X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/d4bb65aef6bed4db7389e777dfa7828bdebd1c02..d317aaf1effb4c9cea4701cf83e0946fd0828b89:/src/mc/mc_dwarf.c

diff --git a/src/mc/mc_dwarf.c b/src/mc/mc_dwarf.c
index 6d7833f395..4f86800751 100644
--- a/src/mc/mc_dwarf.c
+++ b/src/mc/mc_dwarf.c
@@ -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. */
 
@@ -20,25 +19,81 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dwarf, mc, "DWARF processing");
 /** \brief The default DW_TAG_lower_bound for a given DW_AT_language.
  *
  *  The default for a given language is defined in the DWARF spec.
+ *
+ *  \param language consant as defined by the DWARf spec
  */
 static uint64_t MC_dwarf_default_lower_bound(int lang);
 
+/** \brief Computes the the element_count of a DW_TAG_enumeration_type DIE
+ *
+ * This is the number of elements in a given array dimension.
+ *
+ * A reference of the compilation unit (DW_TAG_compile_unit) is
+ * needed because the default lower bound (when there is no DW_AT_lower_bound)
+ * depends of the language of the compilation unit (DW_AT_language).
+ *
+ * \param die  DIE for the DW_TAG_enumeration_type or DW_TAG_subrange_type
+ * \param unit DIE of the DW_TAG_compile_unit
+ */
 static uint64_t MC_dwarf_subrange_element_count(Dwarf_Die* die, Dwarf_Die* unit);
 
-/** \brief Computes the number of elements of a given DW_TAG_array_type
+/** \brief Computes the number of elements of a given DW_TAG_array_type.
  *
+ * \param die DIE for the DW_TAG_array_type
  */
 static uint64_t MC_dwarf_array_element_count(Dwarf_Die* die, Dwarf_Die* unit);
 
-/** \brief Checks if a given tag is a (known) type tag.
+/** \brief Process a DIE
+ *
+ *  \param info the resulting object fot the library/binary file (output)
+ *  \param die  the current DIE
+ *  \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);
+
+/** \brief Process a type DIE
  */
-static int MC_dwarf_tag_type(int tag);
-static void MC_dwarf_handle_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);
-static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit);
-static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit);
-static Dwarf_Die* MC_dwarf_resolve_die(Dwarf_Die* die, int attribute);
 
+/** \brief Calls MC_dwarf_handle_die on all childrend of the given die
+ *
+ *  \param info the resulting object fot the library/binary file (output)
+ *  \param die  the current DIE
+ *  \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);
+
+/** \brief Handle a variable (DW_TAG_variable or other)
+ *
+ *  \param info the resulting object fot the library/binary file (output)
+ *  \param die  the current DIE
+ *  \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);
+
+/** \brief Get the DW_TAG_type of the DIE
+ *
+ *  \param die DIE
+ *  \return DW_TAG_type attribute as a new string (NULL if none)
+ */
+static char* MC_dwarf_at_type(Dwarf_Die* die);
+
+/** \brief Get the name of an attribute (DW_AT_*) from its code
+ *
+ *  \param attr attribute code (see the DWARF specification)
+ *  \return name of the attribute
+ */
 const char* MC_dwarf_attrname(int attr) {
   switch (attr) {
 #include "mc_dwarf_attrnames.h"
@@ -47,6 +102,11 @@ const char* MC_dwarf_attrname(int attr) {
   }
 }
 
+/** \brief Get the name of a dwarf tag (DW_TAG_*) from its code
+ *
+ *  \param tag tag code (see the DWARF specification)
+ *  \return name of the tag
+ */
 const char* MC_dwarf_tagname(int tag) {
   switch (tag) {
 #include "mc_dwarf_tagnames.h"
@@ -57,12 +117,74 @@ const char* MC_dwarf_tagname(int tag) {
   }
 }
 
+#define MC_DW_CLASS_UNKNOWN 0
+#define MC_DW_CLASS_ADDRESS 1   // Location in the address space of the program
+#define MC_DW_CLASS_BLOCK 2     // Arbitrary block of bytes
+#define MC_DW_CLASS_CONSTANT 3
+#define MC_DW_CLASS_STRING 3    // String
+#define MC_DW_CLASS_FLAG 4      // Boolean
+#define MC_DW_CLASS_REFERENCE 5 // Reference to another DIE
+#define MC_DW_CLASS_EXPRLOC 6   // DWARF expression/location description
+#define MC_DW_CLASS_LINEPTR 7
+#define MC_DW_CLASS_LOCLISTPTR 8
+#define MC_DW_CLASS_MACPTR 9
+#define MC_DW_CLASS_RANGELISTPTR 10
+
+static int MC_dwarf_form_get_class(int form) {
+  switch(form) {
+  case DW_FORM_addr:
+    return MC_DW_CLASS_ADDRESS;
+  case DW_FORM_block2:
+  case DW_FORM_block4:
+  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:
+  case DW_FORM_udata:
+  case DW_FORM_sdata:
+    return MC_DW_CLASS_CONSTANT;
+  case DW_FORM_string:
+  case DW_FORM_strp:
+    return MC_DW_CLASS_STRING;
+  case DW_FORM_ref_addr:
+  case DW_FORM_ref1:
+  case DW_FORM_ref2:
+  case DW_FORM_ref4:
+  case DW_FORM_ref8:
+  case DW_FORM_ref_udata:
+    return MC_DW_CLASS_REFERENCE;
+  case DW_FORM_flag:
+  case DW_FORM_flag_present:
+    return MC_DW_CLASS_FLAG;
+  case DW_FORM_exprloc:
+    return MC_DW_CLASS_EXPRLOC;
+  // TODO sec offset
+  // TODO indirect
+  default:
+    return MC_DW_CLASS_UNKNOWN;
+  }
+}
+
+/** \brief Get the name of the tag of a given DIE
+ *
+ *  \param die DIE
+ *  \return name of the tag of this DIE
+ */
 static inline const char* MC_dwarf_die_tagname(Dwarf_Die* die) {
   return MC_dwarf_tagname(dwarf_tag(die));
 }
 
 // ***** Attributes
 
+/** \brief Get an attribute of a given DIE as a string
+ *
+ *  \param 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) {
   Dwarf_Attribute attr;
   if (!dwarf_attr_integrate(die, attribute, &attr)) {
@@ -72,7 +194,151 @@ static const char* MC_dwarf_attr_string(Dwarf_Die* die, int attribute) {
   }
 }
 
-// Return a new string for the type (NULL if none)
+/** \brief Get the linkage name of a DIE.
+ *
+ *  Use either DW_AT_linkage_name or DW_AR_MIPS_linkage_name.
+ *
+ *  \param 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);
+  if (!name)
+    name = MC_dwarf_attr_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(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;
+  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);
+
+    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);
+
+  }
+}
+
+/** \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.
+ *
+ *  \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(mc_object_info_t info, 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_data1:
+  case DW_FORM_data2:
+  case DW_FORM_data4:
+  case DW_FORM_data8:
+    {
+      return MC_dwarf_get_location_list(info, die, attr);
+    }
+    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;
+  }
+}
+
+/** \brief Get the location expression or location list from an attribute
+ *
+ *  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
+ */
+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(info, die, &attr);
+}
+
 static char* MC_dwarf_at_type(Dwarf_Die* die) {
   Dwarf_Attribute attr;
   if (dwarf_hasattr_integrate(die, DW_AT_type)) {
@@ -87,12 +353,38 @@ static char* MC_dwarf_at_type(Dwarf_Die* die) {
   else return NULL;
 }
 
+static uint64_t MC_dwarf_attr_addr(Dwarf_Die* die, int attribute) {
+  Dwarf_Attribute attr;
+  if(dwarf_attr_integrate(die, attribute, &attr)==NULL)
+    return 0;
+  Dwarf_Addr value;
+  if (dwarf_formaddr(&attr, &value) == 0)
+    return (uint64_t) value;
+  else
+    return 0;
+}
+
 static uint64_t MC_dwarf_attr_uint(Dwarf_Die* die, int attribute, uint64_t default_value) {
   Dwarf_Attribute attr;
+  if (dwarf_attr_integrate(die, attribute, &attr)==NULL)
+    return default_value;
   Dwarf_Word value;
   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) {
+  Dwarf_Attribute attr;
+  if ((integrate ? dwarf_attr_integrate(die, attribute, &attr)
+                    : dwarf_attr(die, attribute, &attr))==0)
+    return false;
+
+  bool result;
+  if (dwarf_formflag(&attr, &result))
+    xbt_die("Unexpected form for attribute %s",
+      MC_dwarf_attrname(attribute));
+  return result;
+}
+
 static uint64_t MC_dwarf_default_lower_bound(int lang) {
   switch(lang) {
   case DW_LANG_C:
@@ -124,12 +416,15 @@ static uint64_t MC_dwarf_default_lower_bound(int lang) {
 }
 
 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);
   }
 
-  // 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):
@@ -143,7 +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) {
@@ -173,9 +468,6 @@ Dwarf_Off MC_dwarf_resolve_location(unw_cursor_t* c, dw_location_t location, voi
     }
     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);
@@ -213,11 +505,13 @@ 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);
-  switch (dwarf_whatform(&attr)) {
-
-  case DW_FORM_exprloc:
+  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:
+    // Location expression:
     {
-      //TODO, location can be an integer as well
       Dwarf_Op* expr;
       size_t len;
       if (dwarf_getlocation(&attr, &expr, &len)) {
@@ -229,28 +523,34 @@ static void MC_dwarf_fill_member_location(dw_type_t type, dw_type_t member, Dwar
       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. %i %i",
-          len==1 , expr[0].atom == DW_OP_plus_uconst);
+        xbt_die("Can't groke this location expression yet.");
       }
       break;
     }
-  case DW_FORM_data1:
-  case DW_FORM_data2:
-  case DW_FORM_data4:
-  case DW_FORM_data8:
-  case DW_FORM_sdata:
-  case DW_FORM_udata:
+  case MC_DW_CLASS_CONSTANT:
+    // Offset from the base address of the object:
     {
       Dwarf_Word offset;
       if (!dwarf_formudata(&attr, &offset))
         member->offset = offset;
       else
-        xbt_die("Cannot get DW_AT_data_member_%s location <%p>%s",
+        xbt_die("Cannot get %s location <%p>%s",
           MC_dwarf_attr_string(child, DW_AT_name),
           type->id, type->name);
       break;
     }
+  case MC_DW_CLASS_LOCLISTPTR:
+    // Reference to a location list:
+    // TODO
+  case MC_DW_CLASS_REFERENCE:
+    // 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 (%i) / form 0x%x as DW_AT_member_location",
+      klass, form);
   }
+
 }
 
 static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_type_t type) {
@@ -284,11 +584,22 @@ static void MC_dwarf_add_members(mc_object_info_t info, Dwarf_Die* die, Dwarf_Di
 
       MC_dwarf_fill_member_location(type, member, &child);
 
+      if (!member->dw_type_id) {
+        xbt_die("Missing type for member %s of <%p>%s", member->name, type->id, type->name);
+      }
+
       xbt_dynar_push(type->members, &member);
     }
   }
 }
 
+/** \brief Create a MC type object from a DIE
+ *
+ *  \param info current object info object
+ *  \param DIE (for a given type);
+ *  \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) {
 
   dw_type_t type = xbt_new0(s_dw_type_t, 1);
@@ -352,20 +663,282 @@ 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) */
+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;
+
+  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;
+  }
+  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);
+
+  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 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))
+    return NULL;
+
+  Dwarf_Attribute attr_location;
+  if (dwarf_attr(die, DW_AT_location, &attr_location)==NULL) {
+    // No location: do not add it ?
+    return NULL;
+  }
+
+  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->type_origin = MC_dwarf_at_type(die);
+
+  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:
+    // Location expression:
+    {
+      Dwarf_Op* expr;
+      size_t len;
+      if (dwarf_getlocation(&attr_location, &expr, &len)) {
+        xbt_die(
+          "Could not read location expression in DW_AT_location of variable <%p>%s",
+          (void*) variable->dwarf_offset, variable->name);
+      }
+
+      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_exec : 0;
+        variable->address = (void*) (base + offset);
+      } else {
+        variable->location = MC_dwarf_get_expression(expr, len);
+      }
+
+      break;
+    }
+  case MC_DW_CLASS_LOCLISTPTR:
+  case MC_DW_CLASS_CONSTANT:
+    // Reference to location list:
+    variable->location = MC_dwarf_get_location_list(info, die, &attr_location);
+    break;
+  default:
+    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;
 }
 
+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);
+  if(variable==NULL)
+      return;
+  MC_dwarf_register_variable(info, frame, variable);
+}
 
-static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit) {
+static void MC_dwarf_handle_subprogram_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t parent_frame) {
+  dw_frame_t frame = xbt_new0(s_dw_frame_t, 1);
+
+  frame->start = dwarf_dieoffset(die);
+
+  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 = 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 = ((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:
+  MC_dwarf_handle_children(info, die, unit, frame);
+
+  // Register it:
+  xbt_dict_set(info->local_variables, frame->name, frame, NULL);
+}
+
+static void MC_dwarf_handle_children(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
   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);
+    MC_dwarf_handle_die(info, &child, unit, frame);
   }
 }
 
-static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit) {
+static void MC_dwarf_handle_die(mc_object_info_t info, Dwarf_Die* die, Dwarf_Die* unit, dw_frame_t frame) {
   int tag = dwarf_tag(die);
-
   switch (tag) {
     case DW_TAG_array_type:
     case DW_TAG_class_type:
@@ -391,20 +964,21 @@ 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:
-      // TODO
-      break;
+      MC_dwarf_handle_subprogram_die(info, die, unit, frame);
+      return;
+    // case DW_TAG_formal_parameter:
     case DW_TAG_variable:
-      // TODO
+    case DW_TAG_formal_parameter:
+      MC_dwarf_handle_variable_die(info, die, unit, frame);
       break;
   }
 
   // Recursive processing of children DIE:
-  MC_dwarf_handle_children(info, die, unit);
+  MC_dwarf_handle_children(info, die, unit, frame);
 }
 
-void MC_dwarf_get_variables_libdw(mc_object_info_t info) {
+void MC_dwarf_get_variables(mc_object_info_t info) {
   int fd = open(info->file_name, O_RDONLY);
   if (fd<0) {
     xbt_die("Could not open file %s", info->file_name);
@@ -419,8 +993,9 @@ void MC_dwarf_get_variables_libdw(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);
+      MC_dwarf_handle_die(info, &die, &die, NULL);
     }
     offset = next_offset;
   }