[mc] Prepare support for register location in DWARF location expression evaluation...

[simgrid.git] / src / mc / mc_dwarf_expression.c

diff --git a/src/mc/mc_dwarf_expression.c b/src/mc/mc_dwarf_expression.c
index 3b6c9a4..c0bb110 100644 (file)
--- a/src/mc/mc_dwarf_expression.c
+++ b/src/mc/mc_dwarf_expression.c
@@ -403,11 +403,12 @@ int mc_dwarf_execute_expression(size_t n, const Dwarf_Op * ops,
 /** \brief Resolve a location expression
  *  \deprecated Use mc_dwarf_resolve_expression
  */
-uintptr_t mc_dwarf_resolve_location(mc_expression_t expression,
-                                    mc_object_info_t object_info,
-                                    unw_cursor_t * c,
-                                    void *frame_pointer_address,
-                                    mc_snapshot_t snapshot, int process_index)
+void mc_dwarf_resolve_location(mc_location_t location,
+                               mc_expression_t expression,
+                               mc_object_info_t object_info,
+                               unw_cursor_t * c,
+                               void *frame_pointer_address,
+                               mc_snapshot_t snapshot, int process_index)
 {
   s_mc_expression_state_t state;
   memset(&state, 0, sizeof(s_mc_expression_state_t));
@@ -417,37 +418,53 @@ uintptr_t mc_dwarf_resolve_location(mc_expression_t expression,
   state.object_info = object_info;
   state.process_index = process_index;
 
+  // TODO, handle register
+
   if (mc_dwarf_execute_expression(expression->size, expression->ops, &state))
     xbt_die("Error evaluating DWARF expression");
   if (state.stack_size == 0)
     xbt_die("No value on the stack");
-  else
-    return state.stack[state.stack_size - 1];
+  else {
+    location->memory_location = (void*) state.stack[state.stack_size - 1];
+    location->cursor = NULL;
+    location->register_id = 0;
+  }
 }
 
-uintptr_t mc_dwarf_resolve_locations(mc_location_list_t locations,
+static mc_expression_t mc_find_expression(mc_location_list_t locations, unw_word_t ip) {
+  for (size_t i = 0; i != locations->size; ++i) {
+    mc_expression_t expression = locations->locations + i;
+    if ((expression->lowpc == NULL && expression->highpc == NULL)
+        || (ip && ip >= (unw_word_t) expression->lowpc
+            && ip < (unw_word_t) expression->highpc)) {
+      return expression;
+    }
+  }
+  return NULL;
+}
+
+void mc_dwarf_resolve_locations(mc_location_t location,
+                                     mc_location_list_t locations,
                                      mc_object_info_t object_info,
                                      unw_cursor_t * c,
                                      void *frame_pointer_address,
                                      mc_snapshot_t snapshot, int process_index)
 {
 
-  unw_word_t ip;
+  unw_word_t ip = 0;
   if (c) {
     if (unw_get_reg(c, UNW_REG_IP, &ip))
       xbt_die("Could not resolve IP");
   }
 
-  for (size_t i = 0; i != locations->size; ++i) {
-    mc_expression_t expression = locations->locations + i;
-    if ((expression->lowpc == NULL && expression->highpc == NULL)
-        || (c && ip >= (unw_word_t) expression->lowpc
-            && ip < (unw_word_t) expression->highpc)) {
-      return mc_dwarf_resolve_location(expression, object_info, c,
-                                       frame_pointer_address, snapshot, process_index);
-    }
+  mc_expression_t expression = mc_find_expression(locations, ip);
+  if (expression) {
+    mc_dwarf_resolve_location(location,
+                              expression, object_info, c,
+                              frame_pointer_address, snapshot, process_index);
+  } else {
+    xbt_die("Could not resolve location");
   }
-  xbt_die("Could not resolve location");
 }
 
 /** \brief Find the frame base of a given frame
@@ -458,8 +475,18 @@ uintptr_t mc_dwarf_resolve_locations(mc_location_list_t locations,
 void *mc_find_frame_base(dw_frame_t frame, mc_object_info_t object_info,
                          unw_cursor_t * unw_cursor)
 {
-  return (void *) mc_dwarf_resolve_locations(&frame->frame_base, object_info,
-                                             unw_cursor, NULL, NULL, -1);
+  s_mc_location_t location;
+  mc_dwarf_resolve_locations(&location,
+                             &frame->frame_base, object_info,
+                             unw_cursor, NULL, NULL, -1);
+  switch(mc_get_location_type(&location)) {
+  case MC_LOCATION_TYPE_ADDRESS:
+    return location.memory_location;
+    break;
+  case MC_LOCATION_TYPE_REGISTER:
+  default:
+    xbt_die("Cannot handle non-address frame base");
+  }
 }
 
 void mc_dwarf_expression_clear(mc_expression_t expression)