Implement xfer:libraries-svr4:read packet

Summary:
This is the fourth patch to improve module loading in a series that started here (where I explain the motivation and solution): D62499

Implement the `xfer:libraries-svr4` packet by adding a new function that generates the list and then in Handle_xfer I generate the XML for it. The XML is really simple so I'm just using string concatenation because I believe it's more readable than having to deal with a DOM api.

Reviewers: clayborg, xiaobai, labath

Reviewed By: labath

Subscribers: emaste, mgorny, srhines, krytarowski, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62502

llvm-svn: 363707

3 files changed, 46 insertions, 0 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
index d095c7a057a..9767d3e8b98 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
@@ -825,6 +825,7 @@ GDBRemoteCommunicationServerCommon::Handle_qSupported(
 #if defined(__linux__) || defined(__NetBSD__)
   response.PutCString(";QPassSignals+");
   response.PutCString(";qXfer:auxv:read+");
+  response.PutCString(";qXfer:libraries-svr4:read+");
 #endif
 
   return SendPacketNoLock(response.GetString());
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 196607665bb..190db341ae0 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -2765,6 +2765,24 @@ GDBRemoteCommunicationServerLLGS::ReadXferObject(llvm::StringRef object,
     return std::move(*buffer_or_error);
   }
 
+  if (object == "libraries-svr4") {
+    auto library_list = m_debugged_process_up->GetLoadedSVR4Libraries();
+    if (!library_list)
+      return library_list.takeError();
+
+    StreamString response;
+    response.Printf("<library-list-svr4 version=\"1.0\">");
+    for (auto const &library : *library_list) {
+      response.Printf("<library name=\"%s\" ",
+                      XMLEncodeAttributeValue(library.name.c_str()).c_str());
+      response.Printf("lm=\"0x%" PRIx64 "\" ", library.link_map);
+      response.Printf("l_addr=\"0x%" PRIx64 "\" ", library.base_addr);
+      response.Printf("l_ld=\"0x%" PRIx64 "\" />", library.ld_addr);
+    }
+    response.Printf("</library-list-svr4>");
+    return MemoryBuffer::getMemBufferCopy(response.GetString(), __FUNCTION__);
+  }
+
   return llvm::make_error<PacketUnimplementedError>(
       "Xfer object not supported");
 }
@@ -3283,3 +3301,28 @@ GDBRemoteCommunicationServerLLGS::FindModuleFile(const std::string &module_path,
 
   return GDBRemoteCommunicationServerCommon::FindModuleFile(module_path, arch);
 }
+
+std::string GDBRemoteCommunicationServerLLGS::XMLEncodeAttributeValue(
+    llvm::StringRef value) {
+  std::string result;
+  for (const char &c : value) {
+    switch (c) {
+    case '\'':
+      result += "&apos;";
+      break;
+    case '"':
+      result += "&quot;";
+      break;
+    case '<':
+      result += "&lt;";
+      break;
+    case '>':
+      result += "&gt;";
+      break;
+    default:
+      result += c;
+      break;
+    }
+  }
+  return result;
+}
\ No newline at end of file
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
index 068ea52caaa..088ba92ad11 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
@@ -196,6 +196,8 @@ protected:
   llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
   ReadXferObject(llvm::StringRef object, llvm::StringRef annex);
 
+  static std::string XMLEncodeAttributeValue(llvm::StringRef value);
+
 private:
   void HandleInferiorState_Exited(NativeProcessProtocol *process);