Fix the argument type in get_lo_size (mmtk#32)

This fixes a bug that `get_lo_size` requires a struct, but is called
with a pointer (object reference). This does not affect correctness for
now, as we do not try to get the object size for large objects in MMTk.

Author: qinsoon

.github/scripts/ci-build.sh

@@ -26,6 +26,7 @@ cd $MMTK_JULIA_DIR/mmtk
 cargo build --features $plan $build_args
 
 cd $JULIA_PATH
+
 # Clean first
 make cleanall
 # Build

julia/mmtk_julia.c

@@ -231,9 +231,12 @@ void wait_for_the_world(void)
     }
 }
 
-size_t get_lo_size(bigval_t obj) 
+size_t get_lo_size(jl_value_t* obj) 
 {
-    return obj.sz;
+    jl_taggedvalue_t *v = jl_astaggedvalue(obj);
+    // bigval_header: but we cannot access the function here. So use container_of instead.
+    bigval_t* hdr = container_of(v, bigval_t, header);
+    return hdr->sz;
 }
 
 void set_jl_last_err(int e) 

julia/mmtk_julia.h

@@ -11,7 +11,7 @@ int get_jl_last_err(void);
 
 void set_jl_last_err(int e);
 
-size_t get_lo_size(bigval_t obj);
+size_t get_lo_size(jl_value_t* obj);
 
 int8_t set_gc_initial_state(jl_ptls_t ptls);
 

mmtk/api/mmtk.h

@@ -85,8 +85,7 @@ typedef struct {
     void (* run_finalizer_function) (jl_value_t* obj, jl_value_t* function, bool is_ptr);
     int (* get_jl_last_err) (void);
     void (* set_jl_last_err) (int e);
-    // FIXME: I don't think this is correct, as we pass an object reference to get_lo_size, in the same way as get_so_size.
-    size_t (* get_lo_size) (bigval_t obj);
+    size_t (* get_lo_size) (jl_value_t* obj);
     size_t (* get_so_size) (jl_value_t* obj);
     void* (* get_obj_start_ref) (jl_value_t* obj);
     void (* wait_for_the_world) (void);