From: Michał Górny <mgorny@moritz.systems>
Date: Thu, 8 Apr 2021 21:15:38 +0000 (+0200)
Subject: [lldb] [gdb-remote server] Refactor handling qSupported
X-Git-Tag: llvmorg-14-init~9773
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=aab81c2f40d2098f9014473a1e7c8fb7b074360b;p=platform%2Fupstream%2Fllvm.git

[lldb] [gdb-remote server] Refactor handling qSupported

Refactor handling qSupported to use a virtual HandleFeatures() method.
The client-provided features are split into an array and passed
to the method.  The method returns an array of server features that are
concatenated into the qSupported response to the server.

The base implementation of HandleFeatures()
in GDBRemoteCommunicationServerCommon now includes only flags common
to both platform server and llgs, while llgs-specific flags are inserted
in GDBRemoteCommunicationServerLLGS.

Differential Revision: https://reviews.llvm.org/D100140
---

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
index c933364..a0d88b3 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
@@ -831,26 +831,10 @@ GDBRemoteCommunicationServerCommon::Handle_qPlatform_chmod(
 GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServerCommon::Handle_qSupported(
     StringExtractorGDBRemote &packet) {
-  StreamGDBRemote response;
-
-  // Features common to lldb-platform and llgs.
-  uint32_t max_packet_size = 128 * 1024; // 128KBytes is a reasonable max packet
-                                         // size--debugger can always use less
-  response.Printf("PacketSize=%x", max_packet_size);
-
-  response.PutCString(";QStartNoAckMode+");
-  response.PutCString(";QThreadSuffixSupported+");
-  response.PutCString(";QListThreadsInStopReply+");
-  response.PutCString(";qEcho+");
-  response.PutCString(";qXfer:features:read+");
-#if defined(__linux__) || defined(__NetBSD__) || defined(__FreeBSD__)
-  response.PutCString(";QPassSignals+");
-  response.PutCString(";qXfer:auxv:read+");
-  response.PutCString(";qXfer:libraries-svr4:read+");
-#endif
-  response.PutCString(";multiprocess+");
-
-  return SendPacketNoLock(response.GetString());
+  // Parse client-indicated features.
+  llvm::SmallVector<llvm::StringRef, 4> client_features;
+  packet.GetStringRef().split(client_features, ';');
+  return SendPacketNoLock(llvm::join(HandleFeatures(client_features), ";"));
 }
 
 GDBRemoteCommunication::PacketResult
@@ -1312,3 +1296,18 @@ GDBRemoteCommunicationServerCommon::GetModuleInfo(llvm::StringRef module_path,
 
   return matched_module_spec;
 }
+
+std::vector<std::string> GDBRemoteCommunicationServerCommon::HandleFeatures(
+    const llvm::ArrayRef<llvm::StringRef> client_features) {
+  // 128KBytes is a reasonable max packet size--debugger can always use less.
+  constexpr uint32_t max_packet_size = 128 * 1024;
+
+  // Features common to platform server and llgs.
+  return {
+      llvm::formatv("PacketSize={0}", max_packet_size),
+      "QStartNoAckMode+",
+      "QThreadSuffixSupported+",
+      "QListThreadsInStopReply+",
+      "qEcho+",
+  };
+}
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h
index 0f933c0..51d9fdd 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.h
@@ -145,6 +145,11 @@ protected:
   virtual FileSpec FindModuleFile(const std::string &module_path,
                                   const ArchSpec &arch);
 
+  // Process client_features (qSupported) and return an array of server features
+  // to be returned in response.
+  virtual std::vector<std::string>
+  HandleFeatures(llvm::ArrayRef<llvm::StringRef> client_features);
+
 private:
   ModuleSpec GetModuleInfo(llvm::StringRef module_path, llvm::StringRef triple);
 };
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 2f61586..e9034cb 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -3534,3 +3534,16 @@ GDBRemoteCommunicationServerLLGS::ReadTid(StringExtractorGDBRemote &packet,
 
   return tid;
 }
+
+std::vector<std::string> GDBRemoteCommunicationServerLLGS::HandleFeatures(
+    const llvm::ArrayRef<llvm::StringRef> client_features) {
+  auto ret =
+      GDBRemoteCommunicationServerCommon::HandleFeatures(client_features);
+  ret.insert(ret.end(), {
+    "qXfer:features:read+", "multiprocess+",
+#if defined(__linux__) || defined(__NetBSD__) || defined(__FreeBSD__)
+        "QPassSignals+", "qXfer:auxv:read+", "qXfer:libraries-svr4:read+",
+#endif
+  });
+  return ret;
+}
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
index ef7d447..de7ba68 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
@@ -219,6 +219,9 @@ protected:
 
   static std::string XMLEncodeAttributeValue(llvm::StringRef value);
 
+  virtual std::vector<std::string> HandleFeatures(
+      const llvm::ArrayRef<llvm::StringRef> client_features) override;
+
 private:
   llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> BuildTargetXml();