interceptor: Add get_live_replacement_invocation()

Intended for language bindings that want to find the matching
InvocationContext given the replacement function's address.

gum/guminterceptor.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2022 Ole André Vadla Ravnås <oleavr@nowsecure.com>
+ * Copyright (C) 2008-2024 Ole André Vadla Ravnås <oleavr@nowsecure.com>
  * Copyright (C) 2008 Christian Berentsen <jc.berentsen@gmail.com>
  * Copyright (C) 2024 Francesco Tamagni <mrmacete@protonmail.ch>
  *
@@ -705,6 +705,24 @@ gum_interceptor_get_current_invocation (void)
   return &entry->invocation_context;
 }
 
+GumInvocationContext *
+gum_interceptor_get_live_replacement_invocation (gpointer replacement_function)
+{
+  InterceptorThreadContext * interceptor_ctx;
+  GumInvocationStackEntry * entry;
+
+  interceptor_ctx = get_interceptor_thread_context ();
+  entry = gum_invocation_stack_peek_top (interceptor_ctx->stack);
+  if (entry == NULL)
+    return NULL;
+  if (!entry->calling_replacement)
+    return NULL;
+  if (replacement_function != entry->function_ctx->replacement_function)
+    return NULL;
+
+  return &entry->invocation_context;
+}
+
 GumInvocationStack *
 gum_interceptor_get_current_stack (void)
 {

gum/guminterceptor.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2022 Ole André Vadla Ravnås <oleavr@nowsecure.com>
+ * Copyright (C) 2008-2024 Ole André Vadla Ravnås <oleavr@nowsecure.com>
  * Copyright (C) 2008 Christian Berentsen <jc.berentsen@gmail.com>
  * Copyright (C) 2024 Francesco Tamagni <mrmacete@protonmail.ch>
  *
@@ -62,6 +62,8 @@ GUM_API void gum_interceptor_end_transaction (GumInterceptor * self);
 GUM_API gboolean gum_interceptor_flush (GumInterceptor * self);
 
 GUM_API GumInvocationContext * gum_interceptor_get_current_invocation (void);
+GUM_API GumInvocationContext * gum_interceptor_get_live_replacement_invocation (
+    gpointer replacement_function);
 GUM_API GumInvocationStack * gum_interceptor_get_current_stack (void);
 
 GUM_API void gum_interceptor_ignore_current_thread (GumInterceptor * self);