[Lldb-commits] [lldb] [llvm] [LLDB] Add a target.launch-working-dir setting (PR #113521)

Walter Erquinigo via lldb-commits lldb-commits at lists.llvm.org
Fri Nov 1 14:58:53 PDT 2024


https://github.com/walter-erquinigo updated https://github.com/llvm/llvm-project/pull/113521

>From 819380f93381eff8200c7eb9c55372f9a840c379 Mon Sep 17 00:00:00 2001
From: walter erquinigo <walter at modular.com>
Date: Thu, 24 Oct 2024 00:17:48 -0400
Subject: [PATCH] [LLDB] Add a target.launch-working-dir setting

Internally we use bazel in a way in which it can drop you in a LLDB session with the target launched in a particular cwd, which is needed for things to work. We've been making this automation work via `process launch -w`. However, if later the user wants to restart the process with `r`, then they end up using a different cwd for relaunching the process.
As a way to fix this, I'm adding a target-level setting that allows setting a default cwd used for launching the process without needing the user to specify it manually.
---
 lldb/include/lldb/Target/Target.h             |  3 +
 lldb/source/Commands/CommandObjectProcess.cpp |  7 +++
 lldb/source/Commands/Options.td               |  5 +-
 lldb/source/Target/Target.cpp                 |  5 ++
 lldb/source/Target/TargetProperties.td        |  6 ++
 .../process/launch/TestProcessLaunch.py       | 57 +++++++++++++++++++
 llvm/docs/ReleaseNotes.md                     |  2 +
 7 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/lldb/include/lldb/Target/Target.h b/lldb/include/lldb/Target/Target.h
index e4848f19e64d62..cab21c29a7486f 100644
--- a/lldb/include/lldb/Target/Target.h
+++ b/lldb/include/lldb/Target/Target.h
@@ -37,6 +37,7 @@
 #include "lldb/Utility/RealpathPrefixes.h"
 #include "lldb/Utility/Timeout.h"
 #include "lldb/lldb-public.h"
+#include "llvm/ADT/StringRef.h"
 
 namespace lldb_private {
 
@@ -114,6 +115,8 @@ class TargetProperties : public Properties {
 
   void SetDisableSTDIO(bool b);
 
+  llvm::StringRef GetLaunchWorkingDirectory() const;
+
   const char *GetDisassemblyFlavor() const;
 
   InlineStrategy GetInlineStrategy() const;
diff --git a/lldb/source/Commands/CommandObjectProcess.cpp b/lldb/source/Commands/CommandObjectProcess.cpp
index e7c7d07ad47722..7444e46aa729e7 100644
--- a/lldb/source/Commands/CommandObjectProcess.cpp
+++ b/lldb/source/Commands/CommandObjectProcess.cpp
@@ -201,6 +201,13 @@ class CommandObjectProcessLaunch : public CommandObjectProcessLaunchOrAttach {
     if (target->GetDisableSTDIO())
       m_options.launch_info.GetFlags().Set(eLaunchFlagDisableSTDIO);
 
+    if (!m_options.launch_info.GetWorkingDirectory()) {
+      if (llvm::StringRef wd = target->GetLaunchWorkingDirectory();
+          !wd.empty()) {
+        m_options.launch_info.SetWorkingDirectory(FileSpec(wd));
+      }
+    }
+
     // Merge the launch info environment with the target environment.
     Environment target_env = target->GetEnvironment();
     m_options.launch_info.GetEnvironment().insert(target_env.begin(),
diff --git a/lldb/source/Commands/Options.td b/lldb/source/Commands/Options.td
index 4276d9e7f9c8b0..94d1219b82b87e 100644
--- a/lldb/source/Commands/Options.td
+++ b/lldb/source/Commands/Options.td
@@ -691,7 +691,10 @@ let Command = "process launch" in {
   def process_launch_plugin : Option<"plugin", "P">, Arg<"Plugin">,
     Desc<"Name of the process plugin you want to use.">;
   def process_launch_working_dir : Option<"working-dir", "w">, Arg<"DirectoryName">,
-    Desc<"Set the current working directory to <path> when running the inferior.">;
+    Desc<"Set the current working directory to <path> when running the inferior. This setting "
+         "applies only to the current `process launch` invocation. You can use the "
+         "`target.launch-working-dir` setting to set a working-dir that is persistent "
+         "across launches.">;
   def process_launch_arch : Option<"arch", "a">, Arg<"Architecture">,
     Desc<"Set the architecture for the process to launch when ambiguous.">;
   def process_launch_environment : Option<"environment", "E">,
diff --git a/lldb/source/Target/Target.cpp b/lldb/source/Target/Target.cpp
index 199efae8a728cc..b6d4b28b03a5b3 100644
--- a/lldb/source/Target/Target.cpp
+++ b/lldb/source/Target/Target.cpp
@@ -4428,6 +4428,11 @@ void TargetProperties::SetDisableSTDIO(bool b) {
   const uint32_t idx = ePropertyDisableSTDIO;
   SetPropertyAtIndex(idx, b);
 }
+llvm::StringRef TargetProperties::GetLaunchWorkingDirectory() const {
+  const uint32_t idx = ePropertyLaunchWorkingDir;
+  return GetPropertyAtIndexAs<llvm::StringRef>(
+      idx, g_target_properties[idx].default_cstr_value);
+}
 
 const char *TargetProperties::GetDisassemblyFlavor() const {
   const uint32_t idx = ePropertyDisassemblyFlavor;
diff --git a/lldb/source/Target/TargetProperties.td b/lldb/source/Target/TargetProperties.td
index fb61478fb752dc..3aa7cc41c4d5ca 100644
--- a/lldb/source/Target/TargetProperties.td
+++ b/lldb/source/Target/TargetProperties.td
@@ -201,6 +201,12 @@ let Definition = "target" in {
   def DebugUtilityExpression: Property<"debug-utility-expression", "Boolean">,
     DefaultFalse,
     Desc<"Enable debugging of LLDB-internal utility expressions.">;
+  def LaunchWorkingDir: Property<"launch-working-dir", "String">,
+    DefaultStringValue<"">,
+    Desc<"A default value for the working directory to use when launching processes. "
+         "It's ignored when empty. This setting is only used when the target is "
+         "launched. If you change this setting, the new value will only apply to "
+         "subsequent launches.">;
 }
 
 let Definition = "process_experimental" in {
diff --git a/lldb/test/API/commands/process/launch/TestProcessLaunch.py b/lldb/test/API/commands/process/launch/TestProcessLaunch.py
index 45f9f494ab8f5c..2da75544dd5c90 100644
--- a/lldb/test/API/commands/process/launch/TestProcessLaunch.py
+++ b/lldb/test/API/commands/process/launch/TestProcessLaunch.py
@@ -8,6 +8,7 @@
 from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbutil
+from pathlib import Path
 
 
 class ProcessLaunchTestCase(TestBase):
@@ -206,3 +207,59 @@ def test_environment_with_special_char(self):
         self.assertEqual(value, evil_var)
         process.Continue()
         self.assertState(process.GetState(), lldb.eStateExited, PROCESS_EXITED)
+
+    def test_target_launch_working_dir_prop(self):
+        """Test that the setting `target.launch-working-dir` is correctly used when launching a process."""
+        d = {"CXX_SOURCES": "print_cwd.cpp"}
+        self.build(dictionary=d)
+        self.setTearDownCleanup(d)
+        exe = self.getBuildArtifact("a.out")
+        self.runCmd("file " + exe)
+
+        mywd = "my_working_dir"
+        out_file_name = "my_working_dir_test.out"
+
+        my_working_dir_path = self.getBuildArtifact(mywd)
+        lldbutil.mkdir_p(my_working_dir_path)
+        out_file_path = os.path.join(my_working_dir_path, out_file_name)
+        another_working_dir_path = Path(
+            os.path.join(my_working_dir_path, "..")
+        ).resolve()
+
+        # If -w is not passed to process launch, then the setting will be used.
+        self.runCmd(
+            f"settings set target.launch-working-dir {another_working_dir_path}"
+        )
+        launch_command = f"process launch -o {out_file_path}"
+
+        self.expect(
+            launch_command,
+            patterns=["Process .* launched: .*a.out"],
+        )
+
+        out = lldbutil.read_file_on_target(self, out_file_path)
+
+        self.assertIn(f"stdout: {another_working_dir_path}", out)
+
+        # If -w is passed to process launch, that value will be used instead of the setting.
+        launch_command = f"process launch -w {my_working_dir_path} -o {out_file_path}"
+
+        self.expect(
+            launch_command,
+            patterns=["Process .* launched: .*a.out"],
+        )
+
+        out = lldbutil.read_file_on_target(self, out_file_path)
+        self.assertIn(f"stdout: {my_working_dir_path}", out)
+
+        # If set to empty, then LLDB's cwd will be used to launch the process.
+        self.runCmd(f"settings set target.launch-working-dir ''")
+        launch_command = f"process launch -o {out_file_path}"
+
+        self.expect(
+            launch_command,
+            patterns=["Process .* launched: .*a.out"],
+        )
+
+        out = lldbutil.read_file_on_target(self, out_file_path)
+        self.assertNotIn(f"stdout: {another_working_dir_path}", out)
diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index d5c650e74eeb28..6faa34a379fc76 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -304,6 +304,8 @@ Changes to LLDB
 * Program stdout/stderr redirection will now open the file with O_TRUNC flag, make sure to truncate the file if path already exists.
   * eg. `settings set target.output-path/target.error-path <path/to/file>`
 
+* A new setting `target.launch-working-dir` can be used to set a persistent cwd that is used by default by `process launch` and `run`.
+
 Changes to BOLT
 ---------------------------------
 



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