[lldb] Make `process connect` blocking in synchronous mode.

In synchronous mode, the process connect command and its aliases should
wait for the stop event before claiming the command is complete.
Currently, the stop event is always handled asynchronously by the
debugger.

The implementation takes the same approach as Process::ResumeSynchronous
which hijacks the event and handles it on the current thread. Similarly,
after this patch, the stop event is part of the command return object,
which is the property used by the test case.

Differential revision: https://reviews.llvm.org/D83728

diff --git a/lldb/include/lldb/Target/Platform.h b/lldb/include/lldb/Target/Platform.h
index 52696f1..6234b82 100644 (file)
--- a/lldb/include/lldb/Target/Platform.h
+++ b/lldb/include/lldb/Target/Platform.h
@@ -372,9 +372,13 @@ public:
 
   virtual lldb::ProcessSP ConnectProcess(llvm::StringRef connect_url,
                                          llvm::StringRef plugin_name,
-                                         lldb_private::Debugger &debugger,
-                                         lldb_private::Target *target,
-                                         lldb_private::Status &error);
+                                         Debugger &debugger, Target *target,
+                                         Status &error);
+
+  virtual lldb::ProcessSP
+  ConnectProcessSynchronous(llvm::StringRef connect_url,
+                            llvm::StringRef plugin_name, Debugger &debugger,
+                            Stream &stream, Target *target, Status &error);
 
   /// Attach to an existing process using a process ID.
   ///
@@ -848,6 +852,12 @@ public:
   }
 
 protected:
+  /// Private implementation of connecting to a process. If the stream is set
+  /// we connect synchronously.
+  lldb::ProcessSP DoConnectProcess(llvm::StringRef connect_url,
+                                   llvm::StringRef plugin_name,
+                                   Debugger &debugger, Stream *stream,
+                                   Target *target, Status &error);
   bool m_is_host;
   // Set to true when we are able to actually set the OS version while being
   // connected. For remote platforms, we might set the version ahead of time

diff --git a/lldb/source/Commands/CommandObjectProcess.cpp b/lldb/source/Commands/CommandObjectProcess.cpp
index 3659f0d..f86779d 100644 (file)
--- a/lldb/source/Commands/CommandObjectProcess.cpp
+++ b/lldb/source/Commands/CommandObjectProcess.cpp
@@ -820,9 +820,15 @@ protected:
     Status error;
     Debugger &debugger = GetDebugger();
     PlatformSP platform_sp = m_interpreter.GetPlatform(true);
-    ProcessSP process_sp = platform_sp->ConnectProcess(
-        command.GetArgumentAtIndex(0), plugin_name, debugger,
-        debugger.GetSelectedTarget().get(), error);
+    ProcessSP process_sp =
+        debugger.GetAsyncExecution()
+            ? platform_sp->ConnectProcess(
+                  command.GetArgumentAtIndex(0), plugin_name, debugger,
+                  debugger.GetSelectedTarget().get(), error)
+            : platform_sp->ConnectProcessSynchronous(
+                  command.GetArgumentAtIndex(0), plugin_name, debugger,
+                  result.GetOutputStream(), debugger.GetSelectedTarget().get(),
+                  error);
     if (error.Fail() || process_sp == nullptr) {
       result.AppendError(error.AsCString("Error connecting to the process"));
       result.SetStatus(eReturnStatusFailed);

diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index 95c35ea..1678714 100644 (file)
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -12,9 +12,6 @@
 #include <memory>
 #include <vector>
 
-#include "llvm/Support/FileSystem.h"
-#include "llvm/Support/Path.h"
-
 #include "lldb/Breakpoint/BreakpointIDList.h"
 #include "lldb/Breakpoint/BreakpointLocation.h"
 #include "lldb/Core/Debugger.h"
@@ -40,8 +37,8 @@
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/StructuredData.h"
-
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
 
 // Define these constants from POSIX mman.h rather than include the file so
 // that they will be correct even when compiled on Linux.
@@ -1774,9 +1771,23 @@ Status Platform::UnloadImage(lldb_private::Process *process,
 
 lldb::ProcessSP Platform::ConnectProcess(llvm::StringRef connect_url,
                                          llvm::StringRef plugin_name,
-                                         lldb_private::Debugger &debugger,
-                                         lldb_private::Target *target,
-                                         lldb_private::Status &error) {
+                                         Debugger &debugger, Target *target,
+                                         Status &error) {
+  return DoConnectProcess(connect_url, plugin_name, debugger, nullptr, target,
+                          error);
+}
+
+lldb::ProcessSP Platform::ConnectProcessSynchronous(
+    llvm::StringRef connect_url, llvm::StringRef plugin_name,
+    Debugger &debugger, Stream &stream, Target *target, Status &error) {
+  return DoConnectProcess(connect_url, plugin_name, debugger, &stream, target,
+                          error);
+}
+
+lldb::ProcessSP Platform::DoConnectProcess(llvm::StringRef connect_url,
+                                           llvm::StringRef plugin_name,
+                                           Debugger &debugger, Stream *stream,
+                                           Target *target, Status &error) {
   error.Clear();
 
   if (!target) {
@@ -1803,12 +1814,34 @@ lldb::ProcessSP Platform::ConnectProcess(llvm::StringRef connect_url,
 
   lldb::ProcessSP process_sp =
       target->CreateProcess(debugger.GetListener(), plugin_name, nullptr);
+
   if (!process_sp)
     return nullptr;
 
+  // If this private method is called with a stream we are synchronous.
+  const bool synchronous = stream != nullptr;
+
+  ListenerSP listener_sp(
+      Listener::MakeListener("lldb.Process.ConnectProcess.hijack"));
+  if (synchronous)
+    process_sp->HijackProcessEvents(listener_sp);
+
   error = process_sp->ConnectRemote(connect_url);
-  if (error.Fail())
+  if (error.Fail()) {
+    if (synchronous)
+      process_sp->RestoreProcessEvents();
     return nullptr;
+  }
+
+  if (synchronous) {
+    EventSP event_sp;
+    process_sp->WaitForProcessToStop(llvm::None, &event_sp, true, listener_sp,
+                                     nullptr);
+    process_sp->RestoreProcessEvents();
+    bool pop_process_io_handler = false;
+    Process::HandleProcessStateChangedEvent(event_sp, stream,
+                                            pop_process_io_handler);
+  }
 
   return process_sp;
 }

diff --git a/lldb/test/API/functionalities/gdb_remote_client/TestProcessConnect.py b/lldb/test/API/functionalities/gdb_remote_client/TestProcessConnect.py
new file mode 100644 (file)
index 0000000..34ae8d0
--- /dev/null
+++ b/lldb/test/API/functionalities/gdb_remote_client/TestProcessConnect.py
@@ -0,0 +1,52 @@
+import lldb
+import binascii
+import os
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+from gdbclientutils import *
+
+
+class TestProcessConnect(GDBRemoteTestBase):
+    def test_gdb_remote_sync(self):
+        """Test the gdb-remote command in synchronous mode"""
+        try:
+            self.dbg.SetAsync(False)
+            self.expect("gdb-remote %d" % self.server.port,
+                        substrs=['Process', 'stopped'])
+        finally:
+            self.dbg.GetSelectedPlatform().DisconnectRemote()
+
+    def test_gdb_remote_async(self):
+        """Test the gdb-remote command in asynchronous mode"""
+        try:
+            self.dbg.SetAsync(True)
+            self.expect("gdb-remote %d" % self.server.port,
+                        matching=False,
+                        substrs=['Process', 'stopped'])
+            lldbutil.expect_state_changes(self, self.dbg.GetListener(),
+                                          self.process(), [lldb.eStateStopped])
+        finally:
+            self.dbg.GetSelectedPlatform().DisconnectRemote()
+
+    def test_process_connect_sync(self):
+        """Test the gdb-remote command in synchronous mode"""
+        try:
+            self.dbg.SetAsync(False)
+            self.expect("process connect connect://localhost:%d" %
+                        self.server.port,
+                        substrs=['Process', 'stopped'])
+        finally:
+            self.dbg.GetSelectedPlatform().DisconnectRemote()
+
+    def test_process_connect_async(self):
+        """Test the gdb-remote command in asynchronous mode"""
+        try:
+            self.dbg.SetAsync(True)
+            self.expect("process connect connect://localhost:%d" %
+                        self.server.port,
+                        matching=False,
+                        substrs=['Process', 'stopped'])
+            lldbutil.expect_state_changes(self, self.dbg.GetListener(),
+                                          self.process(), [lldb.eStateStopped])
+        finally:
+            self.dbg.GetSelectedPlatform().DisconnectRemote()