[emulator] Type the stdin callback buffer as void* for a writable binding

The stdin callback's output buffer was a char* in the FFI, so the generated
Python binding exposed it as c_char_p and ctypes handed the callback an
immutable bytes copy, making the memmove into it write to the wrong memory.
Type the buffer void* across the FFI/C++ bridge so the generated binding uses a
writable c_void_p pointer; the Python callback now receives the real buffer
address to write into.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: xusheng6

plugins/emulator/api/emulatorapi.h

@@ -60,7 +60,7 @@ namespace BinaryNinjaEmulatorAPI
 			uint32_t intrinsic, const uint64_t* params, size_t paramCount,
 			uint64_t* outValues, uint32_t* outRegs, size_t maxCount, size_t* outCount);
 		static void StdoutCallbackBridge(void* ctxt, BNILEmulator* emu, const char* data, size_t len);
-		static size_t StdinCallbackBridge(void* ctxt, BNILEmulator* emu, char* buf, size_t maxLen);
+		static size_t StdinCallbackBridge(void* ctxt, BNILEmulator* emu, void* buf, size_t maxLen);
 
 	  public:
 		LLILEmulator(Ref<BinaryView> view);

plugins/emulator/api/ffi.h

@@ -144,8 +144,10 @@ extern "C"
 		bool (*callback)(void* ctxt, BNILEmulator* emu, size_t instrIndex));
 	EMULATOR_FFI_API void BNILEmulatorSetStdoutCallback(BNILEmulator* emu, void* ctxt,
 		void (*callback)(void* ctxt, BNILEmulator* emu, const char* data, size_t len));
+	// buf is a writable output buffer of maxLen bytes (typed void* so the generated bindings
+	// expose it as a writable pointer rather than an immutable string).
 	EMULATOR_FFI_API void BNILEmulatorSetStdinCallback(BNILEmulator* emu, void* ctxt,
-		size_t (*callback)(void* ctxt, BNILEmulator* emu, char* buf, size_t maxLen));
+		size_t (*callback)(void* ctxt, BNILEmulator* emu, void* buf, size_t maxLen));
 	EMULATOR_FFI_API void BNILEmulatorRequestStop(BNILEmulator* emu);
 	EMULATOR_FFI_API void BNILEmulatorReset(BNILEmulator* emu);
 

plugins/emulator/api/ilemulator.cpp

@@ -304,10 +304,10 @@ void LLILEmulator::StdoutCallbackBridge(void* ctxt, BNILEmulator*, const char* d
 }
 
 
-size_t LLILEmulator::StdinCallbackBridge(void* ctxt, BNILEmulator*, char* buf, size_t maxLen)
+size_t LLILEmulator::StdinCallbackBridge(void* ctxt, BNILEmulator*, void* buf, size_t maxLen)
 {
 	LLILEmulator* self = (LLILEmulator*)ctxt;
-	return self->m_stdinCallback(self, buf, maxLen);
+	return self->m_stdinCallback(self, static_cast<char*>(buf), maxLen);
 }
 
 

plugins/emulator/api/python/ilemulator.py

@@ -551,9 +551,12 @@ def set_stdin_callback(
         Return ``b''`` for EOF. Pass ``None`` to remove the callback.
         """
         self._stdin_callback = callback
+        # buf is a writable, non-null-terminated output buffer. It is typed void* in the FFI
+        # (hence c_void_p here) so the callback receives the raw address to memmove into,
+        # rather than the immutable bytes copy ctypes produces for a c_char_p parameter.
         _CB_T = ctypes.CFUNCTYPE(ctypes.c_ulonglong, ctypes.c_void_p,
             ctypes.POINTER(core.BNILEmulator),
-            ctypes.c_char_p, ctypes.c_ulonglong)
+            ctypes.c_void_p, ctypes.c_ulonglong)
         if callback is None:
             core.BNILEmulatorSetStdinCallback(self._get_base(), None, ctypes.cast(None, _CB_T))
             self._stdin_cb = None

plugins/emulator/core/ilemulator.cpp

@@ -806,7 +806,7 @@ void BNILEmulatorSetStdoutCallback(BNILEmulator* emu, void* ctxt,
 
 
 void BNILEmulatorSetStdinCallback(BNILEmulator* emu, void* ctxt,
-	size_t (*callback)(void*, BNILEmulator*, char*, size_t))
+	size_t (*callback)(void*, BNILEmulator*, void*, size_t))
 {
 	if (callback)
 	{