[Lldb-commits] [lldb] [lldb-dap] Add stdio redirection (PR #158609)
Druzhkov Sergei via lldb-commits
lldb-commits at lists.llvm.org
Mon Sep 15 04:27:18 PDT 2025
https://github.com/DrSergei created https://github.com/llvm/llvm-project/pull/158609
As far as I understand, lldb-dap does not currently support stdio redirection. I have added support for this via a new field in the launch configuration named `stdio`. It was inspired by the same named field in [CodeLLDB](https://github.com/vadimcn/codelldb/blob/master/MANUAL.md#stdio-redirection).
>From 4c3e0090328b35fb8d0d92df3bd5378d9d811047 Mon Sep 17 00:00:00 2001
From: Druzhkov Sergei <serzhdruzhok at gmail.com>
Date: Mon, 15 Sep 2025 10:49:44 +0300
Subject: [PATCH] [lldb-dap] Add stdio redirection
---
.../test/tools/lldb-dap/dap_server.py | 3 +++
.../tools/lldb-dap/launch/TestDAP_launch.py | 21 ++++++++++++++++
.../tools/lldb-dap/Handler/RequestHandler.cpp | 25 +++++++++++++++++++
.../lldb-dap/Protocol/ProtocolRequests.cpp | 3 ++-
.../lldb-dap/Protocol/ProtocolRequests.h | 2 ++
lldb/tools/lldb-dap/README.md | 1 +
lldb/tools/lldb-dap/package.json | 8 ++++++
7 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
index 9fe8ca22e820b..daa3e76df6d82 100644
--- a/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
+++ b/lldb/packages/Python/lldbsuite/test/tools/lldb-dap/dap_server.py
@@ -1039,6 +1039,7 @@ def request_launch(
disableSTDIO=False,
shellExpandArguments=False,
console: Optional[str] = None,
+ stdio: Optional[list[str]] = None,
enableAutoVariableSummaries=False,
displayExtendedBacktrace=False,
enableSyntheticChildDebugging=False,
@@ -1090,6 +1091,8 @@ def request_launch(
args_dict["sourceMap"] = sourceMap
if console:
args_dict["console"] = console
+ if stdio:
+ args_dict["stdio"] = stdio
if postRunCommands:
args_dict["postRunCommands"] = postRunCommands
if customFrameFormat:
diff --git a/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py b/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py
index 22fcd42b3d36a..a301e00f6755f 100644
--- a/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py
+++ b/lldb/test/API/tools/lldb-dap/launch/TestDAP_launch.py
@@ -6,6 +6,7 @@
from lldbsuite.test.lldbtest import *
import lldbdap_testcase
import os
+import pathlib
import re
import tempfile
@@ -624,3 +625,23 @@ def test_no_lldbinit_flag(self):
# Verify the initCommands were executed
self.verify_commands("initCommands", output, initCommands)
+
+ def test_stdio_redirection(self):
+ """
+ Test stdio redirection.
+ """
+ temp_file = tempfile.NamedTemporaryFile().name
+ self.build_and_create_debug_adapter()
+ program = self.getBuildArtifact("a.out")
+
+ self.launch(program, stdio=[None, temp_file, None])
+ self.continue_to_exit()
+
+ try:
+ with open(temp_file, "r") as f:
+ lines = f.readlines()
+ self.assertIn(
+ program, lines[0], "make sure program path is in first argument"
+ )
+ finally:
+ pathlib.Path(temp_file).unlink(missing_ok=True)
diff --git a/lldb/tools/lldb-dap/Handler/RequestHandler.cpp b/lldb/tools/lldb-dap/Handler/RequestHandler.cpp
index 4fadf1c22e0e3..4b727e1e33a64 100644
--- a/lldb/tools/lldb-dap/Handler/RequestHandler.cpp
+++ b/lldb/tools/lldb-dap/Handler/RequestHandler.cpp
@@ -177,6 +177,31 @@ llvm::Error BaseRequestHandler::LaunchProcess(
launch_info.SetEnvironment(env, true);
}
+ if (!arguments.stdio.empty() && !arguments.disableSTDIO) {
+ size_t n = std::max(arguments.stdio.size(), static_cast<size_t>(3));
+ for (size_t i = 0; i < n; i++) {
+ std::optional<std::string> path;
+ if (arguments.stdio.size() < i)
+ path = arguments.stdio.back();
+ else
+ path = arguments.stdio[i];
+ if (!path)
+ continue;
+ switch (i) {
+ case 0:
+ launch_info.AddOpenFileAction(i, path->c_str(), true, false);
+ break;
+ case 1:
+ case 2:
+ launch_info.AddOpenFileAction(i, path->c_str(), false, true);
+ break;
+ default:
+ launch_info.AddOpenFileAction(i, path->c_str(), true, true);
+ break;
+ }
+ }
+ }
+
launch_info.SetDetachOnError(arguments.detachOnError);
launch_info.SetShellExpandArguments(arguments.shellExpandArguments);
diff --git a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
index e1806d6230a80..b455112cd37d9 100644
--- a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
+++ b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.cpp
@@ -303,7 +303,8 @@ bool fromJSON(const json::Value &Params, LaunchRequestArguments &LRA,
O.mapOptional("disableSTDIO", LRA.disableSTDIO) &&
O.mapOptional("shellExpandArguments", LRA.shellExpandArguments) &&
O.mapOptional("runInTerminal", LRA.console) &&
- O.mapOptional("console", LRA.console) && parseEnv(Params, LRA.env, P);
+ O.mapOptional("console", LRA.console) &&
+ O.mapOptional("stdio", LRA.stdio) && parseEnv(Params, LRA.env, P);
}
bool fromJSON(const json::Value &Params, AttachRequestArguments &ARA,
diff --git a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
index 0848ee53b4410..92dada2295841 100644
--- a/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
+++ b/lldb/tools/lldb-dap/Protocol/ProtocolRequests.h
@@ -300,6 +300,8 @@ struct LaunchRequestArguments {
/// terminal or external terminal.
Console console = eConsoleInternal;
+ std::vector<std::optional<std::string>> stdio;
+
/// @}
};
bool fromJSON(const llvm::json::Value &, LaunchRequestArguments &,
diff --git a/lldb/tools/lldb-dap/README.md b/lldb/tools/lldb-dap/README.md
index 39dabcc1342c8..52bb009b9c796 100644
--- a/lldb/tools/lldb-dap/README.md
+++ b/lldb/tools/lldb-dap/README.md
@@ -237,6 +237,7 @@ contain the following key/value pairs:
| **stopOnEntry** | boolean | | Whether to stop program immediately after launching.
| **runInTerminal** (deprecated) | boolean | | Launch the program inside an integrated terminal in the IDE. Useful for debugging interactive command line programs.
| **console** | string | | Specify where to launch the program: internal console (`internalConsole`), integrated terminal (`integratedTerminal`) or external terminal (`externalTerminal`). Supported from lldb-dap 21.0 version.
+| **stdio** | [string] | | Destination for program stdio streams (0 - stdin, 1 - stdout, 2 - stderr, ...). Using `null` value means no redirection. Supported from lldb-dap 22.0 version.
| **launchCommands** | [string] | | LLDB commands executed to launch the program.
For JSON configurations of `"type": "attach"`, the JSON configuration can contain
diff --git a/lldb/tools/lldb-dap/package.json b/lldb/tools/lldb-dap/package.json
index 0290a5f18f800..631b768b37c80 100644
--- a/lldb/tools/lldb-dap/package.json
+++ b/lldb/tools/lldb-dap/package.json
@@ -615,6 +615,14 @@
"description": "Specify where to launch the program: internal console, integrated terminal or external terminal.",
"default": "internalConsole"
},
+ "stdio": {
+ "type": "array",
+ "items": {
+ "type": "string"
+ },
+ "description": "Destination for program stdio streams (0 - stdin, 1 - stdout, 2 - stderr, ...). Using null value means no redirection.",
+ "default": []
+ },
"timeout": {
"type": "number",
"description": "The time in seconds to wait for a program to stop at entry point when launching with \"launchCommands\". Defaults to 30 seconds."
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