[lldb] Support Python imports relative the to the current file being sourced

Make it possible to use a relative path in command script import to the
location of the file being sourced. This allows the user to put Python
scripts next to LLDB command files and importing them without having to
specify an absolute path.

To enable this behavior pass `-c` to `command script import`. The
argument can only be used when sourcing the command from a file.

rdar://68310384

Differential revision: https://reviews.llvm.org/D89334

lldb/include/lldb/Interpreter/CommandInterpreter.h

@@ -551,6 +551,8 @@ public:
   bool SaveTranscript(CommandReturnObject &result,
                       llvm::Optional<std::string> output_file = llvm::None);
 
+  FileSpec GetCurrentSourceDir();
+
 protected:
   friend class Debugger;
 
@@ -637,7 +639,13 @@ private:
   ChildrenTruncatedWarningStatus m_truncation_warning; // Whether we truncated
                                                        // children and whether
                                                        // the user has been told
+
+  // FIXME: Stop using this to control adding to the history and then replace
+  // this with m_command_source_dirs.size().
   uint32_t m_command_source_depth;
+  /// A stack of directory paths. When not empty, the last one is the directory
+  /// of the file that's currently sourced.
+  std::vector<FileSpec> m_command_source_dirs;
   std::vector<uint32_t> m_command_source_flags;
   CommandInterpreterRunResult m_result;
 

lldb/include/lldb/Interpreter/ScriptInterpreter.h

@@ -507,7 +507,8 @@ public:
   virtual bool
   LoadScriptingModule(const char *filename, bool init_session,
                       lldb_private::Status &error,
-                      StructuredData::ObjectSP *module_sp = nullptr);
+                      StructuredData::ObjectSP *module_sp = nullptr,
+                      FileSpec extra_search_dir = {});
 
   virtual bool IsReservedWord(const char *word) { return false; }
 

lldb/source/Commands/CommandObjectCommands.cpp

@@ -1272,6 +1272,9 @@ protected:
       case 'r':
         // NO-OP
         break;
+      case 'c':
+        relative_to_command_file = true;
+        break;
       default:
         llvm_unreachable("Unimplemented option");
       }
@@ -1280,11 +1283,13 @@ protected:
     }
 
     void OptionParsingStarting(ExecutionContext *execution_context) override {
+      relative_to_command_file = false;
     }
 
     llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
       return llvm::makeArrayRef(g_script_import_options);
     }
+    bool relative_to_command_file = false;
   };
 
   bool DoExecute(Args &command, CommandReturnObject &result) override {
@@ -1294,6 +1299,17 @@ protected:
       return false;
     }
 
+    FileSpec source_dir = {};
+    if (m_options.relative_to_command_file) {
+      source_dir = GetDebugger().GetCommandInterpreter().GetCurrentSourceDir();
+      if (!source_dir) {
+        result.AppendError("command script import -c can only be specified "
+                           "from a command file");
+        result.SetStatus(eReturnStatusFailed);
+        return false;
+      }
+    }
+
     for (auto &entry : command.entries()) {
       Status error;
 
@@ -1308,7 +1324,7 @@ protected:
       // more)
       m_exe_ctx.Clear();
       if (GetDebugger().GetScriptInterpreter()->LoadScriptingModule(
-              entry.c_str(), init_session, error)) {
+              entry.c_str(), init_session, error, nullptr, source_dir)) {
         result.SetStatus(eReturnStatusSuccessFinishNoResult);
       } else {
         result.AppendErrorWithFormat("module importing failed: %s",

lldb/source/Commands/Options.td

@@ -704,6 +704,10 @@ let Command = "script import" in {
     Desc<"Allow the script to be loaded even if it was already loaded before. "
     "This argument exists for backwards compatibility, but reloading is always "
     "allowed, whether you specify it or not.">;
+  def relative_to_command_file : Option<"relative-to-command-file", "c">,
+    Group<1>, Desc<"Resolve non-absolute paths relative to the location of the "
+    "current command file. This argument can only be used when the command is "
+    "being sourced from a file.">;
 }
 
 let Command = "script add" in {

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -2554,11 +2554,15 @@ void CommandInterpreter::HandleCommandsFromFile(
     debugger.SetAsyncExecution(false);
 
   m_command_source_depth++;
+  m_command_source_dirs.push_back(cmd_file.CopyByRemovingLastPathComponent());
 
   debugger.RunIOHandlerSync(io_handler_sp);
   if (!m_command_source_flags.empty())
     m_command_source_flags.pop_back();
+
+  m_command_source_dirs.pop_back();
   m_command_source_depth--;
+
   result.SetStatus(eReturnStatusSuccessFinishNoResult);
   debugger.SetAsyncExecution(old_async_execution);
 }
@@ -2964,6 +2968,12 @@ bool CommandInterpreter::SaveTranscript(
   return true;
 }
 
+FileSpec CommandInterpreter::GetCurrentSourceDir() {
+  if (m_command_source_dirs.empty())
+    return {};
+  return m_command_source_dirs.back();
+}
+
 void CommandInterpreter::GetLLDBCommandsFromIOHandler(
     const char *prompt, IOHandlerDelegate &delegate, void *baton) {
   Debugger &debugger = GetDebugger();

lldb/source/Interpreter/ScriptInterpreter.cpp

@@ -47,9 +47,11 @@ void ScriptInterpreter::CollectDataForWatchpointCommandCallback(
       "This script interpreter does not support watchpoint callbacks.");
 }
 
-bool ScriptInterpreter::LoadScriptingModule(
-    const char *filename, bool init_session, lldb_private::Status &error,
-    StructuredData::ObjectSP *module_sp) {
+bool ScriptInterpreter::LoadScriptingModule(const char *filename,
+                                            bool init_session,
+                                            lldb_private::Status &error,
+                                            StructuredData::ObjectSP *module_sp,
+                                            FileSpec extra_search_dir) {
   error.SetErrorString(
       "This script interpreter does not support importing modules.");
   return false;

lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.cpp

@@ -124,7 +124,7 @@ void ScriptInterpreterLua::ExecuteInterpreterLoop() {
 
 bool ScriptInterpreterLua::LoadScriptingModule(
     const char *filename, bool init_session, lldb_private::Status &error,
-    StructuredData::ObjectSP *module_sp) {
+    StructuredData::ObjectSP *module_sp, FileSpec extra_search_dir) {
 
   FileSystem::Instance().Collect(filename);
   if (llvm::Error e = m_lua->LoadModule(filename)) {

lldb/source/Plugins/ScriptInterpreter/Lua/ScriptInterpreterLua.h

@@ -25,10 +25,10 @@ public:
 
   void ExecuteInterpreterLoop() override;
 
-  bool
-  LoadScriptingModule(const char *filename, bool init_session,
-                      lldb_private::Status &error,
-                      StructuredData::ObjectSP *module_sp = nullptr) override;
+  bool LoadScriptingModule(const char *filename, bool init_session,
+                           lldb_private::Status &error,
+                           StructuredData::ObjectSP *module_sp = nullptr,
+                           FileSpec extra_search_dir = {}) override;
 
   // Static Functions
   static void Initialize();

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp

@@ -2733,8 +2733,9 @@ uint64_t replace_all(std::string &str, const std::string &oldStr,
 
 bool ScriptInterpreterPythonImpl::LoadScriptingModule(
     const char *pathname, bool init_session, lldb_private::Status &error,
-    StructuredData::ObjectSP *module_sp) {
+    StructuredData::ObjectSP *module_sp, FileSpec extra_search_dir) {
   namespace fs = llvm::sys::fs;
+  namespace path = llvm::sys::path;
 
   if (!pathname || !pathname[0]) {
     error.SetErrorString("invalid pathname");
@@ -2743,44 +2744,23 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
 
   lldb::DebuggerSP debugger_sp = m_debugger.shared_from_this();
 
-  FileSpec target_file(pathname);
-  FileSystem::Instance().Resolve(target_file);
-  FileSystem::Instance().Collect(target_file);
-  std::string basename(target_file.GetFilename().GetCString());
-
-  StreamString command_stream;
-
   // Before executing Python code, lock the GIL.
   Locker py_lock(this,
                  Locker::AcquireLock |
                      (init_session ? Locker::InitSession : 0) | Locker::NoSTDIN,
                  Locker::FreeAcquiredLock |
                      (init_session ? Locker::TearDownSession : 0));
-  fs::file_status st;
-  std::error_code ec = status(target_file.GetPath(), st);
 
-  if (ec || st.type() == fs::file_type::status_error ||
-      st.type() == fs::file_type::type_unknown ||
-      st.type() == fs::file_type::file_not_found) {
-    // if not a valid file of any sort, check if it might be a filename still
-    // dot can't be used but / and \ can, and if either is found, reject
-    if (strchr(pathname, '\\') || strchr(pathname, '/')) {
-      error.SetErrorString("invalid pathname");
-      return false;
-    }
-    basename = pathname; // not a filename, probably a package of some sort,
-                         // let it go through
-  } else if (is_directory(st) || is_regular_file(st)) {
-    if (target_file.GetDirectory().IsEmpty()) {
-      error.SetErrorString("invalid directory name");
-      return false;
+  auto ExtendSysPath = [this](std::string directory) -> llvm::Error {
+    if (directory.empty()) {
+      return llvm::make_error<llvm::StringError>(
+          "invalid directory name", llvm::inconvertibleErrorCode());
     }
 
-    std::string directory = target_file.GetDirectory().GetCString();
     replace_all(directory, "\\", "\\\\");
     replace_all(directory, "'", "\\'");
 
-    // now make sure that Python has "directory" in the search path
+    // Make sure that Python has "directory" in the search path.
     StreamString command_stream;
     command_stream.Printf("if not (sys.path.__contains__('%s')):\n    "
                           "sys.path.insert(1,'%s');\n\n",
@@ -2792,27 +2772,68 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
                                  .SetSetLLDBGlobals(false))
             .Success();
     if (!syspath_retval) {
-      error.SetErrorString("Python sys.path handling failed");
-      return false;
+      return llvm::make_error<llvm::StringError>(
+          "Python sys.path handling failed", llvm::inconvertibleErrorCode());
     }
 
+    return llvm::Error::success();
+  };
+
+  std::string module_name(pathname);
+
+  if (extra_search_dir) {
+    if (llvm::Error e = ExtendSysPath(extra_search_dir.GetPath())) {
+      error = std::move(e);
+      return false;
+    }
   } else {
-    error.SetErrorString("no known way to import this module specification");
-    return false;
+    FileSpec module_file(pathname);
+    FileSystem::Instance().Resolve(module_file);
+    FileSystem::Instance().Collect(module_file);
+
+    fs::file_status st;
+    std::error_code ec = status(module_file.GetPath(), st);
+
+    if (ec || st.type() == fs::file_type::status_error ||
+        st.type() == fs::file_type::type_unknown ||
+        st.type() == fs::file_type::file_not_found) {
+      // if not a valid file of any sort, check if it might be a filename still
+      // dot can't be used but / and \ can, and if either is found, reject
+      if (strchr(pathname, '\\') || strchr(pathname, '/')) {
+        error.SetErrorString("invalid pathname");
+        return false;
+      }
+      // Not a filename, probably a package of some sort, let it go through.
+    } else if (is_directory(st) || is_regular_file(st)) {
+      if (module_file.GetDirectory().IsEmpty()) {
+        error.SetErrorString("invalid directory name");
+        return false;
+      }
+      if (llvm::Error e =
+              ExtendSysPath(module_file.GetDirectory().GetCString())) {
+        error = std::move(e);
+        return false;
+      }
+      module_name = module_file.GetFilename().GetCString();
+    } else {
+      error.SetErrorString("no known way to import this module specification");
+      return false;
+    }
   }
 
   // Strip .py or .pyc extension
-  llvm::StringRef extension = target_file.GetFileNameExtension().GetCString();
+  llvm::StringRef extension = llvm::sys::path::extension(module_name);
   if (!extension.empty()) {
     if (extension == ".py")
-      basename.resize(basename.length() - 3);
+      module_name.resize(module_name.length() - 3);
     else if (extension == ".pyc")
-      basename.resize(basename.length() - 4);
+      module_name.resize(module_name.length() - 4);
   }
 
   // check if the module is already import-ed
+  StreamString command_stream;
   command_stream.Clear();
-  command_stream.Printf("sys.modules.__contains__('%s')", basename.c_str());
+  command_stream.Printf("sys.modules.__contains__('%s')", module_name.c_str());
   bool does_contain = false;
   // this call will succeed if the module was ever imported in any Debugger
   // in the lifetime of the process in which this LLDB framework is living
@@ -2827,9 +2848,9 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
   // this call will fail if the module was not imported in this Debugger
   // before
   command_stream.Clear();
-  command_stream.Printf("sys.getrefcount(%s)", basename.c_str());
+  command_stream.Printf("sys.getrefcount(%s)", module_name.c_str());
   bool was_imported_locally = GetSessionDictionary()
-                                  .GetItemForKey(PythonString(basename))
+                                  .GetItemForKey(PythonString(module_name))
                                   .IsAllocated();
 
   bool was_imported = (was_imported_globally || was_imported_locally);
@@ -2839,12 +2860,12 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
 
   if (was_imported) {
     if (!was_imported_locally)
-      command_stream.Printf("import %s ; reload_module(%s)", basename.c_str(),
-                            basename.c_str());
+      command_stream.Printf("import %s ; reload_module(%s)",
+                            module_name.c_str(), module_name.c_str());
     else
-      command_stream.Printf("reload_module(%s)", basename.c_str());
+      command_stream.Printf("reload_module(%s)", module_name.c_str());
   } else
-    command_stream.Printf("import %s", basename.c_str());
+    command_stream.Printf("import %s", module_name.c_str());
 
   error = ExecuteMultipleLines(command_stream.GetData(),
                                ScriptInterpreter::ExecuteScriptOptions()
@@ -2855,8 +2876,8 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
 
   // if we are here, everything worked
   // call __lldb_init_module(debugger,dict)
-  if (!LLDBSwigPythonCallModuleInit(basename.c_str(), m_dictionary_name.c_str(),
-                                    debugger_sp)) {
+  if (!LLDBSwigPythonCallModuleInit(module_name.c_str(),
+                                    m_dictionary_name.c_str(), debugger_sp)) {
     error.SetErrorString("calling __lldb_init_module failed");
     return false;
   }
@@ -2864,7 +2885,7 @@ bool ScriptInterpreterPythonImpl::LoadScriptingModule(
   if (module_sp) {
     // everything went just great, now set the module object
     command_stream.Clear();
-    command_stream.Printf("%s", basename.c_str());
+    command_stream.Printf("%s", module_name.c_str());
     void *module_pyobj = nullptr;
     if (ExecuteOneLineWithReturn(
             command_stream.GetData(),

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h

@@ -231,10 +231,10 @@ public:
   bool RunScriptFormatKeyword(const char *impl_function, ValueObject *value,
                               std::string &output, Status &error) override;
 
-  bool
-  LoadScriptingModule(const char *filename, bool init_session,
-                      lldb_private::Status &error,
-                      StructuredData::ObjectSP *module_sp = nullptr) override;
+  bool LoadScriptingModule(const char *filename, bool init_session,
+                           lldb_private::Status &error,
+                           StructuredData::ObjectSP *module_sp = nullptr,
+                           FileSpec extra_search_dir = {}) override;
 
   bool IsReservedWord(const char *word) override;
 

lldb/test/Shell/ScriptInterpreter/Python/Inputs/hello.split

@@ -0,0 +1,10 @@
+#--- hello.in
+command script import -c baz.hello
+#--- hello.py
+import lldb
+
+def hello(debugger, command, result, internal_dict):
+    print("Hello, World!")
+
+def __lldb_init_module(debugger, internal_dict):
+    debugger.HandleCommand('command script add -f baz.hello.hello hello')

lldb/test/Shell/ScriptInterpreter/Python/Inputs/relative.split

@@ -0,0 +1,20 @@
+#--- magritte.in
+command script import magritte
+#--- magritte.py
+import lldb
+
+def magritte(debugger, command, result, internal_dict):
+    print("Ceci n'est pas une pipe")
+
+def __lldb_init_module(debugger, internal_dict):
+    debugger.HandleCommand('command script add -f magritte.magritte magritte')
+#--- zip.in
+command script import -c zip
+#--- zip.py
+import lldb
+
+def zip(debugger, command, result, internal_dict):
+    print("95126")
+
+def __lldb_init_module(debugger, internal_dict):
+    debugger.HandleCommand('command script add -f zip.zip zip')

lldb/test/Shell/ScriptInterpreter/Python/command_relative_import.test

@@ -0,0 +1,31 @@
+# REQUIRES: python
+
+# RUN: rm -rf %t && mkdir -p %t/foo/bar/baz
+# RUN: split-file %S/Inputs/relative.split %t/foo
+# RUN: split-file %S/Inputs/hello.split %t/foo/bar
+# RUN: mv %t/foo/bar/hello.py %t/foo/bar/baz
+# RUN: echo 'command source %t/foo/bar/hello.in' >> %t/foo/zip.in
+
+# RUN: %lldb --script-language python \
+# RUN:    -o 'command source %t/foo/magritte.in' \
+# RUN:    -o 'command source %t/foo/zip.in' \
+# RUN:    -o 'command source %t/foo/magritte.in' \
+# RUN;    -o 'zip' \
+# RUN:    -o 'hello'
+# RUN     -o 'magritte' 2>&1 | FileCheck %s
+
+# The first time importing 'magritte' fails because we didn't pass -c.
+# CHECK: ModuleNotFoundError: No module named 'magritte'
+# CHECK-NOT: Ceci n'est pas une pipe
+# CHECK: 95126
+# CHECK: Hello, World!
+# The second time importing 'magritte' works, even without passing -c because
+# we added '%t/foo' to the Python path when importing 'zip'.
+# CHECK: Ceci n'est pas une pipe
+
+# Cannot use `-o` here because the driver puts the commands in a file and
+# sources them.
+command script import -c %t/foo/magritte.py
+quit
+# RUN: cat %s | %lldb --script-language python 2>&1 | FileCheck %s --check-prefix ERROR
+# ERROR: error: command script import -c can only be specified from a command file