[lldb] Emit diagnostics as "important" output

Handle diagnostics events from the debugger (i.e. asynchronous errors
and warnings) in the lldb-dap event handler and emit them as "important"
output.

Author: JDevlieghere

lldb/packages/Python/lldbsuite/test/tools/lldb-dap/lldbdap_testcase.py

@@ -217,16 +217,25 @@ def get_stdout(self, timeout=0.0):
     def get_console(self, timeout=0.0):
         return self.dap_server.get_output("console", timeout=timeout)
 
+    def get_important(self, timeout=0.0):
+        return self.dap_server.get_output("important", timeout=timeout)
+
+    def collect_stdout(self, timeout_secs, pattern=None):
+        return self.dap_server.collect_output(
+            "stdout", timeout_secs=timeout_secs, pattern=pattern
+        )
+
     def collect_console(self, timeout_secs, pattern=None):
         return self.dap_server.collect_output(
             "console", timeout_secs=timeout_secs, pattern=pattern
         )
 
-    def collect_stdout(self, timeout_secs, pattern=None):
+    def collect_important(self, timeout_secs, pattern=None):
         return self.dap_server.collect_output(
-            "stdout", timeout_secs=timeout_secs, pattern=pattern
+            "important", timeout_secs=timeout_secs, pattern=pattern
         )
 
+
     def get_local_as_int(self, name, threadId=None):
         value = self.dap_server.get_local_variable_value(name, threadId=threadId)
         # 'value' may have the variable value and summary.

lldb/test/API/tools/lldb-dap/console/TestDAP_console.py

@@ -164,3 +164,20 @@ def test_exit_status_message_ok(self):
             console_output,
             "Exit status does not contain message 'exited with status'",
         )
+
+    def test_diagnositcs(self):
+        program = self.getBuildArtifact("a.out")
+        self.build_and_launch(program)
+
+        core = self.getBuildArtifact("minidump.core")
+        self.yaml2obj("minidump.yaml", core)
+        self.dap_server.request_evaluate(
+            f"target create --core  {core}", context="repl"
+        )
+
+        output = self.get_important()
+        self.assertIn(
+            "warning: unable to retrieve process ID from minidump file",
+            output,
+            "diagnostic found in important output",
+        )

lldb/test/API/tools/lldb-dap/console/minidump.yaml

@@ -0,0 +1,24 @@
+--- !minidump
+Streams:
+  - Type:            ThreadList
+    Threads:
+      - Thread Id:       0x00003E81
+        Context:         0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000B0010000000000033000000000000000000000006020100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000010A234EBFC7F000010A234EBFC7F00000000000000000000F09C34EBFC7F0000C0A91ABCE97F00000000000000000000A0163FBCE97F00004602000000000000921C40000000000030A434EBFC7F000000000000000000000000000000000000C61D4000000000007F0300000000000000000000000000000000000000000000801F0000FFFF0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000FFFF00FFFFFFFFFFFFFF00FFFFFFFF25252525252525252525252525252525000000000000000000000000000000000000000000000000000000000000000000FFFF00FFFFFFFFFFFFFF00FFFFFFFF0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000FF00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+        Stack:
+          Start of Memory Range: 0x00007FFCEB34A000
+          Content:         ''
+  - Type:            ModuleList
+    Modules:
+      - Base of Image:   0x0000000000400000
+        Size of Image:   0x00017000
+        Module Name:     'a.out'
+        CodeView Record: ''
+  - Type:            SystemInfo
+    Processor Arch:  AMD64
+    Platform ID:     Linux
+    CSD Version:     'Linux 3.13'
+    CPU:
+      Vendor ID:       GenuineIntel
+      Version Info:    0x00000000
+      Feature Info:    0x00000000
+...

lldb/tools/lldb-dap/DAP.cpp

@@ -342,6 +342,9 @@ void DAP::SendOutput(OutputType o, const llvm::StringRef output) {
   case OutputType::Console:
     category = "console";
     break;
+  case OutputType::Important:
+    category = "important";
+    break;
   case OutputType::Stdout:
     category = "stdout";
     break;

lldb/tools/lldb-dap/DAP.h

@@ -67,7 +67,7 @@ typedef llvm::DenseMap<lldb::addr_t, InstructionBreakpoint>
 using AdapterFeature = protocol::AdapterFeature;
 using ClientFeature = protocol::ClientFeature;
 
-enum class OutputType { Console, Stdout, Stderr, Telemetry };
+enum class OutputType { Console, Important, Stdout, Stderr, Telemetry };
 
 /// Buffer size for handling output events.
 constexpr uint64_t OutputBufferSize = (1u << 12);

lldb/tools/lldb-dap/Handler/InitializeRequestHandler.cpp

@@ -9,6 +9,7 @@
 #include "DAP.h"
 #include "EventHelper.h"
 #include "JSONUtils.h"
+#include "LLDBUtils.h"
 #include "Protocol/ProtocolRequests.h"
 #include "RequestHandler.h"
 #include "lldb/API/SBEvent.h"
@@ -117,6 +118,9 @@ static void EventThreadFunction(DAP &dap) {
   lldb::SBEvent event;
   lldb::SBListener listener = dap.debugger.GetListener();
   dap.broadcaster.AddListener(listener, eBroadcastBitStopEventThread);
+  dap.debugger.GetBroadcaster().AddListener(
+      listener, lldb::SBDebugger::eBroadcastBitError |
+                    lldb::SBDebugger::eBroadcastBitWarning);
   bool done = false;
   while (!done) {
     if (listener.WaitForEvent(1, event)) {
@@ -222,6 +226,15 @@ static void EventThreadFunction(DAP &dap) {
             dap.SendJSON(llvm::json::Value(std::move(bp_event)));
           }
         }
+      } else if (event_mask & eBroadcastBitError ||
+                 event_mask & eBroadcastBitWarning) {
+        SBStructuredData data = SBDebugger::GetDiagnosticFromEvent(event);
+        if (!data.IsValid())
+          continue;
+        std::string type = GetStringValue(data.GetValueForKey("type"));
+        std::string message = GetStringValue(data.GetValueForKey("message"));
+        dap.SendOutput(OutputType::Important,
+                       llvm::formatv("{0}: {1}", type, message).str());
       } else if (event.BroadcasterMatchesRef(dap.broadcaster)) {
         if (event_mask & eBroadcastBitStopEventThread) {
           done = true;

lldb/tools/lldb-dap/LLDBUtils.cpp

@@ -10,6 +10,7 @@
 #include "DAP.h"
 #include "JSONUtils.h"
 #include "lldb/API/SBStringList.h"
+#include "lldb/API/SBStructuredData.h"
 
 #include <mutex>
 
@@ -172,4 +173,17 @@ llvm::Error ToError(const lldb::SBError &error) {
       error.GetCString());
 }
 
+std::string GetStringValue(const lldb::SBStructuredData &data) {
+  if (!data.IsValid())
+    return "";
+
+  const size_t str_length = data.GetStringValue(nullptr, 0);
+  if (!str_length)
+    return "";
+
+  std::string str(str_length, 0);
+  data.GetStringValue(&str[0], str_length + 1);
+  return str;
+}
+
 } // namespace lldb_dap

lldb/tools/lldb-dap/LLDBUtils.h

@@ -159,6 +159,9 @@ GetEnvironmentFromArguments(const llvm::json::Object &arguments);
 /// Take ownership of the stored error.
 llvm::Error ToError(const lldb::SBError &error);
 
+/// Provides the string value if this data structure is a string type.
+std::string GetStringValue(const lldb::SBStructuredData &data);
+
 } // namespace lldb_dap
 
 #endif