[lldb] Add completions for plugin list/enable/disable (#147775)

This commit adds completion support for the plugin commands. It will try
to complete partial namespaces to the full namespace string. If the
completion input is already a full namespace string then it will add all
the matching plugins in that namespace as completions.

This lets the user complete to the namespace first and then tab-complete
to the next level if desired.

```
(lldb) plugin list a<tab>
Available completions:
        abi
        architecture
(lldb) plugin list ab<tab>
(lldb) plugin list abi<tab>
(lldb) plugin list abi.<tab>
Available completions:
        abi.SysV-arm64
        abi.ABIMacOSX_arm64
        abi.SysV-arm
        ...
```

8 files changed, 130 insertions, 5 deletions

diff --git a/lldb/include/lldb/Core/PluginManager.h b/lldb/include/lldb/Core/PluginManager.h
index 5499e99..369785c 100644
--- a/lldb/include/lldb/Core/PluginManager.h
+++ b/lldb/include/lldb/Core/PluginManager.h
@@ -787,6 +787,9 @@ public:
 
   static std::vector<RegisteredPluginInfo> GetUnwindAssemblyPluginInfo();
   static bool SetUnwindAssemblyPluginEnabled(llvm::StringRef name, bool enable);
+
+  static void AutoCompletePluginName(llvm::StringRef partial_name,
+                                     CompletionRequest &request);
 };
 
 } // namespace lldb_private
diff --git a/lldb/include/lldb/Interpreter/CommandCompletions.h b/lldb/include/lldb/Interpreter/CommandCompletions.h
index c7292b3..0c0424c 100644
--- a/lldb/include/lldb/Interpreter/CommandCompletions.h
+++ b/lldb/include/lldb/Interpreter/CommandCompletions.h
@@ -123,6 +123,10 @@ public:
   static void ThreadIDs(CommandInterpreter &interpreter,
                         CompletionRequest &request, SearchFilter *searcher);
 
+  static void ManagedPlugins(CommandInterpreter &interpreter,
+                             CompletionRequest &request,
+                             SearchFilter *searcher);
+
   /// This completer works for commands whose only arguments are a command path.
   /// It isn't tied to an argument type because it completes not on a single
   /// argument but on the sequence of arguments, so you have to invoke it by
diff --git a/lldb/include/lldb/lldb-enumerations.h b/lldb/include/lldb/lldb-enumerations.h
index 69e8671..e021c7a 100644
--- a/lldb/include/lldb/lldb-enumerations.h
+++ b/lldb/include/lldb/lldb-enumerations.h
@@ -1321,10 +1321,11 @@ enum CompletionType {
   eTypeCategoryNameCompletion = (1ul << 24),
   eCustomCompletion = (1ul << 25),
   eThreadIDCompletion = (1ul << 26),
+  eManagedPluginCompletion = (1ul << 27),
   // This last enum element is just for input validation.
   // Add new completions before this element,
   // and then increment eTerminatorCompletion's shift value
-  eTerminatorCompletion = (1ul << 27)
+  eTerminatorCompletion = (1ul << 28)
 };
 
 /// Specifies if children need to be re-computed
diff --git a/lldb/packages/Python/lldbsuite/test/lldbtest.py b/lldb/packages/Python/lldbsuite/test/lldbtest.py
index a4ff96e..63fadb5 100644
--- a/lldb/packages/Python/lldbsuite/test/lldbtest.py
+++ b/lldb/packages/Python/lldbsuite/test/lldbtest.py
@@ -2268,7 +2268,7 @@ class TestBase(Base, metaclass=LLDBTestCaseFactory):
             completions, list(match_strings)[1:], "List of returned completion is wrong"
         )
 
-    def completions_contain(self, command, completions):
+    def completions_contain(self, command, completions, match=True):
         """Checks that the completions for the given command contain the given
         list of completions."""
         interp = self.dbg.GetCommandInterpreter()
@@ -2276,9 +2276,16 @@ class TestBase(Base, metaclass=LLDBTestCaseFactory):
         interp.HandleCompletion(command, len(command), 0, -1, match_strings)
         for completion in completions:
             # match_strings is a 1-indexed list, so we have to slice...
-            self.assertIn(
-                completion, list(match_strings)[1:], "Couldn't find expected completion"
-            )
+            if match:
+                self.assertIn(
+                    completion,
+                    list(match_strings)[1:],
+                    "Couldn't find expected completion",
+                )
+            else:
+                self.assertNotIn(
+                    completion, list(match_strings)[1:], "Found unexpected completion"
+                )
 
     def filecheck(
         self, command, check_file, filecheck_options="", expect_cmd_failure=False
diff --git a/lldb/source/Commands/CommandCompletions.cpp b/lldb/source/Commands/CommandCompletions.cpp
index 38231a8..3e22309 100644
--- a/lldb/source/Commands/CommandCompletions.cpp
+++ b/lldb/source/Commands/CommandCompletions.cpp
@@ -87,6 +87,7 @@ bool CommandCompletions::InvokeCommonCompletionCallbacks(
       {lldb::eTypeCategoryNameCompletion,
        CommandCompletions::TypeCategoryNames},
       {lldb::eThreadIDCompletion, CommandCompletions::ThreadIDs},
+      {lldb::eManagedPluginCompletion, CommandCompletions::ManagedPlugins},
       {lldb::eTerminatorCompletion,
        nullptr} // This one has to be last in the list.
   };
@@ -850,6 +851,13 @@ void CommandCompletions::ThreadIDs(CommandInterpreter &interpreter,
   }
 }
 
+void CommandCompletions::ManagedPlugins(CommandInterpreter &interpreter,
+                                        CompletionRequest &request,
+                                        SearchFilter *searcher) {
+  PluginManager::AutoCompletePluginName(request.GetCursorArgumentPrefix(),
+                                        request);
+}
+
 void CommandCompletions::CompleteModifiableCmdPathArgs(
     CommandInterpreter &interpreter, CompletionRequest &request,
     OptionElementVector &opt_element_vector) {
diff --git a/lldb/source/Commands/CommandObjectPlugin.cpp b/lldb/source/Commands/CommandObjectPlugin.cpp
index cdc9006..093ebde 100644
--- a/lldb/source/Commands/CommandObjectPlugin.cpp
+++ b/lldb/source/Commands/CommandObjectPlugin.cpp
@@ -194,6 +194,14 @@ List only the plugin 'foo' matching a fully qualified name exactly
 
   Options *GetOptions() override { return &m_options; }
 
+  void
+  HandleArgumentCompletion(CompletionRequest &request,
+                           OptionElementVector &opt_element_vector) override {
+    lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
+        GetCommandInterpreter(), lldb::eManagedPluginCompletion, request,
+        nullptr);
+  }
+
 protected:
   void DoExecute(Args &command, CommandReturnObject &result) override {
     size_t argc = command.GetArgumentCount();
@@ -293,6 +301,14 @@ public:
     AddSimpleArgumentList(eArgTypeManagedPlugin);
   }
 
+  void
+  HandleArgumentCompletion(CompletionRequest &request,
+                           OptionElementVector &opt_element_vector) override {
+    lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
+        GetCommandInterpreter(), lldb::eManagedPluginCompletion, request,
+        nullptr);
+  }
+
   ~CommandObjectPluginEnable() override = default;
 
 protected:
@@ -309,6 +325,14 @@ public:
     AddSimpleArgumentList(eArgTypeManagedPlugin);
   }
 
+  void
+  HandleArgumentCompletion(CompletionRequest &request,
+                           OptionElementVector &opt_element_vector) override {
+    lldb_private::CommandCompletions::InvokeCommonCompletionCallbacks(
+        GetCommandInterpreter(), lldb::eManagedPluginCompletion, request,
+        nullptr);
+  }
+
   ~CommandObjectPluginDisable() override = default;
 
 protected:
diff --git a/lldb/source/Core/PluginManager.cpp b/lldb/source/Core/PluginManager.cpp
index 3f20a96..bece690 100644
--- a/lldb/source/Core/PluginManager.cpp
+++ b/lldb/source/Core/PluginManager.cpp
@@ -18,6 +18,7 @@
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/StringList.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/Support/DynamicLibrary.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/raw_ostream.h"
@@ -2473,3 +2474,34 @@ bool PluginManager::SetUnwindAssemblyPluginEnabled(llvm::StringRef name,
                                                    bool enable) {
   return GetUnwindAssemblyInstances().SetInstanceEnabled(name, enable);
 }
+
+void PluginManager::AutoCompletePluginName(llvm::StringRef name,
+                                           CompletionRequest &request) {
+  // Split the name into the namespace and the plugin name.
+  // If there is no dot then the ns_name will be equal to name and
+  // plugin_prefix will be empty.
+  llvm::StringRef ns_name, plugin_prefix;
+  std::tie(ns_name, plugin_prefix) = name.split('.');
+
+  for (const PluginNamespace &plugin_ns : GetPluginNamespaces()) {
+    // If the plugin namespace matches exactly then
+    // add all the plugins in this namespace as completions if the
+    // plugin names starts with the plugin_prefix. If the plugin_prefix
+    // is empty then it will match all the plugins (empty string is a
+    // prefix of everything).
+    if (plugin_ns.name == ns_name) {
+      for (const RegisteredPluginInfo &plugin : plugin_ns.get_info()) {
+        llvm::SmallString<128> buf;
+        if (plugin.name.starts_with(plugin_prefix))
+          request.AddCompletion(
+              (plugin_ns.name + "." + plugin.name).toStringRef(buf));
+      }
+    } else if (plugin_ns.name.starts_with(name) &&
+               !plugin_ns.get_info().empty()) {
+      // Otherwise check if the namespace is a prefix of the full name.
+      // Use a partial completion here so that we can either operate on the full
+      // namespace or tab-complete to the next level.
+      request.AddCompletion(plugin_ns.name, "", CompletionMode::Partial);
+    }
+  }
+}
diff --git a/lldb/test/API/commands/plugin/TestPlugin.py b/lldb/test/API/commands/plugin/TestPlugin.py
index fdfb14b..e7de7a3 100644
--- a/lldb/test/API/commands/plugin/TestPlugin.py
+++ b/lldb/test/API/commands/plugin/TestPlugin.py
@@ -60,3 +60,49 @@ class TestFrameVar(TestBase):
         self.expect(
             f"plugin enable {plugin_namespace}", substrs=[plugin_namespace, "[+]"]
         )
+
+    def test_completions(self):
+        # Make sure completions work for the plugin list, enable, and disable commands.
+        # We just check a few of the expected plugins to make sure the completion works.
+        self.completions_contain(
+            "plugin list ", ["abi", "architecture", "disassembler"]
+        )
+        self.completions_contain(
+            "plugin enable ", ["abi", "architecture", "disassembler"]
+        )
+        self.completions_contain(
+            "plugin disable ", ["abi", "architecture", "disassembler"]
+        )
+
+        # A completion for a partial namespace should be the full namespace.
+        # This allows the user to run the command on the full namespace.
+        self.completions_match("plugin list ab", ["abi"])
+        self.completions_contain(
+            "plugin list object", ["object-container", "object-file"]
+        )
+
+        # A completion for a full namespace should contain the plugins in that namespace.
+        self.completions_contain("plugin list abi", ["abi.sysv-x86_64"])
+        self.completions_contain("plugin list abi.", ["abi.sysv-x86_64"])
+        self.completions_contain("plugin list abi.s", ["abi.sysv-x86_64"])
+        self.completions_contain("plugin list abi.sysv-x", ["abi.sysv-x86_64"])
+
+        # Check for a completion that is a both a complete namespace and a prefix of
+        # another namespace. It should return the completions for the plugins in the completed
+        # namespace as well as the completion for the partial namespace.
+        self.completions_contain(
+            "plugin list language", ["language.cplusplus", "language-runtime"]
+        )
+
+        # When the namespace is a prefix of another namespace and the user types a dot, the
+        # completion should not include the match for the partial namespace.
+        self.completions_contain(
+            "plugin list language.", ["language.cplusplus"], match=True
+        )
+        self.completions_contain(
+            "plugin list language.", ["language-runtime"], match=False
+        )
+
+        # Check for an empty completion list when the names is invalid.
+        # See docs for `complete_from_to` for how this checks for an empty list.
+        self.complete_from_to("plugin list abi.foo", ["plugin list abi.foo"])