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[mc] Handle DW_AT_high_pc as offset for DWARF4
[simgrid.git] / src / mc / mc_dwarf.c
index eaff170..45e2d5e 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. */
 
@@ -51,11 +50,11 @@ static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit);
  *  \param unit the DIE of the compile unit of the current DIE
  *  \param frame containg frame if any
  */
-static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame);
+static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace);
 
 /** \brief Process a type DIE
  */
-static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit);
+static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace);
 
 /** \brief Calls MC_dwarf_handle_die on all childrend of the given die
  *
@@ -64,7 +63,7 @@ static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwar
  *  \param unit the DIE of the compile unit of the current DIE
  *  \param frame containg frame if any
  */
-static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame);
+static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace);
 
 /** \brief Handle a variable (DW_TAG_variable or other)
  *
@@ -73,15 +72,7 @@ static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwar
  *  \param unit the DIE of the compile unit of the current DIE
  *  \param frame containg frame if any
  */
-static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame);
-
-/** \brief Convert a libdw DWARF expression into a MC representation of the location
- *
- *  \param expr array of DWARf operations
- *  \param len  number of elements
- *  \return a new MC expression
- */
-static dw_location_t MC_dwarf_get_expression(Dwarf_Op* expr,  size_t len);
+static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace);
 
 /** \brief Get the DW_TAG_type of the DIE
  *
@@ -99,7 +90,7 @@ const char* MC_dwarf_attrname(int attr) {
   switch (attr) {
 #include "mc_dwarf_attrnames.h"
   default:
-    return "DW_AT_unkown";
+    return "DW_AT_unknown";
   }
 }
 
@@ -114,7 +105,70 @@ const char* MC_dwarf_tagname(int tag) {
   case DW_TAG_invalid:
     return "DW_TAG_invalid";
   default:
-    return "DW_TAG_unkown";
+    return "DW_TAG_unknown";
+  }
+}
+
+/** \brief A class of DWARF tags (DW_TAG_*)
+ */
+typedef enum mc_tag_class {
+  mc_tag_unknown,
+  mc_tag_type,
+  mc_tag_subprogram,
+  mc_tag_variable,
+  mc_tag_scope,
+  mc_tag_namespace
+} mc_tag_class;
+
+static mc_tag_class MC_dwarf_tag_classify(int tag) {
+  switch (tag) {
+
+    case DW_TAG_array_type:
+    case DW_TAG_class_type:
+    case DW_TAG_enumeration_type:
+    case DW_TAG_typedef:
+    case DW_TAG_pointer_type:
+    case DW_TAG_reference_type:
+    case DW_TAG_rvalue_reference_type:
+    case DW_TAG_string_type:
+    case DW_TAG_structure_type:
+    case DW_TAG_subroutine_type:
+    case DW_TAG_union_type:
+    case DW_TAG_ptr_to_member_type:
+    case DW_TAG_set_type:
+    case DW_TAG_subrange_type:
+    case DW_TAG_base_type:
+    case DW_TAG_const_type:
+    case DW_TAG_file_type:
+    case DW_TAG_packed_type:
+    case DW_TAG_volatile_type:
+    case DW_TAG_restrict_type:
+    case DW_TAG_interface_type:
+    case DW_TAG_unspecified_type:
+    case DW_TAG_mutable_type:
+    case DW_TAG_shared_type:
+      return mc_tag_type;
+
+    case DW_TAG_subprogram:
+      return mc_tag_subprogram;
+
+    case DW_TAG_variable:
+    case DW_TAG_formal_parameter:
+      return mc_tag_variable;
+
+    case DW_TAG_lexical_block:
+    case DW_TAG_try_block:
+    case DW_TAG_catch_block:
+    case DW_TAG_inlined_subroutine:
+    case DW_TAG_with_stmt:
+      return mc_tag_scope;
+
+    case DW_TAG_namespace:
+      return mc_tag_namespace;
+
+    default:
+      return mc_tag_unknown;
+
   }
 }
 
@@ -131,6 +185,13 @@ const char* MC_dwarf_tagname(int tag) {
 #define MC_DW_CLASS_MACPTR 9
 #define MC_DW_CLASS_RANGELISTPTR 10
 
+/** \brief Find the DWARF data class for a given DWARF data form
+ *
+ *  This mapping is defined in the DWARF spec.
+ *
+ *  \param form The form (values taken from the DWARF spec)
+ *  \return An internal representation for the corresponding class
+ * */
 static int MC_dwarf_form_get_class(int form) {
   switch(form) {
   case DW_FORM_addr:
@@ -140,6 +201,7 @@ 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:
@@ -181,11 +243,11 @@ static inline const char* MC_dwarf_die_tagname(Dwarf_Die* die) {
 
 /** \brief Get an attribute of a given DIE as a string
  *
- *  \param the DIE
+ *  \param die       the DIE
  *  \param attribute attribute
  *  \return value of the given attribute of the given DIE
  */
-static const char* MC_dwarf_attr_string(Dwarf_Die* die, int attribute) {
+static const char* MC_dwarf_attr_integrate_string(Dwarf_Die* die, int attribute) {
   Dwarf_Attribute attr;
   if (!dwarf_attr_integrate(die, attribute, &attr)) {
        return NULL;
@@ -196,135 +258,58 @@ static const char* MC_dwarf_attr_string(Dwarf_Die* die, int attribute) {
 
 /** \brief Get the linkage name of a DIE.
  *
- *  Use either DW_AT_linkage_name or DW_AR_MIPS_linkage_name.
+ *  Use either DW_AT_linkage_name or DW_AT_MIPS_linkage_name.
+ *  DW_AT_linkage_name is standardized since DWARF 4.
+ *  Before this version of DWARF, the MIPS extensions
+ *  DW_AT_MIPS_linkage_name is used (at least by GCC).
  *
- *  \param DIE
+ *  \param  the DIE
  *  \return linkage name of the given DIE (or NULL)
  * */
 static const char* MC_dwarf_at_linkage_name(Dwarf_Die* die) {
-  const char* name = MC_dwarf_attr_string(die, DW_AT_linkage_name);
+  const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_linkage_name);
   if (!name)
-    name = MC_dwarf_attr_string(die, DW_AT_MIPS_linkage_name);
+    name = MC_dwarf_attr_integrate_string(die, DW_AT_MIPS_linkage_name);
   return name;
 }
 
-/** \brief Create a location list from a given attribute
- *
- *  \param die the DIE
- *  \param attr the attribute
- *  \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) {
-
-  dw_location_t location = xbt_new0(s_dw_location_t, 1);
-  location->type = e_dw_loclist;
-  xbt_dynar_t loclist = xbt_dynar_new(sizeof(dw_location_entry_t), NULL);
-  location->location.loclist = loclist;
-
-  ptrdiff_t offset = 0;
-  Dwarf_Addr base, start, end;
-  Dwarf_Op *expr;
-  size_t len;
-
-  while (1) {
-
-    offset = dwarf_getlocations(attr, offset, &base, &start, &end, &expr, &len);
-    if (offset==0)
-      return location;
-    else if (offset==-1)
-      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;
-    new_entry->location = MC_dwarf_get_expression(expr, len);
-
-    xbt_dynar_push(loclist, &new_entry);
-
+static Dwarf_Off MC_dwarf_attr_dieoffset(Dwarf_Die* die, int attribute) {
+  Dwarf_Attribute attr;
+  if (dwarf_hasattr_integrate(die, attribute)) {
+    dwarf_attr_integrate(die, attribute, &attr);
+    Dwarf_Die subtype_die;
+    if (dwarf_formref_die(&attr, &subtype_die)==NULL) {
+      xbt_die("Could not find DIE");
+    }
+    return dwarf_dieoffset(&subtype_die);
   }
+  else return 0;
 }
 
-/** \brief Get the location expression or location list from an attribute
- *
- *  Processes direct expressions as well as location lists.
- *
- *  \param die the DIE
- *  \param attr the 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) {
-  int form = dwarf_whatform(attr);
-  switch (form) {
-
-  // The attribute is an DWARF location expression:
-  case DW_FORM_exprloc:
-  case DW_FORM_block1: // not in the spec
-  case DW_FORM_block2:
-  case DW_FORM_block4:
-  case DW_FORM_block:
-    {
-      Dwarf_Op* expr;
-      size_t len;
-      if (dwarf_getlocation(attr, &expr, &len))
-        xbt_die("Could not read location expression");
-      return MC_dwarf_get_expression(expr, len);
-    }
-
-  // The attribute is a reference to a location list entry:
-  case DW_FORM_sec_offset:
-  case DW_FORM_data2:
-  case DW_FORM_data4:
-  case DW_FORM_data8:
-    {
-      return MC_dwarf_get_location_list(die, attr);
+static Dwarf_Off MC_dwarf_attr_integrate_dieoffset(Dwarf_Die* die, int attribute) {
+  Dwarf_Attribute attr;
+  if (dwarf_hasattr_integrate(die, attribute)) {
+    dwarf_attr_integrate(die, DW_AT_type, &attr);
+    Dwarf_Die subtype_die;
+    if (dwarf_formref_die(&attr, &subtype_die)==NULL) {
+      xbt_die("Could not find DIE");
     }
-    break;
-
-  default:
-    xbt_die("Unexpected form %i list for location in attribute %s of <%p>%s",
-      form,
-      MC_dwarf_attrname(attr->code),
-      (void*) dwarf_dieoffset(die),
-      MC_dwarf_attr_string(die, DW_AT_name));
-    return NULL;
+    return dwarf_dieoffset(&subtype_die);
   }
+  else return 0;
 }
 
-/** \brief Get the location expression or location list from an attribute
+/** \brief Find the type/subtype (DW_AT_type) for a DIE
  *
- *  Processes direct expressions as well as location lists.
- *
- *  \param die the DIE
- *  \param attribute the attribute code
- *  \return MC specific representation of the location represented by the given attribute
- *  of the given die
+ *  \param dit the DIE
+ *  \return DW_AT_type reference as a global offset in hexadecimal (or NULL)
  */
-static dw_location_t MC_dwarf_at_location(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);
-}
-
 static char* MC_dwarf_at_type(Dwarf_Die* die) {
-  Dwarf_Attribute attr;
-  if (dwarf_hasattr_integrate(die, DW_AT_type)) {
-       dwarf_attr_integrate(die, DW_AT_type, &attr);
-       Dwarf_Die subtype_die;
-       if (dwarf_formref_die(&attr, &subtype_die)==NULL) {
-         xbt_die("Could not find DIE for type");
-       }
-       Dwarf_Off subtype_global_offset = dwarf_dieoffset(&subtype_die);
-    return bprintf("%" PRIx64 , subtype_global_offset);
-  }
-  else return NULL;
+  Dwarf_Off offset = MC_dwarf_attr_integrate_dieoffset(die, DW_AT_type);
+  return offset == 0 ? NULL : bprintf("%" PRIx64 , offset);
 }
 
-static uint64_t MC_dwarf_attr_addr(Dwarf_Die* die, int attribute) {
+static uint64_t MC_dwarf_attr_integrate_addr(Dwarf_Die* die, int attribute) {
   Dwarf_Attribute attr;
   if(dwarf_attr_integrate(die, attribute, &attr)==NULL)
     return 0;
@@ -335,7 +320,7 @@ static uint64_t MC_dwarf_attr_addr(Dwarf_Die* die, int attribute) {
     return 0;
 }
 
-static uint64_t MC_dwarf_attr_uint(Dwarf_Die* die, int attribute, uint64_t default_value) {
+static uint64_t MC_dwarf_attr_integrate_uint(Dwarf_Die* die, int attribute, uint64_t default_value) {
   Dwarf_Attribute attr;
   if (dwarf_attr_integrate(die, attribute, &attr)==NULL)
     return default_value;
@@ -343,7 +328,7 @@ static uint64_t MC_dwarf_attr_uint(Dwarf_Die* die, int attribute, uint64_t defau
   return dwarf_formudata(dwarf_attr_integrate(die, attribute, &attr), &value) == 0 ? (uint64_t) value : default_value;
 }
 
-static bool MC_dwarf_attr_flag(Dwarf_Die* die, int attribute, int integrate) {
+static bool MC_dwarf_attr_flag(Dwarf_Die* die, int attribute, bool integrate) {
   Dwarf_Attribute attr;
   if ((integrate ? dwarf_attr_integrate(die, attribute, &attr)
                     : dwarf_attr(die, attribute, &attr))==0)
@@ -356,6 +341,14 @@ static bool MC_dwarf_attr_flag(Dwarf_Die* die, int attribute, int integrate) {
   return result;
 }
 
+/** \brief Find the default lower bound for a given language
+ *
+ *  The default lower bound of an array (when DW_TAG_lower_bound
+ *  is missing) depends on the language of the compilation unit.
+ *
+ *  \param lang Language of the compilation unit (values defined in the DWARF spec)
+ *  \return     Default lower bound of an array in this compilation unit
+ * */
 static uint64_t MC_dwarf_default_lower_bound(int lang) {
   switch(lang) {
   case DW_LANG_C:
@@ -381,18 +374,24 @@ static uint64_t MC_dwarf_default_lower_bound(int lang) {
   case DW_LANG_Cobol85:
     return 1;
   default:
-    xbt_die("No default MT_TAG_lower_bound for language %i and none given", lang);
+    xbt_die("No default DW_TAG_lower_bound for language %i and none given", lang);
     return 0;
   }
 }
 
+/** \brief Finds the number of elements in a DW_TAG_subrange_type or DW_TAG_enumeration_type DIE
+ *
+ *  \param die  the DIE
+ *  \param unit DIE of the compilation unit
+ *  \return     number of elements in the range
+ * */
 static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit) {
   xbt_assert(dwarf_tag(die)==DW_TAG_enumeration_type ||dwarf_tag(die)==DW_TAG_subrange_type,
       "MC_dwarf_subrange_element_count called with DIE of type %s", MC_dwarf_die_tagname(die));
 
   // Use DW_TAG_count if present:
   if (dwarf_hasattr_integrate(die, DW_AT_count)) {
-    return MC_dwarf_attr_uint(die, DW_AT_count, 0);
+    return MC_dwarf_attr_integrate_uint(die, DW_AT_count, 0);
   }
 
   // Otherwise compute DW_TAG_upper_bound-DW_TAG_lower_bound + 1:
@@ -401,17 +400,26 @@ static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit)
        // This is not really 0, but the code expects this (we do not know):
     return 0;
   }
-  uint64_t upper_bound = MC_dwarf_attr_uint(die, DW_AT_upper_bound, -1);
+  uint64_t upper_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_upper_bound, -1);
 
   uint64_t lower_bound = 0;
   if (dwarf_hasattr_integrate(die, DW_AT_lower_bound)) {
-    lower_bound = MC_dwarf_attr_uint(die, DW_AT_lower_bound, -1);
+    lower_bound = MC_dwarf_attr_integrate_uint(die, DW_AT_lower_bound, -1);
   } else {
        lower_bound = MC_dwarf_default_lower_bound(dwarf_srclang(unit));
   }
   return upper_bound - lower_bound + 1;
 }
 
+/** \brief Finds the number of elements in a array type (DW_TAG_array_type)
+ *
+ *  The compilation unit might be needed because the default lower
+ *  bound depends on the language of the compilation unit.
+ *
+ *  \param die the DIE of the DW_TAG_array_type
+ *  \param unit the DIE of the compilation unit
+ *  \return number of elements in this array type
+ * */
 static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit) {
   xbt_assert(dwarf_tag(die)==DW_TAG_array_type,
     "MC_dwarf_array_element_count called with DIE of type %s", MC_dwarf_die_tagname(die));
@@ -428,40 +436,15 @@ static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit) {
   return result;
 }
 
-// ***** Location
-
-Dwarf_Off MC_dwarf_resolve_location(unw_cursor_t* c, dw_location_t location, void* frame_pointer_address) {
-  unw_word_t res;
-  switch (location->type){
-  case e_dw_compose:
-    if (xbt_dynar_length(location->location.compose) > 1){
-      return 0; /* TODO : location list with optimizations enabled */
-    }
-    dw_location_t location_entry = xbt_dynar_get_as(location->location.compose, 0, dw_location_t);
-    switch (location_entry->type){
-    case e_dw_register:
-      unw_get_reg(c, location_entry->location.reg, &res);
-      return res;
-    case e_dw_bregister_op:
-      unw_get_reg(c, location_entry->location.breg_op.reg, &res);
-      return (Dwarf_Off) ((long)res + location_entry->location.breg_op.offset);
-      break;
-    case e_dw_fbregister_op:
-      if (frame_pointer_address != NULL)
-        return (Dwarf_Off)((char *)frame_pointer_address + location_entry->location.fbreg_op);
-      else
-        return 0;
-    default:
-      return 0; /* FIXME : implement other cases (with optimizations enabled) */
-    }
-    break;
-    default:
-      return 0;
-  }
-}
-
 // ***** dw_type_t
 
+/** \brief Initialize the location of a member of a type
+ * (DW_AT_data_member_location of a DW_TAG_member).
+ *
+ *  \param  type   a type (struct, class)
+ *  \param  member the member of the type
+ *  \param  child  DIE of the member (DW_TAG_member)
+ */
 static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwarf_Die* child) {
   if (dwarf_hasattr(child, DW_AT_data_bit_offset)) {
     xbt_die("Can't groke DW_AT_data_bit_offset.");
@@ -479,7 +462,8 @@ 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:
@@ -490,13 +474,13 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
       if (dwarf_getlocation(&attr, &expr, &len)) {
         xbt_die(
           "Could not read location expression DW_AT_data_member_location in DW_TAG_member %s of type <%p>%s",
-          MC_dwarf_attr_string(child, DW_AT_name),
+          MC_dwarf_attr_integrate_string(child, DW_AT_name),
           type->id, type->name);
       }
       if (len==1 && expr[0].atom == DW_OP_plus_uconst) {
         member->offset =  expr[0].number;
       } else {
-        xbt_die("Can't groke this location expression yet.");
+        mc_dwarf_expression_init(&member->location, len, expr);
       }
       break;
     }
@@ -508,7 +492,7 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
         member->offset = offset;
       else
         xbt_die("Cannot get %s location <%p>%s",
-          MC_dwarf_attr_string(child, DW_AT_name),
+          MC_dwarf_attr_integrate_string(child, DW_AT_name),
           type->id, type->name);
       break;
     }
@@ -519,30 +503,55 @@ 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);
   }
 
 }
 
+static void dw_type_free_voidp(void *t){
+  dw_type_free((dw_type_t) * (void **) t);
+}
+
+/** \brief Populate the list of members of a type
+ *
+ *  \param info ELF object containing the type DIE
+ *  \param die  DIE of the type
+ *  \param unit DIE of the compilation unit containing the type DIE
+ *  \param type the type
+ */
 static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_type_t type) {
   int res;
   Dwarf_Die child;
   xbt_assert(!type->members);
-  type->members = xbt_dynar_new(sizeof(dw_type_t), (void(*)(void*))dw_type_free);
+  type->members = xbt_dynar_new(sizeof(dw_type_t), (void(*)(void*))dw_type_free_voidp);
   for (res=dwarf_child(die, &child); res==0; res=dwarf_siblingof(&child,&child)) {
-    if (dwarf_tag(&child)==DW_TAG_member) {
+    int tag = dwarf_tag(&child);
+    if (tag==DW_TAG_member || tag==DW_TAG_inheritance) {
+
+      // Skip declarations:
+      if (MC_dwarf_attr_flag(&child, DW_AT_declaration, false))
+        continue;
+
+      // Skip compile time constants:
+      if(dwarf_hasattr(&child, DW_AT_const_value))
+        continue;
+
       // TODO, we should use another type (because is is not a type but a member)
       dw_type_t member = xbt_new0(s_dw_type_t, 1);
-      member->type = -1;
-      member->id = NULL;
+      member->type = tag;
+
+      // Global Offset:
+      member->id = (void *) dwarf_dieoffset(&child);
 
-      const char* name = MC_dwarf_attr_string(&child, DW_AT_name);
+      const char* name = MC_dwarf_attr_integrate_string(&child, DW_AT_name);
       if(name)
         member->name = xbt_strdup(name);
       else
         member->name = NULL;
 
-      member->byte_size = MC_dwarf_attr_uint(&child, DW_AT_byte_size, 0);
+      member->byte_size = MC_dwarf_attr_integrate_uint(&child, DW_AT_byte_size, 0);
       member->element_count = -1;
       member->dw_type_id = MC_dwarf_at_type(&child);
       member->members = NULL;
@@ -571,7 +580,7 @@ static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die* die, Dwarf_Di
  *  \param unit compilation unit of the current DIE
  *  \return MC representation of the type
  */
-static dw_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit) {
+static dw_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
 
   dw_type_t type = xbt_new0(s_dw_type_t, 1);
   type->type = -1;
@@ -589,9 +598,24 @@ static dw_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die* die, Dwa
   // Global Offset
   type->id = (void *) dwarf_dieoffset(die);
 
-  const char* name = MC_dwarf_attr_string(die, DW_AT_name);
+  const char* prefix = "";
+  switch (type->type) {
+  case DW_TAG_structure_type:
+    prefix = "struct ";
+    break;
+  case DW_TAG_union_type:
+    prefix = "union ";
+    break;
+  case DW_TAG_class_type:
+    prefix = "class ";
+    break;
+  default:
+    prefix = "";
+  }
+
+  const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
   if (name!=NULL) {
-       type->name = xbt_strdup(name);
+    type->name = namespace ? bprintf("%s%s::%s", prefix, namespace, name) : bprintf("%s%s", prefix, name);
   }
 
   XBT_DEBUG("Processing type <%p>%s", type->id, type->name);
@@ -600,7 +624,7 @@ static dw_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die* die, Dwa
 
   // Computation of the byte_size;
   if (dwarf_hasattr_integrate(die, DW_AT_byte_size))
-    type->byte_size = MC_dwarf_attr_uint(die, DW_AT_byte_size, 0);
+    type->byte_size = MC_dwarf_attr_integrate_uint(die, DW_AT_byte_size, 0);
   else if (type->type == DW_TAG_array_type || type->type==DW_TAG_structure_type || type->type==DW_TAG_class_type) {
     Dwarf_Word size;
     if (dwarf_aggregate_size(die, &size)==0) {
@@ -624,182 +648,39 @@ static dw_type_t MC_dwarf_die_to_type(mc_object_info_t info, Dwarf_Die* die, Dwa
   case DW_TAG_union_type:
   case DW_TAG_class_type:
          MC_dwarf_add_members(info, die, unit, type);
+         char* new_namespace = namespace == NULL ? xbt_strdup(type->name)
+           : bprintf("%s::%s", namespace, name);
+         MC_dwarf_handle_children(info, die, unit, frame, new_namespace);
+         free(new_namespace);
+         break;
   }
 
   return type;
 }
 
-static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit) {
-  dw_type_t type = MC_dwarf_die_to_type(info, die, unit);
+static void MC_dwarf_handle_type_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
+  dw_type_t type = MC_dwarf_die_to_type(info, die, unit, frame, namespace);
 
   char* key = bprintf("%" PRIx64, (uint64_t) type->id);
   xbt_dict_set(info->types, key, type, NULL);
-}
-
-/** \brief Convert libdw location expresion elment into native one (or NULL in some cases) */
-static dw_location_t MC_dwarf_get_expression_element(Dwarf_Op* op) {
-  dw_location_t element = xbt_new0(s_dw_location_t, 1);
-  uint8_t atom = op->atom;
-  if (atom >= DW_OP_reg0 && atom<= DW_OP_reg31) {
-    element->type = e_dw_register;
-    element->location.reg = atom - DW_OP_reg0;
-  }
-  else if (atom >= DW_OP_breg0 && atom<= DW_OP_breg31) {
-    element->type = e_dw_bregister_op;
-    element->location.reg = atom - DW_OP_breg0;
-    element->location.breg_op.offset = op->number;
-  }
-  else if (atom >= DW_OP_lit0 && atom<= DW_OP_lit31) {
-    element->type = e_dw_lit;
-    element->location.reg = atom - DW_OP_lit0;
-  }
-  else switch (atom) {
-  case DW_OP_fbreg:
-    element->type = e_dw_fbregister_op;
-    element->location.fbreg_op = op->number;
-    break;
-  case DW_OP_piece:
-    element->type = e_dw_piece;
-    element->location.piece = op->number;
-    break;
-  case DW_OP_plus_uconst:
-    element->type = e_dw_plus_uconst;
-    element->location.plus_uconst = op->number;
-    break;
-  case DW_OP_abs:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("abs");
-    break;
-  case DW_OP_and:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("and");
-    break;
-  case DW_OP_div:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("div");
-    break;
-  case DW_OP_minus:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("minus");
-    break;
-  case DW_OP_mod:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("mod");
-    break;
-  case DW_OP_mul:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("mul");
-    break;
-  case DW_OP_neg:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("neg");
-    break;
-  case DW_OP_not:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("not");
-    break;
-  case DW_OP_or:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("or");
-    break;
-  case DW_OP_plus:
-    element->type = e_dw_arithmetic;
-    element->location.arithmetic = xbt_strdup("plus");
-    break;
-
-  case DW_OP_stack_value:
-    // Why nothing here?
-    xbt_free(element);
-    return NULL;
-
-  case DW_OP_deref_size:
-    element->type = e_dw_deref;
-    element->location.deref_size =  (unsigned int short) op->number;
-    break;
-  case DW_OP_deref:
-    element->type = e_dw_deref;
-    element->location.deref_size = sizeof(void *);
-    break;
-  case DW_OP_constu:
-    element->type = e_dw_uconstant;
-    element->location.uconstant.bytes = 1;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_consts:
-    element->type = e_dw_sconstant;
-    element->location.uconstant.bytes = 1;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-
-  case DW_OP_const1u:
-    element->type = e_dw_uconstant;
-    element->location.uconstant.bytes = 1;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_const2u:
-    element->type = e_dw_uconstant;
-    element->location.uconstant.bytes = 2;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_const4u:
-    element->type = e_dw_uconstant;
-    element->location.uconstant.bytes = 4;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_const8u:
-    element->type = e_dw_uconstant;
-    element->location.uconstant.bytes = 8;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
+  xbt_free(key);
 
-  case DW_OP_const1s:
-    element->type = e_dw_sconstant;
-    element->location.uconstant.bytes = 1;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_const2s:
-    element->type = e_dw_sconstant;
-    element->location.uconstant.bytes = 2;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_const4s:
-    element->type = e_dw_sconstant;
-    element->location.uconstant.bytes = 4;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  case DW_OP_const8s:
-    element->type = e_dw_sconstant;
-    element->location.uconstant.bytes = 8;
-    element->location.uconstant.value = (unsigned long int) op->number;
-    break;
-  default:
-    element->type = e_dw_unsupported;
-    break;
+  if(type->name && type->byte_size!=0) {
+    xbt_dict_set(info->full_types_by_name, type->name, type, NULL);
   }
-  return element;
 }
 
-/** \brief Convert libdw location expresion into native one */
-static dw_location_t MC_dwarf_get_expression(Dwarf_Op* expr,  size_t len) {
-  dw_location_t loc = xbt_new0(s_dw_location_t, 1);
-  loc->type = e_dw_compose;
-  loc->location.compose = xbt_dynar_new(sizeof(dw_location_t), NULL);
+static int mc_anonymous_variable_index = 0;
 
-  int i;
-  for (i=0; i!=len; ++i) {
-    dw_location_t element =  MC_dwarf_get_expression_element(expr+i);
-    if (element)
-      xbt_dynar_push(loc->location.compose, &element);
-  }
-
-  return loc;
-}
-
-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:
+static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
+  // Skip declarations:
   if (MC_dwarf_attr_flag(die, DW_AT_declaration, false))
     return NULL;
 
+  // Skip compile time constants:
+  if(dwarf_hasattr(die, DW_AT_const_value))
+    return NULL;
+
   Dwarf_Attribute attr_location;
   if (dwarf_attr(die, DW_AT_location, &attr_location)==NULL) {
     // No location: do not add it ?
@@ -809,11 +690,15 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
   dw_variable_t variable = xbt_new0(s_dw_variable_t, 1);
   variable->dwarf_offset = dwarf_dieoffset(die);
   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->object_info = info;
+
+  const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
+  variable->name = xbt_strdup(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:
@@ -830,11 +715,10 @@ static dw_variable_t MC_die_to_variable(mc_object_info_t info, Dwarf_Die* die, D
       if (len==1 && expr[0].atom == DW_OP_addr) {
         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 = (Dwarf_Off) MC_object_base_address(info);
+        variable->address = (void*) (base + offset);
       } else {
-        variable->address.location = MC_dwarf_get_expression(expr, len);
+        mc_dwarf_location_list_init_from_expression(&variable->locations, len, expr);
       }
 
       break;
@@ -842,97 +726,194 @@ 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);
+    mc_dwarf_location_list_init(&variable->locations, 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);
+  }
+
+  // Handle start_scope:
+  if (dwarf_hasattr(die, DW_AT_start_scope)) {
+    Dwarf_Attribute attr;
+    dwarf_attr(die, DW_AT_start_scope, &attr);
+    int form  = dwarf_whatform(&attr);
+    int klass = MC_dwarf_form_get_class(form);
+    switch(klass) {
+    case MC_DW_CLASS_CONSTANT:
+    {
+      Dwarf_Word value;
+      variable->start_scope = dwarf_formudata(&attr, &value) == 0 ? (size_t) value : 0;
+      break;
+    }
+    default:
+      xbt_die("Unhandled form 0x%x, class 0x%X for DW_AT_start_scope of variable %s",
+        form, klass, name==NULL ? "?" : name);
+    }
+  }
+
+  if(namespace && variable->global) {
+    char* old_name = variable->name;
+    variable->name = bprintf("%s::%s", namespace, old_name);
+    free(old_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;
 }
 
-static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
-  dw_variable_t variable = MC_die_to_variable(info, die, unit, frame);
+static void MC_dwarf_handle_variable_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
+  dw_variable_t variable = MC_die_to_variable(info, die, unit, frame, namespace);
   if(variable==NULL)
       return;
   MC_dwarf_register_variable(info, frame, variable);
 }
 
-static void MC_dwarf_handle_subprogram_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t parent_frame) {
+static void mc_frame_free_voipd(dw_frame_t* p) {
+  mc_frame_free(*p);
+  *p = NULL;
+}
+
+static void MC_dwarf_handle_scope_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t parent_frame, const char* namespace) {
+  // TODO, handle DW_TAG_type/DW_TAG_location for DW_TAG_with_stmt
+  int tag = dwarf_tag(die);
+  mc_tag_class klass = MC_dwarf_tag_classify(tag);
+
+  // (Template) Subprogram declaration:
+  if(klass==mc_tag_subprogram && MC_dwarf_attr_flag(die, DW_AT_declaration, false))
+    return;
+
+  if(klass==mc_tag_scope)
+    xbt_assert(parent_frame, "No parent scope for this scope");
+
   dw_frame_t frame = xbt_new0(s_dw_frame_t, 1);
 
-  frame->start = dwarf_dieoffset(die);
+  frame->tag   = tag;
+  frame->id = dwarf_dieoffset(die);
+  frame->object_info = info;
+
+  if(klass==mc_tag_subprogram) {
+    const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
+    frame->name = namespace ? bprintf("%s::%s", namespace, name) : xbt_strdup(name);
+  }
+
+  frame->abstract_origin_id = MC_dwarf_attr_dieoffset(die, DW_AT_abstract_origin);
 
-  const char* name = MC_dwarf_at_linkage_name(die);
-  if (name==NULL)
-    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 = 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->end = -1; // This one is now useless:
+  frame->low_pc = ((char*) base) + MC_dwarf_attr_integrate_addr(die, DW_AT_low_pc);
+
+  // DW_AT_high_pc:
+  {
+    Dwarf_Attribute attr;
+    if(dwarf_attr_integrate(die, DW_AT_high_pc, &attr)) {
+      uint64_t high_pc;
+      Dwarf_Addr value;
+      if (dwarf_formaddr(&attr, &value) == 0)
+        high_pc = (uint64_t) value;
+      else
+        high_pc = 0;
+
+      int form = dwarf_whatform(&attr);
+      int klass = MC_dwarf_form_get_class(form);
+      if (klass == MC_DW_CLASS_CONSTANT)
+        frame->high_pc = frame->low_pc + high_pc;
+      else if(klass == MC_DW_CLASS_ADDRESS)
+        frame->high_pc = ((char*) base) + high_pc;
+      else
+        xbt_die("Unexpected class for DW_AT_high_pc");
+    } else {
+      frame->high_pc = 0;
+    }
+  }
 
-  // Handle children:
-  MC_dwarf_handle_children(info, die, unit, frame);
+  if(klass==mc_tag_subprogram) {
+    Dwarf_Attribute attr_frame_base;
+    if (dwarf_attr_integrate(die, DW_AT_frame_base, &attr_frame_base))
+      mc_dwarf_location_list_init(&frame->frame_base, info, die, &attr_frame_base);
+  }
+
+  frame->scopes = xbt_dynar_new(sizeof(dw_frame_t), (void_f_pvoid_t) mc_frame_free_voipd);
 
   // Register it:
-  xbt_dict_set(info->local_variables, frame->name, frame, NULL);
+  if(klass==mc_tag_subprogram) {
+    char* key = bprintf("%" PRIx64, (uint64_t) frame->id);
+    xbt_dict_set(info->subprograms,  key, frame, NULL);
+    xbt_free(key);
+  } else if(klass==mc_tag_scope) {
+    xbt_dynar_push(parent_frame->scopes, &frame);
+  }
+
+  // Handle children:
+  MC_dwarf_handle_children(info, die, unit, frame, namespace);
 }
 
-static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
+static void mc_dwarf_handle_namespace_die(
+    mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
+  const char* name = MC_dwarf_attr_integrate_string(die, DW_AT_name);
+  if(frame)
+    xbt_die("Unexpected namespace in a subprogram");
+  char* new_namespace = namespace == NULL ? xbt_strdup(name)
+    : bprintf("%s::%s", namespace, name);
+  MC_dwarf_handle_children(info, die, unit, frame, new_namespace);
+  xbt_free(new_namespace);
+}
+
+static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
+  // For each child DIE:
   Dwarf_Die child;
   int res;
   for (res=dwarf_child(die, &child); res==0; res=dwarf_siblingof(&child,&child)) {
-    MC_dwarf_handle_die(info, &child, unit, frame);
+    MC_dwarf_handle_die(info, &child, unit, frame, namespace);
   }
 }
 
-static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
+static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame, const char* namespace) {
   int tag = dwarf_tag(die);
-  switch (tag) {
-    case DW_TAG_array_type:
-    case DW_TAG_class_type:
-    case DW_TAG_enumeration_type:
-    case DW_TAG_typedef:
-    case DW_TAG_pointer_type:
-    case DW_TAG_string_type:
-    case DW_TAG_structure_type:
-    case DW_TAG_subroutine_type:
-    case DW_TAG_union_type:
-    case DW_TAG_ptr_to_member_type:
-    case DW_TAG_set_type:
-    case DW_TAG_subrange_type:
-    case DW_TAG_base_type:
-    case DW_TAG_const_type:
-    case DW_TAG_file_type:
-    case DW_TAG_packed_type:
-    case DW_TAG_volatile_type:
-    case DW_TAG_restrict_type:
-    case DW_TAG_interface_type:
-    case DW_TAG_unspecified_type:
-    case DW_TAG_mutable_type:
-    case DW_TAG_shared_type:
-      MC_dwarf_handle_type_die(info, die, unit);
+  mc_tag_class klass = MC_dwarf_tag_classify(tag);
+  switch (klass) {
+
+    // Type:
+    case mc_tag_type:
+      MC_dwarf_handle_type_die(info, die, unit, frame, namespace);
       break;
-    case DW_TAG_inlined_subroutine:
-    case DW_TAG_subprogram:
-      MC_dwarf_handle_subprogram_die(info, die, unit, frame);
+
+    // Subprogram or scope:
+    case mc_tag_subprogram:
+    case mc_tag_scope:
+      MC_dwarf_handle_scope_die(info, die, unit, frame, namespace);
       return;
-    // case DW_TAG_formal_parameter:
-    case DW_TAG_variable:
-    case DW_TAG_formal_parameter:
-      MC_dwarf_handle_variable_die(info, die, unit, frame);
+
+    // Variable:
+    case mc_tag_variable:
+      MC_dwarf_handle_variable_die(info, die, unit, frame, namespace);
+      break;
+
+    case mc_tag_namespace:
+      mc_dwarf_handle_namespace_die(info, die, unit, frame, namespace);
+      break;
+
+    default:
       break;
-  }
 
-  // Recursive processing of children DIE:
-  MC_dwarf_handle_children(info, die, unit, frame);
+  }
 }
 
+/** \brief Populate the debugging informations of the given ELF object
+ *
+ *  Read the DWARf information of the EFFL object and populate the
+ *  lists of types, variables, functions.
+ */
 void MC_dwarf_get_variables(mc_object_info_t info) {
   int fd = open(info->file_name, O_RDONLY);
   if (fd<0) {
@@ -943,13 +924,21 @@ void MC_dwarf_get_variables(mc_object_info_t info) {
     xbt_die("Your program must be compiled with -g");
   }
 
+  // For each compilation unit:
   Dwarf_Off offset = 0;
   Dwarf_Off next_offset = 0;
   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);
+    Dwarf_Die unit_die;
+    if(dwarf_offdie(dwarf, offset+length, &unit_die)!=NULL) {
+
+      // For each child DIE:
+      Dwarf_Die child;
+      int res;
+      for (res=dwarf_child(&unit_die, &child); res==0; res=dwarf_siblingof(&child,&child)) {
+        MC_dwarf_handle_die(info, &child, &unit_die, NULL, NULL);
+      }
+
     }
     offset = next_offset;
   }