repl: Add support for multi line input

.gitignore

@@ -4,3 +4,4 @@
 /build/
 /dist/
 /frida_tools/*_agent.js
+/frida_tools/treesitter.so

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "vendor/tree-sitter-javascript"]
+	path = vendor/tree-sitter-javascript
+	url = https://github.com/tree-sitter/tree-sitter-javascript

build_aux/build_treesitter.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+
+import os
+
+from tree_sitter import Language
+
+
+def build() -> None:
+    Language.build_library(
+        os.path.join("frida_tools", "treesitter.so"),
+        [
+            os.path.join("vendor", "tree-sitter-javascript"),
+        ],
+    )
+
+
+if __name__ == "__main__":
+    build()

build_aux/meson.build

@@ -0,0 +1,2 @@
+python = find_program('python3', 'python')
+run_command(python, 'build_treesitter.py')

frida_tools/repl.py

@@ -20,12 +20,14 @@
 from prompt_toolkit import PromptSession
 from prompt_toolkit.completion import CompleteEvent, Completer, Completion
 from prompt_toolkit.document import Document
+from prompt_toolkit.filters import Condition, Filter
 from prompt_toolkit.history import FileHistory
 from prompt_toolkit.lexers import PygmentsLexer
 from prompt_toolkit.shortcuts import prompt
 from prompt_toolkit.styles import Style as PromptToolkitStyle
 from pygments.lexers.javascript import JavascriptLexer
 from pygments.token import Token
+from tree_sitter import Language, Parser
 
 from frida_tools import _repl_magic
 from frida_tools.application import ConsoleApplication
@@ -34,6 +36,13 @@
 
 T = TypeVar("T")
 
+try:
+    JS_LANGUAGE = Language(os.path.join(os.path.dirname(__file__), "treesitter.so"), "javascript")
+    ERROR_QUERY = JS_LANGUAGE.query("(_ (ERROR) @error)")
+except Exception:
+    JS_LANGUAGE = None
+    ERROR_QUERY = None
+
 
 class REPLApplication(ConsoleApplication):
     def __init__(self) -> None:
@@ -53,6 +62,12 @@ def __init__(self) -> None:
 
         super().__init__(self._process_input, self._on_stop)
 
+        try:
+            self._parser = Parser()
+            self._parser.set_language(JS_LANGUAGE)
+        except Exception:
+            self._parser = None
+
         if self._have_terminal and not self._plain_terminal:
             style = PromptToolkitStyle(
                 [
@@ -69,6 +84,7 @@ def __init__(self) -> None:
                 complete_in_thread=True,
                 enable_open_in_editor=True,
                 tempfile_suffix=".js",
+                multiline=self._input_complete(),
             )
             self._dumb_stdin_reader = None
         else:
@@ -339,6 +355,27 @@ def _monitor(self, path: AnyStr) -> None:
         monitor.enable()
         self._monitored_files[path] = monitor
 
+    def _input_complete(self) -> Filter:
+        """
+        check if the current input is a valid javascript code
+        """
+
+        @Condition
+        def inner() -> bool:
+            assert self._cli is not None
+            if self._parser is None or ERROR_QUERY is None:
+                return False
+
+            tree = self._parser.parse(self._cli.default_buffer.document.text.encode())
+            query_results = ERROR_QUERY.captures(tree.root_node)
+            # It would have been nice to be able to query a MISSING node properly but as of when this code was written
+            # it was just not possible. There is an open issue for it in tree-sitter/tree-sitter#606 so maybe one day we
+            # could fix it. I hope it doesn't break some code that contain the work MISSING or something but I checked it
+            # a bit and it seems to be fine.
+            return len(query_results) or "MISSING" in tree.root_node.sexp()
+
+        return inner
+
     def _process_input(self, reactor: Reactor) -> None:
         if not self._quiet:
             self._print_startup_message()

meson.build

@@ -24,3 +24,4 @@ subdir('agents')
 subdir('frida_tools')
 subdir('scripts')
 subdir('completions')
+subdir('build_aux')

setup.py

@@ -9,6 +9,8 @@
 
 agents = glob.glob(os.path.join(pkg_dir, "*_agent.*"))
 assert len(agents) > 0, "Agents not compiled; run “npm install && npm run build” in agents/*/"
+os.system("python ./build_aux/build_treesitter.py")
+package_data = agents + ["treesitter.so"]
 
 setup(
     name="frida-tools",
@@ -24,6 +26,7 @@
         "frida >= 16.0.0, < 17.0.0",
         "prompt-toolkit >= 2.0.0, < 4.0.0",
         "pygments >= 2.0.2, < 3.0.0",
+        "tree_sitter==0.20.1",
     ],
     license="wxWindows Library Licence, Version 3.1",
     zip_safe=True,
@@ -51,7 +54,7 @@
     ],
     packages=["frida_tools"],
     package_data={
-        "frida_tools": agents,
+        "frida_tools": package_data,
     },
     entry_points={
         "console_scripts": [