMANDS: target create
+# COMMANDS: command source

lldb/source/Commands/CommandObjectReproducer.cpp

 //===-- CommandObjectReproducer.cpp -----------------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 
 #include "CommandObjectReproducer.h"
 
+#include "lldb/Host/OptionParser.h"
 #include "lldb/Utility/Reproducer.h"
 
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Interpreter/CommandReturnObject.h"
 #include "lldb/Interpreter/OptionArgParser.h"
 #include "lldb/Interpreter/OptionGroupBoolean.h"
 
 using namespace lldb;
+using namespace llvm;
 using namespace lldb_private;
+using namespace lldb_private::repro;
+
+enum ReproducerProvider {
+  eReproducerProviderCommands,
+  eReproducerProviderFiles,
+  eReproducerProviderGDB,
+  eReproducerProviderVersion,
+  eReproducerProviderNone
+};
+
+static constexpr OptionEnumValueElement g_reproducer_provider_type[] = {
+    {
+        eReproducerProviderCommands,
+        "commands",
+        "Command Interpreter Commands",
+    },
+    {
+        eReproducerProviderFiles,
+        "files",
+        "Files",
+    },
+    {
+        eReproducerProviderGDB,
+        "gdb",
+        "GDB Remote Packets",
+    },
+    {
+        eReproducerProviderVersion,
+        "version",
+        "Version",
+    },
+    {
+        eReproducerProviderNone,
+        "none",
+        "None",
+    },
+};
+
+static constexpr OptionEnumValues ReproducerProviderType() {
+  return OptionEnumValues(g_reproducer_provider_type);
+}
+
+#define LLDB_OPTIONS_reproducer
+#include "CommandOptions.inc"
 
 class CommandObjectReproducerGenerate : public CommandObjectParsed {
 public:
   CommandObjectReproducerGenerate(CommandInterpreter &interpreter)
       : CommandObjectParsed(
             interpreter, "reproducer generate",
             "Generate reproducer on disk. When the debugger is in capture "
             "mode, this command will output the reproducer to a directory on "
             "disk. In replay mode this command in a no-op.",
             nullptr) {}
 
   ~CommandObjectReproducerGenerate() override = default;
 
 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     if (!command.empty()) {
       result.AppendErrorWithFormat("'%s' takes no arguments",
                                    m_cmd_name.c_str());
       return false;
     }
 
-    auto &r = repro::Reproducer::Instance();
+    auto &r = Reproducer::Instance();
     if (auto generator = r.GetGenerator()) {
       generator->Keep();
     } else if (r.GetLoader()) {
       // Make this operation a NOP in replay mode.
       result.SetStatus(eReturnStatusSuccessFinishNoResult);
       return result.Succeeded();
     } else {
       result.AppendErrorWithFormat("Unable to get the reproducer generator");

 protected:
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     if (!command.empty()) {
       result.AppendErrorWithFormat("'%s' takes no arguments",
                                    m_cmd_name.c_str());
       return false;
     }
 
-    auto &r = repro::Reproducer::Instance();
+    auto &r = Reproducer::Instance();
     if (r.GetGenerator()) {
       result.GetOutputStream() << "Reproducer is in capture mode.\n";
     } else if (r.GetLoader()) {
       result.GetOutputStream() << "Reproducer is in replay mode.\n";
     } else {
       result.GetOutputStream() << "Reproducer is off.\n";
     }
 
     result.SetStatus(eReturnStatusSuccessFinishResult);
     return result.Succeeded();
   }
 };
 
+static void SetError(CommandReturnObject &result, Error err) {
+  result.GetErrorStream().Printf("error: %s\n",
+                                 toString(std::move(err)).c_str());
+  result.SetStatus(eReturnStatusFailed);
+}
+
+class CommandObjectReproducerDump : public CommandObjectParsed {
+public:
+  CommandObjectReproducerDump(CommandInterpreter &interpreter)
+      : CommandObjectParsed(interpreter, "reproducer dump",
+                            "Dump the information contained in a reproducer.",
+                            nullptr) {}
+
+  ~CommandObjectReproducerDump() override = default;
+
+  Options *GetOptions() override { return &m_options; }
+
+  class CommandOptions : public Options {
+  public:
+    CommandOptions() : Options(), file() {}
+
+    ~CommandOptions() override = default;
+
+    Status SetOptionValue(uint32_t option_idx, StringRef option_arg,
+                          ExecutionContext *execution_context) override {
+      Status error;
+      const int short_option = m_getopt_table[option_idx].val;
+
+      switch (short_option) {
+      case 'f':
+        file.SetFile(option_arg, FileSpec::Style::native);
+        FileSystem::Instance().Resolve(file);
+        break;
+      case 'p':
+        provider = (ReproducerProvider)OptionArgParser::ToOptionEnum(
+            option_arg, GetDefinitions()[option_idx].enum_values, 0, error);
+        if (!error.Success())
+          error.SetErrorStringWithFormat("unrecognized value for provider '%s'",
+                                         option_arg.str().c_str());
+        break;
+      default:
+        llvm_unreachable("Unimplemented option");
+      }
+
+      return error;
+    }
+
+    void OptionParsingStarting(ExecutionContext *execution_context) override {
+      file.Clear();
+      provider = eReproducerProviderNone;
+    }
+
+    ArrayRef<OptionDefinition> GetDefinitions() override {
+      return makeArrayRef(g_reproducer_options);
+    }
+
+    FileSpec file;
+    ReproducerProvider provider = eReproducerProviderNone;
+  };
+
+protected:
+  bool DoExecute(Args &command, CommandReturnObject &result) override {
+    if (!command.empty()) {
+      result.AppendErrorWithFormat("'%s' takes no arguments",
+                                   m_cmd_name.c_str());
+      return false;
+    }
+
+    Loader loader(m_options.file);
+    if (Error err = loader.LoadIndex()) {
+      SetError(result, std::move(err));
+      return false;
+    }
+
+    switch (m_options.provider) {
+    case eReproducerProviderFiles: {
+      FileSpec vfs_mapping = loader.GetFile<FileProvider::Info>();
+
+      // Read the VFS mapping.
+      ErrorOr<std::unique_ptr<MemoryBuffer>> buffer =
+          vfs::getRealFileSystem()->getBufferForFile(vfs_mapping.GetPath());
+      if (!buffer) {
+        SetError(result, errorCodeToError(buffer.getError()));
+        return false;
+      }
+
+      // Initialize a VFS from the given mapping.
+      IntrusiveRefCntPtr<vfs::FileSystem> vfs = vfs::getVFSFromYAML(
+          std::move(buffer.get()), nullptr, vfs_mapping.GetPath());
+
+      // Dump the VFS to a buffer.
+      std::string str;
+      raw_string_ostream os(str);
+      static_cast<vfs::RedirectingFileSystem &>(*vfs).dump(os);
+      os.flush();
+
+      // Return the string.
+      result.AppendMessage(str);
+      result.SetStatus(eReturnStatusSuccessFinishResult);
+      return true;
+    }
+    case eReproducerProviderVersion: {
+      FileSpec version_file = loader.GetFile<VersionProvider::Info>();
+      ErrorOr<std::unique_ptr<MemoryBuffer>> buffer =
+          vfs::getRealFileSystem()->getBufferForFile(version_file.GetPath());
+      if (!buffer) {
+        SetError(result, errorCodeToError(buffer.getError()));
+        return false;
+      }
+      StringRef version = (*buffer)->getBuffer();
+      result.AppendMessage(version.str());
+      result.SetStatus(eReturnStatusSuccessFinishResult);
+      return true;
+    }
+    case eReproducerProviderCommands: {
+      // Create a new command loader.
+      std::unique_ptr<repro::CommandLoader> command_loader =
+          repro::CommandLoader::Create(&loader);
+      if (!command_loader) {
+        SetError(result,
+                 make_error<StringError>(llvm::inconvertibleErrorCode(),
+                                         "Unable to create command loader."));
+        return false;
+      }
+
+      // Iterate over the command files and dump them.
+      while (true) {
+        llvm::Optional<std::string> command_file =
+            command_loader->GetNextFile();
+        if (!command_file)
+          break;
+
+        auto command_buffer = llvm::MemoryBuffer::getFile(*command_file);
+        if (auto err = command_buffer.getError()) {
+          SetError(result, errorCodeToError(err));
+          return false;
+        }
+        result.AppendMessage((*command_buffer)->getBuffer());
+      }
+
+      result.SetStatus(eReturnStatusSuccessFinishResult);
+      return true;
+    }
+    case eReproducerProviderGDB: {
+      // FIXME: Dumping the GDB remote packets means moving the
+      // (de)serialization code out of the GDB-remote plugin.
+      result.AppendMessage("Dumping GDB remote packets isn't implemented yet.");
+      result.SetStatus(eReturnStatusSuccessFinishResult);
+      return true;
+    }
+    case eReproducerProviderNone:
+      result.SetError("No valid provider specified.");
+      return false;
+    }
+
+    result.SetStatus(eReturnStatusSuccessFinishNoResult);
+    return result.Succeeded();
+  }
+
+private:
+  CommandOptions m_options;
+};
+
 CommandObjectReproducer::CommandObjectReproducer(
     CommandInterpreter &interpreter)
     : CommandObjectMultiword(
           interpreter, "reproducer",
           "Commands for manipulate the reproducer functionality.",
           "reproducer <subcommand> [<subcommand-options>]") {
   LoadSubCommand(
       "generate",
       CommandObjectSP(new CommandObjectReproducerGenerate(interpreter)));
   LoadSubCommand("status", CommandObjectSP(
                                new CommandObjectReproducerStatus(interpreter)));
+  LoadSubCommand("dump",
+                 CommandObjectSP(new CommandObjectReproducerDump(interpreter)));
 }
 
 CommandObjectReproducer::~CommandObjectReproducer() = default;

lldb/source/Commands/Options.td

let Command = "log" in {
   def log_stack : Option<"stack", "S">, Group<1>,
     Desc<"Append a stack backtrace to each log line.">;
   def log_append : Option<"append", "a">, Group<1>,
     Desc<"Append to the log file instead of overwriting.">;
   def log_file_function : Option<"file-function", "F">, Group<1>,
     Desc<"Prepend the names of files and function that generate the logs.">;
 }
 
+let Command = "reproducer" in {
+  def reproducer_file : Option<"file", "f">, Group<1>, Arg<"Filename">,
+    Required, Desc<"The reproducer path.">;
+  def reproducer_provider : Option<"provider", "p">, Group<1>,
+    EnumArg<"None", "ReproducerProviderType()">,
+    Required, Desc<"The reproducer provider to dump.">;
+}
+
 let Command = "memory read" in {
   def memory_read_num_per_line : Option<"num-per-line", "l">, Group<1>,
     Arg<"NumberPerLine">, Desc<"The number of items per line to display.">;
   def memory_read_binary : Option<"binary", "b">, Group<2>,
     Desc<"If true, memory will be saved as binary. If false, the memory is "
     "saved save as an ASCII dump that uses the format, size, count and number "
     "per line settings.">;
   def memory_read_type : Option<"type", "t">, Groups<[3,4]>, Arg<"Name">,

llvm/include/llvm/Support/VirtualFileSystem.h

public:
   std::error_code isLocal(const Twine &Path, bool &Result) override;
 
   directory_iterator dir_begin(const Twine &Dir, std::error_code &EC) override;
 
   void setExternalContentsPrefixDir(StringRef PrefixDir);
 
   StringRef getExternalContentsPrefixDir() const;
 
+  void dump(raw_ostream &OS) const;
+  void dumpEntry(raw_ostream &OS, Entry *E, int NumSpaces = 0) const;
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   LLVM_DUMP_METHOD void dump() const;
-  LLVM_DUMP_METHOD void dumpEntry(Entry *E, int NumSpaces = 0) const;
 #endif
 };
 
 /// Collect all pairs of <virtual path, real path> entries from the
 /// \p YAMLFilePath. This is used by the module dependency collector to forward
 /// the entries into the reproducer output VFS YAML file.
 void collectVFSFromYAML(
     std::unique_ptr<llvm::MemoryBuffer> Buffer,

llvm/lib/Support/VirtualFileSystem.cpp

 void RedirectingFileSystem::setExternalContentsPrefixDir(StringRef PrefixDir) {
   ExternalContentsPrefixDir = PrefixDir.str();
 }
 
 StringRef RedirectingFileSystem::getExternalContentsPrefixDir() const {
   return ExternalContentsPrefixDir;
 }
 
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-LLVM_DUMP_METHOD void RedirectingFileSystem::dump() const {
+void RedirectingFileSystem::dump(raw_ostream &OS) const {
   for (const auto &Root : Roots)
-    dumpEntry(Root.get());
+    dumpEntry(OS, Root.get());
 }
 
-LLVM_DUMP_METHOD void
-RedirectingFileSystem::dumpEntry(RedirectingFileSystem::Entry *E,
+void RedirectingFileSystem::dumpEntry(raw_ostream &OS,
+                                      RedirectingFileSystem::Entry *E,
                                       int NumSpaces) const {
   StringRef Name = E->getName();
   for (int i = 0, e = NumSpaces; i < e; ++i)
-    dbgs() << " ";
-  dbgs() << "'" << Name.str().c_str() << "'"
-         << "\n";
+    OS << " ";
+  OS << "'" << Name.str().c_str() << "'"
 
   if (E->getKind() == RedirectingFileSystem::EK_Directory) {
     auto *DE = dyn_cast<RedirectingFileSystem::RedirectingDirectoryEntry>(E);
     assert(DE && "Should be a directory");
 
     for (std::unique_ptr<Entry> &SubEntry :
          llvm::make_range(DE->contents_begin(), DE->contents_end()))
-      dumpEntry(SubEntry.get(), NumSpaces + 2);
+      dumpEntry(OS, SubEntry.get(), NumSpaces + 2);
   }
 }
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD void RedirectingFileSystem::dump() const { dump(dbgs()); }
 #endif
 
 /// A helper class to hold the common YAML parsing state.
 class llvm::vfs::RedirectingFileSystemParser {
   yaml::Stream &Stream;
 
   void error(yaml::Node *N, const Twine &Msg) { Stream.printError(N, Msg); }