Call __jit_debug_register_code() indirectly via global variable.

This is speculative future optimization. It allows the debugger to
change the value of the global variable to point to its injected code.
This, in turn, allows it to handle JIT events in-process without
triggering breakpoint and without the inter-process cost of it.

Change-Id: I4961c8862603bfb43c84974a3a51110ee202bb1b

diff --git a/runtime/jit/debugger_interface.cc b/runtime/jit/debugger_interface.cc
index f08a1a9..d9d7a19 100644 (file)
--- a/runtime/jit/debugger_interface.cc
+++ b/runtime/jit/debugger_interface.cc
@@ -58,6 +58,10 @@ extern "C" {
     __asm__("");
   }
 
+  // Call __jit_debug_register_code indirectly via global variable.
+  // This gives the debugger an easy way to inject custom code to handle the events.
+  void (*__jit_debug_register_code_ptr)() = __jit_debug_register_code;
+
   // GDB will inspect contents of this descriptor.
   // Static initialization is necessary to prevent GDB from seeing
   // uninitialized descriptor.
@@ -85,7 +89,7 @@ static JITCodeEntry* CreateJITCodeEntryInternal(
   __jit_debug_descriptor.relevant_entry_ = entry;
 
   __jit_debug_descriptor.action_flag_ = JIT_REGISTER_FN;
-  __jit_debug_register_code();
+  (*__jit_debug_register_code_ptr)();
   return entry;
 }
 
@@ -102,7 +106,7 @@ static void DeleteJITCodeEntryInternal(JITCodeEntry* entry) REQUIRES(g_jit_debug
 
   __jit_debug_descriptor.relevant_entry_ = entry;
   __jit_debug_descriptor.action_flag_ = JIT_UNREGISTER_FN;
-  __jit_debug_register_code();
+  (*__jit_debug_register_code_ptr)();
   delete[] entry->symfile_addr_;
   delete entry;
 }