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[mc] Support DWARF4 DW_FORM_sec_offset (found in libpthread_nonshared.a)
[simgrid.git] / src / mc / mc_dwarf.c
index c95f51e..618ed29 100644 (file)
@@ -1,6 +1,5 @@
 /* Copyright (c) 2008-2013. The SimGrid Team.
  * All rights reserved.                                                     */
-
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
@@ -140,6 +139,7 @@ static int MC_dwarf_form_get_class(int form) {
   case DW_FORM_block:
   case DW_FORM_block1:
     return MC_DW_CLASS_BLOCK;
+  case DW_FORM_data1:
   case DW_FORM_data2:
   case DW_FORM_data4:
   case DW_FORM_data8:
@@ -215,7 +215,7 @@ static const char* MC_dwarf_at_linkage_name(Dwarf_Die* die) {
  *  \return MC specific representation of the location list represented by the given attribute
  *  of the given die
  */
-static dw_location_t MC_dwarf_get_location_list(Dwarf_Die* die, Dwarf_Attribute* attr) {
+static dw_location_t MC_dwarf_get_location_list(mc_object_info_t info, Dwarf_Die* die, Dwarf_Attribute* attr) {
 
   dw_location_t location = xbt_new0(s_dw_location_t, 1);
   location->type = e_dw_loclist;
@@ -236,8 +236,11 @@ static dw_location_t MC_dwarf_get_location_list(Dwarf_Die* die, Dwarf_Attribute*
       xbt_die("Error while loading location list");
 
     dw_location_entry_t new_entry = xbt_new0(s_dw_location_entry_t, 1);
-    new_entry->lowpc = start;
-    new_entry->highpc = end;
+
+    void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
+
+    new_entry->lowpc = (char*) base + start;
+    new_entry->highpc = (char*) base + end;
     new_entry->location = MC_dwarf_get_expression(expr, len);
 
     xbt_dynar_push(loclist, &new_entry);
@@ -245,6 +248,31 @@ static dw_location_t MC_dwarf_get_location_list(Dwarf_Die* die, Dwarf_Attribute*
   }
 }
 
+/** \brief Find the frame base of a given frame
+ *
+ *  \param ip         Instruction pointer
+ *  \param frame
+ *  \param unw_cursor
+ */
+void* mc_find_frame_base(void* ip, dw_frame_t frame, unw_cursor_t* unw_cursor) {
+  switch(frame->frame_base->type) {
+  case e_dw_loclist:
+  {
+    int loclist_cursor;
+    for(loclist_cursor=0; loclist_cursor < xbt_dynar_length(frame->frame_base->location.loclist); loclist_cursor++){
+      dw_location_entry_t entry = xbt_dynar_get_as(frame->frame_base->location.loclist, loclist_cursor, dw_location_entry_t);
+      if((ip >= entry->lowpc) && (ip < entry->highpc)){
+        return (void*) MC_dwarf_resolve_location(unw_cursor, entry->location, NULL);
+      }
+    }
+    return NULL;
+  }
+  // Not handled:
+  default:
+    return NULL;
+  }
+}
+
 /** \brief Get the location expression or location list from an attribute
  *
  *  Processes direct expressions as well as location lists.
@@ -254,7 +282,7 @@ static dw_location_t MC_dwarf_get_location_list(Dwarf_Die* die, Dwarf_Attribute*
  *  \return MC specific representation of the location represented by the given attribute
  *  of the given die
  */
-static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr) {
+static dw_location_t MC_dwarf_get_location(mc_object_info_t info, Dwarf_Die* die, Dwarf_Attribute* attr) {
   int form = dwarf_whatform(attr);
   switch (form) {
 
@@ -274,11 +302,12 @@ static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr
 
   // The attribute is a reference to a location list entry:
   case DW_FORM_sec_offset:
+  case DW_FORM_data1:
   case DW_FORM_data2:
   case DW_FORM_data4:
   case DW_FORM_data8:
     {
-      return MC_dwarf_get_location_list(die, attr);
+      return MC_dwarf_get_location_list(info, die, attr);
     }
     break;
 
@@ -301,13 +330,13 @@ static dw_location_t MC_dwarf_get_location(Dwarf_Die* die, Dwarf_Attribute* attr
  *  \return MC specific representation of the location represented by the given attribute
  *  of the given die
  */
-static dw_location_t MC_dwarf_at_location(Dwarf_Die* die, int attribute) {
+static dw_location_t MC_dwarf_at_location(mc_object_info_t info, Dwarf_Die* die, int attribute) {
   if(!dwarf_hasattr_integrate(die, attribute))
     return xbt_new0(s_dw_location_t, 1);
 
   Dwarf_Attribute attr;
   dwarf_attr_integrate(die, attribute, &attr);
-  return MC_dwarf_get_location(die, &attr);
+  return MC_dwarf_get_location(info, die, &attr);
 }
 
 static char* MC_dwarf_at_type(Dwarf_Die* die) {
@@ -395,7 +424,7 @@ static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit)
     return MC_dwarf_attr_uint(die, DW_AT_count, 0);
   }
 
-  // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound:
+  // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound + 1:
 
   if (!dwarf_hasattr_integrate(die, DW_AT_upper_bound)) {
        // This is not really 0, but the code expects this (we do not know):
@@ -409,7 +438,7 @@ static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit)
   } else {
        lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit));
   }
-  return upper_bound - lower_bound;
+  return upper_bound - lower_bound + 1;
 }
 
 static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit) {
@@ -479,7 +508,8 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
 
   Dwarf_Attribute attr;
   dwarf_attr_integrate(child, DW_AT_data_member_location, &attr);
-  int klass = MC_dwarf_form_get_class(dwarf_whatform(&attr));
+  int form = dwarf_whatform(&attr);
+  int klass = MC_dwarf_form_get_class(form);
   switch (klass) {
   case MC_DW_CLASS_EXPRLOC:
   case MC_DW_CLASS_BLOCK:
@@ -519,7 +549,9 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
     // It's supposed to be possible in DWARF2 but I couldn't find its semantic
     // in the spec.
   default:
-    xbt_die("Can't handle form class 0x%x (%i) as DW_AT_member_location", klass, klass);
+    xbt_die(
+      "Can't handle form class (%i) / form 0x%x as DW_AT_member_location",
+      klass, form);
   }
 
 }
@@ -634,6 +666,10 @@ static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwar
 
   char* key = bprintf("%" PRIx64, (uint64_t) type->id);
   xbt_dict_set(info->types, key, type, NULL);
+
+  if(type->name && type->byte_size!=0) {
+    xbt_dict_set(info->types_by_name, type->name, type, NULL);
+  }
 }
 
 /** \brief Convert libdw location expresion elment into native one (or NULL in some cases) */
@@ -795,6 +831,8 @@ static dw_location_t MC_dwarf_get_expression(Dwarf_Op* expr,  size_t len) {
   return loc;
 }
 
+static int mc_anonymous_variable_index = 0;
+
 static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
   // Drop declaration:
   if (MC_dwarf_attr_flag(die, DW_AT_declaration, false))
@@ -811,9 +849,9 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
   variable->global = frame == NULL; // Can be override base on DW_AT_location
   variable->name = xbt_strdup(MC_dwarf_attr_string(die, DW_AT_name));
   variable->type_origin = MC_dwarf_at_type(die);
-  variable->address.address = NULL;
 
-  int klass = MC_dwarf_form_get_class(dwarf_whatform(&attr_location));
+  int form = dwarf_whatform(&attr_location);
+  int klass = form == DW_FORM_sec_offset ? MC_DW_CLASS_CONSTANT : MC_dwarf_form_get_class(form);
   switch (klass) {
   case MC_DW_CLASS_EXPRLOC:
   case MC_DW_CLASS_BLOCK:
@@ -831,10 +869,10 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
         variable->global = 1;
         Dwarf_Off offset = expr[0].number;
         // TODO, Why is this different base on the object?
-        Dwarf_Off base = strcmp(info->file_name, xbt_binary_name) !=0 ? (Dwarf_Off) info->start_text : 0;
-        variable->address.address = (void*) (base + offset);
+        Dwarf_Off base = strcmp(info->file_name, xbt_binary_name) !=0 ? (Dwarf_Off) info->start_exec : 0;
+        variable->address = (void*) (base + offset);
       } else {
-        variable->address.location = MC_dwarf_get_expression(expr, len);
+        variable->location = MC_dwarf_get_expression(expr, len);
       }
 
       break;
@@ -842,11 +880,17 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
   case MC_DW_CLASS_LOCLISTPTR:
   case MC_DW_CLASS_CONSTANT:
     // Reference to location list:
-    variable->address.location = MC_dwarf_get_location_list(die, &attr_location);
+    variable->location = MC_dwarf_get_location_list(info, die, &attr_location);
     break;
   default:
-    xbt_die("Unexpected calss 0x%x (%i) list for location in <%p>%s",
-      klass, klass, (void*) variable->dwarf_offset, variable->name);
+    xbt_die("Unexpected form 0x%x (%i), class 0x%x (%i) list for location in <%p>%s",
+      form, form, klass, klass, (void*) variable->dwarf_offset, variable->name);
+  }
+
+  // The current code needs a variable name,
+  // generate a fake one:
+  if(!variable->name) {
+    variable->name = bprintf("@anonymous#%i", mc_anonymous_variable_index++);
   }
 
   return variable;
@@ -869,11 +913,16 @@ static void MC_dwarf_handle_subprogram_die(mc_object_info_t info, Dwarf_Die* die
     name = MC_dwarf_attr_string(die, DW_AT_name);
   frame->name = xbt_strdup(name);
 
+  // This is the base address for DWARF addresses.
+  // Relocated addresses are offset from this base address.
+  // See DWARF4 spec 7.5
+  void* base = info->flags & MC_OBJECT_INFO_EXECUTABLE ? 0 : MC_object_base_address(info);
+
   // Variables are filled in the (recursive) call of MC_dwarf_handle_children:
   frame->variables = xbt_dynar_new(sizeof(dw_variable_t), dw_variable_free_voidp);
-  frame->high_pc = (void*) MC_dwarf_attr_addr(die, DW_AT_high_pc);
-  frame->low_pc = (void*) MC_dwarf_attr_addr(die, DW_AT_low_pc);
-  frame->frame_base = MC_dwarf_at_location(die, DW_AT_frame_base);
+  frame->high_pc = ((char*) base) + MC_dwarf_attr_addr(die, DW_AT_high_pc);
+  frame->low_pc = ((char*) base) + MC_dwarf_attr_addr(die, DW_AT_low_pc);
+  frame->frame_base = MC_dwarf_at_location(info, die, DW_AT_frame_base);
   frame->end = -1; // This one is now useless:
 
   // Handle children:
@@ -918,7 +967,6 @@ static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die
     case DW_TAG_shared_type:
       MC_dwarf_handle_type_die(info, die, unit);
       break;
-    case DW_TAG_inlined_subroutine:
     case DW_TAG_subprogram:
       MC_dwarf_handle_subprogram_die(info, die, unit, frame);
       return;
@@ -948,6 +996,7 @@ void MC_dwarf_get_variables(mc_object_info_t info) {
   size_t length;
   while (dwarf_nextcu (dwarf, offset, &next_offset, &length, NULL, NULL, NULL) == 0) {
     Dwarf_Die die;
+
     if(dwarf_offdie(dwarf, offset+length, &die)!=NULL) {
       MC_dwarf_handle_die(info, &die, &die, NULL);
     }