[Reproducers] Refactor reproducer info

In the original reproducer design, I expected providers to be more
dynamic than they turned out. For example, we don't have any instances
where one provider has multiple files. Additionally, I expected there to
be less locality between capture and replay, with the provider being
defined in one place and the replay code to live in another. Both
contributed to the design of the provider info.

This patch refactors the reproducer info to be something static. This
means less magic strings and better type checking. The new design still
allows for the capture and replay code to live in different places as
long as they both have access to the new statically defined info class.

I didn't completely get rid of the index, because it is useful for (1)
sanity checking and (2) knowing what files are used by the reproducer.

Differential revision: https://reviews.llvm.org/D56814

llvm-svn: 351501

2 files changed, 26 insertions, 27 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 797f63d537a..00bdd74eecb 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -157,17 +157,24 @@ static const ProcessKDPPropertiesSP &GetGlobalPluginProperties() {
   return g_settings_sp;
 }
 
+struct ProcessGDBRemoteInfo {
+  static const char *name;
+  static const char *file;
+};
+
+const char *ProcessGDBRemoteInfo::name = "gdb-remote";
+const char *ProcessGDBRemoteInfo::file = "gdb-remote.yaml";
+
 class ProcessGDBRemoteProvider
     : public repro::Provider<ProcessGDBRemoteProvider> {
 public:
+  typedef ProcessGDBRemoteInfo info;
+
   ProcessGDBRemoteProvider(const FileSpec &directory) : Provider(directory) {
-    m_info.name = "gdb-remote";
-    m_info.files.push_back("gdb-remote.yaml");
   }
 
   raw_ostream *GetHistoryStream() {
-    FileSpec history_file =
-        GetRoot().CopyByAppendingPathComponent("gdb-remote.yaml");
+    FileSpec history_file = GetRoot().CopyByAppendingPathComponent(info::file);
 
     std::error_code EC;
     m_stream_up = llvm::make_unique<raw_fd_ostream>(history_file.GetPath(), EC,
@@ -3432,16 +3439,10 @@ Status ProcessGDBRemote::ConnectToReplayServer(repro::Loader *loader) {
   if (!loader)
     return Status("No loader provided.");
 
-  auto provider_info = loader->GetProviderInfo("gdb-remote");
-  if (!provider_info)
-    return Status("No provider for gdb-remote.");
-
-  if (provider_info->files.empty())
-    return Status("Provider for  gdb-remote contains no files.");
-
   // Construct replay history path.
-  FileSpec history_file = loader->GetRoot().CopyByAppendingPathComponent(
-      provider_info->files.front());
+  FileSpec history_file = loader->GetFile<ProcessGDBRemoteInfo>();
+  if (!history_file)
+    return Status("No provider for gdb-remote.");
 
   // Enable replay mode.
   m_replay_mode = true;
diff --git a/lldb/source/Utility/Reproducer.cpp b/lldb/source/Utility/Reproducer.cpp
index 6e85ba41767..d012faf9d76 100644
--- a/lldb/source/Utility/Reproducer.cpp
+++ b/lldb/source/Utility/Reproducer.cpp
@@ -178,10 +178,13 @@ void Generator::AddProvidersToIndex() {
                                                 sys::fs::OpenFlags::F_None);
   yaml::Output yout(*strm);
 
+  std::vector<std::string> files;
+  files.reserve(m_providers.size());
   for (auto &provider : m_providers) {
-    auto &provider_info = provider.second->GetInfo();
-    yout << const_cast<ProviderInfo &>(provider_info);
+    files.emplace_back(provider.second->GetFile());
   }
+
+  yout << files;
 }
 
 Loader::Loader(const FileSpec &root) : m_root(root), m_loaded(false) {}
@@ -196,29 +199,24 @@ llvm::Error Loader::LoadIndex() {
   if (auto err = error_or_file.getError())
     return make_error<StringError>("unable to load reproducer index", err);
 
-  std::vector<ProviderInfo> provider_info;
   yaml::Input yin((*error_or_file)->getBuffer());
-  yin >> provider_info;
-
+  yin >> m_files;
   if (auto err = yin.error())
     return make_error<StringError>("unable to read reproducer index", err);
 
-  for (auto &info : provider_info)
-    m_provider_info[info.name] = info;
+  // Sort files to speed up search.
+  llvm::sort(m_files);
 
+  // Remember that we've loaded the index.
   m_loaded = true;
 
   return llvm::Error::success();
 }
 
-llvm::Optional<ProviderInfo> Loader::GetProviderInfo(StringRef name) {
+bool Loader::HasFile(StringRef file) {
   assert(m_loaded);
-
-  auto it = m_provider_info.find(name);
-  if (it == m_provider_info.end())
-    return llvm::None;
-
-  return it->second;
+  auto it = std::lower_bound(m_files.begin(), m_files.end(), file.str());
+  return (it != m_files.end()) && (*it == file);
 }
 
 void ProviderBase::anchor() {}