[Lldb-commits] [lldb] [lldb-dap] When sending a DAP Output Event break each message into separate lines. (PR #105456)

[John Harrison via lldb-commits]

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@@ -311,10 +309,22 @@ void DAP::SendOutput(OutputType o, const llvm::StringRef output) {
     category = "telemetry";
     break;
   }
-  body.try_emplace("category", category);
-  EmplaceSafeString(body, "output", output.str());
-  event.try_emplace("body", std::move(body));
-  SendJSON(llvm::json::Value(std::move(event)));
+
+  // Send each line of output as an individual event, including the newline if
+  // present.
+  ::size_t idx = 0;
+  do {
+    ::size_t end = output.find('\n', idx);
+    if (end == llvm::StringRef::npos)
+      end = output.size() - 1;
+    llvm::json::Object event(CreateEventObject("output"));
+    llvm::json::Object body;
+    body.try_emplace("category", category);
+    EmplaceSafeString(body, "output", output.slice(idx, end + 1).str());
+    event.try_emplace("body", std::move(body));
+    SendJSON(llvm::json::Value(std::move(event)));
+    idx = end + 1;
+  } while (idx < output.size());
----------------
ashgti wrote:

VS Code append to the previous lines if the previous line don't end in a `\n` or `\r\n`  (https://github.com/microsoft/vscode/blob/d193e4b6f525e90911df21f8f1820cf0fe0fda0c/src/vs/workbench/contrib/debug/common/replModel.ts#L306).

With the previous version of this, if we had an output event like `abc\ndef` followed by `foo\n`, these would have been merged into a single 'output' item in the UI. With this change it will instead have `abc\n` as one output item and `deffoo\n` would become a second output item.

I can also increase the buffer size for the reads.

https://github.com/llvm/llvm-project/pull/105456