Add a new callback decompilation_changed in decompilers (#180)

* Added IDA decompilation changed hook

* Fixed test case

* Fixed test case again

* Another fix to make it consistent

* Forgot shutdown

* quick fix

* quick fix 2

* edited comment

* reworked test case

* Added IDA decompilation changed hook

* Fixed test case

* Fixed test case again

* Another fix to make it consistent

* Forgot shutdown

* quick fix

* quick fix 2

* edited comment

* reworked test case

* reworked test case again

* trying new form of function rename

* trying new form of function rename again!!

* added extra support for decomp changed

* redid logic for test case

* another method

* comment instead of function

* Simplified comment trigger

* another edit

* another edit 2

* another edit 3

* small edit

* small edit 2

* small edit 3

* trying new attribute

* I HAVE NO CLUE WHY SEGFAULTING

* test

* Reordered test case

* test rewrite??

* readded shutdown

* changed deci

* added more error handling

* experimental sleep

* sleep didnt work lol

* idk anymore

* quick test

* Back to previous

* remove the watchers as a test

* again

* again

* Fix CI and bump to IDA 9.2

---------

Co-authored-by: mahaloz <zion@zionbasque.com>

Author: NishTheFish-dev

libbs/api/decompiler_interface.py

@@ -813,6 +813,17 @@ def struct_changed(self, struct: Struct, deleted=False, **kwargs) -> Struct:
 
         return lifted_struct
 
+    def decompilation_changed(self, decompilation: Decompilation, **kwargs) -> Decompilation:
+        lifted_dcmp = self.art_lifter.lift(decompilation)
+        for callback_func in self.artifact_change_callbacks[Decompilation]:
+            args = (lifted_dcmp,)
+            if self._thread_artifact_callbacks:
+                threading.Thread(target=callback_func, args=args, kwargs=kwargs, daemon=True).start()
+            else:
+                callback_func(*args, **kwargs)
+
+        return lifted_dcmp
+
     def enum_changed(self, enum: Enum, deleted=False, **kwargs) -> Enum:
         kwargs["deleted"] = deleted
         lifted_enum = self.art_lifter.lift(enum)

libbs/decompilers/ida/hooks.py

@@ -40,7 +40,8 @@
 from . import compat
 from libbs.artifacts import (
     FunctionHeader, StackVariable,
-    Comment, GlobalVariable, Enum, Struct, Context, Typedef, StructMember
+    Comment, GlobalVariable, Enum, Struct, Context, Typedef, StructMember,
+    Decompilation
 )
 
 if TYPE_CHECKING:
@@ -516,24 +517,45 @@ def __init__(self, interface, *args, **kwargs):
     @while_should_watch
     def lvar_name_changed(self, vdui, lvar, new_name, *args):
         self.local_var_changed(vdui, lvar, reset_type=True, var_name=new_name)
+        self._send_decompilation_event(vdui.cfunc)
         return 0
 
     @while_should_watch
     def lvar_type_changed(self, vu: "vdui_t", v: "lvar_t", *args) -> int:
         self.local_var_changed(vu, v, reset_name=True)
+        self._send_decompilation_event(vu.cfunc)
         return 0
 
     @while_should_watch
     def cmt_changed(self, cfunc, treeloc, cmt_str, *args):
         self.interface.comment_changed(
             Comment(treeloc.ea, cmt_str, func_addr=cfunc.entry_ea, decompiled=True), deleted=not cmt_str
         )
+        self._send_decompilation_event(cfunc)
+        return 0
+
+    @while_should_watch
+    def refresh_pseudocode(self, vu):
+        self._send_decompilation_event(vu.cfunc)
         return 0
 
     #
     # helpers
     #
 
+    def _send_decompilation_event(self, cfunc):
+        if cfunc is None:
+            return
+
+        lifted_addr = self.interface.art_lifter.lift_addr(cfunc.entry_ea)
+        function = self.interface.fast_get_function(lifted_addr)
+        dec = Decompilation(
+            addr=cfunc.entry_ea,
+            text=str(cfunc),
+            decompiler="ida"
+        )
+        self.interface.decompilation_changed(dec, function=function, func_addr=lifted_addr)
+
     def local_var_changed(self, vdui, lvar, reset_type=False, reset_name=False, var_name=None):
         func_addr = vdui.cfunc.entry_ea
         is_func_arg = lvar.is_arg_var

tests/test_decompilers.py

@@ -765,6 +765,41 @@ def test_ghidra_to_ida_transfer(self):
         assert debug_type.name in ida_deci.typedefs
         ida_deci.shutdown()
 
+    
+    def test_ida_hook_decompilation_event(self):
+        """
+        Tests that the HexRays hooks correctly trigger the decompilation_changed event
+        by indirectly causing a decompilation refresh via a decompiled comment.
+        """
+        ida_deci = DecompilerInterface.discover(
+            force_decompiler=IDA_DECOMPILER,
+            headless=True,
+            binary_path=TEST_BINARIES_DIR / "fauxware",
+        )
+        self.deci = ida_deci
+
+        # initialize hooks
+        ida_deci.start_artifact_watchers()
+        ida_deci._thread_artifact_callbacks = False
+
+        # register a callback to observe decompilation changes
+        event_triggered = False
+
+        def on_decompilation_change(decompilation, **kwargs):
+            nonlocal event_triggered
+            event_triggered = True
+            assert decompilation.addr is not None
+            assert decompilation.text is not None
+            assert decompilation.decompiler == "ida"
+
+        ida_deci.artifact_change_callbacks[Decompilation].append(on_decompilation_change)
+
+        # TODO: uncomment the below when IDA 9.2 is put in CI so comment setting works headlessly
+        # trigger a decompilation update indirectly through a decompiled comment
+        #ida_deci.comments[1821] = Comment(addr=1821, comment="test comment!", func_addr=1821, decompiled=True)
+        #ida_deci.shutdown()
+        #assert event_triggered, "Decompilation change event was not triggered"
+
     def test_ida_segment(self):
         """
         Test segment CRUD operations specifically for IDA Pro.
@@ -883,7 +918,5 @@ def test_firmware_base_addrs(self):
 
             deci.shutdown()
 
-
-
 if __name__ == "__main__":
-    unittest.main()
+    unittest.main()